JP2013104820A - Power consumption measurement device and power consumption measurement system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power consumption measurement device and a power consumption measurement system capable of measuring a usage state of an electric device with high accuracy and certainty.SOLUTION: A power consumption measurement device includes: receptacles to which electric devices as measurement targets are connected; a plug connected to an external power source; a conductor connecting between the receptacles and the plug; voltage measurement means for measuring voltage applied to the conductor; current measurement means for measuring current flowing through the conductor; and power acquisition means for acquiring a power consumption value of the electric devices on the basis of a voltage value obtained by the voltage measurement means and a current value obtained by the current measurement means. The current measurement means includes: a current direction change area for changing the flow direction of a measurement target current flowing through the conductor to another direction; a magnetism detection element for detecting magnetism generated by the measurement target current whose flow direction is changed in the current direction change area; and current value acquisition means for obtaining a current value of the measurement target current from output by the magnetism detection element.

Description

  The present invention relates to a power consumption measuring device and a power consumption measuring system for measuring the power consumption of an electrical device.

  The technology for measuring the power consumption of electrical equipment includes a plug connected to an outlet, an outlet plug connected to the electrical equipment to be measured, a power line connecting the plug and the outlet, and a voltage value and current in the power line. There is known a power measurement system that includes a calculation unit that calculates power consumption of an electric device based on a value and wirelessly transmits information related to the power consumption of the electric device to an external device (see Patent Document 1).

JP 2011-137882 A

  The power measurement system described in Patent Document 1 discloses a technique for calculating the power consumption of an electric device and wirelessly transmitting it to an external device such as a personal computer.

  In recent years, there has been a demand for measuring the power consumption of electrical equipment with high accuracy or reliability using the system as described above.

  Therefore, the present invention provides a power consumption measuring device and a power consumption measuring system that can measure the usage state of an electrical device with high accuracy or reliability.

  The power consumption measuring apparatus of the present invention is applied to the outlet to which the electrical device to be measured is connected, the plug connected to the external power supply, the conductor connecting the outlet and the plug, and the conductor. Based on the voltage measuring means for measuring the voltage, the current measuring means for measuring the current flowing through the conductor, the voltage value obtained from the voltage measuring means and the current value obtained from the current measuring means, A power acquisition means for obtaining power consumption, wherein the current measuring means changes a current direction changing area in which the flow direction of the current to be measured flowing through the conductor is changed to another direction, and the current direction is changed by the current direction changing area. A magnetic sensing element that detects magnetism generated by the measured current, and a current value acquisition unit that obtains a current value of the measured current from an output of the magnetic detection element And features.

  In addition, the present invention preferably includes a time measuring unit that measures the use time or use time of the outlet, and a storage unit that stores power consumption information of the electric device corresponding to the use time or use time of the outlet. .

  Further, the storage means according to the present invention is preferably a nonvolatile memory.

  Moreover, it is preferable that the present invention further includes a transmission unit that wirelessly transmits power consumption information based on the power consumption of the electrical device obtained by the power acquisition unit to an external terminal.

  Furthermore, it is preferable that the transmission means according to the present invention transmits the power consumption information of the untransmitted electrical device to the external terminal after the connection with the external terminal shifts from a disconnected state to a connected state.

  Furthermore, the power consumption measuring apparatus of the present invention is applied to the conductor, the outlet connected to the electrical device to be measured, the plug connected to the external power source, the conductor connecting the outlet and the plug, and the conductor. A voltage measuring means for measuring the voltage to be measured, a current measuring means for measuring a current flowing through the conductor, a voltage value obtained from the voltage measuring means and a current value obtained from the current measuring means. Storing power consumption information based on the power consumption of the electrical device corresponding to the use time or use time of the outlet, and the power acquisition means for obtaining the power consumption of the device, the time measuring means for measuring the use time or use time of the outlet Storage means, and transmission means for transmitting power consumption information of the electrical device to an external terminal, wherein the transmission means erases the electrical device from within the storage means. And transmitting the power information to the external terminal. The storage means according to the present invention is preferably a nonvolatile memory.

  Moreover, it is preferable that the said transmission means which concerns on the said invention transmits the power consumption information of the said electric equipment which has not been transmitted to the said external terminal after the connection with the said external terminal transfers from a disconnection state to a connection state.

  Furthermore, it is preferable that the time measuring means according to the present invention starts measuring the use time or the use time of the outlet after the connection between the transmission means and the external terminal shifts to a disconnected state.

  The power consumption measurement system of the present invention includes a power consumption measurement device that measures power consumption of an electrical device to be measured, and the electric power that is connected to the power consumption measurement device and transmitted from the power consumption measurement device. A power consumption measurement system comprising a display device that displays power consumption information based on the power consumption of the device, wherein the power consumption measurement device is connected to an outlet connected to an electrical device to be measured and an external power source. A plug to be connected; a conductor connecting between the outlet and the plug; voltage measuring means for measuring a voltage applied to the conductor; current measuring means for measuring a current flowing through the conductor; and the voltage measuring means Based on the voltage value obtained from the current value obtained from the current measuring means, the power acquisition means for obtaining the power consumption of the electrical equipment, and when using the outlet Alternatively, time measuring means for measuring the usage time, storage means for storing power consumption information based on the power consumption of the electrical device corresponding to the usage time or usage time of the outlet, and the power consumption information of the electrical device in the display device A power transmitting device that transmits power consumption information of the electrical device from within the storage device to the display device after the connection between the transmission device and the display device shifts to a connected state. It is characterized by transmitting. The storage means according to the present invention is preferably a nonvolatile memory.

  Further, the display device according to the present invention is preferably a portable terminal device having a display.

  Note that the present invention described above can be applied to a method or apparatus including the following elements. For example, in a power supply relay device (such as a table tap) to an electrical device, the power (power consumption) supplied to the electrical device is reduced. It can also be applied to a current measurement method used to measure the power consumption of the electrical device for management (monitoring), and the current measurement method flows in part of the conductor through which the current to be measured flows. Providing a direction changing region for changing the direction from the main direction to another direction, disposing at least one magnetic sensing element with respect to the conductor, and changing the flowing direction by the direction changing region. Detecting a magnetic field generated by a current with the magnetic sensing element; estimating a current amount of the current to be measured from an output of the magnetic sensing element; Characterized in that it has.

  Further, in the case where the present invention is a current measuring method, the step of providing a direction changing region for changing the direction in which the current to be measured flows from a main direction to another direction in a part of the conductor through which the current to be measured flows It is preferable that the change region includes a step of providing a non-conductive region through which the current to be measured does not flow.

  Furthermore, when the present invention is a current measuring method, the step of detecting, by the magnetic sensing element, the magnetic field generated by the current to be measured whose direction of flow is changed by the direction changing region is performed by the magnetic sensing element. Preferably, the method includes a step of detecting a magnetic field component of the bypass current that flows outside the conductive region that faces the main direction of the current to be measured.

  Further, in the case where the present invention is a current measuring method, the step of arranging at least one magnetic sensing element with respect to the conductor includes the step of arranging a magnetic sensing element having magnetic field detection sensitivity only in one direction in the vicinity of the non-conductive region. In addition, it is preferable to include a step of arranging the magnetic field detection sensitivity so that the direction of the magnetic field detection sensitivity faces the main direction of the current to be measured.

  Further, in the case where the present invention is a current measuring method, the step of detecting the magnetic field generated by the current to be measured whose direction of flow is changed by the direction changing region by the magnetic sensing element is relative to the axis in the main direction. Steps of detecting magnetic field components in the main direction of the bypass current having different polarities by at least two magnetic sensing elements that are orthogonal to each other and symmetrically arranged with respect to an axis passing through the center of the non-conductive region. It is preferable to contain.

  Furthermore, when the present invention is a current measuring method, the step of detecting the magnetic field generated by the current to be measured whose direction of flow is changed by the direction changing region by the magnetic sensing element is parallel to the axis of the main direction. Detecting at least two magnetic sensing elements arranged in symmetry with respect to an axis passing through the center of the non-conductive region, respectively, the magnetic field components in the main direction of the bypass current having different polarities. It is preferable.

  Further, in the case where the present invention is a current measuring method, the step of detecting the magnetic field generated by the current to be measured whose direction of flow is changed by the direction changing region by the magnetic sensing element is relative to the axis in the main direction. At least two magnetic sensing elements arranged orthogonally with respect to an axis passing through the center of the non-conductive region, and an axis parallel to the axis of the main direction, the center of the non-conductive region Preferably, the method includes a step of detecting each of the magnetic field components in the main direction of the bypass current having different polarities by at least two magnetic sensing elements arranged symmetrically with respect to an axis passing through.

  Further, in the case where the present invention is a current measuring method, the step of disposing at least one magnetic sensing element with respect to the conductor includes the center of the non-conductive region as an origin, the main direction of the current to be measured as a Y axis, The width direction orthogonal to the Y-axis is the X-axis, and the detection part of the magnetic detection element is separated from the center of the non-conductive region by a distance of 0.5 to 2.5 mm between the X-axis and the Y-axis, respectively. It is preferable to include a step of disposing in a separated range.

  Further, in the case where the present invention is a current measuring method, the step of providing a direction changing region for changing the direction in which the current to be measured flows from a main direction to another direction in a part of the conductor through which the current to be measured flows As the change region, an outlet having a width narrower than the width of the main part of the conductor is provided in front of the conductor in which the current to be measured flows in the main direction in which the current to be measured flows, and the width of the conductor is behind the conductor. It is preferable to include a step of providing a narrow-width inlet.

  Furthermore, when the present invention is a current measuring method, the step of arranging at least one magnetic sensing element with respect to the conductor includes arranging the magnetic sensing element offset from the main direction from the center of the conductor. It is preferable that the method includes a step of arranging an offset from a direction orthogonal to the main direction.

  Further, in the case where the present invention is a current measuring method, the step of arranging at least one magnetic sensing element with respect to the conductor includes at least two magnetic elements sandwiching a line connecting the outlet and the inlet in the conductor. Preferably, the method includes the step of disposing the sensing element.

  Furthermore, when the present invention is a current measuring method, the step of disposing at least one magnetic sensing element with respect to the conductor includes at least two magnetic elements sandwiching a line orthogonal to the main direction in the conductor. Preferably, the method includes the step of disposing the sensing element.

  Further, in the case where the present invention is a current measuring method, the step of arranging at least one magnetic sensing element with respect to the conductor includes at least two magnetic elements sandwiching a line perpendicular to the main direction in the conductor. It is preferable to include a step of arranging a sensing element and arranging at least two magnetic sensing elements across a line orthogonal to the main direction.

  Furthermore, when the present invention is a current measuring method, the step of arranging at least one magnetic sensing element with respect to the conductor includes a step of arranging a magnetic impedance element or an orthogonal fluxgate element as the magnetic sensing element. Is preferred.

  Further, a current measuring device suitably mounted on the power consumption measuring device of the present invention is provided on a conductor through which a current to be measured flows and a part of the conductor, and the direction in which the current to be measured flows is different from the main direction. The magnetic detection for detecting a magnetic field generated by the current to be measured whose direction of flow is changed by the direction change region, at least one magnetic detection element arranged with respect to the conductor, and the direction of flow changed by the direction change region It is preferable to have an estimation circuit that estimates the amount of current to be measured from the output of the element.

