System and method for starting engine of HEV (Hybrid Electric Vehicle)

Abstract

The invention discloses a system and a method for starting an engine of an HEV (Hybrid Electric Vehicle). The system comprises a high-voltage battery, the engine, an ISG (Integrated Starter and Generator), a BMS (Battery Management System), an EMS (Engine Management System), a motor controller and an HCU (Hybrid Control Unit), wherein the engine is in rigid connection with the ISG, the energy of the ISG is obtained from the high-voltage battery, the HCU is used for controlling the ISG through the motor controller, battery information is obtained through the BMS, engine information is obtained through the EMS, the HCU is used for determining the starting target rotating speed, the oil injection starting and / or ignition rotating speed and whether to request to reduce the battery discharging capacity limit in a short time by the BMS or not through the battery information and the engine information, the motor controller is instructed for dragging the engine and the ISG to the target rotating speed and maintaining the target rotating speed, and the HCU is used for determining whether the starting is finished or not through a torque which is fed back by the motor controller and an engine state which is fed back by the EMS. According to the system for starting the engine of the HEV, disclosed by the invention, the system does not comprise a traditional starting engine with 12V / 24V low voltage, and the ISG is also utilized for starting the engine under a low-temperature environment.

Description

technical field [0001] The invention relates to the technical field of hybrid electric vehicles, in particular to an engine starting system and method for a hybrid electric vehicle. Background technique [0002] A hybrid electric vehicle (Hybrid Electric Vehicle, HEV) refers to a vehicle whose drive system is composed of two or more single drive systems that can operate simultaneously. supply. Due to the different components, layout methods and control strategies, a variety of classification forms have been formed. Because of its energy saving, environmental protection and new energy features, hybrid electric vehicles are supported by more and more policies. The automotive industry is very concerned about hybrid electric vehicles. Hybrid electric vehicles have become a focus of current automobile research and development. [0003] Hybrid electric vehicles have developed rapidly in recent years. In current real life, most hybrid electric vehicles use traditional internal co...

AI Technical Summary

Problems solved by technology

However, the simultaneous use of two motors in a hybrid vehicle not only increases the cost, but also makes the front-end wheel train of the engine more complicated, increases the weight of the power system, and increases energy consumption

At the same time, the effect of starting the engine with a high-voltage motor and that of a low-voltage starter is significantly different, and the subjective experience is significantly different, which is not conducive to the consistency of vehicle performance.

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