一种新型恒频滞环电流控制策略研究

A New Constant-frequency Current Hysteresis Loop Control Strategy

并联型有源电力滤波器的变环宽滞环电流控制方法是根据电流幅值的变化适时调整滞环宽度,可有效保证滤波器的补偿性能,控制开关器件的开关频率。在传统的变环宽滞环电流控制算法的基础上,加入了电流限幅和频率PI反馈控制环节,限制了较大电流的波动,提高了频率的控制精度,以及有源电力滤波器的电流补偿性能。Matlab仿真结果表明,采用新型恒频滞环电流控制算法进行电流跟踪补偿时,系统的电流总畸变率小于采用传统变环宽滞环电流控制算法时的总谐波畸变率。

Hysteresis circle current control method with variable circle width of the shunt active power filter not only ensures the tracking accuracy of reference current, but controls the switching frequency of inverters effectively through adjusting hysteresis circle width in real-time according to current amplitude. Traditional hysteresis circle cur- rent control method with variable circle width is improved by adding an amplitude limiting element and a frequency feedback PI control method, which limits the abnormal current fluctuations and controls the frequency of the PWM series accurately. The Matlab simulation results show that the total harmonic distortion of the system when harmonic current is tracked and compensated by the improved method is less than the value by the traditional method.