Selection Methods of Main Circuit Parameters for Modular Multilevel Matrix Converters

Abstract

The modular multilevel matrix converter (M3C) with the strengths of varying frequency is increasingly used in AC transmission. The main circuit parameter selection methods of the M3C have a great influence on the economy and operating performance of M3C. This paper studies the parameter selection of main components in M3C, such as the converter transformer, the sub-module (SM) capacitor and the arm reactor. In conclusion, the no-load voltage rating on valve side of transformer is advised to be near 1/2 times of arm rated voltage, the equivalent discharging time is recommended to be 60ms, and the arm reactance needs to be selected to limit characteristic frequency circulating current of M3C.