KR101715350B1 - Fiber optic sensor type device and method for sensing and monitoring temperature of power transmission busbar, including capacitive energy harvesting for self-powered and frequency modulation, or method and device for sensing temperature of busbar without external power - Google Patents

Abstract

A temperature detecting device for detecting the temperature of a bus bar is provided. The temperature detecting apparatus includes a driving power generator for generating a driving power by using a capacitive reactance obtained from the bus bar through a metal antenna; And a temperature arithmetic unit that is driven using the driving power source and measures a temperature of the bus bar and generates a temperature signal having a frequency corresponding to the measured temperature.

Description

TECHNICAL FIELD [0001] The present invention relates to an optical fiber sensor type temperature detection device for monitoring the status of a power transmission bus bar of a frequency modulation type including self-power generation, or a method and device for detecting a temperature of a bus bar without an external power source. AND MONITORING TEMPERATURE OF POWER TRANSMISSION BUSBAR, INCLUDING CAPACITIVE ENERGY HARVESTING FOR SELF-POWERED AND FREQUENCY MODULATION, OR METHOD AND DEVICE FOR SENSING TEMPERATURE OF BUSBAR WITHOUT EXTERNAL POWER}

The present invention relates to a method and an apparatus for detecting the temperature of a voltage sub bus bar existing in a switchboard (for example, a high voltage, a low voltage, an electric motor control panel, and a distribution board) without an external power connection. Here, the bus bar is a large power transmission means.

The switchboard is a device that is installed inside or outside a building or substation that has a lot of electricity. Switchboards include high-voltage, low-voltage, motor control panel, and distribution panel. The switchgear is an electric device in which electric devices such as various switches, instruments, relays (relays), and transformers are arranged and managed uniformly. Inside the switchgear, various facilities are electrically connected through a bus bar that can be energized.

If the coupling between the busbar and the other busbar located in the switchgear is weakened, the connection resistance is increased and the temperature of the corresponding part is increased. The temperature increase further increases the connection resistance, Temperature rushing phenomenon may occur. For safe power supply, monitoring of the relevant part should always be done. However, due to the high voltage (e.g., 6.6 kV, 22.9 kV, 154 kV), it is difficult to obtain the signal.

Conventional techniques can use the characteristic of inductive reactance to obtain the energy required for temperature detection. A magnetic field generated through the bus bar is picked up and sufficient energy necessary for temperature detection can be obtained through the secondary side of the pickup coil.

However, this conventional technique requires a large amount of inductive coupling inductance, so that no power is generated when the current does not flow, the weight of the temperature detecting device is difficult to be reduced, It is difficult to transmit the detection signal to the driving unit of the detection device.

There is also a technology that can detect temperature by applying Rayleigh scattering light in a fiber optic. The technique utilizes the difference in the reflected phase of the light irradiated on the temperature-sensitive optical fiber layer at the temperature detection site or the deformation of the optical fiber itself, which is transferred by the bending of the bimetal.

The technology has the advantage that it can perform telemetry based on non-power operation and excellent insulation, enables ultra-precise broadband measurement, and is not affected by electromagnetic waves. However, the technology is not widely used due to the price of the sensor components and the complex signal processing cost.

SUMMARY OF THE INVENTION An object of the present invention is to provide an apparatus and method for enabling effective temperature sensing in an inexpensive manner while maintaining a temperature sensing structure which is an advantage of an optical fiber temperature sensor.

Another object of the present invention is to provide a method and apparatus for always acquiring energy for temperature detection and consuming low power by using the characteristic of capacitive reactance in order to solve the above problems .

According to an embodiment of the present invention, there is provided a temperature detecting apparatus for detecting a temperature of a bus bar. The temperature detecting apparatus includes a driving power generator for generating a driving power by using a capacitive reactance obtained from the bus bar through a metal antenna; And a temperature arithmetic unit that is driven using the driving power source and measures a temperature of the bus bar and generates a temperature signal having a frequency corresponding to the measured temperature.

The metal antenna may have one of a cylindrical shape, an elliptical shape, and a parabolic shape, and may be disposed to surround the bus bar.

The driving power generator may include a high voltage transformer having a primary side and a secondary side.

