基于滑模变结构及内模控制的SVG无功补偿控制策略仿真研究

Study on Simulation of SVG Reactive Power Compensation Control Strategy Based on Sliding Mode Variable Structure and IMC

针对静止无功发生器(SVG)在无功补偿时存在直流侧电容电压不平衡和系统运行不稳定等问题,以dq0坐标系下的数学模型为基础,提出一种滑模变结构和内模控制相结合的SVG双闭环控制策略。电压环采用滑模变结构提高负载突变时直流侧电容电压的快速精准控制,电流环采用内模控制实现信号的准确跟踪。在Matlab/Simulink中搭建了级联二十一电平SVG仿真模型,仿真结果表明,采用所提控制策略的SVG直流侧电容电压控制良好,系统运行稳定,对配电网的无功补偿效果较好,验证了本文控制策略的可行性及有效性。

In view of such problem as unbalance of capacitive voltage at DC side and instability of system operation of static reactive power generator(SVG)in the reactive power compensation,a kind of SVG dual closed loop control strategybased on the combination of sliding mode variable structure and internal model is proposed with the mathematical model in the dqO coordinate system as the basis.Adoption of sliding mode variable structure by the voltage loop improves the fast and precise control of the DC side capacitive in case of sudden change of load.While the adoption of the internal mode control by the current loop achieves accurate tracking of the signal.The cascaded 21-level SVG simulation model is built in Matlab/Simulink.It is shown by the simulation result that the SVG DC-side capacitive voltage by the proposed control strategy is controlled very well and operation of the system is stable and the reactive power compensation effect on the distribution network is better.The feasibility and effectiveness of the control strategy proposed in this paper is also verified.