Energy management method for hybrid electric vehicle

Abstract

The invention relates to an energy management method for a hybrid electric vehicle. The energy management method sequentially comprises the following steps of reading the current environment temperature; setting an SOC offset factor, and obtaining an SOC offset correction value through calculation; setting a calibrated SOC upper limit threshold value and a calibrated SOC lower limit threshold value, and calculating to obtain a corrected SOC upper limit threshold value and a corrected SOC lower limit threshold value; reading current accelerator, brake and vehicle speed information; calculating to obtain a torque correction factor; establishing a mathematical model of the torque correction factor, the SOC and the torque correction value; if the current SOC is smaller than or equal to the corrected SOC lower limit threshold value, making the automobile enter a low SOC state, and making the engine output power; if the current SOC is larger than or equal to the corrected SOC upper limit threshold value, making the automobile enter a high SOC state, and making the TM motor output power; and if the current SOC is larger than the corrected SOC lower limit threshold value and smaller than the corrected SOC upper limit threshold value, making the automobile enter a normal SOC state, and the engine, the TM motor and the ISG motor are in series-parallel connection to output power. According to the method, the electric quantity of the battery can be stabilized in a reasonable working interval, and the power mode switching frequency is reduced.

Description

technical field [0001] The invention relates to energy management of a hybrid electric vehicle, in particular to an energy management method suitable for a dual-motor dual-clutch hybrid electric vehicle. Background technique [0002] The power system of a hybrid electric vehicle (referred to as a hybrid vehicle) includes an engine drive system and a motor drive system. The power required for driving a hybrid vehicle can be provided independently by a single drive system or jointly provided by two drive systems. The battery is an important part of the motor drive system. The battery can be used as the energy source of the motor drive system to output electric energy, and it can also be used to store the electric energy generated when the motor is in charging mode. Therefore, the charging of the battery in the vehicle system State (i.e. SOC) is the key point of hybrid vehicle energy management. [0003] Usually, see figure 1 , in a hybrid vehicle, the engine 1, the first clu...

AI Technical Summary

Problems solved by technology

[0004] The existing technology mainly uses fixed values ​​as the SOC upper and lower thresholds to constrain the SOC. However, due to the strong followability of the fluctuation range of the battery power with temperature changes, it cannot flexibly respond to changes in battery capacity under various ambient temperatures, which is not conducive to the realization of Reasonable and effective hybrid vehicle energy management

When the ambient temperature drops, the battery capacity will decrease accordingly, resulting in a significant increase in the power mode switching frequency of the hybrid vehicle compared with the normal ambient temperature, thereby deteriorating fuel economy and shortening battery life

In addition, if the torque demand of hybrid vehicles fluctuates frequently, it will also cause frequent switching of power modes, which will seriously affect the driving experience and increase the fuel consumption of the vehicle.

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