CN110231587B - Detection circuit and method of voltage divider circuit parameters and electric energy metering chip - Google Patents
Detection circuit and method of voltage divider circuit parameters and electric energy metering chip Download PDFInfo
- Publication number
- CN110231587B CN110231587B CN201910579837.9A CN201910579837A CN110231587B CN 110231587 B CN110231587 B CN 110231587B CN 201910579837 A CN201910579837 A CN 201910579837A CN 110231587 B CN110231587 B CN 110231587B
- Authority
- CN
- China
- Prior art keywords
- voltage
- voltage divider
- circuit
- signal component
- buffer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R15/00—Details of measuring arrangements of the types provided for in groups G01R17/00 - G01R29/00, G01R33/00 - G01R33/26 or G01R35/00
- G01R15/04—Voltage dividers
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
- G01R19/25—Arrangements for measuring currents or voltages or for indicating presence or sign thereof using digital measurement techniques
- G01R19/2503—Arrangements for measuring currents or voltages or for indicating presence or sign thereof using digital measurement techniques for measuring voltage only, e.g. digital volt meters (DVM's)
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
- G01R19/32—Compensating for temperature change
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R22/00—Arrangements for measuring time integral of electric power or current, e.g. electricity meters
- G01R22/06—Arrangements for measuring time integral of electric power or current, e.g. electricity meters by electronic methods
- G01R22/10—Arrangements for measuring time integral of electric power or current, e.g. electricity meters by electronic methods using digital techniques
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R35/00—Testing or calibrating of apparatus covered by the other groups of this subclass
- G01R35/02—Testing or calibrating of apparatus covered by the other groups of this subclass of auxiliary devices, e.g. of instrument transformers according to prescribed transformation ratio, phase angle, or wattage rating
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Measurement Of Current Or Voltage (AREA)
Abstract
本申请属于电压检测技术领域，提供了一种分压电路参数的检测电路，包括与具有第一频率的第一信号源耦合的分压电路，所述分压电路包括串联的第一分压器、第二分压器和第三分压器，所述第二分压器上并联有电压测量模块，所述检测电路还包括第二信号源和直流信号源；直流信号源用于给所述电压测量模块提供一个直流偏置，电压测量模块输入端设置用于配置输入阻抗、共模抑制以及线性度的缓冲器，电压测量模块用于检测所述第二分压器上的所述第二频率的第一信号分量，根据所述第一信号分量确定所述分压电路的电路参数是否异常。
The present application belongs to the technical field of voltage detection, and provides a detection circuit for parameters of a voltage divider circuit, including a voltage divider circuit coupled to a first signal source having a first frequency, wherein the voltage divider circuit includes a first voltage divider, a second voltage divider, and a third voltage divider connected in series, wherein a voltage measurement module is connected in parallel to the second voltage divider, and the detection circuit further includes a second signal source and a DC signal source; the DC signal source is used to provide a DC bias to the voltage measurement module, and a buffer is provided at the input end of the voltage measurement module for configuring input impedance, common mode suppression, and linearity, and the voltage measurement module is used to detect a first signal component of the second frequency on the second voltage divider, and determine whether the circuit parameters of the voltage divider circuit are abnormal according to the first signal component.
Description
Technical Field
The application belongs to the technical field of voltage detection, and particularly relates to a detection circuit and method for parameters of a voltage dividing circuit and an electric energy metering chip.
Background
The intelligent development of the electric energy metering system requires the establishment of a smart grid, so that the automation and informatization of the power grid can be enhanced, the self-protection capacity of the power grid can be enhanced, and the operation and the safety of the power grid can be better maintained. The intelligent electric energy metering system is required to realize the digitization, standardization, networking and intellectualization of electric energy metering. The digital device is used for realizing the novel digital electric energy metering device by adopting a novel technology, realizing the accuracy and the reliability of basic data, and the intelligent device is used for storing the electricity utilization information of a user, the working information (such as whether the metering accuracy is changed) of an electric energy meter and the abnormal conditions (such as short circuit, open circuit, electricity stealing and the like) of the electric energy meter on the basis of accurate electric energy metering data. Therefore, the electric energy meter with accurate automatic fault detection is an important component of the intelligent electric energy metering system.
