| 摘要 |
PROBLEM TO BE SOLVED: To infer or measure the degree of deterioration of power supply due to a capacitor, and to determine whether there is abnormality in the capacitor and predict its service lifetime, in a simple and quick manner. SOLUTION: In this abnormality determining method, a coefficient of deterioration which is the ratio of the degree of deterioration to a square root of deterioration time is stored in a reference data storing means 3 by using a ratio of deterioration of electrostatic capacity or internal resistance of the capacitor to an initial value as the degree of deterioration and using the time required up to predetermined degree of deterioration as the deterioration time. Voltage and temperature of the capacitor are measured and the coefficient of deterioration is obtained from the reference data storing means 3, to obtain the inferred degree of deterioration of the capacitor during its operation by an inferred degree of deterioration computing means 4. The capacitor is charged or discharged by constant currents, and voltages immediately before and after charging and discharging and during charging and discharging are measured to obtain the actual degree of deterioration of electrostatic capacity or internal resistance of the capacitor by an actual degree of deterioration computing means 5 and obtain difference between the inferred degree of deterioration and the actual degree of deterioration, in order to determine that abnormality has occurred in the capacitor, if the difference exceeds a reference value by an abnormality determining means 7. COPYRIGHT: (C)2009,JPO&INPIT |
