Feasibility analysis of reduced‐scale visual corona tests in high‐voltage laboratories

Corona is a critical effect that must be considered during the design and optimisation stages of high-voltage hardware such as substation connectors, since due to the harmful effects, corona threats power systems reliability. Visual corona tests allow detecting and identifying the critical corona points on the surface of substation connectors, so corrective actions can be applied for product optimisation. This article focuses on reduced-scale (RS) visual corona tests intended to verify and optimise the behaviour of such high-voltage hardware. RS visual corona tests allow reducing the voltage to be applied, laboratory size, instrumentation requirements, assembly, and test times, and finally the overall costs of the tests compared to standard corona tests carried out in large-size high-voltage laboratories. A hybrid approach combining experimental tests and finite element method (FEM) simulations is presented, which allows obtaining the equivalent visual corona onset voltage between RS and full-scale tests. Although the article focuses on the analysis of aluminium substation connectors, the proposed approach can be applied to many other hardware intended for high-voltage applications.