Design And Implementation On UPS Battery Charge Equalization System

UPS is a power supply device, which was made up with energy storing device and inverter. UPS will convert the stored energy as a standard AC power for load when the mains input failure. In the part of UPS, battery occupies an important position. The damage to the battery not only caused direct economic losses, but also is a potential threat to the security of data. Therefore, improving the reliability of power supply has become an urgent research topic.This paper firstly introduces the necessity of battery equalization, analyzes the current situation of rearch. Based on the working principle, the battery equalization technologies were compared. The system use discharge equalization method.Secondly, according to the relationship between the performance and internal resistance of the battery, internal resistance was selected as the criterion of detection. As the battery with a DC voltage, internal resistance detection method realized AC injection.After that, hardware design of the equalization system, separately carried on the detailed analysis of internal resistance detection, discharge tube drive circuit and other peripheral.Finally, the software design of equalization system design was introduced, including detection and equalization control. To avoid the loss of balance caused by frequent switching,a new equalization method was proposed, which is better than average value and the maximum value method. Software design was completed according to the flow chart.