Modular Multilevel Matrix Converter (M3C) is a very promising direct AC/AC converter for Fractional Frequency Transmission System (FFTS), which is also known as Low-frequency AC Transmission System (LFAC). The massively used IGBT devices and complex control of M3C makes the simulation research of FFTS very slow. An averaged-value model (AVM) of M3C is proposed in this paper. The basics of M3C is firstly introduced. Then the AVM of M3C is derived based on M3C operation characteristics. Nine controllable voltage sources are used for arm voltage generation and a controllable current source is used to get capacitor voltage of power modules (PMs). Finally, the AVM of M3C is verified by comparison with a detailed model of M3C.

Averaged-value Model (AVM),modular multilevel matrix converter