Design And Implementation Of Batteries Charging In High Power UPS

UPS (Uninterruptible Power System) is a kind of power electronic equipment which could uninterruptedly provide quality alternating current, while accumulator is an important energy storage device. In order to ensure the normal energy storage and continuous operation of the accumulator set in the UPS system, a new-type charging device based on the dual-switching-tube Buck converter and a battery wireless monitoring system based on MSP430 are studied and designed.In the dual-conversion online UPS system, the accumulator features a large capacity and a large amount, thus relatively large charging current is required. Under the heavy load condition, the traditional DC/DC converter will be in a serious heating state after working for a long time. In the practical charging process, the excessive temperature often results in the charging failure. Besides, since accumulator is an important back-up source, the working situation and the environment temperature of every accumulator in the accumulator cabinet calls for real-time monitoring. Generally speaking, the traditional battery monitoring system adopts the wired connection. Due to a large number of accumulators, the problem of circuit aging and ignition might easily be caused, which is hard to be maintained. Thus, it is imperative to transform the accumulator monitoring system.In order to solve the heating problem of the charging devices, the author studies and makes improvement from two aspects. On the one hand, the charging circuit topological structure of the charging devices is improved; on the other hand, the PCB layout structure and increases the heat radiating area of the radiator is changed. Below are the main research steps:1. A new-type dual-switching-tube paralleled Buck converter structure (hereinafter abbreviated as "dual-switching-tube Buck circuit") is designed. In the dual-switching-tube Buck circuit, the original power switching tube is replaced by two switching tubes of the same model. Besides, the same PWM controller is used to simultaneously drive two switching tubes. The design not only increases the Buck’s rated operational current, but also disperses the quantity of heat in the switching tubes, which could reduce heating in principle and increase the reliability of the charging devices.2. The volume of the radiator is increased so as to speed up the heat dissipation of the charging devices during the design of the hardware circuit for the charging devices, and cooling fans are installed for the charging devices during the practical charging process. In this way, the heating problem of the charging devices is solved from multiple perspectives.3. "MSP430FR5739 + CC1101" combination method is adopted to design the hardware of wireless monitoring system and to realize wireless networking and information transmission. Three parts are designed for the software, including upper computer terminal, data processing center and information collection terminal. The three parts work jointly to achieve real-time test, transmission and display of the operation parameters and temperature of the accumulator.In order to verify the validity of the new-type dual-switching-tube Buck circuit and the accumulator wireless system, this paper conducts practical operation test on the new-type charging devices and the accumulator monitoring system. The test proves the dual-switch Buck circuit boasts favorable heat radiation and stable output voltage; the accumulator wireless monitoring system can obtain accurate data, significantly reduces the line connection among accumulators and makes the later-phase maintenance easier.