Nonlinear optimal control of matrix-converter-excited system
矩阵变换器交流励磁系统的非线性最优控制

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.