CN-121984141-A - Active power control method and related device for low-frequency side outer ring of matrix converter

CN121984141ACN 121984141 ACN121984141 ACN 121984141ACN-121984141-A

Abstract

The invention provides a matrix converter low-frequency side outer ring active power control method and a related device, comprising the steps of judging the connection type of an alternating current side based on collecting operation scene data of the matrix converter low-frequency side, and starting an active power control flow when the alternating current side is connected with a power grid; the method comprises the steps of collecting three-phase electric data of a low frequency side of a matrix converter, obtaining a positive sequence voltage component and a positive sequence current component through coordinate transformation, obtaining actual active power based on the voltage component and the current component, carrying out deviation correction processing on the actual active power and preset target active power to obtain a correction signal, carrying out feedforward compensation processing on the actual active power and the preset target active power to obtain a compensation signal, fusing the correction signal and the feedforward signal to generate a d-axis current control command signal, and driving a current inner ring to carry out active power adjustment on an outer ring of the low frequency side of the matrix converter based on the d-axis current control command signal. The control method improves the dynamic response and the operation reliability of the matrix converter at the low frequency side.

Inventors

LI ZHENG
ZHOU JING
ZHANG JUNYANG
BO QIANG
PAN XIAOFENG
Ba lei
KONG CAN
SHEN ZHENGHUA
Duan Zhouchao

Assignees

中国华能集团清洁能源技术研究院有限公司
华能(浙江)能源开发有限公司玉环分公司
华能(浙江)能源开发有限公司

Dates

Publication Date: 20260505
Application Date: 20260129

Claims (10)

1. The active power control method of the outer ring of the low-frequency side of the matrix converter is characterized by comprising the following steps: Based on the operation scene data of the low-frequency side of the acquisition matrix converter, judging the connection type of the alternating-current side, and starting an active power control flow when the alternating-current side is connected to a power grid; Three-phase electrical data at the low frequency side of the matrix converter are collected, and a positive sequence voltage component and a positive sequence current component under a dq rotating coordinate system are obtained through coordinate transformation; Calculating to obtain actual active power based on the voltage component and the current component; Performing deviation correction processing on actual active power and preset target active power to obtain a correction signal, and performing feedforward compensation processing based on the preset target active power to obtain a compensation signal; Fusing the correction signal and the feedforward signal to generate a d-axis current control command signal; and driving the current inner loop to perform active power adjustment on the matrix converter low-frequency side outer loop based on the d-axis current control command signal.
2. The method for controlling active power of an outer loop of a low frequency side of a matrix converter according to claim 1, wherein the determining a connection type of an ac side based on collecting operation scene data of the low frequency side of the matrix converter comprises: acquiring operation scene data of a low-frequency side of the matrix converter, wherein the operation scene data comprises frequency data and voltage phase fluctuation data; the frequency data and the voltage phase fluctuation data are processed by noise reduction through 100Hz first-order low-pass filtering, Comparing the noise-reduced frequency data with a preset frequency threshold range, and comparing the voltage phase fluctuation data with a preset phase fluctuation threshold range, if the frequency data is positioned in the frequency threshold range and the voltage phase fluctuation data is positioned in the preset phase fluctuation threshold range, judging that the power grid is connected to a scene; And if the state of the circuit breaker is in a closed state and the continuous current data is more than or equal to 5A, judging that the alternating current side is connected to a power grid.
3. The method for controlling active power of an outer loop of a low frequency side of a matrix converter according to claim 1, wherein the collecting three-phase electrical data of the low frequency side of the matrix converter, and obtaining a positive sequence voltage component and a positive sequence current component in a dq rotating coordinate system through coordinate transformation, comprises: collecting three-phase voltage data and three-phase current data of the matrix converter at a low frequency side; the three-phase voltage data and the three-phase current data are converted into voltage digital signals and current digital signals through a converter; The voltage digital signal and the current digital signal are subjected to Clark conversion to obtain a voltage component and a current component under an alpha beta static coordinate system; and performing park transformation on the voltage component and the current component by taking the phase angle of the grid voltage of the phase-locked loop as a reference to obtain a positive sequence voltage component and a positive sequence current component under the dq rotating coordinate system.
4. The matrix converter low-frequency side outer loop active power control method according to claim 3, wherein the process of calculating the actual active power based on the voltage component and the current component is: Wherein, the In order for the actual active power to be the same, For the q-axis component of the positive sequence voltage in the dq rotational coordinate system, For the d-axis component of the positive sequence voltage in the dq rotation coordinate system, For the q-axis component of the positive sequence current in the dq rotational coordinate system, Is the d-axis component of the positive sequence current in the dq rotation coordinate system.
5. The method for controlling active power of a low-frequency side outer loop of a matrix converter according to claim 4, wherein performing offset correction processing on the actual active power and a preset target active power to obtain a correction signal, and performing feedforward compensation processing based on the preset target active power to obtain a compensation signal, comprises: Calculating an active power deviation amount based on the actual active power and the target active power; inputting the active power deviation into a PI regulator for deviation correction to obtain a deviation correction signal; Acquiring low-frequency side voltage, low-frequency side current, power frequency side voltage and power frequency side current, calculating the bridge arm power of each bridge arm, extracting a direct current component, performing double alpha beta coordinate conversion on the direct current component, and performing unbalanced bridge arm power components of an alpha axis and a beta axis under a two-phase static coordinate system; determining a current compensation component based on the bridge arm power unbalance component, and obtaining a current reference value under double alpha beta 0 transformation through coordinate conversion; And correcting the current reference value and the deviation correction signal through proportional control dynamic correction to obtain a correction signal.
6. The method for controlling active power of a low-frequency side outer loop of a matrix converter according to claim 1, wherein the feedforward compensation process is performed based on the preset target active power to obtain a compensation signal, comprising: acquiring power frequency voltage of a power frequency side of the matrix converter; Performing second-order low-pass filtering treatment with cut-off frequency of 10Hz on the power frequency voltage to obtain a smooth voltage; And calculating a compensation signal based on the smoothed voltage and the target active power.
7. The method of claim 1, wherein the step of fusing the correction signal with the feedforward signal to generate the d-axis current control command signal comprises: linearly superposing the fusion correction signal and the feedforward signal to obtain a fusion signal; and carrying out +/-800A amplitude limiting treatment on the fusion signal to obtain a d-axis current control instruction signal.
8. The matrix converter low frequency side outer ring active power control system for implementing the matrix converter low frequency side outer ring active power control method according to any one of claims 1 to 7, comprising: The type judging module is configured to judge the connection type of the alternating current side based on the operation scene data of the low frequency side of the acquisition matrix converter and start an active power control flow when the alternating current side is connected to a power grid; the component processing module is configured to acquire three-phase electrical data at the low frequency side of the matrix converter, and obtain a voltage component and a current component under the dq rotating coordinate system through coordinate transformation; a power calculation module configured to calculate an actual active power based on the voltage component and the current component; The signal processing module is configured to perform deviation correction processing on the actual active power and a preset target active power to obtain a correction signal, and perform feedforward compensation processing based on the preset target active power to obtain a compensation signal; the signal fusion module is configured to fuse the correction signal and the feedforward signal and generate a d-axis current control instruction signal; And the control module is configured to drive the current inner ring to perform active power adjustment on the matrix converter low-frequency side outer ring based on the d-axis current control command signal.
9. A computer device comprising a memory, a processor and a computer program stored in the memory and operable in the processor, the processor implementing the steps of the matrix converter low frequency side outer loop active power control method according to any one of claims 1 to 7 when the computer program is executed by the processor.
10. A computer readable storage medium, wherein the computer readable storage medium stores a computer program, and the computer program when executed by a processor implements the steps of the matrix converter low frequency side outer loop active power control method according to any one of claims 1 to 7.

