Electric car and electric car power system and battery heating method

Abstract

The invention provides an electric car power system which comprises a battery pack, a battery heater, a battery manager, a distribution box, a motor, a motor controller and an isolation inductor. The battery heater is connected with the battery pack. The battery manager is respectively connected with the battery pack and the battery heater and used for alternately controlling the battery heater to heat the battery pack according to accelerator depth change velocity of an electric car when the temperature of the battery pack is lower than a first heating temperature threshold and the residual electric quantity is higher than a shutdown electric quantity threshold. The distribution box is used for distributing voltage output by the battery pack. The motor controller is connected with the motor and the distribution box and provided with a first input end, a second input end and a pre-charging capacitor. The pre-charging capacitor is connected between the first input end and the second input end and matched with the isolation inductor. The power system is capable of realizing heating and greatly lowering use limitation in a low-temperature environment, high in heating efficiency, low in cost, and highly practical. The invention further provides an electric car battery heating method and an electric car.

Description

technical field [0001] The invention relates to the technical field of electric vehicles, in particular to a battery heating method of an electric vehicle, a power system of the electric vehicle using the method, and an electric vehicle with the power system. Background technique [0002] With the continuous development of science and technology, new energy vehicles, especially pure electric vehicles, are slowly entering every family as a means of transportation. Users have higher and higher requirements for vehicle performance, especially for comfort. Vehicles are required to adapt to different driving needs. However, most pure electric vehicles at this stage obviously cannot meet this requirement, especially in the cold winter, when the temperature is too low, the performance of the power battery will decline, both in terms of discharge capacity and battery capacity. Can't even use it. Specifically, the general operating temperature of power batteries, especially lithium...

AI Technical Summary

Problems solved by technology

When the ambient temperature is too low, the internal battery of the electric vehicle will have the following problems: (1) At low temperature, lithium ions are easy to deposit on the negative electrode, lose electrical activity, and may even cause safety problems

Therefore, vehicles and battery packs are often used at low temperatures, which will greatly damage the life of the battery pack, and may cause safety hazards in severe cases

(2) At low temperature, when lithium-ion batteries are charged, lithium ions are easily deposited on the negative electrode and become dead lithium, and the capacity that the battery can exert is significantly reduced, and in the process of continuous use, these deposited lithium grows larger and may even Cause internal short circuit, causing safety hazard

(3) At low temperature, the discharge capacity of the battery is limited, which is not conducive to driving

Most of these schemes use external large heating equipment and power supply to heat the battery, so these schemes are only suitable for instances where the battery is fixed

In addition, using an external power source to heat the battery of a pure electric vehicle has limitations and is not suitable for vehicles that are not fixed

Therefore, these heating technologies have not been widely used in pure electric vehicles

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