This paper presents a condition-monitoring method of dc-link capacitors used in a high-power three-phase PWM inverter with an evaluation circuit intended for ageing tests. Although its power rating is 1/25 of the inverter, the evaluation circuit provides the equivalent ripple current waveform and dc-bias voltage to the high-power inverter. The monitoring method independently extracts the capacitance and ESR of the dc-link capacitor, where the fast Fourier transform is introduced to the ripple current waveform and the dc-link voltage of the evaluation circuit. Experimental results verify that the monitoring method obtains both the ESR and capacitance changes of a capacitor under test.
All Science Journal Classification (ASJC) codes
- Automotive Engineering
- Energy Engineering and Power Technology
- Mechanical Engineering
- Industrial and Manufacturing Engineering
- Electrical and Electronic Engineering