三相电压型PWM整流器的小信号建模及控制器设计

摘要

建立三相电压型PWM整流器功率电路在两相旋转坐标下的数学模型,由于采用开关函数描述的变换器的数学模型为非线性模型,控制器的设计比较困难。本文利用开关周期平均法建立三相电压型PWM整流器的平均模型,扰动分离后分别得到稳态模型和小信号模型,基于小信号模型设计了电压外环和电流内环的PI控制器。最后,通过PSCAD建立了模型仿真电路,仿真验证了小信号建模和控制器设计的正确性。%This paper sets up The mathematical model in dq axis of three-phase PWM rectifier's main circuit. Because the mathematical model of traditional three-phases PWM rectifier which is set up by switching function is a non-linear model, it's relatively difficult to design the controller. In the way of the average switching period, three-phase PWM rectifier is set up, after which the steady-state model and small-signal model are obtained respectively by separating the disturbance. Therefore, the PI controller of the voltage outer loop and the current inner loop is designed in small-signal model. Lastly, the the validity of small-signal model and the controller is verified throng the PSCAD simulation.