CN-121984314-A - Bridge arm capacitor voltage control method, system and storage medium of matrix converter

CN121984314ACN 121984314 ACN121984314 ACN 121984314ACN-121984314-A

Abstract

The invention provides a bridge arm capacitor voltage control method, a system and a storage medium, which comprise the following steps of carrying out coordinate conversion processing on an acquired bridge arm capacitor voltage instantaneous value of a matrix converter to obtain a voltage unbalance initial component; the method comprises the steps of classifying voltage unbalance initial components according to frequency characteristics, respectively configuring wave filtering parameters based on the voltage unbalance initial components with different frequency characteristics to conduct ripple suppression processing to obtain voltage unbalance first components, inputting the voltage unbalance first components into a PI controller to generate branch bridge arm power reference values, adjusting the branch bridge arm power reference values based on a phase transformation matrix of a matrix converter to generate a basic circulating current component and a ripple compensation circulating current component, conducting fusion correction on the basic circulating current component and the ripple compensation circulating current component based on actual operation data to obtain circulating current control instructions, and controlling bridge arm capacitor voltages of the matrix converter based on annular control instruction signals. The method effectively avoids ripple accumulation and reduces the loss of the power switch tube.

Inventors

LI ZHENG
RAO GUOPING
AI JINSHENG
Ba lei
PAN XIAOFENG
LIN ZHONGWEI
CHEN FENG
DU WEIAN
GUO XIAOJIANG
HE WEIGUO
ZHANG JUNYANG
BO QIANG
ZHANG ZHUOYU

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: 20260130

Claims (10)

