基于拍频坐标系的轨道交通牵引系统拍频抑制策略研究OA

In the rail transit traction system,the operation of the four-quadrant pulse rectifier introduces double grid frequency ripple into the DC bus voltage.This ripple voltage interacts with the fundamental frequency volt-age of the inverter,leading to beat-frequency phenomena in the motor stator voltage and current.This phenome-non is particularly pronounced when the motor operating frequency is close to twice the grid frequency.This pa-per elaborates on the generation mechanism of the beat-frequency phenomenon,and analyzes the rotation direc-tion and frequency of each harmonic component in the motor stator current.To address the beat-frequency prob-lem,a beat-frequency rotating coordinate system is proposed to extract the harmonic currents causing the beat-frequency phenomenon,which are converted into DC quantities in the beat-frequency coordinate system,and the compensation voltage for beat-frequency suppression is generated by a proportional-integral controller.A motor simulation model is built in MATLAB/Simulink,and simulation verification is carried out under three dif-ferent motor operating conditions.The simulation results show that the proposed method can effectively sup-press the beat-frequency phenomenon in a wide frequency range where the motor frequency is close to the dou-ble grid frequency.