Research And Application Of Intelligent Charger For Mine

At present,most of the battery chargers used in coal mine batteries electric locomotives are still equipped with transformer and phase-controlled rectifier chargers.This charger has some shortcomings,such as long charging time,low efficiency,large equipment volume,and the need for personnel to switch the charging process according to the charging time or the gas evolution status of the batteries.In practical use,it often results in overcharging and undercharging of batteries.It has a certain impact on the life of batteries.Therefore,it is of great practical significance to study a new charger which can not only improve the charging efficiency and reduce the charging time,but also benefit the service life of lead-acid batteries.Based on the research and development of high-frequency intelligent charger project in Shanxi huaxin Electric Co.,Ltd.,the design parameters of the charger are firstly studied and analyzed,and the overall design scheme of the mine charger based on soft-switching technology is given.In this paper,the soft switching process of the phase-shifted full-bridge topology in the scheme is analyzed,and the parameters of the main circuit devices are calculated and selected.Secondly,according to the advantages and disadvantages of the traditional battery charging method,a batch three-stage charging strategy is proposed.The charging strategy can fit the Mass charging curve well.In the initial stage of lead-acid battery charging,high current charging is adopted,which can charge the battery to 50%-60% in a relatively short period of time.When the first stage charging process is completed for a period of time,the charging current in the second stage is slightly smaller than that in the first stage,and the charging current in the second stage is also slightly smaller than that in the second stage.The third stage is constant voltage floating charging.After the completion of the three stages,the charger can automatically stop charging and the charging process ends.In the process of switching off charge for a period of time,the polarization phenomenon during constant current charging can be reduced,and the acceptable charging current of the battery can be increased,so that the charging time can be shortened and the purpose of fast charging can be achieved.Thirdly,according to the control requirements,the control circuit of the charger is designed in hardware and software.The control circuit takes the ARM chip STM32F103VCT6 as the control core.After sampling the analog information of voltage and charging current of lead-acid batteries,it is sent to ARM for analysis and calculation to control the working state of PWM circuit and realize intelligent charging.The charger program adopts the modular design method,including the main program,charging control,anti-reverse connection,human-computer interaction,Modbus communication and other subroutines.Finally,in order to test the performance of the charger,the prototype charges the matching batteries of 12 tons of battery locomotive.The test data show that the charging time is reduced by about 15% compared with the traditional charger,and the charging efficiency is increased from 70% to 90% of the traditional charger.Moreover,the charging process does not need personnel to watch and switch automatically,thus realizing the high efficiency and fast charging of the battery.Charge.