Study on Capacity Decline of Valve-Controlled Lead-Acid Batteries for Substation
Lead-acid battery(VRLA)has the advantages of good adaptability to high and low temperatures,large discharge power and high safety factor.It is used more and more in the DC system of substation.However,there is a problem of uncertainty in the capacity decay rate of the battery,which cannot predict the failure of the lead-acid battery,and will lead to very serious consequences once it fails.Therefore,it is of great significance to study the capacity attenuation of valve-controlled lead-acid batteries.According to the use of lead-acid batteries in substation,three lead-acid batteries with the same rated capacity from different manufacturers were selected to design and carry out the accelerated charging and discharging cycle test of valve-controlled lead-acid batteries,and the measured capacity results were analyzed to find the law that could reflect the attenuation of battery capacity.The results showed that the capacity attenuation of the three batteries was different.The battery with the lowest capacity retention was only 75％of the first measured capacity after cyclic charging and discharging,and the battery with the best retention rate was 8.52％of the first measured capacity.It was found that the open circuit voltage,the slope of the linear part of the discharge curve,the peak voltage,the bottom voltage and the attenuation of the battery had a certain correlation.These indexes could be used to predict the capacity attenuation of lead-acid batteries,and provide a basis for real-time prediction of battery life by electrochemical AC impedance.
valve-controlled lead-acid batterycapacity attenuationdischarge curvecoup de fouet phenomenonvoltage
万方数据
维普
