Coordinated Control Algorithm of a Dual Motor for an Electric Variable Transmission Hybrid System

Abstract

With the successful application of the electric variable transmission hybrid system, the dynamic quality of electric variable transmission (EVT) has received significant attention. The dual motor integrated by the EVT plays a vital role in riding comfort during mode shifting. Therefore, it is of great significance to study the coordinated control algorithm of the dual motor for improving driving comfort. However, current research on single motor torque compensation indicates that the poor accuracy of the compensation torque affects the coordinated control performance. In this paper, a dual motor coordinated control algorithm for the EVT is presented to solve the problem of shock in the mode transition, which is from the electric starting mode to the engine starting mode. First, the lever analogy is used to analyze the cause of the shock during this mode shifting. Then, the coordinated control algorithm of the dual motor is designed, in which the first motor MG1 adopts compounded feedforward and feedback control and the second motor MG2 adopts the torque compensation based on the engine torque estimation algorithm. Finally, the EVT system model and its dynamic coordination control algorithm model are built in the Simulink environment. The simulation results demonstrate that the presented control algorithm markedly reduces the shock of the mode shifting process. When applied in an actual driving cycle, the coordinated control algorithm proposed in this paper performs well, thus improving the dynamic quality of the EVT system.

Keywords

• Electric variable transmission
• hybrid system
• dual motor
• coordinated control algorithm