Device-Level Parallel-in-Time Simulation of MMC-Based Energy System for Electric Vehicles

The device-level electromagnetic transient (EMT) simulation with the nonlinear behaviour model (NBM) of insulated-gate bipolar transistors (IGBTs) and diodes can provide an accurate insight into the power converters from the perspective of thermal performance and energy efficiency. However, device-level simulation is rarely implemented in electric vehicles (EVs) due to its extreme computation complexity natively introduced by the device models. To solve this problem, an interpolation strategy is designed based on the parallel-in-time algorithm for the device-level simulation of the modular multilevel converter (MMC) connected with the induction machine in EV applications. The MMC is mathematically separated as multiple submodules with the same attributes, which can be processed in a parallel manner in the graphics processing unit (GPU). By implementing the device-level simulation in the different time-step in GPU, the interpolation strategy provides the precise initial values for the nonlinear solution process iteratively. The accuracy of the proposed simulation scheme is validated by commercial simulation tools at the device level. In addition, the system-level simulation of EVs is carried out at different driving cycles, and the results demonstrate a significant reduction in simulation time.