Parallel-in-Time Simulation Algorithm for Power Electronics: MMC-HVdc System

Abstract

The complexity in simulating power electronics, such as modular multilevel converters (MMCs), requires simulation algorithms to speed up the process. Existing simulation algorithms exploit spatial parallelism to speed up the simulation. With the rise in the complexity of power electronics and the presence of an increased number of states within them, there are limits in the speedup using spatial parallelism. In this article, a temporal parallelism algorithm based on parallel-in-time methods is developed for simulation of power electronics systems. The temporal parallelism algorithm is based on the computation of power electronics states on coarse and fine time steps using different models. The models of power electronics systems used in coarse and fine time steps are average-value and detailed models, respectively. The updates to states on coarse time step are computed serially and are used to initialize the states on the fine time step. The updates on fine time step are computed in parallel. A translation method is proposed in this article to update the states on fine time step from the simulations in the coarse time step, and vice versa. The proposed algorithm is applied to simulate MMCs and is validated with respect to a detailed reference MMC model. The proposed algorithm recorded a speedup of up to $3.47 \times $ with five cores.