DC voltage design and corresponding compensation performance analysis for static var generator

摘要

This paper presents an extensive analysis of the influence of the DC voltage on the compensation performance of Static Var Generator (SVG). A method to design the DC voltage rated value is proposed according to the compensation performance. First, a required lowest value of the DC voltage for full compensation (a unity total power factor) is obtained by using the analysis of the equivalent circuit. For the situation where the DC voltage is smaller than the above-obtained lowest value, two basic options which are the sinusoidal modulation and the over modulation for the PWM control of SVG are considered. Then, the quantitative relationship between the DC voltage rated value and the compensation performance is detailed. In addition, the lowest value of the DC voltage in the SVG with a battery energy storage device is also obtained for the reactive and active output current. Based on the above analysis, the design of the DC voltage rated value for SVG is quite straight forward. Both simulation results and the hardware experimental results are finally presented to verify the validity of the analysis results and the proposed design method.