An investigation into space weather impacts on UK power station transformers

Lewis, Zoe and Wild, Jim and Barker, Douglas and Allcock, Matthew (2021) An investigation into space weather impacts on UK power station transformers. In: 17th European Space Weather Week, 2021-10-25 - 2021-10-29, Technology Innovation Centre.

Text (Lewis ESWW2021 Poster Portrait)
ESWW_Poster_Portrait.pdf - Published Version
Available under License Creative Commons Attribution-NonCommercial.
Download (1MB)

Abstract

It is well documented that space weather can impact electricity infrastructure, and several incidents have been observed in recent decades and directly linked to large geomagnetic storms (e.g. the Hydro Quebec incident in 1989). However, less is understood about the impact of lower-level Geomagnetically Induced Currents (GICs) on the health of transformers in the long term. Direct measurements of GIC at power stations are still quite rare, but all transformers sense and record levels of dissolved gases within the insulation, as a way of monitoring transformer health. In this study, the long term impact of geomagnetic activity on 13 power station transformers in the UK was investigated. Dissolved gas measurements between 2010-2015 were used to look for evidence of a link between degradation of the transformer insulation and heightened levels of global SYM-H and the rate of change of the horizontal magnetic field (dB/dt) as measured at the Eskdalemuir magnetometer station. First, case studies of the most significant storms in this time period were examined using dissolved gas analysis (DGA) methods, specifically the Low Energy Degradation Triangle (LEDT). These case studies were then augmented with a statistical survey, including Superposed Epoch Analysis (SEA) of multiple storm events. No evidence of a strong space weather impact can be found during this time period, likely owing to the relatively quiet nature of the Sun during this epoch and the modernity of the transformers studied.