A closed-loop control integral system with amplitude compensation function

Abstract

The application provides a closed-loop control integral system with amplitude compensation function, mainly comprising a non-ideal integrator, a gain-variable amplifier and a control signal generator; the non-ideal integrator receives a Rogowski coil output signal and performs integral operation on the signal to suppress integral overflow caused by interference direct current; after receiving a control signal generated by the control signal generator, the gain-variable amplifier performs amplitude gain adjustment on the output signal of the non-ideal integrator based on the control signal to compensate amplitude gain error caused by temperature drift and time drift of the non-ideal integrator; the control signal generator collects various electrical parameters of the Rogowski coil output end and combines various electrical parameters of the output signal of the gain-variable amplifier to generate a control signal for gain adjustment control of the gain-variable amplifier. By implementing the application, errors caused by device temperature drift and aging can be compensated in real time, and the application has the advantages of high measurement accuracy, low cost and more stable performance.

Description

Technical Field

[0001] This invention relates to the field of power measurement technology, and in particular to a closed-loop control integral system with amplitude compensation function. Background Technology

[0002] A Rogowski coil is a coreless air-core coil with advantages such as simple structure, no magnetic saturation, and good linearity. It is now widely used for high-current measurement. A Rogowski coil current transformer consists of a Rogowski coil and an integrator. The Rogowski coil converts the measured primary current into its differential signal, and the integrator integrates the differential signal to restore it to a voltage signal proportional to the primary current, thus achieving the measurement of the primary current.

[0003] As a crucial component of Rogowski coil current transformers, the performance of the integrator directly impacts the measurement performance of the current transformer. Existing analog integrators can meet the requirements for measuring steady-state AC current within a short timeframe in environments with minimal temperature variations.

[0004] However, since the analog integrator is composed of non-ideal components, the following problems exist: 1) The integrated operational amplifier it is composed of has zero drift, which can easily cause integration saturation after long-term use; 2) The values ​​of the capacitors and resistors it is composed of will change with temperature, and the aging of components will lead to poor stability of the Rogowski coil transformer after long-term use.

[0005] To address the aforementioned issues, some researchers have proposed methods for compensation using digital circuits, including offline and online compensation methods. Offline compensation suffers from a disconnect between the actual application scenario and the compensation data. In particular, its effectiveness hinges on the data fully encompassing the errors within the real-world application scenario, which is difficult to achieve in actual measurements, thus limiting its effectiveness. Online compensation methods fit the error to a limited set of measured data, limiting its compensation effect to the scope of the data coverage. The data fails to fully reflect the integrator's overall operation, and the complex design results in high hardware costs.

[0006] Therefore, there is an urgent need for an integral system with compensation function, which can not only compensate for errors caused by device temperature drift and aging in real time, but also has the advantages of high measurement accuracy, low cost and more stable performance. Summary of the Invention

[0007] The aforementioned problem to be solved by the embodiments of the present invention is to provide a closed-loop control integral system with amplitude compensation function, which can not only compensate for errors caused by device temperature drift and aging in real time, but also has the advantages of high measurement accuracy, low cost and more stable performance.

[0008] To address the aforementioned technical problems, embodiments of the present invention provide a closed-loop control integral system with amplitude compensation, comprising a non-ideal integrator, a variable gain amplifier, and a control signal generator; wherein...

[0009] The input terminal of the non-ideal integrator is connected to the Rogowski coil to receive the output signal of the Rogowski coil and perform integration on the output signal to suppress integral overflow caused by interference DC.

[0010] One input terminal of the variable gain amplifier is connected to the output terminal of the non-ideal integrator, and the other input terminal is connected to the output terminal of the control signal generator. The output terminal is connected to one input terminal of the control signal generator. After receiving the control signal generated by the control signal generator, the amplifier adjusts the amplitude gain of the signal after integration by the non-ideal integrator based on the control signal, so as to compensate online for the amplitude gain error caused by temperature drift and time drift of the non-ideal integrator.

[0011] The other input terminal of the control signal generator is connected to the input terminal of the non-ideal integrator, and is used to collect various electrical parameters of the output terminal of the Rogowski coil, and combine them with various electrical parameters of the output signal of the variable gain amplifier to generate the control signal, and further use the control signal to adjust the gain of the variable gain amplifier.

