阅读说明：本技术 一种基于罗氏线圈的电容器组汇流母排电流测量电路 (Capacitor bank busbar current measuring circuit based on Rogowski coil ) 是由 赵东生 杨贤 梁晓兵 于 2020-12-29 设计创作，主要内容包括：本发明提供了一种基于罗氏线圈的电容器组汇流母排电流测量电路。本发明的测量电路将汇流母排电流经过感应线圈感应,再经过保护电路、整流电路、滤波电路、电压变换电路、稳压电路以及电压变换电路之后为芯片提供工作电压；另一方面,经过稳压电路后的电压为罗氏线圈中的运算放大器供电,罗氏线圈的测量电路包括罗氏线圈、滤波电路和积分电路。本发明的测量电路准确性和实时性更高。(The invention provides a Rogowski coil-based capacitor bank busbar current measuring circuit. The measuring circuit of the invention induces the current of the busbar through the induction coil, and provides working voltage for the chip after passing through the protection circuit, the rectifying circuit, the filter circuit, the voltage conversion circuit, the voltage stabilizing circuit and the voltage conversion circuit; on the other hand, the voltage after passing through the voltage stabilizing circuit supplies power to an operational amplifier in the Rogowski coil, and a measuring circuit of the Rogowski coil comprises the Rogowski coil, a filter circuit and an integrating circuit. The measuring circuit of the invention has higher accuracy and real-time performance.)

1. A Rogowski coil-based capacitor bank busbar current measuring circuit is characterized in that,

the third end (3) of the induction coil (T) is connected with the first end (13) of the first piezoresistor (RV1), and the second end (14) of the first piezoresistor (RV1) is connected with the first end (15) of the first temperature fuse (TF 1); a first end (13) of the first piezoresistor (RV1) is connected with a first input end of the connector (J);

a fourth end (4) of the induction coil (T) is connected with a first end (9) of a second piezoresistor (RV2), a second end (10) of the second piezoresistor (RV2) is connected with a first end (11) of a second temperature fuse tube (TF2), a second end (12) of the second temperature fuse tube (TF2) is connected with a first end (21) of a ceramic gas discharge Tube (TV), and a second end (22) of the ceramic gas discharge Tube (TV) is grounded; a second end (18) of the third piezoresistor (RV3) is connected with a first end (19) of a third temperature fuse (TF3), and two ends (20) of the third temperature fuse (TF3) are connected with a first end (21) of the ceramic gas discharge Tube (TV); a fourth end (4) of the induction coil induction (T), a first end (9) of the second piezoresistor (RV2), a first end (17) of the third piezoresistor (RV3) and a second end (16) of the first temperature fuse (TF1) are connected with a second input end of the connector (J);

a first output terminal of the connector (J) is connected to a first terminal (23) of a first capacitor (C1), a second terminal (24) of the first capacitor (C1) is connected to a first terminal (25) of a second capacitor (C2); a first output end of the connector (J) is connected with a first end (27) of the transient suppression diode (D1), a first output end of the connector (J) is connected with a collector electrode of a first triode (Q1), a base electrode of the first triode (Q1) is connected with a first end (33) of a first voltage stabilizing diode, a second end (34) of the first voltage stabilizing diode is connected with a first end (35) of a second voltage stabilizing diode, and a second end (36) of the second voltage stabilizing diode is connected with a base electrode of a second triode (Q2); the second end (26) of the second capacitor (C2) and the second end (28) of the transient suppression diode (D1) are both connected with the collector of the second triode (Q2); an emitter electrode of the first triode (Q1) is connected with a first end (37) of a third capacitor (C3), a second end (38) of the third capacitor (C3) is connected with a first end (39) of a fourth capacitor, a second end (40) of the fourth capacitor is connected with an emitter electrode of the second triode (Q2), and an emitter electrode of the first triode (Q1) is connected with an input end of a first voltage stabilizer (U1); an emitter of the second triode (Q2) and a second end (40) of the fourth capacitor are both connected with the input end of the second voltage stabilizer (U1); the second end (34) of the first voltage stabilizing diode, the second end (38) of the third capacitor (C3), the grounding end of the first voltage stabilizer (U1) and the grounding end of the second voltage stabilizer (U2) are all grounded;