  Furthermore, in the current measuring device mounted on the power consumption measuring device of the present invention, it is preferable that the direction change region is a non-conductive region where the measured current does not flow.

  The current measuring device mounted on the power consumption measuring device of the present invention is characterized in that the magnetic sensing element detects a magnetic field component of a detour current flowing outside the non-conductive region and detecting a magnetic field component facing the main direction of the measured current. A sensing element is preferred.

  Furthermore, in the current measuring device mounted on the power consumption measuring device of the present invention, the magnetic sensing element has a magnetic field detection sensitivity only in one direction, in the vicinity of the non-conductive region and with the magnetic field detection sensitivity. It is preferable that the magnetic sensing element is disposed so that the direction thereof faces the main direction of the current to be measured.

  Further, in the current measuring device mounted on the power consumption measuring device of the present invention, the magnetic sensing element is an axis orthogonal to the axis of the main direction and is symmetric with respect to an axis passing through the center of the non-conductive region. It is preferable that the at least two magnetic sensing elements detect the magnetic field components in the main direction of the bypass current having different polarities.

  Further, in the current measuring device mounted on the power consumption measuring device of the present invention, the magnetic sensing element is arranged symmetrically with respect to an axis parallel to the axis of the main direction and passing through the center of the non-conductive region. Preferably, the at least two magnetic sensing elements detect magnetic field components in the main direction of the bypass current having different polarities.

  Further, in the current measuring device mounted on the power consumption measuring device of the present invention, the magnetic sensing element is an axis orthogonal to the axis of the main direction and is symmetric with respect to an axis passing through the center of the non-conductive region. And at least two magnetic sensing elements arranged symmetrically with respect to an axis parallel to the axis of the main direction and passing through the center of the non-conductive region. It is preferable.

  Further, in the current measuring device mounted on the power consumption measuring device according to the present invention, the magnetic sensing element has a center of the non-conductive region as an origin, a main direction of the current to be measured is a Y axis, and is orthogonal to the Y axis. The width direction to be performed is an X-axis, and the detection unit of the magnetic detection element is arranged in a range separated from the center of the non-conductive region by a distance of 0.5 to 2.5 mm between the X-axis and the Y-axis, respectively. It is preferable to include the step of carrying out.

  Further, in the current measuring device mounted on the power consumption measuring device of the present invention, the direction change region is a conductor in which the current to be measured flows, and the conductor provided in front of the main direction in which the current to be measured flows. It is preferable that an outlet having a width smaller than the width of the main portion and an inlet having a width smaller than the width of the conductor provided behind the conductor are included.

  Furthermore, in the current measuring device mounted on the power consumption measuring device of the present invention, the magnetic sensing element is arranged offset from the main direction from the center of the conductor, and in a direction orthogonal to the main direction. It is preferable that they are arranged offset from each other.

  The current measuring device mounted on the power consumption measuring device of the present invention is characterized in that the magnetic sensing element is at least two magnetic sensing elements arranged across the line connecting the outlet and the inlet in the conductor. It is preferable to contain.

  Furthermore, the current measuring device mounted on the power consumption measuring device of the present invention is characterized in that the magnetic sensing element is at least two magnetic sensing elements arranged across a line perpendicular to the main direction in the conductor. It is preferable to contain.

  Further, in the current measuring device mounted on the power consumption measuring device of the present invention, the magnetic sensing element includes at least two magnetic sensing elements arranged on the conductor across a line orthogonal to the main direction. And at least two magnetic sensing elements arranged across a line orthogonal to the main direction.

  Furthermore, in the current measuring device mounted on the power consumption measuring device of the present invention, it is preferable that the magnetic sensing element is a magnetic impedance element or an orthogonal fluxgate element.

  ADVANTAGE OF THE INVENTION According to this invention, the power consumption measuring apparatus and power consumption measuring system which can measure the use condition of an electric equipment highly accurately or reliably are realizable.

It is an external view of the table tap which is an example of the power consumption measuring device which concerns on this embodiment. It is a component arrangement | positioning figure showing arrangement | positioning of each component in the inside of the table tap which is an example of the power consumption measuring device which concerns on this embodiment. It is a block diagram showing the structure of the internal board | substrate of the table tap of FIG. It is a figure which shows the sampling in conversion of the analog signal input into a microcomputer. It is a chart figure which shows the processing flow in a microcomputer. It is a chart figure which shows the processing flow in a microcomputer. It is a chart figure which shows the processing flow in a microcomputer. It is a chart figure which shows the processing flow in a microcomputer. It is a chart figure which shows the processing flow in a microcomputer. The figure which shows the DCO circuit which controls an oscillation frequency according to the change of an electrostatic capacitance. It is an example of data in which the current value, apparent power, and active power for each outlet (channel) are stored in the order of measurement. It is a block diagram of Example 1 which performs the current measurement with respect to a to-be-measured current. It is explanatory drawing of the mode of the electric current in a primary conductor, and a magnetic field. It is sectional drawing of the relationship between a primary conductor and a magnetic sensing element. It is a block diagram of a detection circuit. It is a distribution contour map of the magnetic field component of a Y-axis direction using the through-hole of 2 mm in diameter. It is a distribution contour map of the magnetic field component of a Y-axis direction using the through-hole of 3 mm in diameter. It is a related figure of the diameter of a through-hole, and the peak position of a Y-axis direction magnetic field component. It is a related figure of the diameter of a through-hole, and the peak value of a Y-axis direction magnetic field component. It is a block diagram of the modification which performs the current measurement with respect to a to-be-measured current. It is a block diagram of the modification which performs the current measurement with respect to a to-be-measured current. It is a block diagram of the modification which performs the current measurement with respect to a to-be-measured current. It is a block diagram of the modification which performs the current measurement with respect to a to-be-measured current. It is a block diagram of Example 2 which performs the current measurement with respect to a to-be-measured current. It is a characteristic view of a magneto-impedance element. It is a graph figure of a detection electric current and a measurement error. It is a block diagram of the modification which performs the current measurement with respect to a to-be-measured current. It is a perspective view of the basic composition of the current sensor of Example 3 which performs the current measurement to the current to be measured. It is explanatory drawing of the mode of a magnetic field with the electric current in a primary conductor. It is sectional drawing of the relationship between a primary conductor and a magnetic sensing element. It is a block diagram of a detection circuit. It is a block diagram of the modification which performs the current measurement with respect to a to-be-measured current. It is a block diagram of Example 4 which performs the current measurement with respect to a to-be-measured current. It is a block diagram of the modification which performs the current measurement with respect to a to-be-measured current. It is a block diagram of the other modification which performs the current measurement with respect to a to-be-measured current. It is a block diagram of Example 5 which performs the current measurement with respect to a to-be-measured current. It is a block diagram of the modification which performs the current measurement with respect to a to-be-measured current. It is a perspective view of the basic composition of the current sensor of Example 6. It is explanatory drawing of the mode of a magnetic field with the electric current in a primary conductor. It is sectional drawing of the relationship between a primary conductor and a magnetic sensing element. It is a distribution contour map of the magnetic field component of the Y-axis direction in which the width of the current inlet / outlet is changed. It is a distribution contour map of the magnetic field component of the Y-axis direction in which the width of the current inlet / outlet is changed. It is a distribution contour map of the magnetic field component of the Y-axis direction in which the width of the current inlet / outlet is changed. It is a distribution contour map of the magnetic field component of the Y-axis direction in which the width of the current inlet / outlet is changed. FIG. 6 is a relationship diagram between the width of the current inlet / outlet and the peak value of the magnetic field component in the Y-axis direction. It is a block diagram of the modification which performs the current measurement with respect to a to-be-measured current. It is a block diagram of the modification which performs the current measurement with respect to a to-be-measured current. It is a block diagram of the modification which performs the current measurement with respect to a to-be-measured current. It is a block diagram of Example 7 which performs the current measurement with respect to a to-be-measured current. FIG. 5 is a relationship diagram between a current entrance / exit position and a magnetic field component (fixed point) in the Y-axis direction. It is a block diagram of Example 8 which performs the current measurement with respect to a to-be-measured current. It is a graph of the relationship between the measured current and the output when the width of the entrance / exit is changed. It is a block diagram of the modification which performs the current measurement with respect to a to-be-measured current. It is a detailed circuit diagram of a sensor substrate. It is a block diagram showing the structure of the internal board | substrate of the table tap in other embodiment of this invention. It is a data example regarding the measurement time, electric current, electric power, etc. regarding power consumption for each outlet (channel). It is a block diagram showing the structure of the internal board | substrate of the table tap in other embodiment of this invention. It is a block diagram showing the structure of the internal board | substrate of the table tap in other embodiment of this invention.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. The following embodiments do not limit the invention according to the claims, and all combinations of features described in the embodiments are not necessarily essential to the solution means of the invention.

[Embodiment 1]
In FIG. 1, the external view of the table tap which is an example of the power consumption measuring device which concerns on this embodiment is shown. FIG. 2 is a component arrangement diagram showing the arrangement of components in a table tap that is an example of the power consumption measuring apparatus according to the present embodiment. FIG. 3 is a block diagram showing the configuration of the internal substrate of the table tap of FIG.

  As shown in FIG. 1, a table tap 100 according to the present embodiment, which is a power consumption measuring device, is connected to an outlet plug 200 having a plurality of outlets 200a, 200b, 200c, and 200d to which an electrical device is connected, and an external power source. Power cord 300 having a plug (not shown).

  Here, as shown in FIG. 2, 220 is an outlet board mounted in a table tap, and the components described below are mounted respectively.

  A wiring from the power cord 300 is connected to one end of the outlet board 220 in the longitudinal direction. Further, the wiring from the power cord 300 is connected to AC + 201 and AC− 202, and is connected to the wiring patterns 210 and 211 on the outlet board 220, respectively. Reference numeral 24 denotes a current sensor (current measuring device), which is disposed between the wiring pattern 210 on the outlet board 220 and the outlets 200a, 200b, 200c, and 200d. Since the current sensor 24 has various modifications, the details will be described later.

  Reference numeral 231 denotes a bus bar connected to the AC + 201, and the bus bar 232 is connected to one side of each outlet. The other side of each outlet is connected to AC-202. Reference numeral 233 denotes a terminal that supplies power / GND to the inside of the current sensor 12 and outputs a reference voltage and a measurement voltage from the current sensor 12.

  AC + 201 and AC− 202 are input to the common mode choke coil 240, and the output is input to the AC / DC power source 250. The AC-DC power supply 250 generates a power supply for voltage measurement / CPU and the like + 3.3V. Further, AC + 201 and AC− 202 are respectively divided by a capacitor 260 (see FIG. 1). The reference voltage / measurement voltage of each outlet is input to the analog multiplexer 270, the output is selected by the microcomputer 280, and the analog signal is input to the microcomputer 280. Further, as will be described later, the microcomputer 280 converts the continuously input analog signal into a digital signal. The microcomputer 280 is connected to a communication module 290, which is an example of a transmission unit, for example by a serial signal. The communication module 290 has an interface such as a wireless LAN or USB, and can transmit measured current, power, and the like to an external device. Of course, the communication module may be a wired connection module such as a USB.

