Power battery self-heating control method and system and automobile

Abstract

The invention discloses a power battery self-heating control method and system and an automobile. The method comprises the steps: when the real-time temperature of the power battery is lower than a preset low-temperature threshold value, switching to a self-heating mode of the power battery; after the current open-circuit voltage and the alternating-current internal resistance of the power battery are obtained according to the current SOC, determining the switching frequency and the duty ratio needed by the heating circuit for heating the power battery; controlling the opening and closing states of all switching elements in the H-bridge structure module according to the determined switching frequency and duty ratio, so that a self-heating loop between the H-bridge structure module and the power battery is conducted; carrying out self-heating operation on the power battery through the conducted self-heating loop until the real-time temperature of the power battery is higher than a preset target temperature threshold value, disconnecting the self-heating loop and quitting the self-heating mode of the power battery. According to the invention, the power battery is heated through the periodic current which is generated by the self-heating loop and can be continuously kept at a relatively high level, so that the heating efficiency is improved.

Description

technical field [0001] The invention relates to the technical field of power batteries, in particular to a self-heating control method and system of a power battery and an automobile. Background technique [0002] With the development of science and technology, new energy vehicles are gradually being widely used. As the core power source of new energy vehicles, power batteries are used in different environments, but in different environments, the performance of power batteries is easily affected by the ambient temperature. . For example, when the power battery is in a low temperature environment such as minus 20° C., the performance of the power battery will decrease to a greater extent than that at normal temperature. [0003] At present, an external heating system is generally used to preheat the battery to increase and stabilize the ambient temperature, so that the power battery can be discharged at a suitable temperature to drive the motor to work. However, this method...

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Problems solved by technology

[0004] Embodiments of the present invention provide a power battery self-heating control method, system and vehicle to solve the problems of low energy conversion efficiency and uneven temperature distribution of the external heating system

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