At present, in the current voltage measurement device with fault detection, a special detection signal is generally sent to an analog-to-digital converter (Analog to Digital Converter, ADC) after passing through a sampling network, digital output after ADC conversion enters a digital processing unit to process voltage amplitude and phase, the fault of an off-chip component in an off-chip sampling network can be known by observing the amplitude and phase change of the detection signal, so that the voltage measurement error is known, and meanwhile, normal voltage measurement is also carried out by using the ADC (in an electric energy meter, the voltage measurement result is finally used for electric energy measurement). However, the detection signal and the voltage measurement signal supplied to the ADC do not include a dc component, and when a dc potential bias is required, the measurement accuracy of the measured voltage and the measurement accuracy of the fault detection signal are affected.
Disclosure of Invention
The application aims to provide a detection circuit and method for parameters of a voltage dividing circuit and an electric energy metering chip, and aims to solve the problem that the measurement precision of a measured voltage and the measurement precision of a fault detection signal are not high in a scene that the existing voltage measurement circuit needs direct current potential bias.
A first aspect of an embodiment of the present application provides a detection circuit for a voltage dividing circuit parameter, including a voltage dividing circuit coupled to a first signal source having a first frequency, where the voltage dividing circuit includes a first voltage divider, a second voltage divider, and a third voltage divider connected in series, and a voltage measurement module is connected in parallel to the second voltage divider, where the detection circuit further includes:
A second signal source is input at the connecting end of the second voltage divider and the third voltage divider, and the second signal source has a second frequency;
The input end of the voltage measurement module is provided with a buffer for configuring impedance, common mode rejection and linearity according to requirements, and the voltage measurement module is used for detecting a first signal component of the second frequency on the second voltage divider and determining whether the circuit parameters of the voltage division circuit are abnormal according to the first signal component.
A second aspect of an embodiment of the present application provides a method for detecting a voltage dividing circuit parameter, including:
Loading a first signal source with a first frequency at two ends of a voltage dividing circuit, wherein the voltage dividing circuit comprises a first voltage divider, a second voltage divider and a third voltage divider which are connected in series;
A second signal source with a second frequency is connected to the first connecting end of the second voltage divider, and a direct current signal source for providing direct current bias is connected to the first connecting end or the second connecting end of the second voltage divider;
Detecting a first signal component of the second frequency on the second voltage divider, and determining whether a circuit parameter of the voltage dividing circuit is abnormal according to the first signal component.
A third aspect of the embodiment of the application provides an electric energy metering chip, which comprises the detection circuit, and the voltage dividing circuit is arranged outside the electric energy metering chip.
A fourth aspect of the embodiment of the present application provides an electric energy metering chip, including a voltage dividing circuit, where the electric energy metering chip further includes the above detection circuit.
The voltage measurement module of the voltage divider circuit parameter detection circuit has a fault detection function, a direct current signal source is added on the basis, and a direct current bias is provided for the voltage measurement circuit with faults by the current of the direct current signal source flowing through the voltage divider resistor string, so that the situation that the measurement device needs direct current potential bias is met, and the measurement precision of voltage measurement and the measurement precision of fault detection signals are improved.
Drawings
FIG. 1 is a schematic diagram of a voltage divider circuit parameter detection circuit according to a first embodiment of the present application;
FIG. 2 is a schematic diagram of a voltage divider circuit parameter detection circuit according to a second embodiment of the present application;
FIG. 3 is a schematic diagram of a first embodiment of a voltage measurement module in the detection circuit shown in FIG. 1 or FIG. 2;
FIG. 4 is a schematic diagram of a second embodiment of a voltage measurement module in the detection circuit shown in FIG. 1 or FIG. 2;
FIG. 5 is a schematic diagram of a third embodiment of a voltage measurement module in the detection circuit shown in FIG. 1 or FIG. 2;
FIG. 6 is a waveform of the measurement signal and the detection signal in the detection circuit shown in FIG. 5;
FIG. 7 is a schematic diagram of a voltage divider circuit parameter detection circuit according to a third embodiment of the present application;
Fig. 8 is a schematic diagram of a voltage divider circuit parameter detection circuit according to a fourth embodiment of the present application.
Detailed Description
The present application will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present application more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the application.