Wherein the high-voltage transformer is configured such that, when the capacitive reactance is obtained from the bus bar through which the voltage flows, the first voltage generated at the primary side based on the capacitive reactance is lower than the first voltage And can be transformed to the second voltage.

The second voltage may correspond to the driving power.

The driving power generator may further include a TVS (Transient Voltage Suppressor) diode connected to the primary side for overvoltage suppression.

The driving power generator may include a piezoelectric transformer for generating the driving power.

The temperature calculator may include a frequency output controller for changing a duty cycle of the temperature signal through a first resistor and a first resistor connected to the first capacitor.

The frequency output control unit may include a first transistor having a gate to which the temperature signal is applied.

Wherein the frequency output control unit decreases the length of the first section in which the voltage of the temperature signal is higher than the turn-on voltage for turning on the first transistor according to a ratio between the first capacitor and the first resistance element, The voltage of the second section may increase the length of the second section that is lower than the turn-on voltage.

The temperature calculating unit may include: a rectifying unit for rectifying a signal for the driving power through a plurality of rectifying diodes; And a shunt regulator that holds the voltage of the rectified signal at a constant voltage through a smoothing capacitor and a Zener diode.

The temperature detection device may further include a temperature display unit for outputting a notification when the frequency of the temperature signal corresponds to a temperature higher than the threshold temperature.

The temperature calculation unit may include a temperature detection element for measuring the temperature of the bus bar.

There may be a heat transfer material for thermally connecting the bus bar and the temperature detecting element within a predetermined distance between the bus bar and the temperature detecting element.

According to another embodiment of the present invention, there is also provided a method of detecting a temperature of a bus bar without an external power supply. The method of detecting a temperature of the temperature detecting device includes: obtaining a capacitive reactance from the bus bar through a metal antenna; Generating a driving power source using the capacitive reactance; Measuring a temperature of the bus bar through the driving power source, and generating a temperature signal having a frequency corresponding to the measured temperature; And changing a duty cycle of the temperature signal.

According to the embodiment of the present invention, the risk of a safety accident can be prevented in advance by monitoring the temperature of a bus bar located in a switchboard (e.g., a high pressure, a low pressure, an electric motor control board, and a distribution board).

In addition, according to the embodiment of the present invention, the temperature detection operation can be performed in a non-power source without an external power source by internally generating the driving power (driving voltage) for the characteristic of the capacitive reactance and the temperature detecting device of the voltage bus bar . The capacitance is obtained through the antenna, and the value of that capacitance affects the current magnitude of the primary side of the transformer.

Also, according to the embodiment of the present invention, the configuration for temperature display (or blinking) can be realized by a low power frequency output circuit operating in real time.

Further, according to the embodiment of the present invention, the volume of the temperature detecting device can be drastically reduced by using a piezoelectric transformer.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view showing a structure of a bus bar and a temperature detecting device located in a switchboard according to an embodiment of the present invention; FIG.
2 is a diagram showing a configuration of a temperature detecting apparatus according to an embodiment of the present invention.
3 is a diagram showing a configuration of a temperature detecting device according to another embodiment of the present invention.
4 is a view showing a capacitor included in the temperature detecting device according to the embodiment of the present invention.
5 is a circuit diagram illustrating a circuit corresponding to the driving power source generating unit according to the embodiment of the present invention.
6 is a diagram showing a circuit corresponding to the temperature arithmetic unit according to the embodiment of the present invention.
7 is a diagram illustrating a timing sequence for a temperature arithmetic unit according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and similar parts are denoted by like reference characters throughout the specification.

In the present specification, duplicate descriptions are omitted for the same constituent elements.

Also, in this specification, when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, May be present. On the other hand, in the present specification, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that no other element exists in between.

Furthermore, terms used herein are used only to describe specific embodiments and are not intended to be limiting of the present invention.

Also, in this specification, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

Also, in this specification, the terms " comprise ", or " have ", and the like are used to specify that there is a feature, a number, a step, an operation, an element, a component, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, parts, or combinations thereof.

Also, in this specification, the term 'and / or' includes any combination of the listed items or any of the plurality of listed items. In this specification, 'A or B' may include 'A', 'B', or 'both A and B'.

