Electric vehicle non-destructive charging system and charging method based on temperature curve

Abstract

The invention discloses an electric vehicle nondestructive charging system based on a temperature curve and a charging method of the electric vehicle nondestructive charging system based on the temperature curve. The electric vehicle nondestructive charging system comprises a power conversion unit, a power factor correction unit, a driving unit, a protection and logic control unit, a master control unit, a man-machine interaction interface, a communication interface and a storage device. The power conversion unit is mainly used for completing AC / DC and DC / DC conversion. The power factor correction unit is used for completing input side power factor correction and achieving a unit power factor. The driving unit is mainly used for achieving generation of driving pulses. The protection and logic control unit is used for controlling signal output and signal blocking of the driving unit to achieve fault output control and indicating. The master control unit is used for achieving key algorithms and the like. The communication interface is used for communication of an electric vehicle power battery management system. The man-machine interaction interface is used for charging information displaying and user charging setting. According to the electric vehicle nondestructive charging system and the charging method, the service life of a battery and rapid charging are guaranteed, and meanwhile nondestructive rapid charging in the true sense is achieved.

Description

technical field [0001] The invention relates to a charging system and a charging method thereof, in particular to a temperature curve-based non-destructive charging system for an electric vehicle and a charging method thereof. Background technique [0002] Choosing the right charging method can improve the charging efficiency and prolong the service life. There are many charging methods for lithium-ion batteries. The commonly used charging methods include constant current charging method, constant voltage charging method, constant current / constant voltage charging method, variable current charging method (smart charging method), pulse charging method, etc., as follows : [0003] First, the constant current charging method refers to charging with a constant current throughout the charging process. The acceptable charging current of lithium-ion batteries decreases exponentially with the charging time, while the charging current remains unchanged. If the charging current is l...

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Problems solved by technology

[0006] Fourth, the variable current charging method, the acceptable charging current of the lithium-ion battery decreases exponentially with the charging time, if the charging current curve is above the acceptable charging current curve of the battery, it will cause the gasification reaction of the battery electrolyte and affect the battery life

But in reality, as the temperature of the battery increases during charging, the allowable curve of the battery charging current changes dynamically. Therefore, it is possible that the charging current is within the allowable curve, but the battery temperature at this time is no longer suitable for charging. condition

Smart charging is a relatively advanced charging method at present. Its principle is to dynamically track the acceptable charging current of the battery during the entire charging process, and to apply du / dt technology, that is, the charging power source automatically determines the charging parameters according to the charging state of the battery, so that the charging current can be maintained from the beginning to the end. Keep it near the acceptable maximum charging curve, so that the battery can be fully charged quickly with little gas evolution. The disadvantage is that after the battery is used for a period of time, the acceptable ideal charging curve will change, and its charging parameters also need to be adjusted.

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