Referring to fig. 1 and 2, a voltage divider circuit according to an embodiment of the present application includes a voltage divider circuit 20 coupled to a first signal source 10 having a first frequency, the voltage divider circuit 20 includes a first voltage divider 21, a second voltage divider 22, and a third voltage divider 23 connected in series, the second voltage divider 22 is connected in parallel with a voltage measurement module 30, the voltage measurement module 30 further includes a second signal source 40 and a dc signal source 50, the second signal source 40 is input at a connection terminal of the second voltage divider 303 and the third voltage divider, the second signal source 40 has a second frequency, the dc signal source 50 is connected at a first connection terminal (please refer to fig. 1, i.e. a connection terminal of the first voltage divider 21 and the second voltage divider 22) or at a second connection terminal (please refer to fig. 2, i.e. a connection terminal of the second voltage divider 22 and the third voltage divider 23), the dc signal source 50 is used for providing a dc bias to the voltage measurement module 30, the voltage measurement module 30 is used for detecting whether the first signal component of the second frequency on the second voltage divider 22 has an abnormal signal component according to the first signal component. At the same time, it can be determined whether the circuit parameters of the second signal source 40 (the feedback resistance used in the signal source generating circuit) are abnormal.
It will be appreciated that the second signal source 40 may also be accessed via a first switch (not shown), and that the voltage measurement module 30 detects the first signal component if only the first switch is accessed. The second signal source 40 is an ac current source, and the dc signal source 50 is a dc current source. In addition, the measured voltageIs different from the frequency of the second signal source 40, the second frequency being a non-integer multiple of the first frequency. For example the measured voltageAt a frequency of 50Hz, the second signal source 40 may be selected to have a frequency of 432Hz. The second signal source 40 is mainly a current source generated by combining a reference voltage source, an operational amplifier, a current mirror tube and a feedback resistor. The internal circuit of the actual current source can control the output waveform of the current source to be an alternating current signal through a switch. The first voltage divider 21, the second voltage divider 22 and the third voltage divider 23 are all circuits composed of at least one of resistors, inductors and capacitors, and the resistance values are respectively、、。
Referring to fig. 1 and 2, the voltage measurement module 30 includes an analog-to-digital conversion unit (ADC) 31 and a digital signal processing unit (processor) 32. Specifically, the direct current of the direct current signal source 50After flowing through the first voltage divider 21, the second voltage divider 22 and the third voltage divider 23, a dc level is generated at two terminals P/N of the input terminal of the ADC 31, and a dc bias is provided to the ADC 31.
DC level generated at input terminal P/N of ADC 31/The method comprises the following steps:
since the voltage measurement is generally performed by attenuating the voltage to be measured to within the safe range of the input voltage of the ADC through the sampling network (voltage dividing circuit 20), the resistance of the first voltage divider 21 is usually used Resistance of the second voltage divider 22 and the third voltage divider 23 is 1M ohms/1K ohms, the dc difference at the input P/N of the ADC 31 is therefore:
Thus (2) /The dc voltage values of the two are close to each other, and an appropriate dc bias can be provided to the ADC 31.
For the DC difference existing at the input end P/N of the ADC 31, since the digital signal processing unit 31 performs a high-pass filter on the DC portion to filter the DC difference existing at the input end P/N of the DC component ADC 31, the measurement accuracy of the fault detection circuit and the measurement accuracy of the voltage measurement circuit are not affected, and meanwhile, the situation that the measurement device needs DC potential bias can be satisfied, and the measurement accuracy of the voltage measurement and the measurement accuracy of the fault detection signal are improved.
Referring to fig. 3, in another embodiment, the voltage measurement module 30 includes a buffer 33, an analog-to-digital conversion unit 31, and a digital signal processing unit 32. The buffer 33 is used for configuring the input impedance, the common mode rejection and the linearity, and the buffer 33 voltage measurement module 30 is used for measuring the fault detection signal (first signal component), detecting the second signal component (voltage measurement signal) of the first frequency on the second voltage divider 22, correcting the circuit parameters of the voltage division circuit 20 according to the first signal component and the second signal component, and performing normal voltage measurement according to the second signal component and the corrected circuit parameters of the voltage division circuit 20. As an example, the internal resistance r_in of the buffer 33 is above 100M ohms, such as between 200M-300M ohms. The voltage measurement module 30 is added with a buffer 33 with high input impedance/high common mode rejection/high linearity, which can eliminate the phenomenon that the detection signal is changed drastically along with the internal resistance change of the detection circuit, and can reject the common mode part of the detection signal, and meet the linearity requirement of the detection circuit. The measuring accuracy of the detection signal is guaranteed, and the linearity requirement during voltage measurement can be met.
