基于VSG的并网变流器LADRC策略研究

Research on LADRC strategy of grid-connected converter based on VSG

针对复杂工作环境下并网变流器容易受到外界干扰,传统控制策略控制效果不理想的问题,提出了一种基于虚拟同步发电机(Virtual Synchronous Generator, VSG)的并网变流器线性自抗扰控制(Linear Active Disturbance Rejection Controller, LADRC)策略。建立了三相并网变流器的数学模型,分析了VSG控制的基本原理;根据并网变流器详细建模设计了双闭环LADRC控制器;通过MATLAB/Simulink仿真,对基于VSG的PI控制和基于VSG的LADRC控制在改变有功功率和改变网侧电压的工况下变流器运行情况进行了对比分析。仿真结果表明,基于VSG的LADRC略鲁棒性更好、抗干扰性更强。

In order to solve the problem that the grid-connected converter is easy to be interfered by the external environment and the control effect of traditional control strategy is not ideal, a linear active disturbance rejection control(LADRC) strategy based on virtual synchronous generator(VSG) is proposed in this paper. Firstly, the mathematical model of three-phase grid-connected converter is established, and the basic principle of VSG control is analyzed. Then, the double closed-loop LADRC controller is designed according to the detailed modeling of grid-connected converter. Finally, through MATLAB/Simulink simulation, the operation of PI control based on VSG and LADRC control based on VSG under the condition of changing active power and grid side voltage is compared and analyzed. The simulation results show that the VSG-based LADRC control strategy has better robustness and stronger anti-interference ability.