Optimal Structure Selection and Integrated Optimization of Parameters of a Dual-Motor-Driven System in Battery Electric Bus

In this paper, in order to promote the efficiency and control the production cost of a dual-motor-driven system (DMDS), the topology is selected and the parameters of DMDS are optimized based on a bi-level integrated optimization method. In this method, five topologies are considered, including three kinds of speed coupling topologies, one kind of torque coupling topology, and one kind of topology with variable coupling. The dynamic model and efficiency model of each topology are established. The proposed integration optimization method includes a dynamic programming (DP) algorithm and a particle swarm optimization (PSO) algorithm. DP takes energy loss as the objective function to optimize the control strategy of the operation process. PSO takes the linear superposition value of energy loss and motor power level as the objective function to optimize design parameters. The optimization results of five topologies are compared to get the optimal topology. The results of integrated optimization experiments show that the speed coupling - double brake topology is the optimal topology. Compared with the prototype, the energy loss is reduced by 10.37% and the system production cost has been well controlled. The comparison experiments further validate the superiority of utilizing PSO as the upper layer algorithm compared to other comparative algorithms.