Performance Analysis of multi carrier PWM (m-PWM) based Single Phase Modular Multilevel Converter using dSPACE

Abstract

Modular Multi-Level Converter (MMC) is an advanced DC-AC electronic converter. Its modular design, scalable supply voltage, and efficiency are quite popular in medium and high power applications like motor drives and HVDC, etc. The main challenges of MMC are to control the submodule of the capacitor voltage (SM), the circulating current as well as the voltage and current ripples. The handling of a large number of gate pulses is often complicated at medium and high voltage levels. It is also necessary to incorporate an effective control scheme to resolve the difficulties as mentioned earlier. This project addresses PWM control strategies for the Universal Control Modulation Scheme (UCMS) with Phase disposition (PD), Phase Opposition Disposition (POD) and Alternating Phase Opposition Disposition (APOD) in single-phase MMC. The proposed control scheme is constructed in MATLAB Simulink to evaluate the amplitude of the load voltage and its total harmonic distortion for the different amplitude modulation indices. The experimental results are confirmed with the dSPACE microlab box 1202 in the real-time GUI tool. The proposed PD-PWM control system outperforms compared to two different PWM schemes of POD and APOD control methods.

Keywords- Modular Multilevel Converter (MMC), Submodule (SM), Multi carrier PWM method, Total Harmonic Distortion (THD).