Abstract: Methods and power conversion systems in which a capacitor degradation detection system includes an adjustable gain amplifier circuit is calibrated by automatic adjustment of at least one amplifier gain to accommodate current and voltage levels of a particular filter circuit in a first mode. Capacitance values of filter capacitors are calculated according to amplified current signals and compared with an acceptable tolerance range to selectively identify a filter capacitor fault or to store calculated capacitance values as base values in an electronic memory in the first mode. During operation in a second mode with the rectifier and inverter on, the adjusted amplifier gain is used to amplify current sensor signals and/or voltage signals, and capacitance values of the filter capacitors are used to selectively identify capacitor degradation.

Abstract: Methods and power conversion systems in which a capacitor degradation detection system includes an adjustable gain amplifier circuit is calibrated by automatic adjustment of at least one amplifier gain to accommodate current and voltage levels of a particular filter circuit in a first mode. Capacitance values of filter capacitors are calculated according to amplified current signals and compared with an acceptable tolerance range to selectively identify a filter capacitor fault or to store calculated capacitance values as base values in an electronic memory in the first mode. During operation in a second mode with the rectifier and inverter on, the adjusted amplifier gain is used to amplify current sensor signals and/or voltage signals, and capacitance values of the filter capacitors are used to selectively identify capacitor degradation.

Abstract: Methods and apparatus are presented for detecting filter capacitor degradation in a power converter in which filter circuit branch 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.

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

Abstract: Methods and apparatus are presented for detecting filter capacitor degradation in a power converter in which filter circuit branch 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.

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