To provide a voltage balance apparatus and a voltage balance method for series-connected capacitors which have a balancing effect wherein approximately equivalent voltages of respective capacitors can be kept according to the order of the capacitors, and the possibility of a short-circuit can be avoided.
This voltage balance apparatus has variable switches connected in parallel with respective capacitors of a capacitor set which is a series unit and capacitor adjustment means both whose ends are connected to the variable switches and which are connected in parallel with the respective capacitors comprising the capacitor set, i.e., the series unit, by opening/closing the variable switches. In order to make the voltage balance apparatus operate, the variable switches are successively opened/ closed and, every time when each capacitor comprising the capacitor set is adjusted, the capacitor adjustment means is connected in parallel with the capacitor to be adjusted only and the electric charge of the capacitor to be adjusted is partially absorbed or supplied and then the capacitor adjustment means is connected in parallel with the next capacitor. Such a process is repeated. Reciprocally transferred carrier electric charge values of the capacitor adjustment means are utilized to keep respective voltages of the capacitors comprising the battery set, i.e., the series unit, always approximately constant.
WU WEI CHEN
CHEN MING LUNG
