三电平STATCOM新型直接功率控制策略研究

Research on Novel Direct Power Control Strategy of Three-Level STATCOM

摘要: 三电平静止同步补偿器(STATCOM)在配电网无功补偿领域发挥重要的作用。在三电平STATCOM控制策略中，传统的滞环式直接功率控制策略具有开关频率不固定的缺陷，这为网侧滤波器的设计带来了困难。本文提出一种新型三电平STATCOM定频直接功率控制策略。该策略从三电平STATCOM数学模型出发，以三电平SVPWM策略作为调制策略，采用以PI控制器为核心的前馈解耦控制系统对瞬时功率进行控制，以直流总电压的平方项为外环控制目标，在实现系统开关频率固定的同时得到良好的无功补偿效果。最后通过仿真验证了本文提出方法的正确性和合理性。

Abstract: The three-level STATCOM (static synchronous compensator) plays an important role in the reactive power compensation of the distribution system. In all of the control strategies of three-level STATCOM, traditional hysteresis direct power control (DPC) strategy has the characteristics of uncertain switching frequency which made the grid connected filter hard to design. In this paper, it presents a novel constant switching frequency direct power control strategy of three-level STATCOM. The novel strategy based on the mathematical model of three-level STATCOM, and three-level SVPWM strategy is used as modulation strategy. Using PI controller and instantaneous power feedforward and decoupling control, the novel strategy realizes constant switching frequency as while as good reactive compensation effect. Finally, the simulation verified the correctness and rationality of the proposed method.