CAPACITOR CHARGER

PROBLEM TO BE SOLVED: To control a high accuracy-charging voltage even if wiring inductance is interposed between a capacitor that is an object to be charged and its voltage detection circuit. SOLUTION: The capacitor charger rapidly charges the capacitor 6 in OFF control after switches 2, 3 are turned ON up to a voltage that is a charging voltage command value V* higher by several percent, and then discharges the capacitor in a switch 10 ON control until the charging voltage detection value V of the capacitor reaches the command value. A discharge current ib of the capacitor is differentiated with a differentiator 21 to find a voltage drop portion by the wiring inductance interposed in series to the capacitor, and the voltage drop portion is added and compensated to the charging voltage detection value with an adder 22. Oscillating current in a half period is generated between a reactor and the capacitor, if the capacitor is charged in the oscillating current, a voltage drop portion caused by the wiring inductance is obtained by differentiating the oscillating current, the charging voltage detection value of the capacitor is compensated with this voltage drop portion. COPYRIGHT: (C)2010,JPO&INPIT