EFFECT OF INTEGRATION ERROR ON PARTIAL DISCHARGE MEASUREMENTS ON CAST RESIN TRANSFORMERS
Abstract
Partial discharge measurements are routinely used for quality assurance of medium voltage resin encapsulated transformers. Instrumentation and procedures are covered by international Standards and measurements are in general reliable and reproducible. However calibration is performed at the winding terminals, whereas PD pulses are mostly originated well inside the coils: as a result, the shape of the signal being recorded can be very different, with marked oscillations. A comparison between different types of wide band PD detectors has been performed under conditions in which integration errors are experienced. It has been proved that when a PD pulse origin is located inside the MV coil of a cast resin transformer, the propagation towards the terminals can cause a marked distortion: the pulse harmonic content therefore cannot be flat in the frequency measurement range of the PD detectors and consequently the hypothesis upon which the pseudointegration principle is based is no longer valid.
Event details
- Event
- Exploring New Frontiers of Instrumentation and Methods for Electrical and Electronic Measurements
- Technical Committee
- TC4
- Place
- Florence, ITALY
- Time
- 22 September 2008 - 24 September 2008
- Website
- http://www.imeko2008.org/