Izvorni znanstveni članak

Core and frame insulation of power transformers - Part I: History, past and present issues

Vitaly Gurin
Oleg Svyrydenko

Sažetak

This paper reviews the evolution of core and frame (clamp) insulation failures in power transformers and examines representative fault cases attributable to manufacturing defects, transportation-related displacement of the active part, and in-service malfunctions. Drawing on historical experience and recent field evidence, it shows how dominant failure mechanisms have shifted over time, from degraded insulation of bolted core assemblies to increasingly consequential core-ground and multipoint-grounding faults that can drive circulating currents, localized overheating, and abnormal gas generation. The study underscores the need for continued, systematic, and comparable data collection on core damage to strengthen root-cause attribution and improve prevention strategies. To reduce recurrence and enhance diagnosability, the authors recommend standardizing a robust, monitorable grounding design for transformer cores and frames, particularly for units rated 10 MVA and above.

Ključne riječi

circulating currents; core and frame insulation; coreground; multipoint grounding; DGA; earthling; failure; grounding; power transformer

Hrčak ID:

343220

URI

https://hrcak.srce.hr/343220

Datum izdavanja:

9.1.2026.

Posjeta: 242 *