  Here, FIG. 3 shows a block diagram of the outlet board 220 described above. 230 is a capacity voltage dividing circuit, and the divided potentials of AC + 201 and AC− 202 divided by the capacity of the capacitors 260 a (C 1) and 260 b (C 2) are input to the operational amplifier 261. The divided potentials V + 261a and V− 261b are expressed by the following equations 1 and 2.

V + 261a = AC + * (C1 / (C1 + C2)) ... Equation 1
V-261b = AC-* (C1 / (C1 + C2)) ... Equation 2

  The operational amplifier 262 supplies a bias potential. In FIG. 3, + 1.65V, which is an intermediate potential of + 3.3V, is a bias potential, and the output of the operational amplifier 261 outputs a divided potential with the bias potential + 1.65V as the center. Thus, the divided potentials V + 261a, V− 261b, and bias potential (Vref2) 262a are input to the microcomputer 280 and converted into digital signals.

  The outputs Vout 124 a, 124 b, 124 c and 124 d of the outlet current sensors 24 and the bias potentials Vref 1 125 a, 125 b, 125 c and 125 d are input to the analog multiplexer 270. The microcomputer 280 controls the selection signals 281 and 282 to the analog multiplexer 270 and inputs the output Vout of the current sensor of each outlet to the microcomputer 280. In the EEPROM 285, as shown in FIG. 11, the current value, the apparent power VA, and the active power W for each channel are stored as a table in the order of measurement. Data transmitted to the external device is deleted, and new measurement data is overwritten.

  FIG. 4 shows sampling of analog / digital conversion of analog signals Vout, V +, V−, Vref1, and Vref2 input to the microcomputer 280. Each analog signal is simultaneously converted from analog to digital every 32 μsec when the sampling period is, for example, 32 μsec. Note that, in one cycle at an AC power frequency of 50 Hz, 1000 msec / 50 = 20 msec and 20 msec / 32 μsec = 625. That is, 625 pieces of sampling data are acquired. Similarly, approximately 521 pieces of sampling data are acquired in one cycle at an AC power frequency of 60 Hz. That is, (1000 msec / 60) / 32 μsec≈521. Further, in analog-digital conversion (hereinafter referred to as AD conversion), the data is converted into 24-bit digital data (maximum 0xFFFFFFh). Here, Vref1 and 2 which are bias potentials take intermediate values, that is, 0x800000).

  5 to 9 show flowcharts of the microcomputer 280 in the current, voltage, and power measurement shown in this embodiment.

  FIG. 5 is a flowchart for measuring the frequency of the AC power source connected to the power cord 300. As described above, if the frequency is different, the amount of sampling data is different for one period, so the frequency must be measured.

  First, in step S201, a cross point where the AC power source shifts from plus to minus and minus to plus is found. In FIG. 4, the cross point is when the digital value after AD conversion crosses 0x800000. When the cross point is found, when the AC power source is 60 Hz, sampling data of 521 * 3 = 1563 ± α is acquired to acquire data for three cycles (step S202). Cross points are observed six times in the sampling data in three cycles (YES in step S203). If the cross point is not observed six times (NO in step S203), the cross point is found in the same manner as in step 201 (step S204). When the cross point is found, if the AC power supply is 50 Hz, sampling data of 625 * 3 = 1875 ± α is acquired to acquire data for three cycles (step S205). Cross points are observed six times in the sampling data in three cycles (YES in step S206). If the frequency is not determined (NO in step S206), the above steps are repeated a plurality of times. If the frequency is still not determined, the process ends as a measurement error.

  Here, the microcomputer 280 employs a DCO (digitally controlled oscillator) in the present embodiment. The DCO circuit is an LC oscillation circuit controlled by digital input, and by applying a control voltage of “0” or “1” individually to each of many MOS varactors connected in parallel, the capacitance is reduced. Change digitally. The oscillation frequency is controlled according to the change in capacitance (FIG. 10). Unlike crystal oscillation, fluctuation due to temperature and voltage is, for example, 3% at the maximum. It is desirable to reflect these fluctuations in the above sampling number. When the AC power source is 60 Hz, the sixth cross point is observed with a sampling of ± 3% relative to 1563, that is, 1563 ± 47. Similarly, when the AC power supply is 50 Hz, the sixth cross point is observed with sampling of 1875 ± 57 (FIG. 4).

  FIG. 6 is a flowchart for acquiring current data for 10 cycles. Depending on the frequency, the number of samplings for these 10 cycles also changes, and is 625 * 10 = 6250 ± 188 at 50 Hz and 521 * 10 = 5210 ± 157α at 60 Hz. First, a cross point is found (step S301), and data collection is started. Since the analog-digital converted data includes the offset of the entire system, it is desirable to remove the offset. The offset value is 0x800000h when no device is connected to the system. However, when viewed from the whole system, the value is different. When the digital value when not connected is Y, the offset value = (0 × 800000−Y). When the maximum measurement current is 15 A, for example, when a digital value when a resistance load capable of flowing 15 A is connected is X, gain value = (0xffffff−0x800000) / X. In step S302, the offset adjustment and gain adjustment obtained above are performed on the measured Vout. The adjusted value Voutadj is obtained by the following calculation formula 3.

  Voutadj = (Vout + offset value) * gain value (3)

  In step S303, the calculated cumulative Voutadj is squared.

  Further, the power cumulative addition value Voutadj2SUM of Voutadj is obtained by the following equation.

  Voutadj2SUM = Σ (Voutadj * Voutadj) Equation 4

  Next, this is subjected to square accumulation for 10 cycles (step S304).

  FIG. 7 is a flowchart for acquiring voltage data for 10 cycles, as in FIG. 6.

  First, a cross point is found (step S401), and data collection is started. As with current measurement, the offset at no load is measured. Further, a reference AC100V is input from the power cord 3 and its peak value Z is measured to obtain a gain value = (0xffffff−0x800000) / Z.

  Next, in step S402, the offset adjustment and gain adjustment obtained above are performed on the measured V + and V-. The adjusted values V + adj and V-adj are obtained by the following calculation formulas 5 and 6.

V + adj = ((V +) + offset value) * gain value Equation 5
V−adj = ((V −) + offset value) * gain value (Formula 6)

  In step S403, the peak value Vadj of the AC power source is calculated by the following equation (7).

  Vadj = (V + adj) + (0x800000−V−adj) Equation 7

  In step S404, the calculated Vadj squared cumulative addition is performed. Vadj2 square cumulative addition value Vadj2SUM is obtained by the following equation (8).

  Voutadj2SUM = Σ (Voutadj * Voutadj) Equation 8

  Next, this is subjected to square accumulation for 10 cycles (step S405).

  Next, the point of obtaining the active power shown in FIG. 9 will be described before the description of the procedure for obtaining the apparent power according to the flowchart shown in FIG. FIG. 9 is a flowchart for obtaining active power. Power is calculated by multiplying the voltage Vadj obtained in step S403 by the current Voutadj obtained in step S302 (step S601). This is obtained for 10 cycles and cumulative addition is performed (steps S602 and 603). As described above, the number of samplings for these 10 cycles varies depending on the frequency, and 625 * 10 = 6250 + α at 50 Hz and 521 * 10 = 5210 + α at 60 Hz, and the cumulative added value VAadjSUM is divided by the number of samplings (step S604).

  The active power W is obtained by multiplying the VAadjSUM thus obtained by the conversion coefficient (step S605). Here, the conversion coefficient is, for example, measured when a resistance load is actually connected (WL), and the effective power when the resistance load is 100Ω is 100V * 100V / 100Ω = 100 W, so WL / 100 Is the conversion coefficient.

  FIG. 8 is a flowchart for obtaining the apparent power. Voutad2SUMMSAMP is obtained by dividing the current square integrated value Voutadj2SUM for 10 cycles obtained in step S304 by the number of samples (step S501). Similarly, Vadj2SUMMSAMP is obtained by dividing the voltage square integrated value Vadj2SUM for 10 cycles obtained in step S406 by the number of samples (step S503). By obtaining the square root of Voutadj2SUM and SAMPVadj2SUMSAM and multiplying by the conversion coefficient, the current effective value and the voltage effective value can be obtained (steps S502 and S504). Here, the current conversion coefficient is measured when a resistance load, for example, 10Ω is connected, and when the measured value is IS, it is 100V / 10Ω = 10A. Therefore, IS / 10 is a current conversion coefficient. It becomes. The voltage change coefficient is VS / 100 as the voltage conversion coefficient when the value measured at no load is VS. The apparent power VA can be obtained by multiplying the current effective value and the voltage effective value (step S505).

  The table tap 100 shown in FIG. 1 or the like as the power consumption measuring device described above communicates with an external terminal (information processing device) such as a personal computer or a portable terminal directly or via a relay device, although not shown. The power consumption measurement system (which may include a power consumption management system) is configured to be connected. That is, power consumption information based on the power consumption measured by the power consumption measuring device (including power consumption or information related thereto and power consumption information relating to power consumption based on power consumption) is a communication module in the power consumption measuring device. Sent to an external terminal. On the other hand, the external terminal side that has received the power consumption information displays the power consumption information on a display means such as a display. Thereby, the user can efficiently manage the power consumption of one or a plurality of electric devices connected to the table tap 100 having the power consumption measurement function. In addition, although the table tap 100 of this embodiment demonstrated the example which provided four outlets, one may be sufficient and you may provide two or three or five or more.

  Here, as the current sensor 24 constituting at least a part of the current measuring means mounted on the table tap 100 described above, for example, in the present embodiment, although details will be described later, This is caused by a current direction changing region in which the flow direction of the current to be measured flowing between the outlet plugs 200a, 200b, 200c, and 200d is changed to another direction, and a current to be measured whose current direction has been changed by the current direction changing region. It is preferable to use one provided with a magnetic detection element for detecting magnetism.

  Hereinafter, in the power consumption measuring apparatus of the present invention, when measuring the power consumption of an electrical device, a conductor (specifically, a connection wiring on a substrate, for example, the wiring in FIG. The current measuring apparatus optimal for measuring the current value flowing through the pattern 210 and the like will be described in detail, but the present invention is not limited to the following configuration.

  In the case of directly detecting the circular magnetic field generated from the current flowing through the conductor by the magnetic detection element, there are the following problems. In other words, when conductors through which currents of different phases are arranged in parallel and adjacent to the conductor through which the current to be measured flows, they are adjacent when a circular magnetic field having a component perpendicular to the direction of current flow is targeted. A magnetic field from a current line is applied, and sufficient measurement accuracy may not be obtained. Even if these interferences are prevented by the magnetic shield, there is a possibility that the magnetic flux from the current to be measured may disturb the magnetic field itself and there is a concern about the magnetic saturation of the shield member, making it difficult to take effective measures. .

