有源电力滤波器控制时延的研究

Study on control delays of active power filter

针对有源电力滤波器(APF)系统存在的延时情况,分析了延时对APF补偿效果的影响并提出了解决的办法。通过建立APF系统的网络阻抗传递函数,利用pade近似式对其进行简化分析,得到了不同时滞情况下该网络频率响应特性。由此分析时延对系统性能的影响并说明在控制中不能忽略延时的存在。由于固有时延只能减小不能根除,只能从消除时延对补偿效果影响的角度出发,提出了一种利用谐波的周期性特点来延迟补偿谐波输出的方法提高补偿效果。仿真结果表明了该方法的正确性和有效性。

In order to eliminate some influence on compensating effects in active power filter （APF） system, some typical delays are analyzed and effective solutions are presented. The network impedance transfer function of APF is built and the pade approximation is used to simplify and analyze it, then the frequency response character of APF is gotten at different delays. Influences on system capability are researched on and it is clear that delays can not be neglected in application. Because inherent delays can not be erased, it can only be reduced by compensating effect. So a solution is presented to get perfect compensating result, which uses harmonic periodicity characteristic to delay the compensating harmonic output. Finally, simulation results show that this method is valid and effective.