Principles of Charge Estimation Methods Using High-Frequency Current Transformer Sensors in Partial Discharge Measurements

Principles of Charge Estimation Methods Using High-Frequency Current Transformer Sensors in Partial Discharge Measurements

Mor, A. R. (TU Delft DC systems, Energy conversion & Storage)
Muñoz Muñoz, F.A. (TU Delft DC systems, Energy conversion & Storage)
Castro Heredia, L.C. (TU Delft ESP LAB)

2020-04-29

This paper describes a simplified model and a generic model of high-frequency current transformer (HFCT) sensors. By analyzing the models, a universal charge estimation method based on the double time integral of the measured voltage is inferred. The method is demonstrated to be valid irrespective of HFCT sensor, assuming that its transfer function can be modelled as a combination of real zeros and poles. This paper describes the mathematical foundation of the method and its particularities when applied to measure nanosecond current pulses. In practice, the applicability of the method is subjected to the characteristics and frequency response of the sensor and the current pulse duration. Therefore, a proposal to use the double time integral or the simple time integral of the measured voltage is described depending upon the sensor response. The procedures used to obtain the respective calibration constants based on the frequency response of the HFCT sensors are explained. Two examples, one using a HFCT sensor with a broadband flat frequency response and another using a HFCT sensor with a non-flat frequency response, are presented.

high-frequency current transformer
HFCT
Rogowski coils
magnetic loop antenna
partial discharge
PD
magnetically coupled sensors
charge estimation

http://resolver.tudelft.nl/uuid:e5bc44fa-1c14-4541-a91e-055b2941d39a

https://doi.org/10.3390/s20092520

1424-8220

Sensors, 20 (9), 1-16

Institutional Repository

journal article

© 2020 A. R. Mor, F.A. Muñoz Muñoz, L.C. Castro Heredia