基于扰动抑制的三相逆变器模型预测控制策略

Disturbance-rejection-based Model Predictive Control Strategy for Three-phase Inverter

为了提高三相逆变器的鲁棒性,设计了一种基于扰动抑制的模型预测控制(MPC)策略。新型MPC控制器采用了扰动观测器(DOB)以简化预测模型,同时具有无约束和有约束两种工作模式。无约束模式MPC控制下三相逆变器稳态电压可得到精准调节,而在约束模式下通过优化调制可使系统快速进入到无约束模式,这确保了在系统所有运行条件下的较优控制性能和鲁棒性。同时,基于Lyapunov函数证明了所设计基于DOB的MPC控制器的稳定性。搭建了三相逆变器实验平台并开展了实验。实验结果表明,所提出的MPC方案在不同负载条件和不确定参数下具有更快的动态响应,以及更好的输出电压稳态误差和总谐波失真。

In order to improve the robustness of the three-phase inverters,a model predictive control(MPC)strategy based on disturbance rejection was designed.The new MPC controller used a disturbance observer(DOB)to simplify the predictive model,and it could work on the unconstrained mode or constrained mode.The steady-state voltages of the three-phase inverter could be accurately regulated by MPC control under unconstrained mode.In the constrained mode,the system could enter the unconstrained mode quickly by optimizing the modulation,and it ensured good control performances and robustness under all operating conditions of the system.At the same time,the stability of the DOB-based MPC controller was proved based on the Lyapunov function.An experimental platform for threephase inverters was built and experiments were carried out.The experimental results show that the proposed MPC scheme has faster dynamic response under different load conditions and uncertain parameters,and better steady-state error and total harmonic distortion of the output voltage.