并联逆变器馈电PMSM调速系统谐波和环流控制

Harmonics and circulating current suppression in paralleled inverters fed permanent magnet synchronous motor drive system

针对大功率场合下并联逆变器馈电永磁同步电机(PMSM)调速系统中存在的环流问题和电机电流谐波性能差的问题,提出一种并联逆变器馈电永磁同步电机控制策略来协调控制不同并联逆变器模块实现电机总电流波形优化,并有效地抑制并联逆变器模块间环流。分析并联逆变器馈电PMSM调速系统的电路结构及并联逆变器环流的等效电路模型,提出针对并联逆变器PMSM调速系统的移相空间矢量脉宽调制(SVPWM)技术和随机SVPWM技术,并通过在SVPWM中动态分配零矢量作用时间来抑制各逆变器模块间的环流。仿真和实验结果均验证了所提出的控制策略的有效性,采用移相SVPWM和随机SVPWM策略可改善电机电流的谐波性能,采用环流抑制环节后可以有效地消除电路中的环流。

Aiming at the circulating current and poor performance of the motor current harmonics in high- power paralleled inverters fed permanent magnet synchronous motor drive system,a new control strategy was proposed to optimize the motor current waveforms by collaborating operation of paralleled inverters while avoiding the possible circulating current. The system configuration and equivalent model of the paralleled inverters fed permanent magnet synchronous motor drive system were analyzed. Based on that,a phase shifted space vector pulse width modulation（ SVPWM） scheme and a random SVPWM were proposed to suppress the harmonics in motor current. An additional control loop was also designed to suppress the possible circulating current by tuning the dwelling time of zero vectors dynamically. Simulation and experimental results have been given to validate the effectiveness of the proposed control strategies,both phase shifted SVPWM and random SVPWM strategies suppress the harmonics in the motor current,and the circulating current are also decreased by applying the circulating current control.