有源滤波器控制新策略

由于有源滤波器(APF)的性能主要取决于谐波检测和电流控制两个环节,本文对这两个环节做了改进,提出了一种新的控制策略,针对ip-iq谐波电流检测法中的锁相环(PLL)易受电压波动影响,提出了基于广义积分器的相位锁定法,该方法通过提取电网三相电压的正序基波分量来锁定相位,不受电压畸变和不对称的影响。同时将PI参数自整定的广义积分器应用到电流跟踪控制中,利用其在谐振频率的无穷大开环增益实现谐波电流的无静差跟踪。Matlab/Ssimulink仿真结果表明,在电压畸变的情况下该方法可以很好地检测和补偿谐波电流。

A New Control Strategy of Active Power Filter

Because APF performance is impacted by both harmonics detection and current control algorithm, the paper improved these two aspects and proposed a new control strategy. For Vulnerability to voltage fluctuations of ip-iq harmonic current detection by phase-locked loop (PLL), the paper proposed a new method to lock phase based on generalized integrator. The method locked the phase by extracting the positive sequence fundamental component of grid voltage, and it is not affected by the voltage distortion and asymmetry. Meanwhile, the generalized integrator is applied to current tracking control, and the method tracked harmonics without static error using the infinite open-loop gain on resonant frequency. The Matlab/simulink simulation results show that the method can detect and compensate for harmonic current in the case of voltage distortion.