BATTERY FUEL GAUGING SYSTEM

摘要

The present disclosure discloses a battery fuel gauging system, which includes a battery voltage collecting module and a microprocessor module. An input terminal of the battery voltage collecting module is configured to collect a terminal voltage of the battery. The microprocessor module is configured to receive the terminal voltage and estimate the remaining charge in the battery. The microprocessor module estimates an open-circuit voltage of the battery according to the terminal voltage of the battery and a built-in battery model, and further calculates the battery's remaining charge based on SOC-OCV relations of a typical lithium-ion battery. The present disclosure is capable of maintaining the precision of the battery fuel gauging system and can set the battery fuel gauging system inside or outside of the battery.

主权项

1. A battery fuel gauging system, comprising:
a battery comprising a terminal voltage, an open-circuit voltage and a built-in battery model; a battery voltage collecting module comprising an input terminal and an output terminal, the input terminal being connected to a the battery and configured to collect the terminal voltage of the battery, wherein the battery voltage collecting module works intermittently; a microprocessor module, being connected to the output terminal of the battery voltage collecting module and configured to receive the terminal voltage of the battery and estimate remaining charge in the battery; wherein, the microprocessor module estimates the open-circuit voltage of the battery according to the terminal voltage of the battery in conjunction with the built-in battery model, and further calculates the battery's remaining charge based on SOC-OCV (state of charge-open-circuit voltage) relations of a typical lithium-ion battery, the built-in battery model is described by the following equation set:Vo(t)=Vocv(t)-I1(t)*R1-I2(t)*R2(1)I2(t)*R2=VC1(t)(2)∫0tI2-I1C1t=VC1(t)(3)SOC(t)=SOC(0)-∫0tI1(t)t(4) wherein, Vo(t) represents the terminal voltage of the battery, Vocv(t) represents the open-circuit voltage of the battery, R1 represents an equivalent ohmic resistance of the battery, R2 represents an equivalent polarization differential resistance, I1(t) represents charge current or discharge current of the battery, and I2(t) represents the current flowing through the equivalent polarization differential resistance R2, SOC(t) is the present remaining charge in the battery, and SOC(0) is initial charge amount of the battery, C1 represents a responding speed of the polarization voltage differential to current excitation and is decided by the intrinsic characteristics of the battery, the present open-circuit voltage of the battery is calculated according to the built-in battery model in conjunction with the presently collected terminal voltage of the battery, and the present open-circuit voltage of the battery is further utilized to calculate the remaining charge in the battery according to the SOC-OCV relations of the typical lithium-ion battery.