  Accordingly, a current measuring method and a current measuring apparatus that can solve the above-described problems and can stably ensure the measurement accuracy of the current to be measured without depending on the magnetic shield even in an installation environment in which currents of different phases flow in parallel. If so, it is suitable for the power consumption measuring apparatus of the present invention.

  Hereinafter, a current measuring device suitably mounted in the power consumption measuring device of the present invention will be described in detail based on the illustrated embodiment. One feature of the present invention is that a current direction changing region for changing the direction in which the current to be measured flows from the main direction to another direction is provided in a part of the conductor through which the current to be measured flows. Furthermore, the present invention is characterized in that a magnetic field generated by a current to be measured whose direction of flow is changed by a current direction changing region is detected by a magnetic detection element.

<Example 1>
FIG. 12 is a basic configuration diagram of the first embodiment for measuring current with respect to the current to be measured. A current to be measured I to be detected flows through the primary conductor 1, and the primary conductor 1 is in the form of, for example, a bus bar formed of a copper foil pattern or a copper plate on a printed board.

  A circular through hole 2 which is a non-conductive region is provided in the approximate center of the primary conductor 1 in order to partially block the current. For this reason, a part of the current I to be measured is shown in FIG. Thus, the detour current Ia slews symmetrically around the outside on both sides of the through-hole 2. For convenience of explanation, a coordinate axis is set for the primary conductor 1, the center of the through hole 2 is set as the origin O, the main direction in which the current I to be measured flows is the Y axis, the width direction that is the orthogonal axis is the X axis, and the thickness The direction is the Z axis.

  On the primary conductor 1, a magnetic detection element 3 having magnetic field detection sensitivity only in one direction is disposed. The detection unit 4 of the magnetic detection element 3 is set so that the Y-axis direction is the magnetic field detection direction, and the center position of the detection unit 4 is a distance dx in the X-axis direction and the X-axis in the Y-axis direction from the center of the through hole 2. Is placed at a location shifted by a distance dy across the surface.

  Originally, the magnetic flux generated by the current is directed in a direction perpendicular to the current direction, so that the current to be measured I flows in the Y-axis direction, which is the main direction, in a place where the through hole 2 of the primary conductor 1 is not affected. Therefore, like the magnetic field vector component Hc0 shown in FIG. 13, the magnetic field has only the vector component Hx in the X-axis direction within the width w of the primary conductor 1.

  However, in the vicinity of the through hole 2, the bypass current Ia is inclined with respect to the Y-axis direction, so that a magnetic field vector component Hc 1 in which the magnetic field is distorted on both sides of the through hole 2 is generated by this bypass current Ia. That is, the Y-axis direction vector component Hy and the X-axis direction vector component Hx are generated in the slope portion of the bypass current Ia. The vector sum of the vector component Hy and the vector component Hx is proportional to the magnitude of the current I to be measured, and since the current direction is symmetrical on both the positive and negative sides of the Y-axis of the through-hole 2, the vector component Hy is symmetrical across the X-axis. And the polarity is reversed.

  As shown in FIG. 12, even if the primary conductors 1 ′ through which currents of different phases flow are close to each other and the direction of the proximity current I ′ is parallel to the current I to be measured, the magnetic field vector component due to the proximity current I ′ is X It is a component only in the axial direction and has no Y-axis direction component. When the magnetic field detection direction of the detection unit 4 is the Y-axis direction, the magnetic detection element 3 can detect only the vector component Hy of the detour current Ia without being affected by the magnetic field due to the proximity current I ′. Therefore, if the vector component Hy is calibrated and converted, the amount of current I to be measured can be obtained.

  It is not desirable to detect the magnetic field vector component Hx in the X-axis direction as the magnetic sensing element 3 to be used. Therefore, a magnetic impedance element or an orthogonal flux gate element with high directivity is suitable. In the first embodiment, a magnetic impedance element is used, and a magnetic field can be detected only in the Y-axis direction. The magnetic thin film pattern is arranged in parallel in the Y-axis direction of the magnetic field detection direction as the detection unit 4, and a high frequency pulse in the MHz band is applied to the electrodes 5 at both ends. Is obtained as a sensor signal. Although not shown in the drawings, the operation of the detection unit 4 requires a bias magnetic field, and is set by passing a current by installing a bias magnet nearby or winding a bias coil as necessary.

  As shown in FIG. 14, the height h of the detection unit 4 of the magnetic detection element 3 with respect to the primary conductor 1 is a structure that holds the positional relationship between the primary conductor 1 and the magnetic detection element 3. It is determined by the relationship of dielectric strength such as distance.

  FIG. 15 shows a configuration diagram of a detection circuit 100A that functions as a current measuring device. The detection unit 4 of the magnetic detection element 3 is connected to a resistor R that forms a bridge with respect to the CR pulse oscillation circuit 30. The detection circuit 31 extracts an amplitude change from the both-end voltage that is a detection signal of the detection unit 4 and outputs the change to the amplification circuit 32. The amplifier circuit 32 amplifies the amplitude change and outputs it. The estimation circuit 33 is a circuit that estimates the amount of current to be measured from the output of the amplifier circuit 32.

  16 and 17 show the simulation results of the magnetic field component Hy in the Y-axis direction related to the bypass current Ia through the through hole 2. The primary conductor 1 is a sufficiently long copper plate having a cross section with a width w = 10 mm in the X-axis direction and a thickness t = 70 μm in the Z-axis direction and an infinite length in the Y-axis direction. A through hole 2 is formed. The detector 4 was fixed at a height h of 1.6 mm from the primary conductor 1 and examined the change of the magnetic field vector component Hy in the Y-axis direction when the measured current I flowed 1 ampere (A) in the Y-axis direction. .

  16 shows the calculation result of the magnetic field distribution of the vector component Hy of the magnetic field in the Y-axis direction when the through hole is 2 mm, and FIG. 17 shows the distribution of contour lines. The coordinates are the first quadrant of X ≧ 0 and Y ≧ 0, and the contours are drawn in 10% increments with the vertex of the vector component Hy being 100%. In the other quadrants, a magnetic field distribution symmetric with respect to the X axis or the Y axis is formed, the third quadrant has the same polarity as the first quadrant, and the second and fourth quadrants have a magnetic field having the opposite polarity to the first quadrant.

  16 and 17, the peak position where the magnetic field is maximized is in the direction of about 45 degrees from the through hole 2. In the through hole 2 having a diameter of 2 mm, (X, Y) = (1.5 mm, 1.625 mm), 3 mm. In the through hole 2, (X, Y) = (1.75 mm, 1.75 mm). The magnetic field components Hy at the peak positions of these magnetic fields are Hy = 25.6 m Gauss (G) and Hy = 47.9 m Gauss (G), respectively, for a current of 1 ampere (A).

  FIG. 18 is a graph showing the relationship between the diameter of the through hole 2 and the peak position of the magnetic field vector component Hy in the Y-axis direction. Although not shown in the contour diagrams shown in FIGS. 16 and 17, the results for diameters of 1 mm and 4 mm are also shown. As can be seen from FIG. 18, the diameter of the through hole 2 hardly depends on the position of the peak portion. Considering the result of the diameter 1 mm of the through hole 2 at the width w = 5 mm, the peak range of the vector component Hy is about 1-2 mm in both the X and Y axis directions in the practical use range of the primary conductor 1. It can be said that.

  Further, since 90% of the range 10% lower than the peak position is a circle having a radius of about 0.5 mm, the distances dx and dy in FIG. 1 are both 0.5 to 2.5 mm in terms of design. It is only necessary that the detection unit 4 of the magnetic detection element 3 is applied to this range.

  FIG. 19 is a graph of the diameter of the through hole 2 of the primary conductor 1 and the peak value of the vector component Hy in the Y-axis direction. As the diameter increases, the vector component Hy increases as a quadratic function. I understand that. That is, several times measurement is possible by simply fixing the detection unit 4 of the magnetic detection element 3 and changing the size of the diameter of the through hole 2 around the distances dx = 1.5 mm and dy = 1.5 mm shown in FIG. The range can be selected.

  In FIG. 12, the magnetic detection element 3 is provided in the first quadrant on the XY plane, but it can also be arranged in other quadrants due to symmetry.

  FIG. 20 shows a modification, in which a through hole 2 ′ is provided at a 45 degree direction from the origin O where the through hole 2 is located with respect to the X-axis direction, and the magnetic sensing element 3 is disposed at an intermediate position between them. The effect of the detour current Ia by the holes 2 and 2 ′ is overlapped, and the magnetic field of the Y-axis direction component is increased to increase the sensitivity. The two through holes 2, 2 'do not have to be the same size, and the number of the through holes 2 can be further increased, and the installed angular position may be designed according to the current detection specifications.

  As a means for bypassing the current, not only the through-hole 2 but also a notch hole is used to form a non-conductive region, which can correspond to a large or small current. For example, as shown in FIG. 21, a bypass current can be generated by providing a notch hole 8 at the end of the primary conductor 1 in the width direction. This configuration is suitable when it is desired to suppress a magnetic field caused by a bypass current due to a large current.

  On the contrary, as shown in FIG. 22, it is possible to deepen the notch hole 8, concentrate the detour current, increase the magnetic field of the Y-axis direction component, and cope with a small current. Furthermore, as shown in FIG. 23, by providing the notch hole 8 so as to be shifted from the opposite end, it is possible to further increase the detour current and cope with a smaller current.

<Example 2>
FIG. 24 is a configuration diagram of the second embodiment. For example, the primary conductor 12 made of a copper pattern having a width of 10 mm in the X-axis direction, a thickness of 70 μm in the Z-axis direction, and a length of 50 mm in the Y-axis direction is provided on one side of the sensor substrate 11 made of glass epoxy material having a thickness of 1.6 mm. Is provided. A through hole 13 having a diameter of 2 mm, for example, is formed by etching in the center of the primary conductor 12 in the X-axis direction. On the other surface of the sensor substrate 11, an integrated magnetic detection unit 14 is disposed at the same position as in FIG. 25, and electrodes 15 a to 15 b for soldering are drawn out on the sensor substrate 11.

  A magnetic impedance element is used for the magnetic detection unit 14, and the detection unit 16 made of an Fe—Ta—C magnetic thin film has, for example, eleven elongated pieces each having a width of 18 μm, a thickness of 2.65 μm, and a length of 1.2 mm. Patterns are arranged in parallel. The magnetic field detection direction of the detection unit 16 is only the Y-axis direction.

  The position of the detection unit 16 is offset from the center of the through-hole 13 in the X-axis and Y-axis directions by a distance dx = 1.5 mm and dy = 1.5 mm. Although not shown, the plurality of magnetic thin film patterns of the detector 16 are electrically folded in series and connected in series, and both ends are connected to respective electrodes, and soldered to the electrodes 15a and 15b on the sensor substrate 11. Bonded and connected to a sensor circuit (not shown). In FIG. 24, a high frequency pulse is applied by the flow of the electrodes 15a → 15b.

  The magnetic thin film of the magnetic detection unit 14 is provided with an easy magnetization axis in the width direction in the X-axis direction. When a high-frequency pulse is applied to the pattern of the magnetic thin film, the impedance is changed by an external magnetic field, and the magnetic detection unit 14 is converted into a sensor signal by amplitude detection.