1. The bridge arm capacitor voltage control method of the matrix converter is characterized by comprising the following steps of: Carrying out coordinate conversion processing on the acquired bridge arm capacitor voltage instantaneous value of the matrix converter to obtain a voltage unbalance initial component; Classifying the initial voltage unbalance components according to frequency characteristics, and respectively configuring wave filtering parameters based on the initial voltage unbalance components with different frequency characteristics to perform ripple suppression processing to obtain first voltage unbalance components; inputting the first component of the unbalanced voltage into a PI controller to generate a branch bridge arm power reference value; Adjusting a branch bridge arm power reference value based on a phase transformation matrix of the matrix transformer to generate a basic circulating current component and a ripple compensation circulating current component; Performing fusion correction on the basic circulation component and the ripple compensation circulation component based on actual operation data to obtain a circulation control command signal; and controlling the bridge arm capacitor voltage of the matrix converter based on the annular control command signal.
2. The bridge arm capacitor voltage control method of a matrix converter according to claim 1, wherein performing coordinate conversion processing on the acquired bridge arm capacitor voltage instantaneous value of the matrix converter to obtain a voltage imbalance initial component comprises: sampling a capacitance-voltage sensor signal of a bridge arm in the matrix converter to obtain a capacitance-voltage sampling value; performing ratio standardization processing on the capacitor voltage sampling value to obtain a per unit value; calculating a voltage average value based on the plurality of per unit values, and performing difference with the per unit value to obtain a normalized value; the normalized values are arranged in a matrix mode to obtain a normalized matrix; performing matrix transformation and expansion on the normalized matrix to obtain a voltage matrix; and removing zero-axis self-coupling components in the voltage matrix by utilizing orthogonality of the transformation matrix, and extracting other components to obtain a voltage unbalance component.
3. The bridge arm capacitor voltage control method of a matrix converter according to claim 1, wherein classifying the voltage unbalance initial components according to frequency characteristics, and respectively configuring wave filtering parameters based on the voltage unbalance initial components with different frequency characteristics to perform ripple suppression processing to obtain voltage unbalance first components, includes: respectively performing fast Fourier transform on the voltage unbalance components to acquire amplitude distribution data of the voltage unbalance components; judging the amplitude distribution data based on preset judging conditions to obtain a fundamental wave frequency component group, a harmonic wave frequency component group and a direct current offset component group; inputting the fundamental frequency component group into a first low-pass filter preset with a first suppression frequency to obtain a filtered unbalanced voltage first component, wherein the first suppression frequency is twice the input frequency, Inputting the harmonic frequency component group into a second low-pass filter with a preset second suppression frequency to be processed, so as to obtain a filtered unbalanced voltage second component; And inputting the direct current offset component group into a third low-pass filter preset with a third suppression frequency to be processed, so as to obtain a filtered unbalanced voltage third component, wherein the third suppression frequency is an output frequency.
4. The bridge arm capacitor voltage control method of a matrix converter of claim 3, wherein inputting the first component of voltage imbalance to a PI controller generates a branch bridge arm power reference value; Processing the first component of the unbalanced voltage and the zero matrix difference value to obtain a first difference value, and inputting the first difference value to a first PI controller configured with a first proportional coefficient for processing to obtain a first reference value of the power of the branch bridge arm; processing the unbalanced second component of the voltage and the zero vector difference value to obtain a second difference value, and inputting the second difference value to a second PI controller configured with a second proportionality coefficient for processing to obtain a second reference value of the power of the branch bridge arm; processing the third unbalanced voltage component and the zero vector difference value to obtain a third difference value, and inputting the third difference value to a third PI controller configured with a third proportional coefficient for processing to obtain a third reference value of the power of the branch bridge arm; and counting the first reference value, the second reference value and the third reference value of the branch bridge arm power.
5. The bridge arm capacitor voltage control method of a matrix converter of claim 4, wherein adjusting the leg power reference values based on the phase conversion matrix of the matrix converter generates a base circulating current component and a ripple compensation circulating current component, comprising: defining a first transformation matrix, a second transformation matrix and a third transformation matrix, wherein the first transformation matrix and the second transformation matrix are based on the voltage phase of a phase-locked loop at the input side of a matrix transformer The third transformation matrix is constructed based on the voltage phase of the phase-locked loop at the output side of the matrix converter Constructing and obtaining; calculating a basic circulation component matrix based on the first reference value of the power of the branch bridge arm and the first transformation matrix; calculating a first ripple compensation circulation component matrix based on the second reference value of the power of the branch bridge arm and the second transformation matrix; And calculating a second ripple compensation circulation component matrix based on the third reference value of the power of the branch bridge arm and the third transformation matrix.
6. The bridge arm capacitor voltage control method of a matrix converter according to claim 5, wherein performing fusion correction on the fundamental cyclic current component and the ripple compensation cyclic current component based on actual operation data to obtain a cyclic current control command signal, includes: fusing the basic circulation component matrix, the first ripple compensation circulation component matrix and the second ripple compensation circulation component matrix to obtain an initial circulation control instruction signal; calculating a loop tracking error and a voltage balancing residual error based on the acquired actual bridge arm loop data and capacitor voltage data; And inputting the loop tracking error, the voltage balance residual error and the initial loop control command signal to a proportional-resonance controller for closed-loop correction to obtain a loop control command signal.
7. The bridge arm capacitor voltage control method of a matrix converter according to claim 1, wherein controlling the bridge arm capacitor voltage of the matrix converter based on the ring control command signal comprises: acquiring a basic voltage modulation wave of a bridge arm; The annular control command signal is subjected to double Clark inverse transformation to obtain a voltage compensation quantity, and the voltage compensation quantity is overlapped with the basic voltage modulation wave to obtain a bridge arm modulation wave; comparing the modulated wave with a corresponding triangular carrier wave; Generating an input command signal if the modulated wave is greater than the triangular carrier wave, and generating a cutting command signal if the modulated wave is less than or equal to the triangular carrier wave; The operation of the legs of the matrix converter is controlled based on the input command signal or the cut command signal.
8. The bridge arm capacitor voltage control system of a matrix converter, configured to implement the bridge arm capacitor voltage control method of a matrix converter according to any one of claims 1 to 7, is characterized by comprising: the conversion processing module is configured to perform coordinate conversion processing on the acquired capacitance voltage instantaneous value of the matrix converter to obtain a voltage unbalance initial component; The ripple suppression module is configured to classify the voltage unbalance initial components according to frequency characteristics, and respectively configure wave filtering parameters based on the voltage unbalance initial components with different frequency characteristics to perform ripple suppression processing to obtain voltage unbalance first components; A PI controller configured to input the first component of voltage imbalance to the PI controller to generate a leg power reference value; The circulating current component processing module is configured to adjust the power reference value of the branch bridge arm based on the phase transformation matrix of the matrix transformer, and generate a basic circulating current component and a ripple compensation circulating current component; the control signal generation module is configured to perform fusion correction on the basic circulation component and the ripple compensation circulation component based on actual operation data to obtain a circulation control command signal; And the control module is configured to control the bridge arm capacitor voltage of the matrix converter based on the annular 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 bridge arm capacitance voltage control method of the matrix converter of 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 bridge arm capacitor voltage control method of the matrix converter of any one of claims 1 to 7.

