Filter capacitor degradation identification using computed power

摘要

Methods and apparatus are presented for detecting (70) filter capacitor degradation in a power converter (10) in which filter circuit (20) branch (22) currents and voltages are concurrently measured, nominal and measured power values are automatically computed according to the measured voltages, the operating frequency and nominal capacitance values, and power change values are calculated based on the difference between the measured and calculated nominal power values, and the change values are evaluated to selectively identify filter capacitor degradation conditions in the filter circuit.