Life-cycle of switching power converters is mostly defined with the reliability of in-build electrolytic capacitors.
On-line life-cycle monitoring of these capacitors enables timely predictions of their failure, which can reduce maintenance expenses and power converter down time.
The following thesis describes the design and construction of an equivalent series resistance meter for life-cycle monitoring of electrolytic capacitors.
For current measuring, a special Rogowski coil made on a printed circuit board, was designed.
Test of multiple Rogowski coil variants shown good linearity, with coupling inductance varying only +/- 1.5 % from the mean value.
Based on preliminary test results, an equivalent series resistance measurement prototype was designed and tested on a reference capacitor with known (added) series resistance.
The test results show that the measurement uncertainty was +/- 5 % which is sufficient for the purpose of life-cycle monitoring.
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