王艳青,薛花,王育飞.电网电压不平衡时MMC基于非线性微分平滑控制方法*[J].电测与仪表,2020,57(12):118-124. Wang Yanqing,Xue Hua,Wang Yufei.Nonlinear differential flatness control method for modular multilevel converter with unbalanced grid voltage[J].Electrical Measurement & Instrumentation,2020,57(12):118-124.
电网电压不平衡时MMC基于非线性微分平滑控制方法*
Nonlinear differential flatness control method for modular multilevel converter with unbalanced grid voltage
In the case of the unbalanced grid voltage, modular multilevel converter(MMC) system has an asymmetrical problem with the grid current, and the nonlinear differential flatness control method is proposed. According to the topology of MMC system, the transient mathematical model is established, and the differential flatness of positive and negative order systems is analyzed. The power outer loop adopts the differential flatness control method based on power feedforward to provide reference value for the current inner loop. The current inner loop adopts the differential flatness control method based on Lyapunov stability theory, which can quickly suppress the negative sequence current and realize the three-phase symmetry of the system"s output current. The simulation comparison between the control method and the traditional vector control method on Matlab/Simulink platform verifies that the nonlinear differential flatness control method has better rapidity and stability.
