Electric vehicle, power system thereof and battery heating method

Abstract

The invention provides a power system of an electric vehicle and a battery heating method. The system comprises a battery pack, a battery heater, a battery manager, a power distributing box, a motor, a motor controller and an isolated inductor. The battery heater is connected with the battery pack, the battery manager is connected with the battery pack and the battery heater and is used for controlling the battery heater for heating the battery pack according to the temperature of the battery pack and remaining power when the temperature of the battery pack is smaller than a first heating temperature threshold value and the remaining power is larger than a parking power threshold value, and controlling the electric vehicle to drive in limited power when driving heating. The power distributing box is used for distributing the voltage outputted by the battery pack. The motor controller is connected with the motor and the power distributing box and is provided with a first input end, a second input end and a pre-charge capacitor connected between the first input end and the second input end. The isolated inductor is required to match with the pre-charge capacitor. The power system can realize heating, heating efficiency is high, cost is lower, and practicability is high. The invention further provides an electric vehicle.

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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