A Fast MMC Loss Assessment Method and Application for the ThéVenin's Equivalent Electromagnetic Transient Model

Aiming at the existing modular multilevel converter (MMC) loss calculation speed and accuracy is difficult to take into account, this paper proposes a rapid loss assessment method based on the Thévenin's equivalent model of MMC. Firstly, we analyze the loss components of MMC based on the Thévenin's equivalent model, then we establish a pass-state loss model and a switching loss model based on switching frequency, fit the curve of the device datasheet and correct the switching loss model with voltage, and give a method to obtain the average switching frequency of the bridge arm submodule in the process of implementation; finally, we build a Thévenin's equivalent MMC model example in PSCAD to validate the computational efficiency and accuracy of the proposed method. computational efficiency and accuracy of the proposed method. The research results provide a new way to quickly and accurately evaluate the MMC valve loss in the electromagnetic transient simulation environment, which can be used as a reference for heat dissipation design and control optimization.