Device and method for managing energy of lithium batteries of electric vehicles

Abstract

The invention discloses a device for managing energy of lithium-ion power batteries of electric vehicles and provides a system for managing energy of lithium-ion power batteries of electric vehicles. The system is installed on the vehicle, can monitor the lithium-ion power batteries in real time and can properly control charge and discharge according to the charge and discharge requirements of the lithium-ion power batteries. In the invention, each integrated lithium-ion power battery is controlled by a special control chip, the trickle precharge, quick constant-current charge, constant-voltage charge and supplementary pulse charge occluded stage methods are adopted in the charge process, and equalization discharge control is adopted in the discharge process, which is beneficial to stability of the output voltage and ensures good running smoothness of the electric vehicles. The special control chips have unique address codes and a microprocessor of the system can read and write the information of the special chips. Equalization of charge and discharge processes of each group of lithium-ion power batteries is achieved according to the acquired battery voltage, charge and discharge current and voltage variation of energy transmission control modules of the temperature information control system.

Description

technical field [0001] The invention belongs to the field of energy management of electric vehicles, and in particular relates to a management and control method for the charging and discharging process of a lithium power battery pack used in electric vehicles. Background technique [0002] With the soaring price of international crude oil, the research of various new energy sources has become the focus of public attention. There has been an upsurge in the development of various electric vehicles in China. Lithium power battery has high specific energy density and specific power, which greatly reduces the weight of the on-board battery pack, has no memory effect, can be recharged many times, and has a long service life. It has become the first choice for power electric energy. Batteries are still the bottleneck in the commercialization of electric vehicles. In order to use the battery safely and efficiently, it is very important to develop a battery energy management syste...

AI Technical Summary

Problems solved by technology

[0003] As a new type of power technology, lithium power batteries must be connected in series in order to meet the requirements of the operating voltage. However, due to the obvious nonlinearity, inconsistency and time-varying nature of lithium batteries, certain management is required during application.

In addition, lithium batteries have high requirements for charging and discharging. When overcharging, overdischarging, excessive discharge current or short circuit occur, the temperature of lithium batteries will rise, which will seriously damage the performance of the battery pack and shorten the battery life.

When lithium batteries are used in power equipment in series, due to the inconsistency of the internal characteristics of each single-cell lithium battery, it will lead to inconsistent charging and discharging of each single-cell lithium battery

When the performance of a single cell deteriorates, the behavior of the entire battery pack will be limited by this battery, reducing the overall performance of the battery pack

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