1 is a diagram showing a structure of a bus bar and a temperature detection device located in a switchboard of a high pressure, a low pressure, a motor control panel, and a distribution board according to an embodiment of the present invention. As illustrated in FIG. 1, The temperature detecting device 200 can be located in the vicinity of the bus bar 100 (for example, near the binding portion between the bus bar and the high-voltage line) located in the high voltage, low voltage, motor control panel, The temperature detecting device 200 is arranged to be physically spaced from the bus bar 100.

Specifically, the temperature detecting device 200 generates a driving power source (or a driving voltage) for temperature detection, using the capacitive reactance obtained through the metal antenna 300 from the bus bar 100. The temperature detecting device 200 is electrically connected to the metal antenna 300. For example, the bus bar 100 may be located inside the metal antenna 300, and the temperature detecting device 200 may be located outside the metal antenna 300. A material for thermally connecting the periphery of the bus bar 100 and the temperature detecting device 200 may be additionally disposed when the temperature detecting device 200 is located outside the metal antenna 300. [

The metal antenna 300 may be arranged to be a predetermined distance RD1 away from the switchboard 10 (e.g., a housing such as a high-voltage, low-voltage, motor control panel, and distribution board).

The metal antenna 300 has a metal material and may have a cylindrical shape surrounding the bus bar 100. The metal antenna 300 and the bus bar 100 are not in electrical contact with each other. On the other hand, the metal antenna 300 is not limited to a cylindrical shape, and may have another form of metal material (e.g., elliptical shape, parabolic shape, etc.) for obtaining capacitive reactance. The metal antenna 300 may have a circular shape at both ends in order to prevent the electric field from being concentrated. On the other hand, the inner surface (e.g., the surface in the direction of the bus bar 100) of the metal antenna 300 can be wrapped (or covered) with an insulator.

2 is a diagram showing a configuration of a temperature detecting apparatus according to an embodiment of the present invention.

The temperature detection device 200 may include a driving power source generation unit 210, a temperature calculation unit 220, and a temperature display unit 230. The temperature detecting device 200 is disposed in the housing of the switchboard 10 (e.g., high-voltage, low-voltage, motor control panel, and distribution panel, etc.).

The driving power supply generating unit 210 generates driving power for the temperature calculating unit 220 using the capacitive reactance acquired (picked up) through the metal antenna 300 from the voltage flowing through the bus bar 100, Driving voltage). Specifically, the driving power generator 210 may include a transformer 211 to generate energy (or power, voltage) necessary for driving the temperature calculator 220.

The temperature calculator 220 is driven based on the driving power (or driving voltage) generated by the driving power generator 210 to detect the temperature of the bus bar 100. Specifically, the temperature arithmetic unit 220 may include a temperature sensor 221 for measuring the temperature of the bus bar 100 (or the periphery of the bus bar 100). The temperature calculator 220 generates (outputs) a signal having a frequency corresponding to the measured temperature.

The temperature display unit 230 may display a temperature corresponding to a frequency of a signal output from the temperature calculator 220. Specifically, when the frequency of the signal output from the temperature calculator 220 corresponds to a temperature higher than the critical temperature, the temperature display unit 230 can output a notification indicating this fact. For example, when the frequency of the signal output from the temperature calculator 220 corresponds to a temperature higher than the critical temperature, the temperature display unit 230 may display a temperature corresponding to the frequency. Or the temperature display unit 230 may display the temperature corresponding to the frequency at all times. Alternatively, when the frequency of the signal output from the temperature calculator 220 corresponds to a temperature higher than the threshold temperature, the temperature display unit 230 can notify the user of the fact through the flicker signal or the alarm signal.

As a result, when sufficient driving power (or driving voltage) is generated through the voltage-based operation based on the capacitive reactance after the capacitive reactance is obtained from the bus bar 100 through the metal antenna 300, The temperature calculation unit 220 can be driven based on the generated driving power. The temperature measured by the temperature calculator 220 can be converted into a frequency and output. The temperature corresponding to the frequency may be displayed by the temperature display unit 230. Or when the temperature corresponding to the frequency is higher than the set threshold temperature, a flicker signal indicating the fact may be output.

3 is a diagram showing a configuration of a temperature detecting device according to another embodiment of the present invention.

