Experimental and Characteristic Analysis during the Engine Start-Up Process for a Compound Power-Split Hybrid Electric Vehicle

Yanzhao Su,Jin Huang,Datong Qin,Ling Su,Minghui Hu

doi:10.3390/app11041846

Abstract

Experimental research is essential in the development of a hybrid electric vehicle. In this study, a bench test was conducted for a compound power-split hybrid electric vehicle (PSHEV) to analyze the real dynamic characteristics of its components and the factors of system shock and vibration during the engine start-up process. Firstly, the mode switching process with an engine start-up was divided into four stages by the lever method. The basic control strategy of mode switching with engine start-up was formulated and tested on a bench test platform. Secondly, based on the bench test data, the output characteristics of the battery motor, engine, and driveshaft were analyzed in detail. The main variable parameters of the engine control unit were investigated in the engine start-up process. Ultimately, the results showed that the engine’s pulsating torque was the main reason for system jerk and vibration during the engine start-up process, and the excessive intake manifold pressure before the engine’s ignition was one of the main reasons for the large output torque ripple. When initiating the electric engine starting process, the jerk and vibration presented a wide fluctuation. The maximum value of the equivalent jerk was 92.12 m/s3, and the maximum value of the absolute value of the vibration acceleration was 4.077 m/s2.

Highlights

Hybrid electric vehicles (HEVs), with the potential to reduce the effects of the current energy crisis and environmental pollution, have become the main trend in automotive technology and industrial development [1,2]
The dynamic characteristics of the motor and engine are inconsistent during the engine start-up process
The results showed that the engine cylinder pressure and the initial rotation angle of the engine during start-up are the main reasons for vibration and noise

Summary

Introduction

Hybrid electric vehicles (HEVs), with the potential to reduce the effects of the current energy crisis and environmental pollution, have become the main trend in automotive technology and industrial development [1,2]. Hwang [21] and Chen [22] studied the dynamic characteristics of the transmission system in the start-up process They found that the initial angle of the engine crankshaft has a great impact on the angular acceleration of the seat track. Current research mainly focuses on the impact of the engine cylinder pressure/pulsation torque, engine starting initial angle, engine/motor/clutch torque mutation, and other factors affecting vehicle jerk. There is a need for further research into the dynamic response characteristics of the components of the hybrid powertrain and the influencing factors of shock and vibration in the mode switching process during engine start-up.

Structure of Compound Power-Split Hybrid Powertrain System

Test Bench System for Compound Power-Split Hybrid Electric Vehicle

Characteristic Analysis of Bench Test Results during Engine Starting Process

Findings

Conclusions