Electromagnetic radiation spectrum from partial discharge in air-insulated medium voltage switchgear

The ability to accurately characterize the partial discharge events in switchgear systems can help to prevent effectively the breakdown of the system. In this work the electromagnetic radiation spectrum from partial discharge is investigated in the entire structure of medium voltage switchgear (Type D24-121114 of Driescher). The components of the switchgear simulated include voltage and current transformers, terminal studs, fuses, earthing switches, connection parts and the metallic enclosure. Finite Element Method has been used in this work. The partial discharge is situated on the surface of insulators being modeled by a Gaussian pulse. The intensity of the electromagnetic field which propagates from partial discharge is influenced by the switchgear components. The work shows that by analyzing the radiation spectra caused by partial discharge in a switchgear system the positioning of the electromagnetic sensors for fault detection can be optimized.