[0012] The non-ideal integrator includes an integrating circuit consisting of an integrating resistor R and an integrating capacitor C, a first operational amplifier U1, and a feedback resistor R. f ;in,

[0013] In the integrating circuit, one end of the integrating resistor R is connected to the Rogowski coil, and the other end is connected to the inverting input terminal of the operational amplifier U1; one end of the integrating capacitor C is connected to the inverting input terminal of the first operational amplifier U1, and the other end is connected to the output terminal of the operational amplifier U1.

[0014] The non-inverting input terminal of the first operational amplifier U1 is grounded, and its output terminal is connected to one input terminal of the variable gain amplifier.

[0015] The feedback resistor R f It is connected in parallel with the integrating capacitor C.

[0016] The transfer function of the non-ideal integrator circuit is: in,

[0017] If the input signal of the non-ideal integrator is a DC signal, the amplitude gain K of the non-ideal integrator is... D for

[0018] If the input signal of the non-ideal integrator is an AC signal and satisfies R f When Cw>>1, the amplitude gain K of the non-ideal integrator AC for

[0019] The variable gain amplifier includes an amplification circuit composed of a MOSFET D1, resistors R1, R2, R6, R7, and a second operational amplifier U2, and a decoupling drive circuit composed of resistors R3, R4, R5, capacitors C1 and C2; wherein,

[0020] In the decoupling drive circuit, resistors R3 and R4 and capacitor C2 are connected in series and then in parallel between the source and drain of MOSFET D1 in the amplifier circuit; one end of resistor R5 is connected to the gate of MOSFET D1 in the amplifier circuit, and the other end is connected to the output terminal of the control signal generator; one end of capacitor C1 is connected to the gate of MOSFET D1, and the other end is connected to the connection point between resistors R3 and R4.

[0021] In the amplifier circuit, one end of resistor R6 is connected to the non-inverting input of the second operational amplifier U2, and the other end is connected to the output of the non-ideal integrator; one end of resistor R7 is connected to the non-inverting input of the second operational amplifier U2, and the other end is grounded; the drain of MOSFET D1 is connected to the inverting input of the second operational amplifier U2 through resistor R2, and the source is grounded; resistor R1 is a negative voltage feedback network, which is connected between the inverting input and output of the second operational amplifier U2; the output of the second operational amplifier U2 is connected to one input of the control signal generator.

[0022] The decoupling drive circuit is functionally divided into a DC path and an AC path; wherein,

[0023] The AC path is used to provide a path for the decoupled drive AC signal, extracting the decoupled drive AC signal from the source and drain terminals of the MOS transistor D1, correcting its amplitude and phase angle, and further decoupling the voltage V between the source and drain terminals of the MOS transistor D1 when the variable resistor of the MOS transistor D1 is linearized. DS and the voltage V between the gate and source GS Eliminate V DS The effect on the resistance value of the variable resistance region;

[0024] The DC path is used to provide a direct path between the DC control signal and the gate of the MOS transistor D1, isolate the path between the DC signal and the amplifier circuit, and reduce the impact of the DC control signal on the amplifier circuit.

[0025] The gain of the variable gain amplifier is shown in the following formula:

[0026]

[0027] Where K(Crl) is the gain of the variable gain amplifier; R D The variable resistor of the MOS transistor D1 is... V TN k is the turn-on voltage of the MOSFET D1. n V′ represents the internal parameter coefficients of the MOS transistor D1. GS The DC control voltage introduced to the gate of the MOS transistor D1 is the voltage of the control signal generated by the control signal generator.

[0028] The control signal generated by the control signal generator is obtained by executing the following algorithm, specifically:

[0029] Constructing the error function

[0030] When e < -e0, - is generated, Cr is decreased, and V is set to... ouyt (Crl) decreases; when e>e0, ΔCrl is generated, increasing Crl and letting V out (Crl) increases; when e0>e>-e0 and e0 is sufficiently small, the system gain is k. D Among them, V out It is the pre-processed output signal, V IN It is the pre-processed non-ideal integrator input signal, K D It is the software-defined gain, Cr is the control signal voltage, e0 is the absolute error and is a positive number, and ΔCr is the voltage iteration amount.