  In the evaluation of the influence of currents other than the current I to be measured flowing in parallel, as shown in FIG. 24, a copper rod 18 having a diameter of 2 mm is arranged in parallel at an interval of 10 mm from the primary conductor 12 and a current of 10 Arms at 50 Hz. Measurement was performed under the condition that I ′ was passed and no current was passed through the primary conductor 12. Then, in the magnetic detection unit 14, the influence of the current I ′ flowing through the copper rod 18 was not observed, and it was below the noise level (10 mVpp or below).

  The magnetic field from the adjacent parallel current line is in the X-axis or Z-axis direction, and it has an effective effect that it has no component in the Y-axis direction and that the magneto-impedance element has no sensitivity in the X-axis direction, It was confirmed that the influence of the magnetic field due to the adjacent current is at a level that does not cause a problem.

  In the 5 V pulse drive of 5 V, the magnetic detection unit 14 exhibits a V-shaped impedance change characteristic with respect to a magnetic field as shown in FIG. For this purpose, as shown in FIG. 24, a bias magnet 17 is arranged on the back surface of the magnetic detection unit 14 so that a bias magnetic field of about 10 gauss (G) is applied to the detection unit 16. The range of good linearity is about ± 3 gauss (G) across the bias operating point in the case of the magnetic detection unit 14.

  FIG. 26 shows data obtained by measuring the current when the primary conductor 1 is energized with an AC current (50 Hz) variable from 0.1 to 40 Arms. 10 Arms is a sine wave of 28.28 App, and the magnetic field at that time is 724 mGpp from the simulation result. FIG. 15 shows an error between the ideal value and the actual measurement value with reference to 10 Arms, and the upper limit is set to 40 Arms because the adjustment is made so that 1 Vpp is obtained at 10 Arms with a 5 V power source. As accuracy, an error within ± 1% is guaranteed at 0.2 Arms or more.

  In the case where the diameter of the through hole 13 is 2 mm and the linearity range of the magnetic detection unit 14 is 6 gauss (G), the diameter exceeds 80 Arms. If it is possible to deal with up to 200 Arms, the magnetic field applied to the magnetic detection unit 14 is reduced to 1/3 only by setting the diameter of the through hole 13 to 1 mm, and a large current such as 270 Arms can be obtained with the same layout. On the contrary, the specification of small current can be dealt with by simply increasing the through hole 13.

  In the second embodiment, it is assumed that the primary conductor 12 is arranged on the sensor substrate 11. However, as shown in the modification of FIG. 27, in the case of the bus bar 19 in which the primary conductor is made of a copper plate, a module obtained by removing the primary conductor 12 from the configuration of FIG. 24 can be modularized on the sensor substrate 20. In this case, it is possible to position the sensor substrate 20 in the through hole 21 formed in the bus bar 19 and fix the sensor substrate 20 to the bus bar 19 by bonding or the like. In addition, 22 is a circuit element provided on the sensor substrate 20, and 23 is a signal line for extracting a signal of the magnetic detection unit 14.

  With such a configuration, even after the bus bar 19 is laid in advance, the magnetic detection unit 14 can be modularized and assembled to the bus bar 19 for easy assembly.

  In each of the above-described embodiments, the current is diverted by providing a non-conductive region with a through hole and a notch hole, but the current can be diverted by arranging an insulating material instead of the hole. .

<Example 3>
According to Japanese Patent Laid-Open No. 2006-184269, a proposal has been made to avoid a disturbance magnetic field by differential detection by using two magnetic detection elements. In this patent document, in order to avoid the influence of the external magnetic field when the magnetic field detection by the measured current is detected by a single magnetic sensor, an opening is formed in the central portion of the bus bar as the primary conductor to measure the measured current. Is diverted. In the opening, magnetic detection elements are arranged in the vicinity of the two conductors so that the magnetic fields from the currents have opposite phases, and only the magnetic field generated from the bus bar is detected by differential amplification.

  However, even if this method can eliminate the influence on the uniform magnetic field, if the current lines flow adjacently, the two magnetic sensing elements are not equally applied with the disturbance magnetic field. A magnetic shield is indispensable. As a method for solving this problem, the first and second embodiments have proposed that a non-conductive region is provided in the primary conductor and that one magnetic sensing element is provided in the vicinity of the non-conductive region. Here, a plurality of magnetic sensing elements may be provided. Therefore, in the third embodiment, a plan for providing a plurality of magnetic sensing elements will be described.

  FIG. 28 is a configuration diagram of a basic current sensor of Example 3 that performs current measurement on a current to be measured. A current to be measured I to be detected flows through the primary conductor 1, and the primary conductor 1 is in the form of, for example, a bus bar formed of a copper foil pattern or a copper plate on a printed board.

  Near the center of the primary conductor 1, a circular through hole 2 which is a non-conductive region is provided in order to partially block the current. For this reason, a part of the current I to be measured is as shown in FIG. A detour current Ia that goes around the outside symmetrically on both sides of the through hole 2 is obtained. For convenience of explanation, a coordinate axis is set for the primary conductor 1, the center of the through hole 2 is set as the origin O, the main direction in which the current I to be measured flows is the Y axis, the width direction that is the orthogonal axis is the X axis, and the thickness The direction is the Z axis.

  On the primary conductor 1, two magnetic detection elements 3a and 3b are arranged in series in the Y-axis direction to perform differential detection. The detection units 4a and 4b of the magnetic detection elements 3a and 3b are arranged such that the Y-axis direction is the magnetic field detection direction, and the center positions of the detection units 4a and 4b are distances dx and Y in the X-axis direction from the center of the through hole 2. In the axial direction, it is arranged at a position shifted by a distance dy across the X axis. As shown in FIG. 28, even if the primary conductor 1 ′ through which currents of different phases flow is close and the direction of the proximity current I ′ is parallel to the current I to be measured, the influence of the magnetic field due to the magnetic flux F of the proximity current I ′ is It becomes a vector component in the X-axis direction and has no Y-axis direction component. When the magnetic field detection direction of the detection units 4a and 4b is taken in the Y-axis direction, the magnetic detection elements 3a and 3b are not affected by the magnetic field due to the proximity current I 'and can detect only the vector component Hy of the current I to be measured. Therefore, if the vector component Hy is calibrated and converted, the amount of current I to be measured can be obtained.

  Since it is not desirable to detect the magnetic field vector component Hx in the X-axis direction as the magnetic sensing elements 3a and 3b to be used, a highly directional magnetic impedance element or orthogonal fluxgate element is suitable. An element is used. Magnetic thin film patterns are arranged in parallel in the Y-axis direction of the magnetic field detection direction as the detection units 4a and 4b, a high frequency pulse in the MHz band is applied to the electrodes 5 at both ends, and from both ends of the detection units 4a and 4b due to a change in magnetic field Is obtained as a sensor signal.

  As shown in FIG. 30, the height h of the detection portions 4a and 4b of the magnetic detection elements 3a and 3b with respect to the primary conductor 1 is necessary because of the structure that holds the positional relationship between the primary conductor 1 and the magnetic detection elements 3a and 3b. It is determined by the relationship between dielectric strength such as space, space distance, and creepage distance.

  FIG. 31 shows a configuration diagram of the detection circuit 100A. The detection units 4a and 4b of the magnetic detection elements 3a and 3b are connected to a resistor R that forms a bridge with respect to the CR pulse oscillation circuit 30. After the amplitude change from the voltage across the detection units 4a and 4b is taken out by the detection circuit 31, the differential amplification circuit 32 performs differential amplification on the outputs of the detection units 4a and 4b, and outputs the current sensor output. obtain.

  In this case, the outputs of the detection units 4a and 4b have the same sensitivity and have the same absolute value if they are located symmetrically across the X axis, and have different polarities. This is twice the absolute value of the part 4a or 4b. In addition, the external magnetic field noise is in phase with the detection units 4a and 4b in a narrow range, and by detecting the outputs of the detection units 4a and 4b differentially, the magnetic field noise is canceled and superimposed on the output of the current sensor. In other words, only the vector component Hy of the bypass current is measured. In order to detect the output of the magnetic detection element differentially, at least two detection units may be used.

  As apparent from a comparison between FIG. 31 and FIG. 15, the four resistors forming the bridge circuit are replaced with the detection unit. For example, if three detection units are employed, three of the four resistors are replaced with the detection unit. Furthermore, if four detection units are employed, all the resistances are replaced with detection units.

  In FIG. 28, the magnetic detection elements 3a and 3b are provided in the first and fourth quadrants on the XY plane, respectively. However, it is also possible to arrange them adjacent to other quadrants due to symmetry.

  FIG. 32 shows a modification in this case, and the same result is obtained even when the magnetic detection element 3a is provided in the first quadrant and the magnetic detection element 3b is provided in the second quadrant and arranged symmetrically with respect to the Y axis. It is done. The magnetic field vector component Hc1 due to the detour current Ia is a target with respect to the Y axis in the first quadrant and the second quadrant. Therefore, the magnetic detection elements 3a and 3b can be arranged in the first quadrant and the second quadrant, respectively, and the vector components Hy in the Y-axis direction having the same absolute value and the opposite polarity can be detected. In this case, although it is slightly affected by the adjacent current lines, the magnetic field noise can be substantially canceled by differential detection because the distance between the magnetic detection elements 3 is narrow.

<Example 4>
When the detection magnetic field range must be managed within a certain range in terms of magnetic saturation and linearity, such as a magnetic impedance element or an orthogonal fluxgate sensor which is a magnetic detection element, the primary conductor 1 It is preferable that the measurement range can be adjusted only by the diameter of the through hole 2.

  FIG. 33 is a configuration diagram of the current sensor of the fourth embodiment. Since the distance between the detection portions 4a and 4b of the magnetic detection elements 3 and 4 in FIG. 28 is short, a magnetic detection unit in which magnetic detection elements 3a and 3b arranged symmetrically with respect to the X axis are attached to the same element substrate 6 as an integrated type. The variation in performance can be suppressed.

  As shown in the modification of FIG. 34, the idea is to use only the positive region of the X-axis of the primary conductor 1, and the bypass current can be used by providing the notch hole 8 at the end in the width direction. With this cutout hole 8, measurement can be performed in the same manner as in the case where the through hole 2 is provided as shown in FIG. In order to flow the bypass current symmetrically with respect to the X axis, the notch hole 8 needs to be symmetrical with respect to the X axis.

  FIG. 35 is a configuration diagram of another modification. In the magnetic detection unit 7 in which the four magnetic detection elements 3a to 3d are integrated, the detection units 4a, 4b, 4c, and 4d are arranged in the first, second, third, and fourth quadrants, respectively, and a bridge is formed by the four elements. When operated as a configuration, the S / N can be further improved. As described above, when the detection units 4a to 4d are arranged symmetrically with respect to the X axis and the Y axis on both sides of the through hole 2, the vector component Hy is symmetrical with respect to the X axis and the Y axis, respectively.

