CAPACITOR-CHARGING DEVICE

PROBLEM TO BE SOLVED: To improve the accuracy of a charging voltage of a capacitor by making sure the operation of finely adjusted charging time even when charging is repeated at high frequency. SOLUTION: This charging device charges a power capacitor 8 rapidly in a rapid charging circuit (1-6) up to a value close to a charging voltage command value and afterward charges the capacitor in a finely adjusted charging circuit (10-15) with a constant current up to the charging voltage command value. In this device, a control circuit 9 obtains and controls a finely adjusted charging time ΔT of the finely adjusted charging circuit from a charging voltage detection value V of the capacitor charged rapidly by the rapid charging circuit, the charging voltage command value V*, capacitance C of the capacitor, and a constant current value I'. A digital control circuit obtains the current capacitance of the capacitor when operating the finely adjusted charging time and adjusts the finely adjusted charging time again according to the change of the capacitance of the capacitor. COPYRIGHT: (C)2009,JPO&INPIT