Charge-discharge control method for hybrid electric vehicle

Abstract

The invention discloses a charge-discharge control method for a hybrid electric vehicle, which comprises the following steps of: (1) judging whether a vehicle is in a driven mode, if not, entering into other control modes, and if yes, executing the next step; (2) calculating a required torque and a threshold value thereof and calculating a present SOC (State Of Charge) of a battery and a threshold value thereof; (3) judging a present control region of the vehicle; and (4) according to the present control region of the vehicle, performing charge-discharge selection and charge-discharge power control: in the region which is lower in required torque and higher in SOC, being free from charging and assisting, and discharging the battery until meeting the power requirement; in the region which is higher in required torque and higher in SOC, assisting by a motor; and in the region which is lower in SOC, charging to a certain extent, wherein the higher the SOC is, the lower the charging power is. An economic region of an engine is taken into account by the threshold value of the torque, and the efficiency, the service life and the possibility of regenerative braking recycling of the battery are taken into account by the threshold value of the SOC, thereby being capable of promoting the entire efficiency of a hybrid power system.

Description

technical field [0001] The invention belongs to the field of hybrid electric vehicle control, and relates to a charging and discharging control method of a hybrid electric vehicle. Background technique [0002] Hybrid electric vehicles introduce electric motors and larger capacity batteries on the basis of conventional vehicles. When the driver needs a large torque under acceleration or climbing conditions, the battery discharges, the motor assists, and the engine and the motor jointly output torque; when the driver is coasting, decelerating or braking, the The motor goes into generating mode to charge the battery. [0003] In order to realize the motor assist function, the state of charge (SOC) of the battery during driving should not be too low; in order to recover the kinetic energy of the vehicle under coasting, deceleration or braking conditions, the SOC of the battery should not be too high. In the driving process, in order to improve the efficiency of the entire hyb...

AI Technical Summary

Problems solved by technology

[0004] In the current research on the charge and discharge of hybrid electric vehicles, either the comprehensive influence of battery SOC, vehicle speed, demand power and power consumption on the timing of charge and discharge has not been considered in detail, or the size of charge and discharge power has not been considered.

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