Power battery pre-heating method

Abstract

The invention belongs to the technical field of power battery pre-heating, in particular to a power battery pre-heating method. The power battery pre-heating method comprises the following steps: controlling the stator current component in the rotor magnetic field direction in an automobile AC drive motor to change at a certain frequency so that the stator current vector and the rotor magnetic field direction are always the same or opposite; and exciting the DC side of the power battery to generate a high-frequency current, and charging and discharging the power battery at a high frequency. The invention combines the motor rotor magnetic field orientation technology and the stator current vector control method, so that the electric energy exchanged between the automobile AC drive motor andthe power battery is used as the reactive power, and then converted into the heat energy required for heating the power battery, thereby not causing additional energy loss except the loss of the transmission line, the motor coil and the inverter; no additional heating device or material is needed, and the pre-heating of the power battery is realized by using the drive system of the electric vehicle itself, and the method is simple to implement and the cost is low.

Description

technical field [0001] The invention belongs to the technical field of power battery preheating, in particular to a power battery preheating method. Background technique [0002] At present, with the rapid development of new energy vehicles, electric vehicles are more and more widely used; however, the power and energy of the power battery of electric vehicles will be greatly reduced at low temperatures, especially below -20°C, which will affect the electric vehicles. normal use of the car. For this reason, it is necessary to preheat the power battery of the electric vehicle in a low temperature environment. [0003] At present, there are mainly internal heating and external heating methods for power battery preheating. Among them, the internal heating is to add an additional inverter to conduct AC heating on the power battery. Although this method has high heating efficiency, the volume and weight of the inverter are relatively large, and its layout and installation incre...

AI Technical Summary

Problems solved by technology

Among them, the internal heating is to add an additional inverter to conduct AC heating on the power battery. Although this method has high heating efficiency, the volume and weight of the inverter are relatively large, and its layout and installation increase the cost of electric vehicles. extra burden

External heating is to use external materials to transfer heat to the power battery through heat conduction or heat convection. This method is more convenient than internal heating, but the heating efficiency is low, and the heat is lost during the transfer process.

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