With reference to fig. 2 and 3, it is assumed that the second signal source 40 has a frequency ofAssume that a voltage signal to be measuredIs an alternating current signal and has a frequencyAnd (2) andThe input impedance of buffer 33 is defined as。
The voltage signal generated at the input of the buffer 33 by the second signal source 40 through the voltage dividing circuit 20 is defined as。
Separately calculating differential voltage signals generated by the second signal source 40 through the voltage dividing circuit 20:
Since the voltage measurement is generally performed by attenuating the voltage to be measured to within the safe range of the input voltage of the ADC 31 through the sampling network (voltage dividing circuit 20), the resistance of the first voltage divider 21 is usually usedResistance of the second voltage divider 22 and the third voltage divider 23 is 1M ohms、1K ohms, if the internal resistance of the buffer isThe difference voltage part of the detection signal is changed between 200M and 300M ohms (the worst buffer internal resistance change range)The change is about 0.1%, so that the measurement accuracy of the detection signal is not substantially affected by the change of the internal resistance of the buffer.
Separately calculating the common mode voltage signal generated by the second signal source 40 through the voltage dividing circuit 20:
According to the internal resistances of the first, second and third voltage dividers 21, 22 and 23 and the buffer 33The value can be obtainedThe common mode signal of the analog-to-digital conversion unit 31 is higher than the differential signal by more than 2000 times, so that the buffer 33 has strong common mode rejection capability, can eliminate the common mode value of the detection signal, ensures that the detection signal at the input end of the analog-to-digital conversion unit 31 has only a differential part, thereby reducing the common mode rejection requirement of the analog-to-digital conversion unit 31, and meanwhile, the buffer itself can not convert the common mode part of the detection signal into the differential signal. The above-mentioned characteristics of the buffer ensure that the measurement accuracy of the detection signal is not affected by the common mode portion of the detection signal.
At the same time, the buffer 33 requires a high degree of linearity itself, since the measured voltageIs a strong input signal, has large signal amplitude, and requires enough linearity of the measuring device to meet the measured voltageIs used for measuring the precision of the test piece.
Referring to fig. 4, as another embodiment, the voltage measurement module 30 includes a first buffer 301, a second buffer 302, a measurement correction unit 303, and a voltage measurement unit 304.
The first buffer 301 is used for configuring input impedance and common mode rejection, the first buffer 301 is connected in parallel with the second voltage divider, and the measurement correction unit 303 is connected to the first buffer 301, and it is understood that the measurement correction unit 303 includes an analog-to-digital converter and a digital signal processor. The measurement correction unit 303 is configured to detect a first signal component of a second frequency at the second voltage divider, determine whether a circuit parameter of the voltage division circuit is abnormal according to the first signal component, and correct the voltage division circuit parameter when the circuit parameter is abnormal. The second buffer 302 is used for configuring linearity, the second buffer 302 is connected in parallel with the second voltage divider, and the voltage measurement unit 304 is connected with the second buffer 302, and it is understood that the voltage measurement unit 304 includes an analog-to-digital converter and a digital signal processor. The voltage measurement unit 304 is configured to detect a second signal component of the first frequency on the second voltage divider, and the measurement correction unit 303 corrects the voltage division circuit parameter according to the first signal component and the second signal component. The voltage measurement unit 304 performs voltage measurement according to the second signal component and the corrected voltage dividing circuit parameter.
In the embodiment, the voltage measurement signal and the fault detection signal are measured by different channels respectively, so that the normal measurement of the measurement signal is not influenced while the fault detection signal is corrected, and the situation that the normal measurement of the voltage measurement device is influenced by the correction of the detection signal due to the fact that the detection signal and the measurement signal are simultaneously introduced into the voltage measurement channel is avoided.
Referring to fig. 5, the voltage measurement module 30 further includes an error correction switch 305, the error correction switch 305 is connected in parallel with the second voltage divider 22, the error correction switch 305 is connected in series with the first buffer 301, and the error correction switch 305 is used for performing positive-negative inversion on the signal of the analog-to-digital converter connected to the measurement correction unit 303. Referring to fig. 6, when the correction function of the band measurement correction unit 303 is turned on, the error correction switch 305 switches the positive and negative inputs of the measurement correction unit 303 between the time period T1 and the time period T2, and the detection signal at the input of the measurement correction unit 303 is named asFig. 6 shows a measurement correction unit 303Waveform and voltage measurement module 30As can be seen from fig. 6, when the measurement correction unit 303 pairsWhen the signal is corrected, the voltage measuring module 30The signal is not affected at all, and the normal operation can be realized, so that the electric energy measurement of the final electric energy meter is not affected.
