Non-Contact High Voltage Measurement in the Online Partial Discharge Monitoring System
[ 1 ] Instytut Elektroenergetyki, Wydział Inżynierii Środowiska i Energetyki, Politechnika Poznańska | [ P ] employee
2021
scientific article
english
- partial discharge (PD)
- power transformer monitoring
- capacitive probe
- high voltage measurement
- non-contact measurement
EN The article presents an innovative system for non-contact high voltage (HV) measurement, which extends the measurement capabilities of a portable partial discharges (PD) monitoring system intended for diagnostics of power transformers. The proposed method and the developed measuring system are based on the use of a capacitive probe, thanks to which the high voltage measurement is safe (galvanic separation from the objects at ahigh potential). It is also flexible because the voltage ratio of this system can be configured in a wide range by changing the probe’s position. The proposed solution makes the portable PD monitoring system fully autonomous and independent of the substation systems and devices. The article presents both the concept of the non-contact HV measurement system and its practical implementation. The procedure for determining the voltage ratio and measurement uncertainty, which is at an acceptable level of 1–5% in laboratory conditions, was discussed in detail. In addition, the article discusses the digital filtering and wavelet de-noising methods implemented in the software of the monitoring system, which makes it possible to measure the voltage in the presence of strong electromagnetic disturbances occurring at the substation. Finally, the results of field tests carried out on a 250 MVA power transformer are presented, which confirmed the high accuracy of the HV measurement using a capacitive probe and the advantages of this technique.
14.09.2021
5777-1 - 5777-19
Article Number: 5777
CC BY (attribution alone)
open journal
final published version
at the time of publication
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