Static Var Generator Based on Accurate Linearization Combined with Sliding Mode Controller

The active and reactive current are hard to be decoupled completely with strong robustness when the traditional proportional integral (PI) algorithm is adopted to feedforward decoupling control for static var generator (SVG). This paper proposed a compound control strategy for SVG based on precise linearization and sliding mode control (SMC). To be specific, first, the theory of differential geometry is used to prove that the mathematical model of SVG satisfies the necessary and sufficient condition of precise linearization. Second, the precise linearized high-order system of SVG was transformed into two completely independent decoupled first-order linear systems, and realize complete decoupling of active current and reactive current. Finally, SMC was used to design both the voltage outer loop and the current inner loop. Simulations ware carried out for the SVG mathematical model under three conditions which were inductive load, capacitive load and sudden change load. The results of those simulation showed that the controller designed by the proposed control strategy has the advantages of quick reactive power compensation, strong robustness and anti-interference performance.