[0031] The preprocessing includes filtering, normalization, error compensation, and data transformation.

[0032] Implementing the embodiments of the present invention has the following beneficial effects:

[0033] This invention introduces a variable gain amplifier to effectively compensate for errors caused by changes in the integrator circuit parameters due to temperature variations. It also provides online control for real-time error compensation, which is more accurate and reliable than offline compensation. Furthermore, the control signal generator is controlled by a microcontroller, which is less expensive than DSP and FPGA control. As a result, it can not only compensate for errors caused by device temperature drift and aging in real time, but also has the advantages of high measurement accuracy, low cost, and more stable performance. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, obtaining other drawings based on these drawings without creative effort still falls within the scope of the present invention.

[0035] Figure 1 This is a schematic diagram of a closed-loop control integral system with amplitude compensation function provided in an embodiment of the present invention;

[0036] Figure 2 for Figure 1 Circuit diagram of an ideal integrator in China and Africa;

[0037] Figure 3 for Figure 1 Circuit diagram of a medium-gain variable amplifier;

[0038] Figure 4 for Figure 3 The circuit structure diagram of the medium-gain variable amplifier covering the decoupling drive circuit (b) of the DC drive signal path (a) and the AC decoupling signal path;

[0039] Figure 5 The following are simulation results of a closed-loop control integral system with amplitude compensation function provided in this embodiment of the invention when the circuit parameters change; wherein, (a) is the simulation result of RC=0.6; (b) is the simulation result of RC=0.57; and (c) is the simulation result of RC=0.63.

[0040] Figure 6 The figures provided in this embodiment of the invention show the simulation results of a closed-loop control integral system with amplitude compensation under constant input conditions and with and without control, with varying circuit parameters. The circuit parameter variation diagrams are shown in Figure (a) for a 1V input signal with control; (b) for a 1V input signal without control; (c) for a 0.01V input signal with control; (d) for a 0.01V input signal without control; and (e) for RC parameter variation.

[0041] Figure 7 The following are simulation results of a closed-loop control integral system with amplitude compensation provided in this embodiment of the invention when circuit parameter changes and input signal changes are mixed; wherein, (a) is the simulation result of a random signal with a change period of 0.1s when the RC value changes according to a triangular wave; (b) is the simulation result of a random signal with a change period of 1s when the RC value changes according to a triangular wave; and (c) is the RC parameter change diagram. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings.

[0043] like Figure 1 As shown in the figure, a closed-loop control integral system with amplitude compensation function is provided in an embodiment of the present invention, including a non-ideal integrator 1, a variable gain amplifier 2, and a control signal generator 3; wherein,

[0044] The input terminal of the non-ideal integrator 1 is connected to a Rogowski coil (not shown) to receive the output signal of the Rogowski coil and perform integration on the output signal to suppress integral overflow caused by interference DC.

[0045] One input terminal of the gain variable amplifier 2 is connected to the output terminal of the non-ideal integrator 1, and the other input terminal is connected to the output terminal of the control signal generator 3. The output terminal is connected to one input terminal of the control signal generator 3. After receiving the control signal generated by the control signal generator 3, the amplifier adjusts the amplitude gain of the signal after integration by the non-ideal integrator 1 based on the control signal, so as to compensate for the amplitude gain error caused by temperature drift and time drift of the non-ideal integrator 1 online.

[0046] Another input terminal of the control signal generator 3 is connected to the Rogowski coil to receive various electrical parameters from the output terminal of the Rogowski coil. Combined with various electrical parameters from the output signal of the variable gain amplifier 2, a control signal is generated, and the gain of the variable gain amplifier 2 is further adjusted and controlled by the control signal.

[0047] In this embodiment of the invention, the non-ideal integrator 1 is essentially a large time constant inertial element. The characteristic of this non-ideal integrator is that it can effectively suppress integral overflow caused by DC signals, and exhibits an integral effect for signals of a certain frequency, such as... Figure 2 As shown.