Description

Bridge arm capacitor voltage control method, system and storage medium of matrix converter Technical Field The invention belongs to the technical field of flexible low-frequency power transmission, and particularly relates to a bridge arm capacitor voltage control method, a system and a storage medium of a matrix converter. Background The modularized multi-level matrix converter (M3C) is widely applied to the fields of new energy grid connection and the like by virtue of the advantages of no intermediate direct current link and power bidirectional transmission, and the capacitance and voltage balance of the submodules of the bridge arm is a key for guaranteeing the reliable operation of the device. In the prior art, the bridge arm capacitor voltage balance control generally extracts a voltage unbalance component through double alpha beta 0 conversion, then generates a bridge arm power reference value through a PI controller, derives a loop current reference value based on a fixed proportionality coefficient, and controls the bridge arm power through adjusting the bridge arm loop current to realize voltage balance. However, the control method has inherent defects that the frequency characteristics of unbalanced voltage components are not classified, unbalanced voltage components mixed with multiple frequency components are directly input into a controller, so that the generated bridge arm power reference value contains inherent ripple waves, the stability of the matrix converter is regulated and controlled through the bridge arm power reference value, the circulation deducing adopts a fixed proportion coefficient, the dynamic change of voltage fluctuation cannot be adapted, the ripple wave inhibition effect is limited, the voltage fluctuation amplitude of the bridge arm capacitor is large, meanwhile, a closed loop correction mechanism for ripple waves is lacked, the ripple wave accumulation can aggravate the power switching tube loss, the operation reliability of the device is reduced, and the high-precision control requirement of a high-power scene is difficult to meet. Disclosure of Invention In order to solve the problem that the control accuracy and reliability are insufficient due to the fact that the frequency characteristic of the unbalanced voltage component is not classified and inhibited in the conventional capacitance-voltage control method of the matrix converter, the invention provides a bridge arm capacitance-voltage control method, a bridge arm capacitance-voltage control system and a storage medium of the matrix converter. In order to achieve the above purpose, the present invention provides the following technical solutions: The invention provides a bridge arm capacitor voltage control method of a matrix converter, which comprises the following steps: Carrying out coordinate conversion processing on the acquired bridge arm capacitor voltage instantaneous value of the matrix converter to obtain a voltage unbalance initial component; Classifying the initial voltage unbalance components according to frequency characteristics, and respectively configuring wave filtering parameters based on the initial voltage unbalance components with different frequency characteristics to perform ripple suppression processing to obtain first voltage unbalance components; inputting the first component of the unbalanced voltage into a PI controller to generate a branch bridge arm power reference value; Adjusting a branch bridge arm power reference value based on a phase transformation matrix of the matrix transformer to generate a basic circulating current component and a ripple compensation circulating current component; Performing fusion correction on the basic circulation component and the ripple compensation circulation component based on actual operation data to obtain a circulation control command signal; and controlling the bridge arm capacitor voltage of the matrix converter based on the annular control command signal. Preferably, coordinate conversion processing is performed on the acquired instantaneous value of the bridge arm capacitor voltage of the matrix converter to obtain an initial component of voltage unbalance, including: sampling a capacitance-voltage sensor signal of a bridge arm in the matrix converter to obtain a capacitance-voltage sampling value; performing ratio standardization processing on the capacitor voltage sampling value to obtain a per unit value; calculating a voltage average value based on the plurality of per unit values, and performing difference with the per unit value to obtain a normalized value; the normalized values are arranged in a matrix mode to obtain a normalized matrix; performing matrix transformation and expansion on the normalized matrix to obtain a voltage matrix; and removing zero-axis self-coupling components in the voltage matrix by utilizing orthogonality of the transformation matrix, and extracting other components to obtain a voltage unbalance component.