Control and Design for Mission Profile Emulator of Individual Submodule in CPS-PWM-Based Modular Multilevel Converter

Modular multilevel converter (MMC) may contain a large number of submodules (SMs). The overall reliability of MMC strongly relies on the comprehensive testing and validation of SMs. However, building a relatively complete MMC system/arm for the testing of SMs is time-consuming and costly. In this article, mission profile emulator (MPE) for individual SM of MMC is presented along with the design and control methods. By the proposed schemes, the complete electrical characteristics including the load current and capacitor voltage of SM under test can behave closely to the actual SM in an MMC system. Moreover, the current ripple, which is an important loading factor for SM, can be accurately designed and restrained. Both the simulation and experimental results are provided to validate the effectiveness of the proposed methods.