[0048] Figure 2 In the non-ideal integrator 1, there are an integrating circuit consisting of an integrating resistor R and an integrating capacitor C, a first operational amplifier U1, and a feedback resistor R. f ;in,

[0049] In the integrating circuit, one end of the integrating resistor R is connected to the Rogowski coil IN, and the other end is connected to the inverting input terminal (-) of the operational amplifier U1; one end of the integrating capacitor C is connected to the inverting input terminal (-) of the first operational amplifier U1, and the other end is connected to the output terminal OUT of the operational amplifier U1.

[0050] The positive input terminal (+) of the first operational amplifier U1 is grounded, and the output terminal OUT is connected to one input terminal of the variable gain amplifier 2.

[0051] Feedback resistor R f It is connected in parallel with the integrating capacitor C.

[0052] At this point, the transfer function of the non-ideal integrator 1 circuit is: in,

[0053] If the input signal of the non-ideal integrator 1 is a DC signal, the amplitude gain K of the non-ideal integrator 1 is... D for

[0054] If the input signal of the non-ideal integrator is an AC signal and satisfies R f When Cw>>1, the amplitude gain K of the non-ideal integrator 1 AC for and It should be noted that when a sinusoidal AC signal of a certain frequency is used as input, the amplitude gain of the non-ideal integrator 1 is easily affected by the circuit parameters integrating resistor R and integrating capacitor C, while the phase angle change is less affected by the circuit parameters. Therefore, to improve the conversion accuracy of the integrator, reducing the influence of circuit parameters on the amplitude gain is crucial.

[0055] In this embodiment of the invention, to compensate for the error caused by the amplitude gain variation of the non-ideal integrator 1, a variable gain amplifier 2 is connected after the non-ideal integrator 1, such as... Figure 3 As shown.

[0056] Figure 3 In the middle, the variable gain amplifier 2 includes an amplification circuit composed of MOSFET D1, resistors R1, R2, R6, R7 and a second operational amplifier U2, and a decoupling drive circuit composed of resistors R3, R4, R5, capacitors C1 and C2; wherein,

[0057] In the decoupling drive circuit, resistors R3 and R4 and capacitor C2 are connected in series and then connected in parallel between the source and drain of MOSFET D1 in the amplifier circuit; one end of resistor R5 is connected to the gate of MOSFET D1 in the amplifier circuit, and the other end is connected to the output of control signal generator 3; one end of capacitor C1 is connected to the gate of MOSFET D1, and the other end is connected to the connection point between resistors R3 and R4.

[0058] In the amplifier circuit, one end of resistor R6 is connected to the non-inverting input (+) of the second operational amplifier U2, and the other end is connected to the output terminal OUT of the non-ideal integrator 1; one end of resistor R7 is connected to the non-inverting input (+) of the second operational amplifier U2, and the other end is grounded; the drain of MOSFET D1 is connected to the inverting input (-) of the second operational amplifier U2 through resistor R2, and the source is grounded; resistor R1 is a negative voltage feedback network, which is connected between the inverting input (-) and the output terminal OUT of the second operational amplifier U2; the output terminal OUT of the second operational amplifier U2 is connected to one input terminal of the control signal generator 3.

[0059] At this point, the gain-variable amplifier 2 utilizes the variable resistance region R of the MOSFET D1. D By changing the gate voltage of MOSFET D1, the gain of the amplifier circuit can be controlled. It should be noted that the resistance values ​​of resistors R3 and R4 are much larger than the resistance value of MOSFET D1 when it is in the variable resistance region.

[0060] The gain of the variable-gain amplifier 2 is shown in the following formula:

[0061]

[0062] Where K(Crl) is the gain of variable gain amplifier 2; R D The variable resistor is D1 of the MOSFET, and V TN k is the turn-on voltage of MOSFET D1. n V′ represents the internal parameter coefficients of MOSFET D1. GS The DC control voltage introduced to the gate of MOSFET D1 is the voltage of the control signal generated by control signal generator 3.

[0063] As shown in the above equation, changing the gate voltage of MOSFET D1 changes the gain of the variable amplifier 2. From the IV curve of MOSFET D1, we can see that the variable resistance R of MOSFET D1... D The variable resistor R is inversely related to the control signal Cr1. When the control signal Cr1 is small, the variable resistor R... D The variable resistor R is very large; when the control signal Cr is large, the variable resistor R... D The gain K(Crl) is relatively small. Therefore, there is a positive correlation between the gain K(Crl) and the control signal Crl.