the first end (1) and the second end (2) of the induction coil (T) are used for collecting current of a capacitor bank busbar;

the first end of the output side of the Rogowski coil (L) is connected with the first end (45) of a third resistor (R3), the second end (46) of a third resistor (R3) is connected with the first end (47) of a fourth resistor (R4), the second end (48) of a fourth resistor (R4) is connected with the first end (51) of a fifth resistor (R5), the second end (52) of a fifth resistor (R5) is connected with the first input end of an operational amplifier (A), the first input end of the operational amplifier (A) is connected with the first end (59) of a ninth capacitor (C9), the second end (60) of a seventh capacitor (C1) is connected with the first input end of an oscilloscope, the first input end of the operational amplifier (A) is connected with the first end (61) of a seventh resistor (R7), the second end (62) of a seventh resistor (R7) is connected with the first end (63) of an eighth resistor (R8), and the second end (R8) of the oscilloscope is connected with the second end (R8), a second end (62) of the seventh resistor (R7) and two ends (63) of the eighth resistor (R8) are both connected with a first end (65) of a tenth capacitor (C10), and a second end (66) of the tenth capacitor (C10) is grounded; and the second end of the output side of the Rogowski coil (L) is connected with the second input end of the operational amplifier (A) and the second end input end of the oscilloscope.

2. Rogowski coil-based capacitor bank busbar current measuring circuit according to claim 1, characterized in that the first terminal (27) of the transient suppression diode (D1) is connected to the first terminal (29) of a first resistor (R1), the second terminal (30) of the first resistor (R1) is connected to the base of the first transistor (Q1), the second terminal (28) of the transient suppression diode (D1) is connected to the first terminal (31) of the second resistor (R2), and the second terminal (32) of the second resistor (R2) is connected to the base of the second transistor (Q2).

3. The Rogowski coil-based capacitor bank busbar current measuring circuit according to claim 2, wherein an output terminal of the first voltage regulator (U1) is connected with a first terminal (41) of a fifth capacitor (R5), an output terminal of the second voltage regulator (U2) is connected with a second terminal (44) of a sixth capacitor (R6), and a second terminal (42) of the fifth capacitor (R5) and a first terminal (43) of the sixth capacitor (R6) are both grounded.

4. The Rogowski coil-based capacitor bank busbar current measuring circuit according to claim 2, wherein a second end (48) of a fourth resistor (R4) and a first end (51) of a fifth resistor (R5) are connected with a first end (49) of a seventh capacitor (C7), the second end (48) of the fourth resistor (R4) and the first end (51) of the fifth resistor (R5) are connected with a first end (53) of a fifth resistor (R5), a second end (52) of the fifth resistor (R5) and a first input end of an operational amplifier (A) are connected with a first end (55) of an eighth capacitor (C8), and a second end (50) of the seventh capacitor (C7), a second end (54) of the fifth resistor (R5) and a second end (56) of the eighth capacitor (C8) are connected with a second end on an output side of the Rogowski coil (L).

Technical Field

The invention relates to the technical field of Rogowski coil application, in particular to a Rogowski coil-based capacitor bank busbar current measuring circuit.

Background

With the interconnection of the whole network, higher requirements are made on the safety and reliability of the power grid. The reactive compensation equipment plays an important role in improving the stability of the power system, improving the quality of electric energy and reducing the loss of a power grid. The power capacitor is used as a main reactive power compensation device and is applied to a power system in a large scale. However, due to the complex operation conditions inside the power grid, the capacitor is easily affected by the severe conditions such as the voltage fluctuation of the power grid, the overhigh temperature and the like in the long-term operation process, the dielectric strength and the insulation level of the capacitor are reduced, the capacitor is damaged, and further the operation of the power grid is unsafe and unstable, so that the real-time monitoring of the capacitor is very important.