Referring to fig. 7 and 8, the detection circuit further includes a third signal source 60 having a third frequency. The third signal source 60 is input at the connection end of the first voltage divider 21 and the second voltage divider 22, and the measurement correction unit 303 is further configured to detect a third signal component of a third frequency on the second voltage divider 22, and determine whether the circuit parameter of the voltage division circuit is abnormal according to the third signal component. As another embodiment, the third signal source 60 and the second signal source 40 are the same signal source, and are input at the connection end of the first voltage divider 21 and the second voltage divider 22 through another branch.
As a preferred embodiment, the measurement correction unit 303 is specifically configured to process the first signal component and the third signal component, obtain an amplitude value and a phase value of the first signal component and an amplitude value and a phase value of the third signal component, respectively, and determine whether the circuit parameter of the voltage division circuit 20 is abnormal according to at least one of an amplitude value change of the first signal component, an amplitude value change of the third signal, a phase change of the first signal component, and a phase change of the third signal component.
The third signal source 60 is also an ac current source, and the frequencies of the second signal source 40 and the third signal source 60 may be the same or different, and the amplitudes may be the same or different.
The third signal source 60/the second signal source 40 can also be switched in via a second switch (not shown), and the measurement correction unit 303 detects the second signal component if only the second switch is switched in. The third signal source 60 is an alternating current source, and is a measured voltageIs different from the frequency of the third signal source 60, and the third frequency is a non-integer multiple of the first frequency. For example the measured voltageAt a frequency of 50Hz, the third signal source 60 may be at a frequency of 432Hz. The third signal source 60 is mainly a current source generated by combining a reference voltage source, an operational amplifier, a current mirror tube and a feedback resistor. The internal circuit of the actual current source can control the output waveform of the current source to be an alternating current signal through a switch.
As an embodiment, the internal resistance feedback resistors used in the signal source circuits of the second signal source 40 and the third signal source 60 are the same as the temperature coefficient of the first voltage divider 21. While the temperature coefficient of the measurement channel first voltage divider 21 can be counteracted by means of the temperature coefficient of the feedback resistor. In this way, the feedback resistors of the second and third signal sources 40, 60 can be placed off-chip, mainly because an ac current source with any temperature coefficient can be obtained by selecting an off-chip resistor with any temperature coefficient.
The second voltage divider 22, the third voltage divider 23 and the voltage measurement module 30 are on-chip devices of an integrated circuit, and the feedback resistors used in the generating circuits of the first voltage divider 21, the second signal source 40 and the third signal source 60 are off-chip devices of the integrated circuit. The main reason for choosing the feedback resistors of the second and third signal sources 40, 60 to be off-chip is that a current source of arbitrary temperature coefficient can be obtained by choosing the off-chip resistor of arbitrary temperature coefficient. At the same time, the first resistance of the measuring channel can be counteracted by means of the temperature coefficient of the feedback resistanceIs a temperature coefficient of (c) a.
The voltage divider circuit 20 is not limited to the type of impedance, and Z0, Z1, Z2 in the following figures may be resistors, capacitors, inductors, or the like, or may be a combination thereof, for example, resistors and capacitors connected in parallel. If the sampling network comprises components such as capacitance, inductance and the like, the fault source can be positioned by monitoring the amplitude and phase change amount of the detection signal at the same time.
And introducing an additional alternating current source into a conventional voltage measurement channel, and positioning whether the off-chip component fails or not by means of the known information of the alternating current source and certain switch time sequence information so as to achieve the function of accurately positioning the failure source. Meanwhile, by reasonably selecting the off-chip resistors with the same temperature coefficient through the voltage measuring device, the voltage measuring system can have a temperature compensation effect, the voltage measuring precision can be further improved, and the influence of temperature drift on the voltage measuring result is reduced. The applied ac current source signal may be various periodic signals, such as a sine wave signal, a square wave signal, a triangular wave signal, and the like.
The embodiment of the application also provides a detection method of the voltage dividing circuit parameters, which comprises the following steps:
Step one:
Loading a first signal source with a first frequency at two ends of a voltage dividing circuit, wherein the voltage dividing circuit comprises a first voltage divider, a second voltage divider and a third voltage divider which are connected in series;
Step two:
A second signal source with a second frequency is connected to the first connecting end of the second voltage divider, and a direct current signal source for providing direct current bias is connected to the first connecting end or the second connecting end of the second voltage divider;
Step three:
Detecting a first signal component of the second frequency on the second voltage divider, and determining whether a circuit parameter of the voltage dividing circuit is abnormal according to the first signal component.
In a further embodiment, step three is performed by configuring input impedance, common mode rejection and linearity configuration of the first signal component with a buffer while detecting the first signal component at the second frequency at the second voltage divider.
