Rechargeable Power Management System using Active Balancing for Biomedical Devices

摘要

Rechargeable power management system (RPMS) is significantly necessary to monitor the performance of powerstorage in biomedical devices. Failure of power storage device due to the battery pack, in a medical device, canentail dire consequences such as respiratory devices defibrillators and severe trembling. During charging anddischarging the cell might become overstressed or underutilized, of which former may degrade the cell's lifespan.We applied an active balancing technique to distribute charges uniformly into the cell and thus increasing itsefficiency and lifespan. In this technique, cells in the stack are monitored at regular intervals for their state of charge(SOC) and the average charge among them is calculated. The cell having the lowest voltage is charged by the seriescombination of the rest of the cells, by using switching device through isolation transformer which acts as the chargetransferring device. In this research, the amount of charge transferred to the low voltage cell was controlled bycontrolling the frequency of the switching ranging from 100-500kHz. This RPMS includes modules for dataacquisition and data logger by which the history of battery pack can be checked for any possible future breakdownand prediction of available run time for the battery pack. RPMS also features cell temperature monitoring to keep itwithin its safe limits. In this presentation, we will discuss the circuit simulation results using Multisim™ andhardware implementation in progress.