The current on the capacitor bank bus bar is also an important monitoring quantity, so the current measurement on the capacitor bank bus bar is also very important. Because the current on the capacitor group bus bar is the sum of dozens of capacitor currents, and the current can reach 1000A, the electromagnetic current transformer with the problem of magnetic saturation when measuring large current cannot meet the design requirement.

Disclosure of Invention

The invention provides a method for solving the problems in the prior art. In order to achieve the purpose of the invention, the technical scheme of the invention is as follows.

A Rogowski coil-based capacitor bank busbar current measuring circuit comprises a third end (3) of an induction coil (T) and a first end (13) of a first piezoresistor (RV1), wherein a second end (14) of the first piezoresistor (RV1) is connected with a first end (15) of a first temperature fuse (TF 1); a first end (13) of the first piezoresistor (RV1) is connected with a first input end of the connector (J);

a fourth end (4) of the induction coil (T) is connected with a first end (9) of a second piezoresistor (RV2), a second end (10) of the second piezoresistor (RV2) is connected with a first end (11) of a second temperature fuse tube (TF2), a second end (12) of the second temperature fuse tube (TF2) is connected with a first end (21) of a ceramic gas discharge Tube (TV), and a second end (22) of the ceramic gas discharge Tube (TV) is grounded; a second end (18) of the third piezoresistor (RV3) is connected with a first end (19) of a third temperature fuse (TF3), and two ends (20) of the third temperature fuse (TF3) are connected with a first end (21) of the ceramic gas discharge Tube (TV); a fourth end (4) of the induction coil induction (T), a first end (9) of the second piezoresistor (RV2), a first end (17) of the third piezoresistor (RV3) and a second end (16) of the first temperature fuse (TF1) are connected with a second input end of the connector (J);

a first output terminal of the connector (J) is connected to a first terminal (23) of a first capacitor (C1), a second terminal (24) of the first capacitor (C1) is connected to a first terminal (25) of a second capacitor (C2); a first output end of the connector (J) is connected with a first end (27) of the transient suppression diode (D1), a first output end of the connector (J) is connected with a collector electrode of a first triode (Q1), a base electrode of the first triode (Q1) is connected with a first end (33) of a first voltage stabilizing diode, a second end (34) of the first voltage stabilizing diode is connected with a first end (35) of a second voltage stabilizing diode, and a second end (36) of the second voltage stabilizing diode is connected with a base electrode of a second triode (Q2); the second end (26) of the second capacitor (C2) and the second end (28) of the transient suppression diode (D1) are both connected with the collector of the second triode (Q2); an emitter electrode of the first triode (Q1) is connected with a first end (37) of a third capacitor (C3), a second end (38) of the third capacitor (C3) is connected with a first end (39) of a fourth capacitor, a second end (40) of the fourth capacitor is connected with an emitter electrode of the second triode (Q2), and an emitter electrode of the first triode (Q1) is connected with an input end of a first voltage stabilizer (U1); an emitter of the second triode (Q2) and a second end (40) of the fourth capacitor are both connected with the input end of the second voltage stabilizer (U1); the second end (34) of the first voltage stabilizing diode, the second end (38) of the third capacitor (C3), the grounding end of the first voltage stabilizer (U1) and the grounding end of the second voltage stabilizer (U2) are all grounded;

the first end (1) and the second end (2) of the induction coil (T) are used for collecting current of a capacitor bank busbar;

