Design of a Power Hardware-in-the-loop System for Modular Multilevel Converter

The modular multilevel converter (MMC) in the use of high voltage direct current (HVDC) transmission is a hot research and has attracted extensive research efforts in the last few years. With the development of power hardware in the loop (PHIL), it has been considered as a promising trend to investigate and verify the performance of MMC-HVDC based on PHIL system. Even though the stability and some applications of the PHIL system is discussed in many literatures, the practical MMC-PHIL system is lack of detailed description. This paper introduces the design of a back-to-back (BTB) MMC-PHIL platform and compares two kinds of interface algorithms. Then, it is demonstrated that the controlled current source can't be directly connected in series with the inductor and two solutions are proposed. Finally, it is validated that the performance of MMC can be captured effectively using this system with suitable algorithm.