三角波脉宽调制电流控制有源电力滤波器电路参数与跟随性能的关系

三角波脉宽调制电流控制方法是有源电力滤波器APF(Active P0wer Filter)常用的一种控制方法,该方法电路简单,开关频率恒定,但跟随误差较大.根据三角渡脉宽调制电流控制方法的跟随特性,发现补偿电流在一个周期内上升、下降时间不相等而造成误差较大,为此可控制其时间来减小误差,并根据控制条件得到了三角波参数与APF参数之间的关系.为了验证此关系的正确性,对三角波脉宽调制电流控制的单相并联型APF系统进行了仿真研究.仿真结果表明,若按此关系来选择三角波脉宽调制电流控制APF的参数,可提高跟随速度,减小跟随误差.

Relationship between following performance and circuit parameters of APF controlled by triangle-wave pulse width modulated current

TPWMC (Triangle -wave Pulse Width Modulated Current) control is widely used in APF (Active Power Filter),which has simple circuit and fixed switching frequency,but great following error. By analyzing the following performance of TPWMC control,it is found that the great error is induced by the difference between the rising time and falling time of compensating current in a cycle and it can be lowered by time control. The relationship between triangle -wave parameter and APF is set according to the control conditions. The system with single -phase shunt APF controlled by TPWMC is simulated to verify the correctness of the set relationship. Simulation results show that,the following speed of TPWMC -controlled APF can be improved and its error reduced by properly setting its parameters according to the relationship.