Battery impedance measurement method and system based on analog alternating current small signal

Abstract

The invention relates to battery detection, in particular to a battery impedance measurement method and system based on an analog alternating current small signal. The battery impedance measurement method based on the analog alternating current small signal comprises the following steps: setting a frequency f of a pulse constant current source; applying an alternating current small signal of frequency f at both ends of the battery to be tested to perform pulsed discharge on the battery; performing RC filtering on an instantaneous feedback signal generated by the battery, then sending to an operational amplifier for amplification processing, and then performing analog-to-digital conversion by an ADC; and sending the analog-to-digital conversion signal to the MCU for analysis and calculatingthe impedance. The technical scheme provided by the invention can effectively overcome the defects of the prior art that the measurement speed is slow and the measurement accuracy is low.

Description

technical field [0001] The invention relates to battery detection, in particular to a battery impedance measurement method and system based on an analog AC small signal. Background technique [0002] A storage battery is a device that directly converts chemical energy into electrical energy. It is a rechargeable battery designed to be recharged through a reversible chemical reaction. Battery usually refers to lead-acid battery, which is a kind of battery and belongs to secondary battery. Its working principle: when charging, use external electric energy to regenerate the internal active material, store electric energy as chemical energy, and convert chemical energy into electric energy output when discharging. For example, car batteries, motorcycle batteries, battery car batteries and electric bicycle batteries that are commonly seen in the streets, as well as some UPS backup power batteries, mobile base station backup power batteries, etc. are commonly used in daily life. ...

AI Technical Summary

Problems solved by technology

[0005] Resistance test method, the resistance test method uses the DC discharge method, the frequency of the electrical signal is 0, and it is impossible to measure the parts of the battery that show capacitance

In the actual test, the repeatability of the results of the resistance test method is not high, especially when testing the battery with large interference such as UPS, the test of the same battery cannot obtain stable and repeatable test results, and the final test results lose value. Unable to determine battery health

[0006] The conductivity test method basically uses a lower test frequency, a few Hz to 30 Hz, which is lower than the ideal test frequency, and cannot completely obtain information about Rp and W, and is susceptible to interference from external power frequency signals

Although it can also reflect the health status of the battery to a certain extent, its effect is not as good as the method of detecting impedance

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