the first end of the output side of the Rogowski coil (L) is connected with the first end (45) of a third resistor (R3), the second end (46) of a third resistor (R3) is connected with the first end (47) of a fourth resistor (R4), the second end (48) of a fourth resistor (R4) is connected with the first end (51) of a fifth resistor (R5), the second end (52) of a fifth resistor (R5) is connected with the first input end of an operational amplifier (A), the first input end of the operational amplifier (A) is connected with the first end (59) of a ninth capacitor (C9), the second end (60) of a seventh capacitor (C1) is connected with the first input end of an oscilloscope, the first input end of the operational amplifier (A) is connected with the first end (61) of a seventh resistor (R7), the second end (62) of a seventh resistor (R7) is connected with the first end (63) of an eighth resistor (R8), and the second end (R8) of the oscilloscope is connected with the second end (R8), a second end (62) of the seventh resistor (R7) and two ends (63) of the eighth resistor (R8) are both connected with a first end (65) of a tenth capacitor (C10), and a second end (66) of the tenth capacitor (C10) is grounded; and the second end of the output side of the Rogowski coil (L) is connected with the second input end of the operational amplifier (A) and the second end input end of the oscilloscope.

Preferably, the first terminal (27) of the transient suppression diode (D1) is connected to the first terminal (29) of the first resistor (R1), the second terminal (30) of the first resistor (R1) is connected to the base of the first transistor (Q1), the second terminal (28) of the transient suppression diode (D1) is connected to the first terminal (31) of the second resistor (R2), and the second terminal (32) of the second resistor (R2) is connected to the base of the second transistor (Q2).

Preferably, the output terminal of the first voltage regulator (U1) is connected to the first terminal (41) of the fifth capacitor (R5), the output terminal of the second voltage regulator (U2) is connected to the second terminal (44) of the sixth capacitor (R6), and the second terminal (42) of the fifth capacitor (R5) and the first terminal (43) of the sixth capacitor (R6) are both grounded.

Preferably, the second end (48) of the fourth resistor (R4) and the first end (51) of the fifth resistor (R5) are both connected to the first end (49) of the seventh capacitor (C7), the second end (48) of the fourth resistor (R4) and the first end (51) of the fifth resistor (R5) are both connected to the first end (53) of the fifth resistor (R5), the second end (52) of the fifth resistor (R5) and the first input end of the operational amplifier (a) are both connected to the first end (55) of the eighth capacitor (C8), and the second end (50) of the seventh capacitor (C7), the second end (54) of the fifth resistor (R5) and the second end (56) of the eighth capacitor (C8) are both connected to the second end on the output side of the rogowski coil (L).

Compared with the prior art, the invention has the beneficial technical effects that: the measuring circuit of the container group busbar current is used for monitoring the busbar real-time current when the capacitor operates, and the Rogowski coil is free of magnetic core saturation phenomenon when large current is measured, so that the linearity is high, the measuring range is wide, the structure is simple, the use is flexible, the Rogowski coil is used for measuring the busbar current, the measuring precision of the capacitor group busbar current can be improved, the capacitor state monitoring accuracy and real-time performance are higher, and the safe operation of equipment is ensured.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained from the drawings without inventive effort.

FIG. 1 is a schematic diagram of system logic;

FIG. 2 is a schematic diagram of a power-taking circuit;

fig. 3 is a schematic diagram of a rogowski coil measurement circuit.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all the embodiments.

Fig. 1 provides a logic block diagram of the whole system, on one hand, the bus bar current is induced by the induction coil, and then passes through the protection circuit, the rectification circuit, the filter circuit, the voltage conversion circuit, the voltage stabilizing circuit and the 12V to 3.3V voltage conversion circuit to provide the working voltage for the CC2530 chip; on the other hand, the voltage after passing through the voltage stabilizing circuit supplies power to an operational amplifier in the Rogowski coil, a measuring circuit passing through the Rogowski coil comprises the Rogowski coil, a filter circuit and an integrating circuit, and the measured current value of the capacitor bank busbar is input to a CC2530 chip through a signal conditioning circuit. The CC2530 chip inputs data into the data collection unit, the data collection unit transmits the data to the upper computer through a Zigbee networking technology, and the upper computer further processes and analyzes the data.