In a further embodiment, the detection method further comprises:
Detecting a second signal component of the first frequency at the second voltage divider;
Correcting the voltage dividing circuit parameter according to the first signal component and the second signal component.
In a further embodiment, the detection method further comprises:
A third signal source with a third frequency is connected to a second connecting end of the second voltage divider;
detecting a third signal component of the third frequency on the second voltage divider, and determining whether the circuit parameter of the voltage dividing circuit is abnormal according to the third signal component.
The embodiment of the application also provides an electric energy metering chip, which comprises the detection circuit. In the embodiment of the application, the voltage dividing circuit is arranged outside the electric energy metering chip. Specifically, the detection circuit is integrated inside the chip, at this time, the detection circuit inside the chip is not influenced by external environment, and further, the switch states of the first switch and the second switch can be set in the voltage measurement module in advance to be switched after being started.
The embodiment of the application also provides another electric energy metering chip which comprises a voltage dividing circuit and the detection circuit.
The voltage measurement module for detecting the voltage dividing circuit parameters has a fault detection function, a direct current signal source is added on the basis, and a direct current bias is provided for the voltage measurement module with faults by the current of the direct current signal source flowing through the voltage dividing resistor string, so that the scene that the measuring device needs direct current potential bias is satisfied, and the measuring precision of voltage measurement and the measuring precision of fault detection signals are improved.
In addition, a buffer is added on the input side, the buffer can be set to have the characteristic of high input impedance, the influence of limited internal resistance of the ADC on the precision of fault detection signals can be eliminated, the buffer can also be set to have the characteristic of high common mode rejection, the common mode part of detection signals can be inhibited, the fault detection signals at the output (input) of the high common mode buffer are ensured not to have high common mode signals, the common mode rejection pressure of the ADC is reduced, the measurement precision of the fault detection signals is improved, meanwhile, the buffer can be set to have the characteristic of high linearity, and the linearity requirement of a voltage measurement device when measuring the voltage signals with high amplitude can be ensured.
The foregoing description of the preferred embodiments of the application is not intended to be limiting, but rather is intended to cover all modifications, equivalents, and alternatives falling within the spirit and principles of the application.
Claims (7)
1. A detection circuit for a voltage divider circuit parameter, comprising a voltage divider circuit coupled to a first signal source having a first frequency, the voltage divider circuit comprising a first voltage divider, a second voltage divider, and a third voltage divider connected in series, the second voltage divider having a voltage measurement module connected in parallel thereto, the detection circuit further comprising:
A second signal source with a second frequency is input at the connecting end of the second voltage divider and the third voltage divider;
The direct current signal source is connected to the first connecting end or the second connecting end of the second voltage divider and is used for providing a direct current bias for the voltage measurement module;
The voltage measurement module is used for detecting a first signal component of the second frequency on the second voltage divider and determining whether the circuit parameter of the voltage division circuit is abnormal or not according to the first signal component;
The voltage measurement module comprises a first buffer, a second buffer, a voltage measurement unit and a measurement correction unit, wherein:
the first buffer is used for configuring input impedance and common mode rejection, the first buffer is connected with the second voltage divider in parallel, and the measurement correction unit is connected with the first buffer; the measurement correction unit is used for detecting a first signal component of the second frequency on the second voltage divider, determining whether the circuit parameter of the voltage division circuit is abnormal according to the first signal component, and correcting the voltage division circuit parameter when the circuit parameter is abnormal;
The second buffer is used for configuring linearity, the second buffer is connected with the second voltage divider in parallel, and the voltage measurement unit is connected with the second buffer; the voltage measurement unit is used for detecting a second signal component of the first frequency on the second voltage divider and performing voltage measurement according to the second signal component and the corrected voltage division circuit parameter;
the detection circuit further includes:
A third signal source with a third frequency is input at the connecting end of the first voltage divider and the second voltage divider;
The voltage measurement module is further used for detecting a third signal component of the third frequency on the second voltage divider, and determining whether the circuit parameter of the voltage division circuit is abnormal according to the third signal component;
The voltage measurement module is specifically configured to process the first signal component and the third signal component to obtain an amplitude value and a phase value of the first signal component and an amplitude value and a phase value of the third signal component, respectively, and determine whether a circuit parameter of the voltage division circuit is abnormal according to at least one of an amplitude value change of the first signal component, an amplitude value change of the third signal, a phase change of the first signal component, and a phase change of the third signal component;
The voltage measurement module further comprises an error correction switch, the error correction switch is connected with the second voltage divider in parallel, the error correction switch is connected with the first buffer in series, and the error correction switch is used for carrying out positive and negative overturn on a signal connected to the measurement correction unit;
The input end of the voltage measurement module is provided with a buffer for configuring input impedance, common mode rejection and linearity.
