双三点式STATCOM的电压电流波形分析

对双三点式STATCOM在基频调制方式下的电压和电流进行了理论分析,给出了相应的解析表达式。并利用Matlab/Simulink对STATCOM的电压和电流波形进行了仿真分析。理论和仿真分析结果的一致性证明了所提出的理论分析方法是正确、有效的。最后,对STATCOM的电压和电流谐波特性与电感和电容参数的关系进行仿真分析的结果表明,直流侧上下电容电压以3倍于基波的交变频率在平均值上下波动,且其波动范围随电感和电容值的增加而减小;当电感较大时,交流侧输出电压和电流的谐波畸变率受直流侧电容的影响很小,而当电感较小时,输出电压和电流的谐波畸变率随电容值的增加而减小。

Voltage and Current Waveform Analysis of the Dual Three-point STATCOM

On the assumption that STATCOM has no active power losses,the current and voltage analytical expressions of the dual three-point STATCOM under the fundamental frequency modulation(FFM) control were presented by means of the theoretical analysis method.Meanwhile,the current and voltage waveforms of the dual three-point STATCOM were simulated with the help of Matlab/Simulink.The good agreement between theoretical analysis and simulation results verify that the proposed theoretical analysis method is valid and feasible.At last,the influence of the inductance and dc-link capacitance on the voltage and current harmonic performance of the dual three-level STATCOM was analyzed.The simulation results show that the dc-link voltages vary about the average of the dc-link voltage at three times of fundamental frequency,but the fluctuation range decreases as the inductance and capacitance increase;the influence of the dc-link capacitance on the AC voltage and current THD of STATCOM is very small when the inductance is large,while the AC voltage and current THD of STATCOM increases with the decreasing of the dc-link capacitance when the inductance is small.