As shown in fig. 2, the energy obtaining circuit of the rogowski coil integrating circuit specifically includes a protection circuit, a rectification circuit, a filter circuit, a voltage conversion circuit, a voltage stabilizing circuit, and a 12V to 3.3V voltage conversion circuit. The protection circuit shown in fig. 2 is commonly used in lightning protection of a lightning arrester and is composed of a voltage dependent resistor RV, a temperature fuse TF and a ceramic gas discharge tube TV. The invention is a bus bar current measuring device of a capacitor, which is often exposed outdoors and is easily influenced by lightning to generate line overvoltage. The voltage dependent resistor RV in the protection circuit has clamping characteristics, the voltage dependent resistor is equivalent to a circuit disconnection state in normal operation, and when overvoltage occurs due to lightning, the voltage dependent resistor RV can clamp the voltage value to a relatively fixed voltage value, so that the subsequent circuit is protected. The temperature fuse tube TF can be fused when the piezoresistor is overheated to avoid fire, thereby not only protecting the safety of the circuit, but also prolonging the service life of the piezoresistor. The ceramic gas discharge tube TV can be punctured instantly when encountering overvoltage, releases large current through the ground, ensures the safety of the circuit, and then quickly recovers to a high-resistance state to ensure the normal work of the protection circuit.

The rectifying circuit in fig. 2 uses MB6S rectifying bridge to construct the rectifying circuit, and the rectifying circuit works by the principle of unidirectional conduction of diodes, which are forward-conducting and reverse-blocking, that is, the diodes only allow the positive pole to be positive and the negative pole to be negative. A rectifier bridge is a bridge circuit formed by several diodes, which ensures that when it is connected to an ac circuit, it enables the current in the circuit to flow only in one direction, so-called "rectification". The MB6S rectifier bridge is an integrated rectifier bridge, and has the function of converting alternating current with the level floating up and down at the zero point into unidirectional direct current through the unidirectional conduction characteristic of a diode, and direct current voltage containing harmonic waves can be obtained after the alternating current passes through the rectifier circuit.

The filter circuit in fig. 2 is a series capacitance type filter circuit composed of 2 capacitors, and functions to cancel out ac components in dc voltage containing harmonics as much as possible, and retain the dc components, so that output voltage ripple is reduced, ripple factor is reduced, and waveform is smoothed. The series capacitance type filter circuit is a typical passive filter circuit, has a simple structure, is easy to design, and is commonly used for filtering after power supply rectification. In the series capacitance type filter circuit, the capacitor C has a certain blocking effect on the alternating current component, and is equivalent to open circuit for the direct current component, so that the circuit can counteract most of the alternating current component to obtain a relatively pure direct current voltage. 2 capacitors are selected to be connected in series, so that the voltage resistance of the circuit can be improved, the filtering function of the circuit cannot be influenced when one capacitor is damaged, and the reliability of the circuit is improved.

D3 in fig. 2 is a transient suppression diode that provides an extra path to protect the circuit from damage when the voltage is too high due to sudden changes in current. Two voltage stabilizing diodes BZT52C15 are selected, the output voltage can be stabilized at 15V, and the effect of converting the voltage is achieved. The voltage stabilizing circuit shown in fig. 2 is a circuit capable of keeping the output voltage substantially unchanged when the voltage at the input end fluctuates or the load changes, and has the function of stabilizing the power supply voltage which has larger fluctuation and cannot meet the requirements of the electrical equipment within the range of the set value thereof, so that various circuits or electrical equipment can work under the rated working voltage. The CJ79L09 voltage stabilizer and the CJ78L12 voltage stabilizer are selected to obtain +12V direct-current voltage and-12V direct-current voltage respectively, and power is provided for an operational amplifier in the Rogowski coil measuring circuit.