2. The detection circuit of claim 1, wherein the second and third sources are AC sources and the DC source is a bypass source, and wherein the second and third frequencies are the same or different and are each in a non-integer multiple relationship with the first frequency.
3. The detection circuit of claim 1, wherein the second voltage divider, the third voltage divider, and the voltage measurement module are on-chip devices of an integrated circuit, and the feedback resistors used in the first voltage divider and the second signal source generating circuit are off-chip devices of an integrated circuit.
4. A method for detecting a voltage divider circuit parameter, comprising:
Loading a first signal source with a first frequency at two ends of a voltage dividing circuit, wherein the voltage dividing circuit comprises a first voltage divider, a second voltage divider and a third voltage divider which are connected in series;
A second signal source with a second frequency is connected to the first connecting end of the second voltage divider, and a direct current signal source for providing direct current bias is connected to the first connecting end or the second connecting end of the second voltage divider;
Detecting a first signal component of the second frequency on the second voltage divider by adopting a voltage measurement module, and determining whether the circuit parameter of the voltage division circuit is abnormal according to the first signal component;
A third signal source with a third frequency is connected to a second connecting end of the second voltage divider;
Detecting a third signal component of the third frequency on the second voltage divider, and determining whether the circuit parameter of the voltage dividing circuit is abnormal according to the third signal component;
The voltage measurement module comprises a first buffer, a second buffer, a voltage measurement unit and a measurement correction unit, wherein:
the first buffer is used for configuring input impedance and common mode rejection, the first buffer is connected with the second voltage divider in parallel, and the measurement correction unit is connected with the first buffer; the measurement correction unit is used for detecting a first signal component of the second frequency on the second voltage divider, determining whether the circuit parameter of the voltage division circuit is abnormal according to the first signal component, and correcting the voltage division circuit parameter when the circuit parameter is abnormal;
The second buffer is used for configuring linearity, the second buffer is connected with the second voltage divider in parallel, and the voltage measurement unit is connected with the second buffer; the voltage measurement unit is used for detecting a second signal component of the first frequency on the second voltage divider and performing voltage measurement according to the second signal component and the corrected voltage division circuit parameter;
The voltage measurement module further comprises an error correction switch, the error correction switch is connected with the second voltage divider in parallel, the error correction switch is connected with the first buffer in series, and the error correction switch is used for carrying out positive and negative overturning on signals connected to the measurement correction unit.
5. The method of detecting as claimed in claim 4, wherein said first signal component at said second frequency at said second voltage divider is configured for input impedance, common mode rejection and linearity configuration using a buffer.
6. An electric energy metering chip, characterized in that the electric energy metering chip comprises the detection circuit according to any one of claims 1 to 3, and the voltage dividing circuit is arranged outside the electric energy metering chip.
7. An electrical energy metering chip comprising a voltage dividing circuit, wherein the electrical energy metering chip further comprises a detection circuit as claimed in any one of claims 1 to 3.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910579837.9A CN110231587B (en) | 2019-06-28 | 2019-06-28 | Detection circuit and method of voltage divider circuit parameters and electric energy metering chip |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910579837.9A CN110231587B (en) | 2019-06-28 | 2019-06-28 | Detection circuit and method of voltage divider circuit parameters and electric energy metering chip |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110231587A CN110231587A (en) | 2019-09-13 |
| CN110231587B true CN110231587B (en) | 2025-03-07 |
Family
ID=67857470
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910579837.9A Active CN110231587B (en) | 2019-06-28 | 2019-06-28 | Detection circuit and method of voltage divider circuit parameters and electric energy metering chip |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110231587B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114113761A (en) * | 2020-09-01 | 2022-03-01 | 中兴通讯股份有限公司 | Current detection circuit, detection method, detection device, and resonance circuit |
