Modeling and Dynamic Response Analysis of a Compound Power-Split Hybrid Electric Vehicle During the Engine Starting Process

Abstract

This study is aimed at revealing the dynamic response characteristics of a power-split hybrid electric vehicle (HEV) during the mode transition process with the engine starting. In this paper, for a hybrid powertrain system whose engine is directly connected to a compound power-split transmission, the equivalent lever method is first used to analyze the mode transition process with the engine starting. Then, based on the theoretical formulations and lookup tables, a dynamic model of the compound power-split HEV is established in detail, taking into consideration the engine ripple torque, battery-motor characteristics, dynamic meshing force between gears, and shaft spring-damping characteristics. The powertrain dynamic model is verified by a bench test. Moreover, taking the vehicle jerk and engine starting time as the evaluation indexes of the dynamic response characteristics, the influencing factors of the dynamic response characteristics in the engine starting process are analyzed comprehensively from the aspects of the engine, battery-motor, and engine starting condition. Finally, the engine starting process is synthetically optimized based on the obtained impact law of different influencing factors. The simulation results show that the synthesis optimization method can effectively reduce vehicle jerks and the engine starting time and improve driving comfort during the engine starting process. INDEX TERMS Dynamic response characteristics, engine starting, powertrain modeling, hybrid electric vehicle (HEV), power-split transmission.

Adaptive Mode Selection Strategy for Series-Parallel Hybrid Electric Vehicles Based on Variable Power Reserve

“…However, the limitation imposed by BMS on the battery request power through the proportional-integral (PI) controller will result in a reduction in the driving power [14]. Su et al [15] simulated the impact of battery power limitation on the dynamic response characteristics of the engine starting process. The simulation results show that the torque output fluctuation of the drive system increases significantly because the compensation ability of the motor torque is limited by the battery discharge power.…”

Mode Transition Control of a Power-Split Hybrid Electric Vehicle Based on Improved Extended State Observer

“…Wang et al [14] established the transient torque fluctuation model of the engine cranking process, and applied the active damping control to reduce the jerk problem caused by engine interference. Su et al [15], [16] built a transient model of the entire engine working state, and verified the effectiveness of active feedback compensation based on drive shaft torque estimation for improving the ride comfort during mode switching process. However, even though the above studies have established a more accurate engine torque fluctuation model, the model is based on the combination of cylinder pressure measurement in the engine bench test and the theoretical modeling, which inevitably ignores the interference factors such as modeling errors and actuator noise.…”