Battery management system and method for fast charging of electric bicycle battery pack

Abstract

The invention provides a battery management system for rapidly charging a battery pack of an electric bicycle. The battery management system is used for managing and controlling the battery pack and a charging machine for charging the battery pack. The battery management system comprises a sampling and charging control module and a discharging control module. The invention further provides a battery pack charging and discharging management method. The battery management system can manage battery charging and discharging more accurately and efficiently under the large current charging condition, and determination of the battery capacity can be more accurate. Besides, the battery management system designs a more reasonable charging process for high rate charging, the charging effect is better, and the charged electric quantity is more.

Description

technical field [0001] The invention relates to the field of electrical control, in particular to a management system and a corresponding method for BMS management of a battery pack of an electric vehicle. Background technique [0002] As the demand for mobile devices and energy storage power sources increases, the use of lithium batteries as energy sources is becoming more and more common. Due to the limitation of the electrolyte composition of the lithium battery, in order to maintain its service life and charging safety, the charging rate of the general lithium battery is controlled at about 0.3 ~ 1C. It takes about 1 to 3 hours to charge a fully discharged lithium battery at such a charging rate. The commonly used battery management system (BMS) often takes the charging rate of not more than 1C as the management target in the charging management link. [0003] The new lithium titanate battery breaks through the charging rate limit of traditional lithium batteries, which...

AI Technical Summary

Problems solved by technology

The disadvantage of this approach is that since the charge and discharge detection share a current-sense resistor, when the charge current is much greater than the discharge current, it will not be possible to select a suitable resistance value

[0009] However, when this solution is applied to high-current and high-rate charging, there are often some inapplicable situations:

[0010] 1. Since the current detection method of this type of scheme is basically detected by the current detection resistor connected in series on the discharge circuit, when the charge and discharge current gap is too large, if the current detection resistor is set too large, the corresponding charge current detection voltage may be reduced. Exceeding the single-chip ADC range, or the discharge current cannot be accurately detected due to the setting of the current-sensing resistor is too small, and one of the main functions of this type of battery management system solution is to perform SOC calculation, and the detection error of the discharge current will greatly affect the SOC calculation

[0011] 2. Since this type of solution is the same as the solution described in the prior art 1, it uses a general-purpose switching power supply or a voltage-limiting and current-limiting power supply for charging, so the voltage and current during the charging process cannot be controlled according to the battery condition, and it is impossible to target different Optimized charging control based on battery characteristics

This method is more accurate when the battery condition is good, but when the battery condition declines, the actual capacity cannot reach the preset value after the battery is set to 100%, and the capacity calculation result will be larger than the actual value.

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