Embedded Model Control for Dynamic Mission Profile Emulation of Submodule in Modular Multilevel Converter

Modular Multilevel Converters (MMCs) are widely utilized in high-power applications, thereby advanced tests and validations of components of MMCs before field operations are becoming crucial. To achieve the tests and validations in a low-cost and efficient way, the concept of Mission Profile Emulation (MPE) for submodule of MMC system has been proposed. However, most of the existing MPE methods are valid for the mission profile in steady states but cannot well emulate the dynamic mission profile in transient processes. Thus, when it comes to short-term overload test where both the amplitudes and duration time of the dynamic mission profiles in transient processes need to be recreated accurately, the existing methods could fail to achieve this goal. In this paper, the dynamic MPE is enhanced by embedding a virtual MMC system in the control strategy. The virtual MMC reshapes the dynamic responses of the emulated mission profile to resemble the responses of an actual MMC, which improves the emulation accuracy, especially in transient processes. Finally, Simulation and experimental validations are given to verify the effectiveness of the proposed control strategy.