The temperature detecting device 200 illustrated in FIG. 3 is different from the temperature detecting device 200 shown in FIG. 2 in that a piezoelectric transformer 240 (for example, a PZT (Piezo-transformer)) is used instead of the transforming unit 211 of the driving power source generating unit 210 The remaining configuration of the temperature detecting device 200 illustrated in FIG. 3 is the same as or similar to the temperature detecting device 200 illustrated in FIG. 2, except that the illustrated temperature detecting device 200 is illustrated.

Specifically, the temperature detecting apparatus 200 may include a driving power supply generating unit 210, a temperature calculating unit 220, and a temperature display unit 230. The driving power supply generating unit 210 includes a piezoelectric transformer 240 instead of the transforming unit 211.

The piezoelectric transformer 240 may be a thin film piezoelectric transformer using a thin film type piezoelectric element. Piezoelectric transformer 240 is smaller and lighter than a conventional transformer (e.g., 211). Specifically, when the electret responds to the radially spreading E-field, the sensitive piezo transformer 240 can be moved (driven) to generate the necessary power (required voltage). Even though the piezoelectric transformer 240 is small, it can supply sufficient energy to the secondary side of the pickup coil without installing an additional transformer.

If the piezoelectric transformer 240 (e.g., Piezo-transformer) is used instead of the driving power generator 210, the temperature detecting device 200 can be implemented in a small size, ) Can be supplied with sufficient energy. In addition, since the piezoelectric transformer 240 (e.g., a piezoelectric transformer) is very thin and lightweight, the overall size of the temperature detecting device 200 can be drastically reduced.

4 is a view showing a capacitor included in the temperature detecting device according to the embodiment of the present invention.

The bus bar 100, the temperature detecting device 200 and the capacitor C _CR1 located in the temperature detecting device 200 can be considered to be connected in series with each other. That is, as illustrated in FIG. 4, the active line H1, the primary side of the transformer TR1, the capacitor _CCR1 , and the ground GND are connected in series with each other. In Fig. 4, the circuit 200C corresponds to the temperature detecting device 200 and the ground GND corresponds to the housing of the switchboard 10 (e.g., high voltage, low voltage, motor control panel, and distribution panel).

Capacitors _(CR1 C) may have a capacitive reactance depends on the distance (RD1) between the switchgear (10) (for example, high pressure, low pressure, the motor control board, and distribution boards, etc.) and the metal antenna 300. For example, the capacitor C _CR1 may have a capacitance of 6 pF. The current I _TR flowing through the capacitor _CCR1 and the ground GND and the current flowing through the secondary side of the transformer TR1 can be derived based on the following Equation 1:

In the equation (1), V _bus is the voltage of the bus bar 100, j is the imaginary number, w is the frequency applied to the _CCR1 , I _TR is the current flowing from the bus bar 100 to ground (GND) ) Denotes a ratio between the number of turns of the primary coil at the transformer TR1 and the number of turns of the secondary coil, and I _amp means the current flowing at the secondary side of the transformer TR1.

The transformer TR1 corresponds to the transformer 211 in Fig. 2 or the piezoelectric transformer 240 in Fig. Specifically, the transformer TR1 may be a transformer using a 40 kH inductance, and may be a transformer having a voltage ratio of 100: 1 between the primary side and the secondary side. On the other hand, even if the transformer TR1 is located between the capacitor _CCR1 and the bus bar 100, there is almost no change in the magnitude of the current I _TR . Assuming that the ratio of the number of turns of the transformer TR1 is 100: 1, the magnitude of the current I _amp can be amplified to 3 mA.

The temperature detection module TC1 corresponds to the temperature calculation unit 220 of FIG. 2 or FIG. Specifically, the temperature detection module TC1 can be driven with an electromotive force of 4.5 V and a power based on a current of 3 mA (e.g., 0.01 W).

The active line H1 corresponds to the bus bar 100 being energized.

The current I _TR is a microcurrent generated when the state of the bus bar 100 is active. For example, the current I _TR may be 30 uA.

The driving power required for the temperature detecting device 200 can be obtained through the relationship with the time-varying voltage applied to the bus bar 100. [ The active state of bus bar 100 is always AC power. When an AC power source, that is, a time-varying voltage, is applied to the bus bar 100, a displacement current flows through the metal antenna 300 and the earth capacitance.

