A low-temperature heating system and method for electric vehicle batteries based on hydraulic energy storage

Abstract

A low-temperature heating system and method for an electric vehicle battery based on hydraulic energy storage, including a generator, a hydraulic pump, a hydraulic motor, a transmission belt, a clutch, a DC / DC converter, a heating film, a battery pack, a one-way valve I, and a one-way valve Ⅱ. Energy storage control valve, heating control valve, overflow valve, accumulator group, pressure relay, controller and temperature sensor. The system utilizes a hydraulic energy storage device and regenerative braking energy to achieve rapid heating of the power battery when the electric vehicle starts at low temperature without an external heating source. This method is simple and reliable, and is easy to integrate with other heating methods, which can make up for the problem that battery self-heating is difficult to implement at a lower state of charge, thereby effectively solving the problem of large battery performance degradation and large battery performance when the electric steam is started under low temperature and severe cold conditions. The problem of poor work performance.

Description

technical field [0001] The invention belongs to the technical field of low-temperature thermal management of electric vehicle power batteries, and in particular relates to a low-temperature heating system and method for electric vehicle batteries based on hydraulic energy storage. Background technique [0002] When the power battery is used at low temperature, its capacity performance declines sharply, which leads to a serious reduction in the mileage of the electric vehicle when driving in severe cold areas. In addition, the low temperature causes a large increase in battery impedance, which causes the power battery's charge and discharge power capacity to decrease, and the charging time It is greatly extended, and it is easy to produce negative electrode lithium precipitation during charging, which brings safety hazards and hinders the application of electric vehicles in low temperature environments. Therefore, low-temperature heating is an important technical means to imp...

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Problems solved by technology

However, there are some technical bottlenecks in the existing low-temperature heating technology, in which the external heating method has high stability, but most of the external heating methods need to rely on the existing external heat source, so heating can only be implemented in specific occasions, which limits its use. Flexible use in electric vehicles, and the internal heating method uses the battery's own current to generate heat inside the battery. This method consumes the battery's own power while heating, and it is difficult to implement when the battery's state of charge is low.

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