Design of a charge equalizer based on multi-winding transformer

A charge equalizer based on a multi-winding transformer is presented in this paper. Constant frequency and 50 % duty cycle are selected to achieve a simple control and soft-switching of power switches of proposed charge equalizer. Both the amount of transformer windings and the conduction losses of the rectifier can be halved by using a voltage doubler type rectifier. On the other hand, the proposed equalizer has an excellent feature that charge current is all limited by the transformer leakage inductance. Therefore, choke inductor is not required in the equalizer because charge equalization is achieved by regulating the turn ratio of transformer. Finally, the proposed charge equalizer is verified by simulation.