Electric vehicle and power battery active temperature equalization system thereof

Abstract

The invention discloses an electric vehicle and a power battery active temperature equalization system thereof. The system comprises a power battery, a temperature detector, a heat exchange cold plate, a water pump and a controller, wherein the temperature detector is used to detect the temperature of each battery cell in the power battery; the heat exchange cold plate is arranged corresponding tothe power battery to heat or cool the power battery through heat exchange liquid; the water pump is connected with the heat exchange cold plate, when the water pump rotates forwards, the heat exchange liquid flows from a first end of the heat exchange cold plate to a second end, and when the water pump rotates reversely, the heat exchange liquid flows from the second end of the heat exchange coldplate to the first end; and the controller is separately connected with the temperature detector and the water pump, and the controller controls the water pump to switch between positive rotation andreverse rotation to change the flow direction of the heat exchange liquid when determining that the temperature difference between any two battery cells is greater than or equal to a preset temperature threshold based on the temperature of each battery cell, and thus the temperature equalization of the power battery can be achieved.

Description

technical field [0001] The invention relates to the technical field of automobiles, in particular to an active temperature equalization system for electric automobiles and power batteries thereof. Background technique [0002] Temperature has a great influence on the working state of the power battery. For example, under low temperature conditions, the discharge capacity of the power battery drops rapidly, especially for lithium-ion batteries; At the same time, the power battery is a relatively closed environment. If the heat is not discharged in time, it will lead to thermal runaway, shortened life and damage of the power battery. Therefore, it is necessary to heat or cool the power battery. [0003] However, no matter whether it is heating or cooling the power battery, due to the dense arrangement of single cells in the power battery, the heat accumulated in the middle area must be more, while the heat in the edge area must be less, which will lead to each unit of the pow...

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Problems solved by technology

[0003] However, no matter whether it is heating or cooling the power battery, due to the dense arrangement of single cells in the power battery, the heat accumulated in the middle area must be more, while the heat in the edge area must be less, which will lead to each unit of the power battery. The temperature between the cells is unbalanced, causing the performance of each single battery to be unbalanced, which affects the consistency of the performance of the power battery and the accuracy of the estimation of the state of charge of the power battery, and then affects the control of the electric vehicle.

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