Partial Discharge Measurement Based on an Inductive Mode Air-Core Sensor

Abstract

In this paper, an alternative technique for partial discharge (PD) measurement using an air-core sensor is proposed. The air-core sensor consists of an inductive mode air-core coil and the appropriate additional resistor. The approach for inductive mode enhancement of an air-core coil is presented. In the inductive mode operation, an output voltage which is proportional to an induced voltage from the air-core coil is utilized to determine PD currents and charges by a numerical integration. In the design process of the air-core sensor, parameter estimation with a computation algorithm is employed for extracting unknown circuit parameters of the air-core coil from a unit step response. These estimated parameters are crucial in an effective design of the PD measuring system. With the design circuit parameters, experiments in PD measurement were performed. From experimental results, the developed system has promising performance, and the sensitivity is in the range of a few picocoulombs. From this achievement, the proposed technique is a choice in PD measurement for high-voltage equipment in the laboratory and in the on-site measurement.