[0064] From the output characteristics of MOSFET D1, it can be seen that when V GS >V DS +V TN At this time, MOSFET D1 operates in the variable resistance region, and the VI characteristic of the variable resistance region can be approximately understood as:

[0065]

[0066] From the above formula, we can see that the resistance of the variable resistance region of MOSFET D1 and the measured signal V DS There is a coupling relationship between them, namely V DS Changes in voltage will cause changes in resistance. This will lead to an asymmetry in the amplitude of the positive and negative cycles of the measured AC signal. Generally, this will cause V to... DS If the value is small, the effect of the quadratic term can be ignored, but this will reduce the dynamic range of the measured signal, i.e., V. DS The value of should not be too large.

[0067] Therefore, the present invention adds a decoupling drive circuit to make V DS The change will not affect the change of the MOSFET resistance, so that the resistance of MOSFET D1 in the variable resistance region is completely transformed into a controllable linear resistance, which greatly improves the dynamic range of the measurement signal.

[0068] The idea behind adding a decoupling drive circuit is to first introduce a mixed AC / DC control voltage V at the gate of the MOSFET D1. GS ,make Among them, V′ GS The DC control voltage, V DS The first step is to determine the AC control voltage; secondly, a conversion is performed to obtain i. D1 =2k n (V′ GS -V TN V DS Further deformation yields the resistance of MOSFET D1 as follows: Therefore, it can be concluded that the resistance of the MOSFET D1 in the variable resistance region and the input signal V... DS Achieve decoupling.

[0069] The circuit that achieves the above decoupling is based on circuit analysis theory and is designed to include both DC drive signal paths and AC decoupling signal paths, such as... Figure 4 As shown, the decoupling drive circuit is functionally divided into a DC path and an AC path. The AC path provides a pathway for the decoupling drive AC signal, extracting the signal from the source and drain of the MOS transistor D1, correcting its amplitude and phase angle, and further decoupling the voltage V between the source and drain of the MOS transistor D1 when the variable resistor of D1 is linearized. DS and the voltage V between the gate and source GS Eliminate V DSThe effect on the resistance value of the variable resistor region; the DC path, used to directly provide a path between the DC control signal and the gate of the MOS transistor D1, isolates the path between the DC signal and the amplifier circuit, and reduces the impact of the DC control signal on the amplifier circuit. The low-pass filtering exhibited by the DC path relative to the gate of the MOS transistor D1 is due to the fact that capacitor C1 isolates DC current and resistor R4 short-circuits resistor R3 and capacitor C1, therefore the low-pass filtering transfer function of the DC path is... The transfer function of the AC path is

[0070] Frequency domain analysis of the transfer function of the AC path yields its frequency response as follows:

[0071]

[0072]

[0073] The ideal design for a decoupled drive circuit is |G1(ω)|=20lg0.5, θ(ω)=0, and R5C1 should be as small as possible.

[0074] In this embodiment of the invention, the main function of the control signal generator 3 is to generate a DC drive voltage signal to control the amplitude gain of the integral system. The control signal processor 3 can be divided into two stages: data preprocessing and signal generation. Data preprocessing mainly involves filtering, normalizing, error compensation, and data transformation of the sampled data to generate the data required by the algorithm; signal generation uses a specific algorithm to generate control signals.

[0075] In data preprocessing, because the sampled signal contains high-frequency interference, random signals, sampling errors, and other interference signals, the sampled signal first needs to undergo low-pass filtering, average value filtering, and error compensation. Secondly, normalization aims to reduce the adverse effects of large-scale dynamic changes in the input signal on the algorithm. Next, error compensation is an operation to compensate for initial errors in the sampling circuit, etc. Finally, data transformation mainly includes converting the acquired signal into electrical parameters such as voltage values ​​and frequencies, and correcting the available variables of the error function. It should be noted that this data preprocessing process is a flow that researchers in the art can easily conceive of after understanding the algorithm principle of this invention, and will not be elaborated upon in detail.