  Therefore, differential detection of the outputs of the detection units 4a and 4d with respect to the X axis, differential detection of the detection units 4b and 4c, differential detection of the detection units 4a and 4b with respect to the Y axis, and differential detection of the detection units 4d and 4c. The measurement accuracy can be further improved by obtaining the average of these detection results.

<Example 5>
FIG. 36 is a configuration diagram of the current sensor according to the third embodiment. A primary conductor 12 made of a copper pattern having a width of 10 mm in the X-axis direction, a thickness of 70 μm in the Z-axis direction, and a longitudinal direction of 50 mm in the Y-axis direction is provided on one surface of the sensor substrate 11 made of glass epoxy material having a thickness of 1.6 mm. ing. A through hole 13 having a diameter of 2 mm is formed by etching in the center of the primary conductor 12 in the X-axis direction. On the other surface of the sensor substrate 11, an integrated magnetic detection unit 14 is disposed at the same position as in FIG. 33, and electrodes 15 a to 15 c for soldering are drawn out on the sensor substrate 11.

  The magnetic detection unit 14 uses a magneto-impedance element, and the detection units 16a and 16b made of an Fe-Ta-C magnetic thin film have eleven elongated portions each having a width of 18 μm, a thickness of 2.65 μm, and a length of 1.2 mm. Are arranged in parallel. And the magnetic field detection direction of the detection parts 16a and 16b is made into the Y-axis direction.

  The positions of the detectors 16a and 16b are offset from the center of the through-hole 13 by a distance dx = 1.5 mm in the X-axis direction, the center interval of the detectors 16a and 16b is dy = 3 mm, and the center O of the through-hole 13 is set. Are arranged symmetrically with respect to the X axis extending in the width direction.

  Although not shown, the plurality of magnetic thin film patterns of the detectors 16a and 16b are electrically connected in series in a zigzag manner, and both ends are connected to respective electrodes, and electrodes 15a to 15c on the sensor substrate 11 are connected. And is connected to a sensor circuit (not shown). In FIG. 36, a high frequency pulse is applied by the flow of the electrodes 15a → 15c and the electrodes 15b → 15c drawn to the sensor substrate 11.

  The magnetic detection unit 14 is provided with an easy magnetization axis in the width direction in the X-axis direction, and by passing a high-frequency pulse to the magnetic thin film pattern, the impedance is changed by an external magnetic field, and the voltage across the magnetic detection unit 14 is changed. The sensor signal is converted by amplitude detection.

  In the evaluation of the influence of currents other than the current I to be measured flowing in parallel, a copper rod 18 having a diameter of 2 mm is disposed in parallel with a distance of 10 mm from the primary conductor 12, and a current I ′ of 50 Arms of 10 Arms is flowed. The measurement was performed under the condition that no current was passed through the conductor 12. Then, in the magnetic detection unit 14, the influence of the current I ′ flowing through the copper rod 18 was not observed, and it was below the noise level (10 mVpp or below). The magnetic field from the adjacent parallel current lines is in the X or Z axis direction, does not have a component in the Y axis direction, and the distance between the detection units 16a and 16b and the adjacent copper rod 18 is equal. Worked effectively, and it was confirmed that the influence of the noisy magnetic field was almost completely eliminated.

  In Example 5, the example which has arrange | positioned the primary conductor 12 on the sensor board | substrate 11 was assumed. However, in the case of the bus bar 19 in which the primary conductor is made of a copper plate as shown in the modification of FIG. 37, a module obtained by removing the primary conductor 12 from the configuration of FIG. 36 can be modularized on the sensor substrate 20. In this case, it is possible to position the sensor substrate 20 in the through hole 21 formed in the bus bar 19 and fix the sensor substrate 20 to the bus bar 19 by bonding or the like. In addition, 22 is a circuit element provided on the sensor substrate 20, and 23 is a signal line for extracting a signal of the magnetic detection unit 14.

  With such a configuration, even after the bus bar 19 is laid in advance, the magnetic detection unit 14 can be modularized and assembled to the bus bar 19 for easy assembly.

  In each of the above-described embodiments, the current is diverted by providing a non-conductive region with a through hole and a notch hole, but the current can be diverted by arranging an insulating material instead of the hole. . These non-conductive regions need to be symmetrical on both sides with respect to the X axis.

<Example 6>
In Examples 1 to 5, a non-conductive region is employed as the direction change region. That is, the first to fifth embodiments are inventions that detect a distorted magnetic field generated when a current flows around a non-conductive region and estimate the amount of current from the detected magnetic field. A common concept in the first to fifth embodiments is to provide a region in the primary conductor that promotes a non-linear flow of current. In other words, the non-conductive region is not necessarily required as long as the current flowing direction can be bent. Accordingly, in the sixth embodiment, another example of the direction change area will be described.

  FIG. 38 is a configuration diagram of a basic current sensor of Example 6 that performs current measurement on a current to be measured. A current to be measured I to be detected flows through the primary conductor 1. The form of the primary conductor 1 is, for example, a form of a bus bar formed of a copper foil pattern or a copper plate on a printed board.

  A portion (main portion) of the primary conductor 1 that is a magnetic field detection target is a rectangular portion having a length L and a width W0. In the main part, an inlet 9a and an outlet 9b having widths W1 and W2 are formed at the rear and the front where current flows, respectively. The widths W1 and W2 are both narrower than the width W0. In order to make the explanation easy to understand, the inlet 9a and the outlet 9b are installed in the center with respect to the width W0.

  A coordinate axis is set for the primary conductor 1. Here, the center of the magnetic detection unit is the origin O. As shown in FIGS. 38 and 39, a line connecting the inlet 9a and the outlet 9b, which is an intersection of a straight line that divides the width W0 of the magnetic detection unit into two and a straight line that divides the length L of the magnetic detection unit into two. Is the origin O. As in the other examples, the main direction in which the current I to be measured flows is the Y axis, the width direction that is the orthogonal axis is the X axis, and the thickness direction is the Z axis.

  On the primary conductor 1, two magnetic detection elements 3a and 3b are arranged in series in the Y-axis direction to perform differential detection. Note that the number of magnetic sensing elements may be one as in the first and second embodiments. The configuration of the magnetic detection elements 3a and 3b is the same as in the first to fifth embodiments. The detection units 4a and 4b of the magnetic detection elements 3a and 3b are arranged such that the Y-axis direction is the magnetic field detection direction, and the magnetic detection elements 3a and 3b are arranged. The center positions of the detectors 4a and 4b are arranged at positions shifted from the center of the origin O by a distance dx in the X-axis direction and distances dy1 and dy2 with the X-axis in the Y-axis direction.

  Originally, the magnetic flux generated by the current is directed in the direction orthogonal to the current direction. Therefore, a magnetic field HC1 having only a vector component Hx in the X-axis direction on the X-axis passing through the origin O, where there is no current component facing in the width direction of the primary conductor 1 is generated.

  However, the current at a position shifted in the front-rear direction where the current flows from the origin O has a current component that flows toward the inlet 9a and the outlet 9b in an inclined manner with respect to the Y-axis direction. As a result, a vector component Hy in the Y-axis direction is generated, and the magnetic field meanders like Hc2 and Hc3. The magnetic fields of Hc2 and Hc3 are line symmetric with respect to the X axis. The vector component Hy has a reverse polarity across the X axis.

  As shown in FIG. 38, even if the primary conductor 1 ′ through which currents of different phases flow is close and the direction of the proximity current I ′ is parallel to the current I to be measured, the influence of the magnetic field by the proximity current I ′ is in the X-axis direction. Vector component and no Y-axis direction component. When the magnetic field detection direction of the detection units 4a and 4b is taken in the Y-axis direction, the magnetic detection elements 3a and 3b are not affected by the magnetic field due to the proximity current I 'and can detect only the vector component Hy of the current I to be measured. Therefore, if the vector component Hy is calibrated and converted, the amount of current I to be measured can be obtained.

  When the magnetic detection elements 3a and 3b detect the magnetic field vector component Hx in the X-axis direction, the current estimation accuracy decreases. For this reason, examples of the magnetic sensing elements 3a and 3b include a highly directional magnetic impedance element and an orthogonal fluxgate element. In the sixth embodiment, magnetic impedance elements are used as the magnetic detection elements 3a and 3b. Magnetic thin film patterns are arranged side by side in the Y-axis direction of the magnetic field detection direction as the detection units 4a and 4b. A high frequency pulse in the MHz band is applied to the electrodes 5 at both ends, and a change in voltage amplitude from both ends of the detection units 4a and 4b due to a change in the magnetic field is obtained as a sensor signal. When a bias magnetic field is required, although not shown, it is applied by a magnet or a wound coil adjacent to the magnetic sensing elements 3a and 3b.

  As shown in FIG. 40, the height h of the detection portions 4a and 4b of the magnetic detection elements 3a and 3b with respect to the primary conductor 1 is, for example, the adjustment of the magnitude of the generated magnetic field, and the position of the primary conductor 1 and the magnetic detection elements 3a and 3b. It is determined by the relationship of dielectric strength such as the space necessary for the structure to maintain the relationship, the spatial distance, and the creepage distance.

  The configuration of the detection circuit 100A that functions as a current detection device can employ the circuit configuration shown in FIG. This is because the basic part of the current detection device of the present invention can be used as it is even if the specific configuration of the region direction changing region for changing the direction of current flow is changed.

  41, FIG. 42, FIG. 43 and FIG. 44, and FIG. 45 show the simulation results of the magnetic field component Hy in the Y-axis direction related to the diffusion current from the narrow entrance / exit. The primary conductor 1 has a cross section with a width W0 = 8 mm in the X-axis direction and a thickness t = 0.8 mm in the Z-axis direction. The distance L between the inlet 9a and the outlet 9b is 7.5 mm, and the position in the width direction is the width W0. In the center of The width of the inlet 9a and the outlet 9b is set to W1 = W2 = d, and d = 0.8, 1.2, 2.4, 3.6 mm, and the surface of the primary conductor (height H = 1.6 mm) The magnetic field Hy in the main direction through which the current flows was calculated. The measured current I was 1 ampere (A).

  41 to 41D show simulation results for d = 0.8, 1.2, 2.4, and 3.6 mm, respectively. The coordinates are the first quadrant of X ≧ 0 and Y ≧ 0, and the contours are drawn in 10% increments with the vertex of the vector component Hy being 100%. In the other quadrants, a magnetic field distribution symmetric with respect to the X axis or the Y axis is formed, the third quadrant has the same polarity as the first quadrant, and the second and fourth quadrants have a magnetic field having the opposite polarity to the first quadrant.

  The peak position P is almost unchanged at 2.5 mm in the Y direction, and moves slowly from 1.7 mm to 2.15 mm in the X direction as the width of the entrance / exit increases.

  Let the distance in the Y direction from the doorway be L. The peak position P is 1.25 (= L / 2−2.5) mm at L = 7.5 mm, but it is 1.35 mm even when calculated at L = 11.5 mm, and both are not greatly changed. . The dimension of the practical distance L is determined in consideration of the fact that a peak can be clearly formed and does not interfere with an adjacent peak in reverse phase. For example, the distance L should be secured 5 mm or more, which is four times 1.25 mm.

