可选择谐波型有源滤波器的检测及其闭环控制

为了实现对电力系统谐波的实时和精确补偿,该文提出了一种用于有源电力滤波器任意指定次谐波的检测方法以及基于该检测方法的闭环控制方法。这种有源电力滤波器由选择性谐波检测环节、电压控制和电流控制环节组成。为了补偿数字控制器和逆变器带来的延时,在检测环节中加入了预测补偿角。电压闭环控制方法借助检测环节实现了对谐波电流发生电路中逆变器直流侧的电压控制。电流闭环控制方法使得实际补偿电流精确地跟踪检测出的谐波指令电流。仿真结果验证了该控制方法的正确性,在采用上述方法后,电源电流得到根本的改善。

Close-loop control for selective harmonic compensation active power filter

A selective harmonic detection method and a closed-loop control algorithm was developed for selective-harmonic- compensation active power filters (SHC-APF) to provide precise compensation. The SHC-APF include a selective detection unit and a closed loop for DC voltage control and current control. The selective harmonic detection unit precisely detects selected harmonic currents instead of all the harmonics produced by distorted loads. At the same time, the unit adds a preceding compensating angle to compensate for the delays caused by the digital controller and voltage-source inverter (VSI). The DC control provides the VSI voltage control while the current control provides the compensation current that follows the harmonic detection signal. Simulations confirme that the method effectively compensates for the harmonics.