基于SPWM-VSI结构的DSTATCOM的实验研究

论述了配电系统静止补偿器(DSTATCOM)的工作原理,并分析了DSTATCOM的四象限工作状态及其与系统的功率交换关系.针对基于SPWM-VSI结构的DSTATCOM,从其数学模型出发,讨论了三种可行的控制策略,并提出了通过调节相移角δ来稳定直流电压、调节PWM调制深度λ来控制无功功率的双变量协调控制的参数通用计算方法.实验系统采用SPWM电压源逆变器结构和DSP控制技术,实现了无功功率的双向快速调节功能,实验结果表明了双变量协调控制具有响应速度快和谐波发生量小的特点.

Experimental research on SPWM-VSI-based DSTATCOM

In this paper, the principle of distribution static synchronous compensator (DSTATCOM) was described, and the four quadrant operating status of DSTATCOM was analyzed. Two operating status will exist in the steady state and other two status may appear in the transient state to rapidly decrease the DC voltage. From the mathematic model of SPWM-VSI-based STATCOM, three control modes are available, but the bi-variable control strategy that the phase-shift is used as a variable to regulate the DC voltage and the PWM modulation index to control the reactive power was proposed to obtain the rapid response and less harmonic content, and the general formulae for the calculation of DC voltage levels and bound of modulation index was presented. An IGBT-SPWM-VSI with DSP controller is employed in the experimental system, and a rapid bidirectional adjustment of reactive power is obtained. The experimental results also show that DSTATCOM with bi-variable control characterizes a rapid response and less harmonic content.