并联型有源电力滤波器直流侧电压分析

Analysis on DC side voltage of shunt active power filter

为了解决并联型有源电力滤波器(SAPF)直流侧电压传统控制存在超调量静差较大的问题,针对并联型电力有源滤波器直流电容平均电压与纹波电压的变化规律进行了深入分析。提出了一种基于电流分解的有源电力滤波器的直流侧电容电压波动算法,导出了相应的电压纹波估算的表达式,进而导出直流侧电容容量与电压纹波的关系。同时通过由能量PI控制取代传统的简单PI控制,经过PI参数校正,将原来非线性较强的控制系统进行线性化,减少了非线性因数的影响。仿真结果证明系统具有良好的控制效果。说明了直流侧电容电压纹波取决于被补偿电流的谐波分布以及电容值,按照整定的PI控制器参数,扩大了PI控制对于系统运行状态变化的适用范围,同时超调量和静差也有很大的改善。

To deal with the weakness of larger static error and overshoot about conventional DC -side voltage of shunt active power filter （SAPF） control, the change role of DC capacitor average voltage and fluctuant voltage were analyzed, which influence on the performance of SAPF. An algorithm of SAPF DC capacitor voltage fluctuation based on the current proposed was showed out, the expression of the corresponding ripple voltage was worked out, and then further derived out the relationship between DC capacitor capacity and the ripple capacitor voltage. At the same time, with the energy-PI control method to replace the traditional simple PI control, the PI parameters of correction and the original nonlinear strong control system of linear, had reduced the impact of the nonlinear factor. The prefect controlling affection of the system was proved in simulation results. That the DC side ripple capacitor voltage depends on the harmonic current distribution and capacitance values is showed, and according to the corrected parameters of the PI controller, the application of PI control of the running system is expanded, and overshoot is poor and static error also is greatly improved.