Redesign of passive balancing battery management system to active balancing with integrated charger converter

The use of high power high efficiency battery systems is increasing as the fields of personal electric vehicles and other fields requiring DC energy storage elements are growing. A typical battery pack consists of series connected cells that need to be monitored and controlled to achieve optimal performance. In this article the author previous work regarding passive balancing circuit is described and the performance of a passive balancing circuit is given and drawbacks are discussed. Another method of active balancing is proposed. The new method combines an active balancing method and a charger topology to develop an integrated charger-balancer solution. The basic calculations of the converter are given. To evaluate the operation of the system a three supercapacitor cell charger circuit was developed and tested with three different capacitor initial voltages. The obtained results and system performance is discussed.