基于改进载波移相SPWM的链式STATCOM电容电压平衡控制策略

介绍了传统载波移相SPWM及脉冲循环换位调制策略,指出了上述方法由于级联H逆变桥的电路参数及损耗差异等因素,无法真正实现链式STATCOM的电容电压平衡。笔者通过对传统载波移相SPWM调制策略进行改进,提出了一种新的链式STATCOM电容电压平衡控制策略,分析了该策略的基本原理与实现过程。通过PSCAD/EMTDC对该控制策略进行了仿真,结果说明,该策略可以很好地实现电容电压的平衡,而且对上层控制、装置的谐波特性不会产生影响。

Novel Strategy of Capacitor Voltage Balancing Control for Cascaded STATCOM Based on Advanced Carrier Phase Shifting SPWM

This paper inspects the conventional carrier phase shifting SPWM and pulse cycle transposition strategy,and points out that the DC capacitor voltage balance problem can't be absolutely solved by the strategy above for the diversity of circuit parameters and loss of series-connected H-bridge inverters.Therefore,a novel strategy of DC capacitor voltage balancing control is proposed based the conventional carrier phase shifting SPWM modulation.The principle and realization of the novel strategy is provided,and the novel control strategy is simulated in PSCAD/EMTDC.The simulation results show that the strategy on the DC capacitor voltage balancing control is valid and has no influence on the upper control and harmonic characteristic of the STATCOM.