| TWI775479B (en) * | 2021-06-08 | 2022-08-21 | 黑澤科技股份有限公司 | Circuit detection device |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107870298A (en) * | 2017-11-29 | 2018-04-03 | 深圳市锐能微科技有限公司 | Circuit parameter detection circuit, method and the electric energy meter of a kind of bleeder circuit |
| CN108089142A (en) * | 2017-12-29 | 2018-05-29 | 深圳市锐能微科技有限公司 | Detection circuit, method and the electric energy computation chip of bleeder circuit parameter |
| CN109728818A (en) * | 2017-10-27 | 2019-05-07 | 美国亚德诺半导体公司 | Tracking and holding circuit for high speed and staggered ADC |
| CN110221238A (en) * | 2019-06-28 | 2019-09-10 | 深圳市锐能微科技有限公司 | Detection circuit, method and the electric energy computation chip of bleeder circuit parameter |
| CN210982710U (en) * | 2019-06-28 | 2020-07-10 | 深圳市锐能微科技有限公司 | Detection circuit for parameters of voltage division circuit and electric energy metering chip |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101556322A (en) * | 2009-05-27 | 2009-10-14 | 深圳市科陆电子科技股份有限公司 | Auto-calibration method for single-phase electric energy meter on-site calibrator split-core type current mutual inductor |
| CN105334487A (en) * | 2015-11-20 | 2016-02-17 | 湖南省湘电试验研究院有限公司 | Direct-current watt-hour meter calibrating device |
-
2019
- 2019-06-28 CN CN201910579837.9A patent/CN110231587B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109728818A (en) * | 2017-10-27 | 2019-05-07 | 美国亚德诺半导体公司 | Tracking and holding circuit for high speed and staggered ADC |
| CN107870298A (en) * | 2017-11-29 | 2018-04-03 | 深圳市锐能微科技有限公司 | Circuit parameter detection circuit, method and the electric energy meter of a kind of bleeder circuit |
| CN108089142A (en) * | 2017-12-29 | 2018-05-29 | 深圳市锐能微科技有限公司 | Detection circuit, method and the electric energy computation chip of bleeder circuit parameter |
| CN110221238A (en) * | 2019-06-28 | 2019-09-10 | 深圳市锐能微科技有限公司 | Detection circuit, method and the electric energy computation chip of bleeder circuit parameter |
| CN210982710U (en) * | 2019-06-28 | 2020-07-10 | 深圳市锐能微科技有限公司 | Detection circuit for parameters of voltage division circuit and electric energy metering chip |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110231587A (en) | 2019-09-13 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US9722729B2 (en) | Extracting zero cross information in a powerline communication device | |
| CN108089142B (en) | Detection circuit and method for voltage dividing circuit parameters and electric energy metering chip | |
| JP6257188B2 (en) | measuring device | |
| US11835554B2 (en) | Current sensing circuitry | |
| JP2017215303A (en) | Resistance value measurement circuit | |
| CN110231587B (en) | Detection circuit and method of voltage divider circuit parameters and electric energy metering chip | |
| WO2022164533A1 (en) | Current sensing circuitry | |
| JP2019509491A (en) | Crosstalk calibration for multi-channel systems | |
| CN108089143B (en) | Detection circuit and method for voltage dividing circuit parameters and electric energy metering chip | |
| AU2019383717A1 (en) | Mutual inductance-type current sensing | |
| CN210982709U (en) | Detection circuit for parameters of voltage division circuit and electric energy metering chip | |
| CN111713020B (en) | Reference noise suppression improvement based on sample and hold circuit | |
| CN110221240B (en) | Voltage divider circuit parameter detection circuit and electric energy metering chip | |
| CN210982710U (en) | Detection circuit for parameters of voltage division circuit and electric energy metering chip | |
| CN115436694A (en) | Voltage measurement method, system, electronic device and non-volatile storage medium | |
| CN109061293B (en) | A detection circuit for voltage measurement circuit parameters and electric energy metering chip | |
| JP6809189B2 (en) | Insulation resistance measurement method for DC power supply circuit | |
| CN110221238B (en) | Detection circuit and method of voltage divider circuit parameters and electric energy metering chip | |
| US10048323B2 (en) | Power supply device including a filter circuit that attenuates a specified frequency component of analog signals corresponding to terminal potentials of battery cells connected in series | |
| US6483318B1 (en) | Electric circuit providing selectable short circuit for instrumentation applications | |
| CN210427784U (en) | Detection circuit for parameters of voltage division circuit and electric energy metering chip | |
| US11892474B2 (en) | Universal measurement input for connecting a small signal transformer and electrical device with such a measurement input | |
| CN210982711U (en) | Three-phase current detection circuit and electric energy metering chip | |
| JP2017188733A (en) | Signal processing circuit, coulomb counter circuit, electronic equipment | |
| CN114062764B (en) | Direct-current small-current measurement system and method based on standard current |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |