A search method integrating configuration synthesis, screening, and optimization for a dual-planetary gear set four-mode configuration in battery electric vehicles

Planetary gear sets (PGS) are regarded for their compact structure, high efficiency, and other advantages. They have been successfully implemented in several battery electric vehicles, delivering outstanding performance. This paper examines a dual-motor, dual-PGS four-mode configuration and introduces an innovative matrix-based search method. This approach integrates configuration synthesis, screening, and optimization to identify the most appropriate structure and parameters for the vehicle intended to utilize this configuration. In this process, connection units and structure matrices are defined to complete configuration synthesis. By leveraging the characteristics of PGS and the structure matrices, the speed, torque, and efficiency are calculated for each working mode. Configuration screening is conducted based on the performance requirements of the motor, PGS, and vehicle to preemptively eliminate unqualified configurations. To reduce the computational burden of configuration optimization, a novel energy management strategy is designed that approximates the performance of dynamic programming. This search method is applied to an example vehicle. The results demonstrate that this method can effectively search for the optimal configuration and corresponding parameters under specific requirements.