  FIG. 45 is a graph showing the magnetic field Hy at the peak position. According to FIG. 45, when the ratio between the widths W1 and W0 of the inlet 9a and the outlet 9b is 10% (W0 = 8 mm, d = 0.8 mm), a magnetic field of 0.08 gauss per 1 A is generated. Recognize. A magnetic sensing element capable of detecting milligauss or less can detect a small target current of 1 A or less with sufficient S / N by placing it at the peak position.

  When the widths W1 and W2 of the inlet 9a and the outlet 9b are increased, the current component spreading in the width direction is reduced, and the magnetic field Hy is rapidly reduced. Therefore, in order to detect a large current, the widths W1 and W2 may be widened. When the ratio between the widths W1 and W0 is 100%, that is, d = 8 mm, the magnetic field becomes zero. This means that the adjustment range for a large current can be widened. From the above, if the magnetic sensing element is fixed at X = 2 mm and Y = 2.5 mm, it means that it is possible to meet the specifications of various current detection ranges simply by changing the widths W1 and W2.

  Such characteristics are extremely convenient for elements that must manage the detection magnetic field range within a certain range in terms of magnetic saturation and linearity, such as magneto-impedance elements and orthogonal fluxgate sensors. . In terms of productivity, it is possible to meet various current specifications by fixing the position of the element and changing the width of the entrance and exit of the primary conductor, greatly contributing to the cost reduction of the current sensor. Let's go.

  In FIG. 38, the magnetic detection elements 3a and 3b are provided in the first and fourth quadrants on the XY plane, respectively. However, of course due to symmetry, it can also be placed adjacent to other quadrants. FIG. 46 shows an example in which the magnetic detection element 3a is arranged in the first quadrant and the magnetic detection element 3b is arranged in the second quadrant. FIG. 47 shows an example in which magnetic detection elements are provided in all quadrants.

  In FIG. 47, in the magnetic detection element unit in which the four magnetic detection elements 3a to 3d are integrated, the detection units 4a, 4b, 4c, and 4d are arranged in the first, second, third, and fourth quadrants, respectively. Yes. Furthermore, when the detection units 4a, 4b, 4c, and 4d are operated as a bridge configuration as shown in FIG. 31, the S / N of the detection circuit 100A can be improved. As described above, when the detectors 4a to 4d are arranged symmetrically with respect to the X axis and the Y axis on both sides of the two origins O, the vector component Hy is symmetrical with respect to the X axis and the Y axis, respectively.

  Therefore, differential detection of the outputs of the detection units 4a and 4d with respect to the X axis, differential detection of the detection units 4b and 4c, differential detection of the detection units 4a and 4b with respect to the Y axis, and differential detection of the detection units 4d and 4c. The measurement accuracy can be further improved by obtaining the average of these detection results.

  When the inlet 9a and the outlet 9b are in the center of the primary conductor 1 in the width direction, the primary conductor 1 can be differentially operated by symmetrically installing elements whose sensitivity of the elements are adjusted to be equal to each other in the X axis or Y axis. The output from the magnetic field is doubled, and the external magnetic field having the same phase is canceled.

  FIG. 48 shows a modification. If the width of the conductor reaching the inlet 9a or the width of the conductor after the outlet 9b is too thin, a problem of heat generation may occur when a large current is applied. Therefore, as shown in FIG. 48, by restricting the current inlet / outlet with the slit grooves 7a, 7b, 7c, 7d, heat generation itself can be suppressed and thermal diffusion can be improved. 48, it can be understood that the main portion, the inlet 9a, and the outlet 9b described above are formed by inserting the slit grooves 7a, 7b, 7c, and 7d in the primary conductor 1. FIG.

<Example 7>
In the sixth embodiment, if the detection portions 4a and 4b of the magnetic detection elements 3a and 3b are placed in the vicinity of (2, 2.5) and (2, -2.5) in the coordinate positions, the inlet 9a and the outlet 9b It was shown that the specification of the current to be measured can be accommodated only by changing the widths W1, W2. As another method, the arrangement positions of the inlet 9 a and the outlet 9 b may be offset in the width direction of the primary conductor 1. FIG. 49 shows the layout. In the layout of FIG. 39, the entrance 9a and the exit 9b are shifted by dw in the width direction. Thereby, since the spread of the current changes, the direction of the magnetic field at the position where the detection units 4a and 4b of the magnetic detection elements 3a and 3b are arranged can be changed.

  FIG. 50 shows the result of a simulation of the magnetic field component Hy in the Y-axis direction for Example 7. The width W0 = 8 mm in the X-axis direction of the primary conductor 1 and the thickness t = 0.8 mm in the Z-axis direction. The inlet 9a and outlet 9b are both 1.2 mm in width W1 and W2. The length L in the Y-axis direction of the primary conductor 1 that is a magnetic detection unit is set to 7.5 mm. In the state where the positions of the inlet 9a and the outlet 9b are in the center of the width W0 as in the sixth embodiment, the offset amount dw = 0. In Example 7, the simulation was performed for each of the offset amounts dw = −2, −1, 0, 1, and 2 mm.

  The coordinate position of the magnetic detection element 3a is fixed to X = 2 and Y = 2.5 mm. As shown in FIG. 50, the magnetic field of the magnetic field component Hy in the direction in which the current mainly flows has less adjustment white when the offset amount becomes negative. On the other hand, when the offset amount becomes positive, that is, when the distance between the entrance 9a and the exit 9b and the magnetic sensing element is shortened, the magnetic field is rapidly reduced to the opposite polarity. Therefore, in the region where the offset amount is positive, the magnetic field component Hy can be significantly adjusted.

<Example 8>
FIG. 51 is a configuration diagram of the current sensor of the eighth embodiment. The sensor substrate 11 is made of a glass epoxy material and has a thickness of 1.6 mm. A primary conductor 12 is provided on one side of the sensor substrate 11. The primary conductor 12 is a copper pattern having a width of 8 mm in the X-axis direction, a length of 7.5 mm in the Y-axis direction, and a thickness of 70 μm in the Z-axis direction. The origin O of the X and Y axes is set at the center of the primary conductor 12.

  The inlet 9a and the outlet 9b of the primary conductor 12 are drawn from the center of the width W in the X-axis direction along the Y axis with a width W1 = W2 = 1.2 mm. If the inlet 9a and the outlet 9b are pulled out for a long time with a width of 1.2 mm, heat may be generated on the large current side. Therefore, in the experiment, a cable wire having a core wire diameter of 1.6 mm was soldered in the immediate vicinity of the inlet 9a and the outlet 9b, and a current to be measured was applied.

  On the other surface of the sensor substrate 11, a magnetic detection unit 14 in which two magnetic detection elements are integrated is disposed. From the magnetic detection unit 14, electrodes 15 a to 15 c for soldering are drawn on the sensor substrate 11.

  A magnetic impedance element is used for the magnetic detection unit 14. The detectors 16a and 16b made of a Fe-Ta-C magnetic thin film are constituted by eleven patterns arranged in parallel in a narrow shape having a width of 18 μm, a thickness of 2.65 μm, and a length of 1.2 mm. And the magnetic field detection direction of the detection parts 16a and 16b is made into the Y-axis direction.

  As shown in FIG. 51, the positions of the detection units 16a and 16b are offset from the center of the through hole 13 by a distance dx = 2 mm in the X-axis direction. The center interval dy between the detectors 16a and 16b is 5 mm. As described above, the magnetic detection unit 14 is disposed symmetrically with respect to the X axis.

  The plurality of magnetic thin film patterns of the detectors 16a and 16b are not shown in the figure but are electrically connected in series by zigzag folding. Both ends of the magnetic thin film pattern connected in series are connected to respective electrodes. As shown in FIG. 51, the ends of the magnetic thin film pattern are soldered to the electrodes 15a to 15c on the sensor substrate 11 and connected to the detection circuit 100A. In FIG. 51, a high frequency pulse is applied with the electrode 15a to the electrode 15c drawn to the sensor substrate 11 and the electrode 15b to the electrode 15c as a pair.

  The magnetic detection unit 14 is provided with an easy magnetization axis in the X-axis direction (width direction). By applying a high-frequency pulse to the pattern of the magnetic thin film, the impedance is changed by an external magnetic field, and the voltage across the magnetic detection unit 14 is converted into a sensor signal by amplitude detection. If the bias magnetic field and circuit gain of each element are matched so that there is no relative difference, the effect of differential detection is enhanced.

  In the evaluation of the influence of currents other than the current I to be measured flowing in parallel, a copper rod 18 having a diameter of 2 mm was arranged in parallel with a distance of 10 mm from the end of the primary conductor 12. Measurement was performed under the condition that a current I 'of 10 Arms and 50 Hz was passed through the copper rod 18 and no current was passed through the primary conductor 12. In the magnetic detection unit 14, the influence of the current I ′ flowing through the copper rod 18 is less than the noise level (10 mVpp or less). The magnetic field from adjacent parallel current lines is in the X or Z axis direction, does not have a component in the Y axis direction, and the distance between the detection units 16a and 16b and the adjacent copper rod 18 is equal, so that differential removal is performed. It was confirmed that the function worked effectively and the influence of the noisy magnetic field was almost completely eliminated.

  FIG. 52 shows the relationship between the measured current and the output voltage when the width W1 (= W2) of the inlet 9a and outlet 9b of the primary conductor 1 is 1.2 mm and 4.8 mm. Since the detection circuit 100A is driven by a single power source of 5V, the output voltage for the measurement current 0A is adjusted to 2.5V.

  As shown in FIG. 45, the magnetic field Hy in the Y direction applied to the element is 0.078 gauss per 1A, and in the sensor in which the above linearity is ensured within a range of ± 3 gauss, it exceeds ± 38.5A. Linearity will decrease. It can be seen from the actual measurement data shown in FIG. 52 that the straight line accuracy decreases from around 40A. Under this condition, the specification is ± 40A.

  In order to widen the range with good linearity, the width of the inlet 9a and the outlet 9b may be increased. When the widths W1 and W2 are set to 4.8 mm, the magnetic field Hy is 0.038 gauss per 1A, and linear accuracy is ensured up to ± 79A. You can see that The difference in sensitivity may be adjusted by the gain of differential amplification.

  This means that the linearity accuracy can be secured in a desired measurement current range by changing the width of the current inlet / outlet with the same magnetic sensing element and circuit configuration to be used.

  In the eighth embodiment, an example in which the primary conductor 12 is disposed on the sensor substrate 11 is assumed. However, as shown in the modification of FIG. 53, in the case of the bus bar 19 whose primary conductor is made of a copper plate, the magnetic sensing element and the sensor board 20 on which the electrical components and terminals of the processing circuit are mounted are aligned and modularized. Can be kept. The bus bar 19 has a thin tip so that it can be used by being inserted into a mating board and soldered. Although holding of the magnetic detection unit 14 is a simple illustration, it can be assembled to a non-conductive member 24 such as a resin mold member to ensure both positional accuracy and insulation. In addition, 22 is a circuit element provided on the sensor board | substrate 20, 23 is a terminal which connects the signal of the magnetic detection unit 14 with another circuit board.