[0076] In signal generation, the control signal is obtained by executing the following algorithm, specifically:

[0077] Constructing the error function

[0078] When e < -e0, -ΔCrl is generated. Decrease Crl and let V oit (Crl) decreases; when e>e0, ΔCrl is generated, increasing Crl and letting Vout (Crl) increases; when e0>e>-e0 and e0 is sufficiently small, the system gain is k. D Among them, V out It is the pre-processed output signal, V IN It is the pre-processed non-ideal integrator input signal, K D It is the software-defined gain, Cr is the control signal voltage, e0 is the absolute error and is a positive number, and ΔCr is the voltage iteration amount.

[0079] It should be noted that the above is the principle of the control signal generation algorithm based on this integral system. Algorithms evolved from this principle, such as common algorithms that determine the change of ΔCrl in each iteration, such as fuzzy control algorithms and advanced PID control algorithms, all belong to this algorithm category.

[0080] like Figures 5 to 7 As shown, a simulation verification of a closed-loop control integral system with amplitude compensation function in an embodiment of the present invention is performed, as detailed below:

[0081] Simulation verification was performed on the Matlab Simulink platform. The application scenario of this invention is to measure AC current signals with drastic amplitude changes under wide temperature variations. The simulation experiment used an AC signal with randomly varying amplitude to simulate an actual AC signal, and the circuit parameters were changed slowly. The interference sources in the integrator of this invention are changes in the input signal amplitude and changes in circuit parameters caused by temperature. The former determines the dynamic range of the measured signal, while the latter determines the operating temperature range of the integrating circuit and the degree of device aging.

[0082] This invention sets up three sets of experiments to examine the static error and dynamic performance of the integrator system under the conditions of varying simulation circuit parameters, varying input signals, and mixed variations.

[0083] This experiment uses the RC value of a non-ideal integrator as a variable to examine the anti-interference capability of the integrator of this invention to changes in circuit parameters. The values ​​are set to 0.54, 0.6, and 0.66 respectively. The input signal is a 2V AC signal. After the differentiating element, the input signal to the integrator of this invention is a 0.2V AC signal. The amplitude gain of the integrator of this invention is 10.

[0084] Implementing the embodiments of the present invention has the following beneficial effects:

[0085] This invention introduces a variable gain amplifier to effectively compensate for errors caused by changes in the integrator circuit parameters due to temperature variations. It also provides online control for real-time error compensation, which is more accurate and reliable than offline compensation. Furthermore, the control signal generator is controlled by a microcontroller, which is less expensive than DSP and FPGA control. As a result, it can not only compensate for errors caused by device temperature drift and aging in real time, but also has the advantages of high measurement accuracy, low cost, and more stable performance.

[0086] The above description is merely a preferred embodiment of the present invention and should not be construed as limiting the scope of the invention. Therefore, any equivalent variations made in accordance with the claims of the present invention are still within the scope of the present invention.

Claims

1. A closed-loop control integral system with amplitude compensation function, used in conjunction with a Rogowski coil, characterized in that, It includes a non-ideal integrator, a variable gain amplifier, and a control signal generator; among which, The input terminal of the non-ideal integrator is connected to the Rogowski coil to receive the output signal of the Rogowski coil and perform integration on the output signal to suppress integral overflow caused by interference DC. One input terminal of the variable gain amplifier is connected to the output terminal of the non-ideal integrator, and the other input terminal is connected to the output terminal of the control signal generator. The output terminal is connected to one input terminal of the control signal generator. After receiving the control signal generated by the control signal generator, the amplifier adjusts the amplitude gain of the signal after integration by the non-ideal integrator based on the control signal, so as to compensate online for the amplitude gain error caused by temperature drift and time drift of the non-ideal integrator. The other input terminal of the control signal generator is connected to the input terminal of the non-ideal integrator, and is used to collect various electrical parameters of the output terminal of the Rogowski coil, and combine them with various electrical parameters of the output signal of the variable gain amplifier to generate the control signal, and further use the control signal to adjust the gain of the variable gain amplifier. The variable gain amplifier includes a MOSFET D1, resistors R1, R2, R6, R7, and a second operational amplifier. An amplifier circuit composed of resistors R3, R4, and R5, and capacitors C1 and C2; wherein, In the decoupling drive circuit, resistors R3 and R4 and capacitor C2 are connected in series and then in parallel between the source and drain of MOSFET D1 in the amplifier circuit; one end of resistor R5 is connected to the gate of MOSFET D1 in the amplifier circuit, and the other end is connected to the output terminal of the control signal generator; one end of capacitor C1 is connected to the gate of MOSFET D1, and the other end is connected to the connection point between resistors R3 and R4. In the amplifier circuit, one end of resistor R6 is connected to the second operational amplifier. One end of the resistor is connected to the non-inverting input terminal, and the other end is connected to the output terminal of the non-ideal integrator; one end of the resistor R7 is connected to the second operational amplifier. One end is the non-inverting input terminal, and the other end is grounded; the drain of the MOS transistor D1 is connected to the second operational amplifier through the resistor R2. The inverting input terminal is grounded; the resistor R1 forms a negative voltage feedback network connected to the second operational amplifier. Between the inverting input and output terminals; the second operational amplifier The output terminal is connected to one input terminal of the control signal generator.

