A new control method for improving the performance of Modular multilevel converter

Abstract

One of the main challenges in the control of modular multilevel converters (MMC) is reducing circulating currents and keeping sub-modules capacitors voltage regulated. This paper introduces a method which controls the voltage and current simultaneously by controlling the reference values using the equations of the MMC and genetic optimization algorithm. The proposed method controls the converter by adding the second harmonic component of the reference waveform, then calculating the working condition to reach the minimum circulating current and voltage ripples. The method is verified using MATLAB Simulink.