Research And Application On Charging-Discharging System Of The Storage Battery For Medical Equipment

Storage battery is one kind of energy storage equipment,whose conventional charging principle frequently results in overcharge and undercharge issues,and hence the battery capacity is greatly reduced,which has a severe impact on battery life.In the field of medical equipment,storage battery failure will affect the normal operation of medical equipment,therefore,in this thesis,the charging and discharging scheme of the storage battery is mainly studied.The control strategies of the charging and discharging equipment are first introduced,which consist of linear regulation control mode,uncontrolled rectifier mode and thyristor phase controlled rectifier mode.Then the shortcomings of each strategy are analyzed,mainly including large power consumption,low efficiency,grid feedback failure due to the unaccomplished energy one-way flow,low energy utilization and increasing harmonic pollution.After the electrochemical characteristics,common parameters and related calculation equations for the storage battery are presented,the commonly used modes of the charging and discharging course,such as constant-voltage charging,constant-current charging,fast pulse charging and equalizing charging,are emphatically introduced in this thesis,as well as the charging curve of each charging mode and the scope of application are analyzed.In terms of the demands for the practical applications,the functional and technical requirements of the charging and discharging system are proposed.Moreover,the overall scheme is presented in this thesis,which can be divided into three parts,i.e.,charging module,discharging module,voltage inspection module,and the schematic diagram of each module are designed,which emphatically designed the adjustable power hardware circuit and chip control software supply technology of ARM Cortex-M3 microprocessor.It’s characterized by the PFC technology,PWM rectifier and bi-directional DC-DC converter are proposed to reduce the harmonics of the adjustable power supply.Finally the block diagram of the charging and discharging system is introduced from the perspective of hardware,as well as the operational approach is described by using a maintenance process under one work modes,which are background computer work mode,respectively.The voltage,current parameters and waveform of the charging and discharging system are tested by using a test platform.The empirical results show that charging and discharging system of the storage battery for medical equipment is of good performance.