The third end (3) of the induction coil (T) is connected with the first end (13) of the first piezoresistor (RV1), and the second end (14) of the first piezoresistor (RV1) is connected with the first end (15) of the first temperature fuse (TF 1); a first end (13) of the first piezoresistor (RV1) is connected with a first input end of the connector (J);

a fourth end (4) of the induction coil (T) is connected with a first end (9) of a second piezoresistor (RV2), a second end (10) of the second piezoresistor (RV2) is connected with a first end (11) of a second temperature fuse tube (TF2), a second end (12) of the second temperature fuse tube (TF2) is connected with a first end (21) of a ceramic gas discharge Tube (TV), and a second end (22) of the ceramic gas discharge Tube (TV) is grounded; a second end (18) of the third piezoresistor (RV3) is connected with a first end (19) of a third temperature fuse (TF3), and two ends (20) of the third temperature fuse (TF3) are connected with a first end (21) of the ceramic gas discharge Tube (TV); a fourth end (4) of the induction coil induction (T), a first end (9) of the second piezoresistor (RV2), a first end (17) of the third piezoresistor (RV3) and a second end (16) of the first temperature fuse (TF1) are connected with a second input end of the connector (J);

a first output terminal of the connector (J) is connected to a first terminal (23) of a first capacitor (C1), a second terminal (24) of the first capacitor (C1) is connected to a first terminal (25) of a second capacitor (C2); a first output end of the connector (J) is connected with a first end (27) of the transient suppression diode (D1), a first output end of the connector (J) is connected with a collector electrode of a first triode (Q1), a base electrode of the first triode (Q1) is connected with a first end (33) of a first voltage stabilizing diode, a second end (34) of the first voltage stabilizing diode is connected with a first end (35) of a second voltage stabilizing diode, and a second end (36) of the second voltage stabilizing diode is connected with a base electrode of a second triode (Q2); the second end (26) of the second capacitor (C2) and the second end (28) of the transient suppression diode (D1) are both connected with the collector of the second triode (Q2); an emitter electrode of the first triode (Q1) is connected with a first end (37) of a third capacitor (C3), a second end (38) of the third capacitor (C3) is connected with a first end (39) of a fourth capacitor, a second end (40) of the fourth capacitor is connected with an emitter electrode of the second triode (Q2), and an emitter electrode of the first triode (Q1) is connected with an input end of a first voltage stabilizer (U1); an emitter of the second triode (Q2) and a second end (40) of the fourth capacitor are both connected with the input end of the second voltage stabilizer (U1); the second end (34) of the first voltage stabilizing diode, the second end (38) of the third capacitor (C3), the grounding end of the first voltage stabilizer (U1) and the grounding end of the second voltage stabilizer (U2) are all grounded;

the first end (1) and the second end (2) of the induction coil (T) are used for collecting current of a capacitor bank busbar; the first terminal (27) of the transient suppression diode (D1) is connected to the first terminal (29) of the first resistor (R1), the second terminal (30) of the first resistor (R1) is connected to the base of the first transistor (Q1), the second terminal (28) of the transient suppression diode (D1) is connected to the first terminal (31) of the second resistor (R2), and the second terminal (32) of the second resistor (R2) is connected to the base of the second transistor (Q2).

The output end of the first voltage stabilizer (U1) is connected with the first end (41) of the fifth capacitor (R5), the output end of the second voltage stabilizer (U2) is connected with the second end (44) of the sixth capacitor (R6), and the second end (42) of the fifth capacitor (R5) and the first end (43) of the sixth capacitor (R6) are both grounded.