For example, assume that a capacitance of 6 pF is generated in the capacitor C _CR1 by the metal antenna 300 of the circuit (for example, 200 C) implemented under an environment of 22.9 kV (effective value 13,500 V = 22.9 kV / 1.73) . The capacitor C _CR1 may be included in the metal antenna 300. Here, the capacitance of the capacitor _(CR1 C) is dependent on the distance (RD1) (for example, 1000mm) between the metal antenna 300 and the switchgear (10) (for example, high pressure, low pressure, the motor control board, and distribution boards, and so on).

The magnitude of the induced current I _TR in this case is 30 uA.

If the transformer (TR1) of 40kH inductance transformer, the impedance is 15 because MOhm, very small relative to the impedance due to the capacitor (C _CR1). It can be assumed that most of the current flows to the primary side of the transformer TR1 and the minute current induced in the primary side of the transformer TR1 is necessary for driving the temperature detection module TC1 in the secondary side of the transformer TR1 Current can be amplified. An electromotive force of 450 V is generated at both ends of the primary side of the transformer TR1. The corresponding voltage can be adjusted through the TVS diodes D12 and D13 disposed at both ends of the primary side of the transformer TR1. Specifically, when the capacitive reactance is obtained from the bus bar 100 through which the voltage is flowing through the metal antenna 300, the transformer TR1 transforms the voltage generated on the primary side based on the capacitive reactance to a low voltage can do. The transformed voltage can be used as a driving voltage for the temperature detection module TC1 together with the current. On the other hand, the transformer TR1 may be a high voltage (e.g., 6.6 kV) transformer or an extra high voltage (e.g., 22.9 kV) transformer.

Further, when the transformer TR1 is a 100: 1 transformer, an electromotive force of 4.5 V and a current of 3 mA can be obtained from the secondary side of the transformer TR1.

The temperature detection module (TC1) can be driven with power based on an electromotive force of 4.5 V and a current of 3 mA.

Meanwhile, a transient voltage suppressor (TVS) diode may be used for overvoltage limitation on the primary side of the transformer TR1.

The driving power generation unit 210 will be further described with reference to FIG.

5 is a circuit diagram illustrating a circuit (hereinafter referred to as 'driving power supply generating circuit') corresponding to the driving power supply generating unit 210 according to the embodiment of the present invention.

Specifically, the drive power generation circuit includes an antenna ANT1, a transformer TR1, and TVS diodes D12 and D13.

The antenna ANT1 is an antenna made of metal, and corresponds to the metal antenna 300. [ Antenna (ANT1) may comprise a capacitor (C _CR1).

The transformer TR1 may be a 1: 100 transformer. Specifically, the transformer TR1 includes a transformer TR1a and a transformer TR1b.

The TVS diodes D12 and D13 are arranged (connected) on the primary side of the transformers TR1a and TR1b to suppress the overvoltage. That is, the TVS diode D12 is disposed on the primary side of the transformer TR1a, and the TVS diode D13 is disposed on the primary side of the transformer TR1b. For example, the clamping voltage of the TVS diodes D12 and D13 may be 300V.

The driving power supply generating circuit includes a plurality of resistive elements R9, R10 and R11. Or the driving power supply generation circuit may not include the resistance elements R9, R10, and R11.

The ground GND1 may correspond to the housing of the switchboard 10 (e.g., high voltage, low voltage, electric motor control panel, and distribution panel).

The driving power generation circuit is connected to a circuit (hereinafter referred to as a 'temperature calculation circuit') corresponding to the temperature calculation unit 220 of FIG. 6 to be described later. For example, the driving power generation circuit may be connected to the temperature calculation circuit through the connection part CN10.

On the other hand, the piezoelectric transformer 240 can be implemented by a circuit similar to that of Fig.

6 is a diagram showing a circuit (temperature arithmetic circuit) corresponding to the temperature arithmetic unit according to the embodiment of the present invention. Specifically, FIG. 6 illustrates a temperature arithmetic circuit implemented to consume low power.

