基于反馈线性化控制的级联H桥SVG的控制

摘要

级联H桥静止无功发生器(SVG)在两相同步旋转dq坐标系下的数学模型是多变量、非线性、强耦合的.通过非线性状态反馈变换使SVG实现状态反馈线性化,SVG降阶为线性系统,从而实现有功和无功分量的解耦.首先判断该系统数学模型是否符合状态空间精确线性化的充要条件,若满足条件则确定输出函数,对SVG系统电流环进行状态空间精确线性化,并对系统进行稳定性分析.为了验证控制策略的稳态和动态性能,搭建MATLAB仿真模型和10 kV实验样机.仿真和实验样机的实验结果表明:采用所提算法,SVG无功补偿精度较高、稳态特性好、动态响应较快.%Because the mathematical model of cascaded H-bridge SVG(Static Var Generator) in the synchronous rotating dq coordinates system is multivariable,nonlinear and strongly-coupled,the nonlinear state feedback transformation is applied to linearize the state feedback of SVG for making it a linear system to decouple its active and reactive components.The mathematic model of SVG system is first checked if the necessary and sufficient conditions for its precise linearization in the state space are satisfied.If they are satisfied,the output function is then determined to precisely linearize the current-loop of SVG in the state space and analyze the system stability.A MATLAB simulation model and a 10 kV experimental proto-type are built to verify the steady-state and dynamic performances of control strategy.Results show that,with the proposed control algorithm,the reactive power compensation of SVG has higher precision,better steady-state performance and quicker dynamic response.