MMC在船舶中压直流电力系统中的应用

在船舶中压直流(medium voltage direct current,MVDC)电力系统中,为解决功率为36 MW的发电机电压的整流问题,建立适用于船舶MVDC电力系统的模块化多电平换流器(modular multilevel converter,MMC)模型。在空间矢量控制方法的基础上,加入桥臂电压控制。在直流电压为5kV及负载不同的情况下,应用MATLAB/Simulink对该模型进行仿真,验证模型和控制方法的有效性。基于此,研究该模型在不同直流电压(5~30 kV)等级下的性能表现。仿真结果表明:在36MW/5 kV的额定工况下MMC存在效率低的问题;直流电压等级对MMC输出直流电压的纹波影响不大,但对MMC的效率有明显的影响。

Application of MMC in ship MVDC power system

In order to solve the voltage rectification problem of generators with the power of 36 MW in the ship medium voltage direct current (MVDC) power system, a modular multilevel converter (MMC) model is established for ship MVDC power system. On the basis of the space vector control method, the bridge arm voltage control is joined. The model is simulated by MATLAB/Simulink in the condition of 5 kV DC voltage and the different loads so as to validate the effectiveness of the model and the control method. Based on the above, the performance of the model in different DC voltage (between 5 kV and 30 kV) grades is studied. The simulation results show that: the efficiency of MMC is lower under the rated condition of 36 MW/5 kV; the DC voltage grade has slight influence on the DC voltage ripple output by MMC, but has significant influence on the efficiency of MMC.