The temperature arithmetic circuit is driven by using a driving power source generated through the driving power source generating circuit of FIG. Specifically, the temperature calculation circuit may include a rectification part REC1, a shunt regulator SNT1, a temperature sensing circuit SEN1, a frequency output control circuit FOC1, and diodes D2 and D7.

The rectification part REC1 rectifies a signal (a signal for driving power) of driving power (or driving voltage) generated through the driving power generation circuit of Fig. The rectification section REC1 includes a plurality of rectification diodes D3, D4, D8, and D9.

The shunt regulator SNT1 maintains the voltage of the signal rectified through the rectification section REC1 at a constant voltage. The shunt regulator SNT1 includes a zener diode D5 and a smoothing capacitor C1.

The temperature sensing circuit SEN1 (or the temperature sensing unit) measures the ambient temperature of the bus bar 100, and then outputs a signal having a frequency corresponding to the measured temperature. The temperature sensing circuit SEN1 includes a temperature detection element U1 and a capacitor C3. The temperature detecting element U1 includes a temperature sensor (e.g., a frequency output temperature sensor) therein.

The frequency output control circuit (FOC1) (or frequency output control section) controls the frequency output for low-power temperature detection. The frequency output control circuit FOC1 changes the duty cycle of the signal. The frequency output control circuit FOC1 includes a capacitor C2, resistance elements R1 and R2, and a transistor Q2. Transistor Q2 may be a metal-oxide-semiconductor field-effect transistor. The low power consumption of the temperature calculation circuit can be achieved through the capacitor C2, the resistance element R2, and the transistor Q2.

The diode D2 is an element associated (or connected) to the temperature display unit 230. [ In the case where the diode D2 is replaced with a light emitting diode, the diode D2 can emit an alarm or the like. Or the diode D2 may be replaced by a device such as a speaker or the like. Or the diode D2 is replaced by a laser diode, the diode D2 can be connected to the light-receiving unit of the measuring device via the optical cable. Here, the measurement apparatus corresponds to a monitoring apparatus, and the degree of flickering of the diode D2 is received as a frequency signal, and the temperature can be displayed using the mapping value between the frequency signal and the temperature.

The operation of the temperature calculation circuit will be described.

The drive power (or drive voltage) signal generated through the drive power generation circuit of FIG. 5 is rectified through the rectification unit REC1. In order to maintain the constant voltage at this time, the driving power supply signal rectified through the rectifying section REC1 passes through a shunt regulator SNT1. For example, the magnitude of the constant voltage maintained through the Zener diode D5 included in the shunt regulator SNT1 may be about 3.5V.

And the driving power signal passes through a smoothing capacitor C1 included in the shunt regulator SNT1. The driving power supply signal that has passed through the smoothing capacitor C1 conducts the diode D2 in accordance with the operation sequence of the transistor Q2.

On the other hand, the temperature sensing circuit SEN1 measures the ambient temperature of the bus bar 100 and outputs a signal having a frequency corresponding to the measured temperature. For example, the temperature detection element U1 included in the temperature sensing circuit SEN1 measures the ambient temperature of the bus bar 100, generates a signal having a frequency corresponding to the measured temperature, U1) through the output terminal of the inverter.

The frequency output control circuit FOC1 can change the duty cycle of the signal output from the temperature sensing circuit SEN1 through the capacitors C2 and R2 (that is, through the RC circuit) . For example, the duty cycle of the signal applied to the gate of the transistor Q2 (that is, the signal of the node ND2) is the duty cycle of the signal (that is, the signal of the node ND1) output from the temperature sensing circuit SEN1 Duty cycle. Thereby, the power consumption of the temperature calculation circuit connected to the temperature display unit 230 (e.g., associated with the diode D2) can be reduced. This will be described in detail with reference to FIG.

When the voltage applied to the gate of the transistor Q2 (that is, the voltage of the node ND2) is larger than the turn-on voltage of the transistor Q2, the transistor Q2 is turned on and the diode D2 is turned on ). When the voltage applied to the gate of the transistor Q2 (that is, the voltage of the node ND2) is lower than the turn-on voltage of the transistor Q2, the transistor Q2 is turned off and the current flowing to the diode D2 is erased So that the diode D2 is also turned off. The period during which the diode D2 is turned on corresponds to the ambient temperature of the bus bar 100. [ For example, the temperature display unit 230 may indicate that the ambient temperature of the bus bar 100 is relatively high when the turn-on period of the diode D2 is short (high frequency) It is possible to indicate that the ambient temperature of the bus bar 100 is relatively low (low frequency).

