基于虚阻尼控制的T-SAPF滤波系统谐振抑制研究

为了降低整流桥、变频器等强非线性负载向电网引入的谐波污染,提出一种由并联型有源电力滤波器(SAPF)与晶闸管投切滤波器(TSF)构成的T-SAPF混合滤波系统。针对TSF可能与电网发生并联谐振的问题,在对谐振机理进行分析的基础上,提出一种可以抑制系统并联谐振的SAPF虚阻尼控制策略,将自调谐滤波算法应用于阻尼电流指令的提取,并根据三个约束条件来界定阻尼系数的有效值域。仿真结果表明,该虚阻尼控制策略能够有效抑制系统的并联谐振,降低谐振时PCC电压的畸变程度,同时保证谐波电流的补偿效果。

Research on Resonance Suppression Strategy of T-SAPF Filtering System Based on Virtual Damping Control

In order to reduce the harmonic pollution in the grid caused by strong nonlinear loads such as rectifier and inverter,a hybrid filtering system T-SAPF composed of shunt active power filter (SAPF) and thyristor switched filter (TSF) is proposed in this paper.In view of the parallel resonance potentially arised between TSF and the grid,the resonance mechanism is analyzed in detail and a virtual damping control strategy of SAPF for suppressing parallel resonance of the system is proposed.The self-tuned filtering algorithm is used to extract the instruction of damping current and the effective range of the damping coefficient is defined by three constraint conditions.The simulation results show that the parallel resonance of the system can be effectively restrained by the proposed virtual damping control strategy,the distortion degree of the PCC voltage in the resonance is reduced,and the effect of harmonic current compensation is also guaranteed.