模块化多电平换流器实时仿真的快速实现方法

The use of FPGA can achieve nanosecond simulation for modular multilevel converter, however, there are still some problems, such as the difficulty of the solver development and lack of versatility. Consequently, we proposed an equivalent model rapid realization method, which adopts the backward Euler method to discretize inductance of bridge arms and capacitance of submodules, as well as Thevenin’s theorem to achieve equivalent bridge circuit, by which a fast simulation model is established. While ensuring accuracy of the simulation, the method significantly lowers the degree of difficulty of the model solver design and improves simulation rate, which realizes the 100 ns-step simulation on the FPGA board. Through the comparison among the results of primary simulation and hybrid simulation, waves of the two simulations are highly overlapped, and the error is kept within 0.5%. Besides, FPGA in loop simulation can completely simulate the operational status of bridge MMC switch, which verifies the effectiveness of the method.