7 is a diagram illustrating a timing sequence for a temperature arithmetic unit according to an embodiment of the present invention. Specifically, in Fig. 7, a timing sequence for low power consumption of the temperature calculation circuit is illustrated.

7, the voltage Vout is the voltage of the signal (the signal of the node ND1) output from the temperature sensing circuit SEN1 and the voltage Vfet is the voltage of the signal ND2).

The signal (the signal of the node ND1) output from the temperature sensing circuit SEN1 has a frequency corresponding to the temperature of the bus bar 100 measured through the temperature sensing circuit SEN1. The duty cycle of the signal of the node ND1 is equal to the length of the section P2a in which the voltage Vout of the signal of the node ND1 is larger than the turn on voltage for turning on the transistor Q2 And the length of the section P2b in which the voltage Vout of the signal of the node ND1 is smaller than the turn-on voltage of the transistor Q2. FIG. 7 illustrates a case where the first duty cycle is 50% (that is, 0.5).

The duty cycle (hereinafter referred to as a second duty cycle) of the signal (the signal of the node ND2) applied to the gate of the transistor Q2 is set such that the voltage Vfet of the signal of the node ND2 is turned on The ratio of the length of the section P1a that is larger than the voltage and the length of the section P1b where the voltage Vfet of the signal of the node ND2 is smaller than the turn-on voltage of the transistor Q2. The second duty cycle is less than the first duty cycle. That is, the duty cycle of the signal is changed from the first duty cycle to the second duty cycle through the capacitor C2 and the resistance element R2 of the frequency output control circuit FOC1. As a result, compared with the case where a signal having the first duty cycle is applied to the gate of the transistor Q2, the time when the transistor Q2 is turned on when a signal having the second duty cycle is applied to the gate of the transistor Q2 Can be reduced. As a result, since the unnecessary time during the turn-on of the transistor Q2 is reduced, the power consumption can be reduced. On the other hand, even if the time period during which the transistor Q2 is turned on is shortened, the temperature display unit 230 can operate normally.

The change of the duty cycle will be described again.

The temperature information signal output from the temperature sensing circuit SEN1 has a square wave form frequency of 0.5 duty (duty cycle 50%). The frequency magnitude of the square wave type temperature information signal depends on the measured temperature. That is, the frequency magnitude of the temperature information signal follows the ratio between the frequency (Hz) and the temperature (K). For example, if the measured temperature is room temperature (e.g., 300K), the frequency magnitude of the temperature information signal may be 300Hz, and if the measured temperature is 600K, the frequency magnitude of the temperature information signal may be 600Hz .

If the turn-on duty of the square wave output from the temperature sensing circuit SEN1 (for example, the voltage at which the voltage of the signal is higher than the turn-on voltage of the transistor Q2) can be adjusted very small, the driving time of the transistor Q2 can be minimized have. As a result, power consumption can be reduced.

RC circuits based on the capacitors C2 and R2 are used to reduce the time the transistor Q2 is turned on with the voltage of the square wave having a duty of 0.5 being higher than the gate turn on voltage of the transistor Q2 do.

By the ratio between the capacitor C2 and the resistance element R2, the duty cycle of the square wave can be adjusted. For example, the duty cycle of the square wave may be changed to a value corresponding to the length P1a of the section P1a (for example, 2:98). When the gate of the transistor Q2 is turned on during the period P1a, the diode D2 is turned on. That is, the period of turn-on of the transistor Q2 or the diode D2 is reduced from the period P2a to the period P1a, so that the turn-on power consumption of the transistor Q2 or the diode D2 can be minimized.

On the other hand, in order that the temperature detecting element U1 can detect the temperature around the bus bar 100 more effectively, it is preferable that the heat transfer is good near the bus bar 100 and within the vicinity of the temperature detecting element U1 A heat transfer material (eg copper) may be present. Through this, the bus bar 100 and the temperature detecting element U1 can be thermally connected.

