Electric car and electric car power system and battery heating method

Abstract

A power system of an electric vehicle, an electric vehicle comprising the same and a method for heating a battery group of the electric vehicle are provided. The power system comprises: a battery group (101); a battery heater (102) connected with the battery group; a battery management device (103), configured to control the battery heater to heat the battery group when a temperature of the battery group is lower than a first heating threshold and a residual electric quantity of the battery group is larger than a running electric quantity threshold, to obtain a current throttle depth change rate of an electric vehicle in real time, and to control the battery heater to stop heating the battery group when the current throttle depth change rate reaches a preset throttle depth change rate threshold; an electric distribution box (104); a motor (105); a motor controller (106); and an isolation inductor (L2).

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

For pure electric vehicles, adding a huge heating system increases the weight of the vehicle, thereby increasing the energy consumption of the vehicle

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

Images