Coordinated control strategy to reduce torque fluctuation for parallel hybrid electric vehicles

Hybrid Electric Vehicles (HEVs) require the power to drive the vehicle via a combination of internal combustion engine (ICE) and electric motors. To improve the drivability, the smooth torque change during the driving mode switching is essential. This task can be achieved by using the coordinated control strategy. This paper presents a coordinated control strategy which can effectively suppress the torque surge during the driving mode switching processes. The coordinated control strategy is to reduce the torque fluctuation during the driving mode switching processes based on considering the different dynamic response characteristic of the engine and the electric motor (EM). The objective is to minimize torque fluctuation which maintaining or improving the driving performance characteristics of the vehicle. Results from the computer simulation demonstrate the effectiveness of this approach in reducing the torque surge without sacrificing vehicle performance.