一种具有频率适应性的nk±m次谐波重复控制策略及其在四桥臂APF中的应用

Frequency Adaptive nk±m Order Harmonic Repetitive Controller and Its Application in Four-leg APF

针对重复控制动态性能和频率适应性差的缺点,提出一种具有频率适应性的nk±m次谐波重复控制器,采用该重复控制器的有源电力滤波器可以选择性地补偿nk±m次谐波,满足不同应用场合的需求;与传统重复控制CRC(conventional repetitive controller)相比,该重复控制器具有延时时间小、动态响应速度快等优点。当电网电压频率波动时,该重复控制器通过采用新型有限冲激响应FIR(finite impulse response)滤波器逼近CRC内模无法实现的小数延时部分z^(-F),并根据电网实际频率快速调整FIR滤波器的系数,实现其对电网频率变化的适应。仿真结果验证了该重复控制器的有效性和优越性。

To improve the dynamic performance and frequency adaptivity of repetitive control, this paper presents a frequency adaptive nk±m order harmonic repetitive controller. With proposed controller active power filter （APF） can compe-nsate nk ±m order harmonic selectively to meet the needs of different applications and gain faster dynamic response compared with conventional repetitive control（CRC）. Moreover, when the grid frequency varies slightly, by using the new type FIR filter, the proposed repetitive controller can approach the fractional part of delay segment that conventional repetitive controller can not achieve. The parameters of the FIR filter are adjusted rapidly according to the practical grid frequency, and then the proposed repetitive controller adaptability to the grid frequency varying is achieved. Simulation results verify the validity and superiority of the proposed repetitive controller.