Abstract
Current of a three-phase multilevel modular converter (MMC) is controlled. The control is a division-summation (D-.SIGMA.) method yet uses integration to replace the two steps of division and summation. Common D-.SIGMA. characteristic equations are used for all areas. Inductance changes are considered in the characteristic equations. Current source is used to control converter. Therefore, the current of the converter can be traced to sinusoidal reference current even when the inductance changes become big. The modulation method and the capacitor-voltage balancing method are submodule unified pulse width modulation (SUPWM) and sorted voltage-balancing method, respectively. The current control directly obtains a law of the current change on each conducting module of an arm. It does not need complex sector judgments and table look-ups. Thus, the amount of computation and memory for a processor can be relatively reduced.