Noncontacting Electromagnetic-Acoustic Measurement Technique for Partial Discharge Detection and Localization

Partial discharge (PD) detection is crucial for maintaining insulation systems of high-voltage equipment. Enhancing diagnostic credibility and expanding additional system functionalities can be achieved by correlating signals detected from multiple measurement techniques. In this article, a noncontacting electromagnetic-acoustic (EMA) measurement technique is proposed for high-accuracy PD detection and localization. The proposed method integrates a wideband electromagnetic (EM) sensor with 3-D omnidirectional sensing property and a broadband high-sensitivity acoustic emission (AE) sensor based on a third-order resonator and meta-focusing lens. To verify the feasibility of the proposed measurement technique, a prototype of the integrated sensor is fabricated, and extensive experiments are performed. The experimental results demonstrate that the proposed EMA sensor can not only provide the 3-D omnidirectional sensing for EM PD but also ensure the broadband highly sensitive detection for AE PD coherently, which indeed enhance the PD diagnosis credibility and expand system functionalities. This innovative approach provides notable advantages over existing methods, showcasing its superior potential for PD detection and localization.