矩阵变换器交流励磁系统的非线性最优控制

摘要

传统的矩阵变换器交流励磁控制策略是基于PI调节器的功率解耦控制,但在电网电压出现大扰动时,系统调节时间较长,影响发电机的安全稳定运行.本文基于非线性微分几何理论,证明了双馈电机(DFIG)动态模型满足完全线性化条件,建立了线性化的动态模型,在此模型基础上采用最优控制求出相应控制率,再结合矩阵变换器的间接空间矢量调制策略,实现了矩阵变换器交流励磁系统非线性最优控制.仿真结果表明,在电网电压出现大扰动情况下,非线性最优控制方法较PI控制具有较短的调节时间.%The PI regulator-based AC-excitation control for a matrix converter(MC) may cause a long regulation time when a big power grid voltage disturbance occurs, which affects the safety and stability of the generator operation. According to the nonlinear differential geometry theory, we prove that the dynamic model of double-fed induction generator(DFIG) satisfies linearization conditions, thus a linear dynamic model is justified. Based on this model, we develop the optimal control strategy by combining the indirect space vector modulation strategy of MC to achieve the MC-excited nonlinear optimal control. Simulation results show that this nonlinear optimal control method in the case of big grid voltage disturbance has a shorter regulation time, in the comparison with the PI control.