On the other hand, the embodiments of the present invention are not only implemented by the apparatuses and / or methods described so far, but may also be realized through a program realizing a function corresponding to the configuration of the embodiment of the present invention or a recording medium on which the program is recorded And such an embodiment can be easily implemented by those skilled in the art from the description of the embodiments described above.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, It belongs to the scope of right.

Claims (14)

A temperature detection device for detecting a temperature of a bus bar,
A driving power generator for generating a driving power by using a capacitive reactance obtained from the bus bar via a metal antenna; And
A temperature calculation unit that is driven using the driving power source and generates a temperature signal having a frequency corresponding to the measured temperature by measuring a temperature of the bus bar,
And a temperature detector. The method according to claim 1,
The metal antenna has one of a cylindrical shape, an elliptical shape, and a parabolic shape and is arranged to surround the bus bar
Temperature detecting device. The method according to claim 1,
Wherein the driving power generator includes a high-voltage transformer having a primary side and a secondary side,
Wherein the high-voltage transformer is configured such that, when the capacitive reactance is obtained from the bus bar through which the voltage flows, the first voltage generated at the primary side based on the capacitive reactance is lower than the first voltage Transformed to a second voltage,
The second voltage corresponding to the drive power source
Temperature detecting device. The method of claim 3,
The driving power generator may further include a transient voltage suppressor (TVS) diode connected to the primary side for overvoltage suppression
Temperature detecting device. The method according to claim 1,
Wherein the driving power generator includes a piezoelectric transformer for generating the driving power
Temperature detecting device. The method according to claim 1,
The temperature calculation unit calculates,
And a frequency output controller for changing a duty cycle of the temperature signal through a first resistor and a first resistor connected to the first capacitor,
Temperature detecting device. The method according to claim 6,
Wherein the frequency output control unit includes a first transistor having a gate to which the temperature signal is applied,
Wherein the frequency output controller comprises:
And a second resistor connected between the first capacitor and the first resistor, wherein the first resistor reduces the length of the first section in which the voltage of the temperature signal is higher than the turn-on voltage for turning on the first transistor, To increase the length of the lower second section
Temperature detecting device. The method according to claim 1,
The temperature calculation unit calculates,
A rectifying unit for rectifying a signal for the driving power source through a plurality of rectifying diodes; And
And a shunt regulator that maintains the voltage of the rectified signal at a constant voltage through a smoothing capacitor and a Zener diode
Temperature detecting device. The method according to claim 1,
A temperature display unit for outputting a notification when the frequency of the temperature signal corresponds to a temperature higher than the threshold temperature,
Further comprising a temperature sensor. The method according to claim 1,
Wherein the temperature calculation unit includes a temperature detection element for measuring a temperature of the bus bar,
There is a heat transfer material for thermally connecting the bus bar and the temperature detecting element within a predetermined distance between the bus bar and the temperature detecting element
Temperature detecting device. CLAIMS What is claimed is: 1. A method of detecting a temperature of a busbar without an external power supply,
Obtaining a capacitive reactance from the bus bar via a metal antenna;
Generating a driving power source using the capacitive reactance;
Measuring a temperature of the bus bar through the driving power source, and generating a temperature signal having a frequency corresponding to the measured temperature; And
Changing a duty cycle of the temperature signal;
And a temperature detecting device for detecting a temperature of the temperature detecting device. 12. The method of claim 11,
Wherein changing the duty cycle comprises:
Through the RC circuit including the first capacitor and the first resistance element, the voltage of the temperature signal decreases the length of the first section higher than the turn-on voltage for turning on the first transistor having the gate to which the temperature signal is applied And increasing the length of the second section in which the voltage of the temperature signal is lower than the turn-on voltage
A method for detecting a temperature of a temperature detecting device. 12. The method of claim 11,
Wherein the step of generating the temperature signal comprises:
Rectifying a signal for the driving power source through a plurality of rectifying diodes; And
And maintaining the voltage of the rectified signal at a constant voltage through a smoothing capacitor and a Zener diode
A method for detecting a temperature of a temperature detecting device. 12. The method of claim 11,
Wherein the metal antenna has a shape that surrounds the bus bar,
The inner surface of the metal antenna is surrounded by an insulator
A method for detecting a temperature of a temperature detecting device.

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