Description

Active power control method and related device for low-frequency side outer ring of matrix converter Technical Field The invention belongs to the technical field of converter control, and particularly relates to a matrix converter low-frequency side outer ring active power control method and a related device. Background The modularized multi-level matrix converter (M3C) is a high-performance power electronic device without an intermediate direct current link, and becomes core equipment in the fields of new energy grid connection, low-frequency power transmission and the like by virtue of the characteristics of bidirectional power transmission and excellent electric energy quality, and the stability and the accuracy of active power transmission are directly determined by the outer ring control of the low-frequency side. The prior art shows that the low-frequency side outer ring control of the M3C is similar to a Modular Multilevel Converter (MMC), and the power angle decoupling is realized based on a dq rotating coordinate system, but a control scheme aiming at active power still has a remarkable short board. The current M3C low-frequency side active power control lacks scene adaptation mechanism, namely the M3C alternating-current side is connected with various load types, active instructions need to be tracked when the power grid is accessed, and collaborative voltage control is needed when the island is accessed, but the scene difference is not distinguished by the existing method, so that control blind start in a non-target scene is easy to cause, and power regulation disorder is caused. Meanwhile, the existing control mostly adopts single PI closed-loop adjustment, feedforward compensation is not introduced, and when an active instruction suddenly changes (such as new energy output fluctuation), the response time exceeds 0.5s, so that millisecond response requirements of new energy grid connection are difficult to meet. Disclosure of Invention The invention provides a matrix converter low-frequency side outer ring active power control method and a related device, which are used for solving the problems of poor adaptation, slow response, complex calculation and insufficient adjustment precision of the existing M3C low-frequency side active control scene. In order to achieve the above purpose, the present invention provides the following technical solutions: The invention provides a matrix converter low-frequency side outer ring active power control method, which comprises the following steps: Based on the operation scene data of the low-frequency side of the acquisition matrix converter, judging the connection type of the alternating-current side, and starting an active power control flow when the alternating-current side is connected to a power grid; Three-phase electrical data at the low frequency side of the matrix converter are collected, and a positive sequence voltage component and a positive sequence current component under a dq rotating coordinate system are obtained through coordinate transformation; Calculating to obtain actual active power based on the voltage component and the current component; Performing deviation correction processing on actual active power and preset target active power to obtain a correction signal, and performing feedforward compensation processing based on the preset target active power to obtain a compensation signal; Fusing the correction signal and the feedforward signal to generate a d-axis current control command signal; and driving the current inner loop to perform active power adjustment on the matrix converter low-frequency side outer loop based on the d-axis current control command signal. Preferably, the determining the connection type of the ac side based on the operation scene data of the low frequency side of the acquisition matrix converter includes: acquiring operation scene data of a low-frequency side of the matrix converter, wherein the operation scene data comprises frequency data and voltage phase fluctuation data; the frequency data and the voltage phase fluctuation data are processed by noise reduction through 100Hz first-order low-pass filtering, Comparing the noise-reduced frequency data with a preset frequency threshold range, and comparing the voltage phase fluctuation data with a preset phase fluctuation threshold range, if the frequency data is positioned in the frequency threshold range and the voltage phase fluctuation data is positioned in the preset phase fluctuation threshold range, judging that the power grid is connected to a scene; And if the state of the circuit breaker is in a closed state and the continuous current data is more than or equal to 5A, judging that the alternating current side is connected to a power grid. Preferably, the collecting three-phase electrical data at the low frequency side of the matrix converter, and obtaining a positive sequence voltage component and a positive sequence current component under the dq ro