Charge equalization apparatus and method

Abstract

The present invention relates, in general, to a battery voltage equalization apparatus and method, and, more particularly, to a charge equalization apparatus and method, which decrease the withstand voltages of semiconductor switching elements while maintaining charge equalization performance, thus making it easy to implement the secondary windings of transformers while reducing the costs of the charge equalization apparatus. The charge equalization apparatus includes N first transformers (T1 to Tn) connected in series with N series-connected batteries (B1 to Bn) and adapted to decrease voltages of overcharged batteries among the N batteries. A charge storage device (Cdump) stores energy supplied from the first transformers. A second transformer (TS) redistributes energy stored in the charge storage device to the N series-connected batteries. A voltage detection and drive signal generation unit (20) detects voltages of N respective series-connected batteries, and generates a first drive signal and a second drive signal.