并联电感型混合有源滤波器及其控制策略

A Novel Parallel Inductor Type Hybrid Active Power Filter and Its Control Strategy

提出一种适用于三相电路的并联电感型混合有源滤波器拓扑结构,对其工作原理进行分析,并对这种拓扑结构下的3种控制策略进行比较研究,通过电路的等效变换,揭示出各种控制策略下有源滤波器的作用。该混合有源滤波器的有源部分通过单相变压器与附加电感并联后再与无源滤波器串联,最后并入电网。附加电感提供了基波电流通路,控制有源滤波器为谐波电流源,就可以迫使基波电流流入附加电感,而有源滤波器仅流过谐波电流,从而有效降低了有源部分的容量,使之适用于大功率场合。通过仿真和实验,证明新型混合有源滤波器可以有效抑制谐波,3种控制策略中以复合控制的滤波效果最好。

A topological structure of a parallel inductor type hybrid active power filter for three-phase circuit is proposed and its working principle is analyzed, meanwhile the comparative research on three control strategies for such a topological structure is carried out. By means of equivalent transformation of circuit, the behaviors of the proposed hybrid active power filter under different control strategies are revealed. Firstly, via coupling transformers, the active parts of this hybrid active power filter are in parallel with additional inductors, then the parallel components are connected in series with passive power filter to compose hybrid active power filter, finally the hybrid active power filter is connected in parallel with power network. The additional inductors provide the path for fundamental current of the filter branch and the active filter is controlled as a harmonic current source, thus the fundamental current will be forced to flow into additional inductor while only harmonic currents pass through active filter, thus the capacity of active filter can be effectively decreased, for this reason it makes the active filter suitable for the occasion of high power. The proposed topology and three kinds of control strategies are validated by experiments and simulation with laboratory prototype of the proposed hybrid active power filter, and simulation and experiment results show that the proposed hybrid active power filter can effectively suppress harmonics, besides, among the three control strategies the compound control can provide the best filtering effect.