Fig. 3 is a rogowski coil measuring circuit, which mainly comprises a rogowski coil, a filter circuit and an integrating circuit. The current is measured by passing through the Rogowski coil, the electric quantity passing through the Rogowski coil firstly is equivalent to a transformation ratio, the obtained electric quantity value is reduced compared with the original value, and an integral amplifying circuit is arranged subsequently. And the obtained electric quantity must contain some harmonic components, so that some harmonic components must be filtered out through a filter circuit firstly. The filtered component is amplified by the integrating circuit, and the magnitude of the current measured by the Rogowski coil can be obtained. The integrating circuit is a composite integrating circuit, a self-integrating circuit, a passive integrating circuit and an active integrating circuit with a low-frequency attenuation network are connected end to end, and signals pass through the passive integrating circuit and then become the input of the active integrating circuit. In a high-frequency band, the coil restores the signal through self-integration; in the middle frequency band, a passive integration circuit is used for signal integration, so that the integration effect in the middle frequency band is ensured, and the error is reduced; in a low frequency range, the low frequency noise and drift amplification effect of the integrator is effectively inhibited by integrating through an active integration circuit with a low frequency attenuation network. The advantages of the three integration circuits are combined, and the accuracy of the integration circuits is improved.

As shown in FIG. 3, the first terminal of the output side of the Rogowski coil (L) is connected to the first terminal (45) of the third resistor (R3), the second terminal (46) of the third resistor (R3) is connected to the first terminal (47) of the fourth resistor (R4), the second terminal (48) of the fourth resistor (R4) is connected to the first terminal (51) of the fifth resistor (R5), the second terminal (52) of the fifth resistor (R5) is connected to the first input terminal of the operational amplifier (A), the first input terminal of the operational amplifier (A) is connected to the first terminal (59) of the ninth capacitor (C9), the second terminal (60) of the seventh capacitor (C1) is connected to the first input terminal of the oscilloscope, the first input terminal of the operational amplifier (A) is connected to the first terminal (61) of the seventh resistor (R7), the second terminal (62) of the seventh resistor (R7) is connected to the first terminal (63) of the eighth resistor (R8), and the first terminal (R8) of the oscilloscope is connected to the first terminal (51), a second end (62) of the seventh resistor (R7) and a second end (63) of the eighth resistor (R8) are both connected with a first end (65) of a tenth capacitor (C10), and a second end (66) of the tenth capacitor (C10) is grounded; and the second end of the output side of the Rogowski coil (L) is connected with the second input end of the operational amplifier (A) and the second end input end of the oscilloscope.

The second end (48) of the fourth resistor (R4) and the first end (51) of the fifth resistor (R5) are connected with the first end (49) of the seventh capacitor (C7), the second end (48) of the fourth resistor (R4) and the first end (51) of the fifth resistor (R5) are connected with the first end (53) of the fifth resistor (R5), the second end (52) of the fifth resistor (R5) and the first input end of the operational amplifier (A) are connected with the first end (3555) of the eighth capacitor (C8), and the second end (50) of the seventh capacitor (C7), the second end (54) of the fifth resistor (R5) and the second end (56) of the eighth capacitor (C8) are connected with the second end of the output side of the Rogowski coil (L).

The measuring circuit of the container group busbar current of the embodiment is used for monitoring the real-time current of the busbar when the capacitor operates, and the Rogowski coil has the advantages of no magnetic core saturation phenomenon during large-current measurement, high linearity, wide measuring range, simple structure and flexible use, so that the Rogowski coil is adopted to measure the busbar current. The measuring precision of the bus bar current of the capacitor bank can be improved, the accuracy and the real-time performance of capacitor state monitoring are higher, and the safe operation of equipment is guaranteed.

The above-mentioned embodiments are only specific embodiments of the present application, and are used for illustrating the technical solutions of the present application, but not limiting the same, and the scope of the present application is not limited thereto, and although the present application is described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: any person skilled in the art can modify or easily conceive the technical solutions described in the foregoing embodiments or equivalent substitutes for some technical features within the technical scope disclosed in the present application; such modifications, changes or substitutions do not depart from the spirit and scope of the present disclosure, which should be construed in light of the above teachings. Are intended to be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.