  With such a configuration, the bus bar 19 can be adapted to a wide range of current specifications by simply preparing several types of bus bars 19 with different widths and positions of the notch portions that serve as the entrance / exit 21 of the current detection unit, and the degree of freedom of the product. It can be secured.

  53, for example, when mounted on the table tap 100 in FIG. 1, each terminal of the bus bar 19 is connected to the outlet board 22. A sensor board 20 is disposed on the bus bar 19. On the sensor board 20, a magnetic detection unit 14, a logic circuit / op-amp, a power supply for the logic circuit / op-amp +3.3 V, GND, and an output voltage of the current sensor Vout and bias potential Vref1 are connected to terminal 23.

  FIG. 54 is a detailed circuit diagram of the sensor substrate 20 in FIG. The magnetic detection unit 14 is connected to a resistor 153 that forms a bridge with respect to the CR pulse oscillation circuit 150. The detection circuit 151 extracts an amplitude change from the both-end voltage, which is a detection signal of the detection unit, and outputs the change to the amplification circuit 152. The operational amplifier 154 amplifies the amplitude change and outputs it.

  As described above, according to the present invention, one feature resides in that a direction changing region for changing the direction in which the measured current flows from the main direction to another direction is provided in a part of the conductor through which the measured current flows. is there. Further, the present invention is characterized in that a magnetic detection element detects a magnetic field generated by a current to be measured whose direction of flow is changed by the direction change region. Thereby, it becomes difficult to receive the influence of the magnetic field which the electric current which flows into another conductor arrange | positioned in parallel with the primary conductor which is an electric current measurement object generate | occur | produces. That is, the current measurement accuracy can be improved. Therefore, by using such a current sensor 24 for the table tap 100 of FIG. 1, it is possible to accurately detect the power consumption of the electrical device.

  The direction change region includes a non-conductive region that prevents current flow. In the embodiment described above, a hole is adopted as the non-conductive region, but a non-conductive member such as an insulator may be inserted into the hole. Moreover, it may be a hole with a bottom instead of a through hole. When forming a hole instead of a hole, the thickness of the portion forming the bottom of the hole must be sufficiently thin with respect to the depth of the hole so that the direction of the magnetic field can be sufficiently changed.

  Since the current becomes a bypass current that bypasses the non-conductive region, the magnetic field is distorted in the vicinity of the non-conductive region. In particular, if a magnetic detection element having magnetic field detection sensitivity is arranged only in the main current direction (Y-axis direction), the measurement accuracy is improved because it is not affected by magnetic fields in other directions such as the X-axis direction.

  In order to improve the measurement accuracy, the number of magnetic sensing elements may be plural. For example, two magnetic sensing elements are arranged so as to be line symmetric with respect to the Y axis passing through the center of the primary conductor, or two magnetic sensing elements are arranged so as to be line symmetric with respect to the X axis. Or you may. Furthermore, a total of four magnetic sensing elements may be arranged by combining these.

  From the experimental results, it is possible to improve the measurement accuracy by arranging the detection part of the magnetic detection element within a range of 0.5 to 2.5 mm away from the center of the non-conductive region on the X axis and the Y axis, respectively. To do.

  In addition, the direction change region includes an outlet 9b having a width W2 narrower than the width W0 of the main portion and a width W2 narrower than the width W0 of the main portion behind the main portion with respect to the main portion of the primary conductor through which current flows. An inlet 9a may be provided. In addition, although accuracy will fall, you may arrange | position only any one of the entrance 9a and the exit 9b in the principal part. The arrangement position and number of the magnetic sensing elements may be substantially the same as the arrangement position and number of the non-conductive regions.

  Further, the detection range of the current to be measured can be easily adjusted by simply changing the size of the non-conductive region, so that the degree of freedom in design is large.

  The present invention is not limited to the above-described embodiment, and various changes and modifications can be made without departing from the spirit and scope of the present invention.

[Other Embodiments]
As mentioned above, although this invention was demonstrated in detail based on Embodiment 1, this invention is not limited to Embodiment 1 mentioned above. For example, as shown in FIG. 55, a real-time clock 286 having a calendar function may be added to the outlet board 220 of the first embodiment described above. In this case, the microcomputer (CPU) 280 stores data such as current and power in the nonvolatile memory of the EEPROM 285 together with the measurement time, as shown in FIG. Thereby, an external device such as a computer having a display function can receive the data shown in FIG. 56 and display the power and the like with the time. At this time, as the data displayed on the external device, the received data may be displayed as it is, or secondary data converted into data such as a graph may be displayed as appropriate.

  With such a configuration shown in FIG. 55, the usage state of the electric device can be measured more reliably. Specifically, when the external terminal such as a personal computer is not turned on, the measured current value, power consumption, power consumption, etc. are transmitted because the power is off at the external device to be transmitted. It is assumed that the measurement data at the OFF time is lost. On the other hand, the power consumption information based on the power consumption of the electrical equipment corresponding to the usage time or usage time of the outlet is provided like the EEPROM while providing a time measuring means such as a real time clock for measuring the usage time or usage time of each outlet. By storing in a non-volatile storage means, when data can be transmitted to the external terminal (when connected), power consumption information is transmitted as it is, and when data cannot be transmitted to the external terminal (connection is disconnected) Power consumption information can be stored in the storage means (when it is in a state), it is possible to reliably transmit untransferred power consumption information when data communication is possible. Note that the microcomputer (CPU) performs data transmission in real time when communication is in the connected state, and continues to count the usage time or usage time of each outlet even when the connected state is disconnected. It is also possible to provide the information, or it is possible to start measuring the use time or use time of each outlet for the next transmission after the disconnection state. As a result, the transferred power consumption information and the untransferred power consumption information can be managed separately, and the information management is performed on the external terminal side by transmitting the untransferred power consumption information in a later connection state. Can be done appropriately. Note that the timing means described above may be provided in the current sensor, may be provided on a substrate on which the current sensor is mounted, or may be provided on the external terminal side.

  In the present invention, for example, as shown in FIG. 57, voltage measurement by capacitive voltage division may be replaced with a step-down transformer 1000. In this case, the step-down transformer 1000 lowers the input AC voltage, and its output is set to a voltage that does not exceed the input operating voltage of the operational amplifier. As a result, the withstand voltage and the insulation resistance of the AC input power supply can be increased as compared with the capacitive voltage dividing method and the resistance voltage dividing method, so that safety can be increased.

  Further, the present invention is basically the same as FIG. 3 except that, for example, as shown in FIG. 58, the voltage measurement based on the capacitive voltage division shown in FIG. In the case of the circuit shown in FIG. 58, ± 100 * √2 * (3.3 / 1003.3) = ± 0.465 V centered on +1.65 V, that is, ± 0. 465V is output and input to the operational amplifier through the filter.

  The present invention can also be realized by executing the following processing. That is, software (program) that realizes the functions of the above-described embodiments is supplied to a system or apparatus via a network or various storage media, and a computer (or CPU, MPU, or the like) of the system or apparatus reads the program. It is a process to be executed.

100 Table tap 200 Outlet plug 201 AC +
202 AC-
210 Wiring pattern 211 Wiring pattern 220 Outlet board 240 Common mode choke coil 250 Power supply 260 Capacitor 270 Multiplexer 280 Microcomputer (CPU)
290 Communication module 300 Power cord

Claims (12)

An outlet to which the electrical device to be measured is connected;
A plug connected to an external power supply;
A conductor connecting between the outlet and the plug;
Voltage measuring means for measuring a voltage applied to the conductor;
Current measuring means for measuring a current flowing through the conductor;
Based on the voltage value obtained from the voltage measurement means and the current value obtained from the current measurement means, the power acquisition means for obtaining the power consumption of the electrical equipment,
The current measuring means detects a current direction changing region in which the flow direction of the current to be measured flowing through the conductor is changed to another direction, and magnetism generated by the current to be measured whose current direction is changed by the current direction changing region. An apparatus for measuring power consumption, comprising: a magnetic sensing element; and a current value obtaining means for obtaining a current value of the current to be measured from an output of the magnetic sensing element. A time measuring means for measuring the use time or use time of the outlet;
The power consumption measuring apparatus according to claim 1, further comprising a storage unit that stores power consumption information of the electric device corresponding to a use time or a use time of the outlet.   The power consumption measuring apparatus according to claim 2, wherein the storage unit is a nonvolatile memory.   The consumption according to any one of claims 1 to 3, further comprising a transmission unit that wirelessly transmits power consumption information based on the power consumption of the electrical device obtained by the power acquisition unit to an external terminal. Power measuring device.   5. The consumption according to claim 4, wherein the transmission unit transmits power consumption information of the electric device that has not been transmitted to the external terminal after the connection with the external terminal shifts from a disconnected state to a connected state. Power measuring device. An outlet to which the electrical device to be measured is connected;
A plug connected to an external power supply;
A conductor connecting between the outlet and the plug;
Voltage measuring means for measuring a voltage applied to the conductor;
Current measuring means for measuring a current flowing through the conductor;
Based on the voltage value obtained from the voltage measurement means and the current value obtained from the current measurement means, a power acquisition means for obtaining power consumption of the electrical device;
A time measuring means for measuring the use time or use time of the outlet;
Storage means for storing power consumption information based on the power consumption of the electrical device corresponding to the use time or use time of the outlet;
Transmission means for transmitting power consumption information of the electrical equipment to an external terminal,
The power transmission measuring apparatus characterized in that the transmission means transmits power consumption information of the electric device from the storage means to the external terminal.   The consumption according to claim 6, wherein the transmission unit transmits power consumption information of the electric device that has not been transmitted to the external terminal after the connection with the external terminal shifts from a disconnected state to a connected state. Power measuring device.   The power consumption measuring device according to claim 6 or 7, wherein the time measuring unit starts measuring the use time or the use time of the outlet after the connection between the transmission unit and the external terminal shifts to a disconnected state. .   9. The power consumption measuring apparatus according to claim 6, wherein the storage unit is a nonvolatile memory. A power consumption measuring device for measuring power consumption of an electrical device to be measured; and a display device connected to the power consumption measuring device and displaying the power consumption of the electrical device transmitted from the power consumption measuring device. A power consumption management system comprising:
The power consumption measuring device includes an outlet connected to an electrical device to be measured, a plug connected to an external power source, a conductor connecting the outlet and the plug, and a voltage applied to the conductor. Based on the voltage measuring means for measuring, the current measuring means for measuring the current flowing through the conductor, the voltage value obtained from the voltage measuring means and the current value obtained from the current measuring means, the power consumption of the electrical equipment Power acquisition means for obtaining the time, a time measuring means for measuring the use time or use time of the outlet, and a storage means for storing power consumption information based on the power consumption of the electrical equipment corresponding to the use time or use time of the outlet; Transmission means for transmitting power consumption information of the electrical equipment to the display device,
The power consumption measuring device transmits power consumption information of the electric device from the storage unit to the display device after the connection between the transmission unit and the display device is changed to a connected state. Measuring system.   The power consumption measuring system according to claim 10, wherein the display device is a portable terminal device having a display. The power consumption measuring system according to claim 10 or 11, wherein the storage means is a nonvolatile memory.

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