2. The closed-loop control integral system with amplitude compensation function as described in claim 1, characterized in that, The non-ideal integrator includes an integrating resistor. and integrating capacitor Integrating circuit, first operational amplifier and feedback resistor ;in, In the integrating circuit, the integrating resistor One end is connected to the Rogowski coil, and the other end is connected to the operational amplifier. The inverting input terminal is connected; the integrating capacitor One end is connected to the first operational amplifier The inverting input terminal is connected to the other end of the operational amplifier. Connect to the output terminal; First operational amplifier The non-inverting input terminal is grounded, and the output terminal is connected to one input terminal of the variable gain amplifier; The feedback resistor With the integrating capacitor Parallel connection.

3. The closed-loop control integral system with amplitude compensation function as described in claim 2, characterized in that, The transfer function of the circuit of the non-ideal integrator is If the input signal of the non-ideal integrator is a DC signal, the amplitude gain of the non-ideal integrator... for ; If the input signal of the non-ideal integrator is an AC signal and satisfies At that time, the amplitude gain of the non-ideal integrator for .

4. The closed-loop control integral system with amplitude compensation function as described in claim 1, characterized in that, The decoupling drive circuit is functionally divided into a DC path and an AC path; among which, The AC path is used to provide a path for the decoupling drive AC signal, extracting the decoupling drive AC signal from the source and drain terminals of the MOS transistor D1, correcting its amplitude and phase angle, and further decoupling the voltage between the source and drain terminals of the MOS transistor D1 when the variable resistor of the MOS transistor D1 is linearized. and the voltage between the gate and the source ,eliminate The effect on the resistance value of the variable resistance region; The DC path is used to provide a path for the DC control signal and the gate of the MOS transistor D1, isolate the path between the DC signal and the amplifier circuit, and reduce the impact of the DC control signal on the amplifier circuit.

5. The closed-loop control integral system with amplitude compensation function as described in claim 4, characterized in that, The gain of the variable gain amplifier is shown in the following formula: ； in, The gain of the variable gain amplifier; The variable resistor of the MOS transistor D1 is... ; The turn-on voltage of the MOSFET D1; These are the internal parameter coefficients of the MOS transistor D1; The DC control voltage introduced to the gate of the MOS transistor D1 is the voltage of the control signal generated by the control signal generator.

6. The closed-loop control integral system with amplitude compensation function as described in claim 1, characterized in that, The control signal generated by the control signal generator is obtained by executing the following algorithm: Constructing the error function ; When e<- At that time, it produces , reduce ,make Decrease; when e> At that time, it produces Increase ,make Increase; when >e> and When the value is sufficiently small, the system gain is ;in, It is the pre-processed output signal. It is the pre-processed non-ideal integrator input signal. It is a software-defined gain, To control signal voltage, The absolute error is a positive number. This represents the voltage iteration quantity.

7. The closed-loop control integral system with amplitude compensation function as described in claim 6, characterized in that, The preprocessing includes filtering, normalization, error compensation, and data transformation.

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