~ Excitation Engineering Services presents fault analysis project ~
Generator excitation engineering firm, Excitation & Engineering Services (EES), delivered a presentation at the Steam Turbine and Generator User Group (STGUG) at Emirates Old Trafford Cricket Ground, Manchester, on March 13, 2025. The presentation explained and analysed a fault investigation and solution project at Kinlochleven Power Station hydroelectric facility in Scotland.
Kinlochleven hydroelectric power plant, situated in the village of Kinlochleven in south-west Scotland, generates an average of 23.27 MW of clean, renewable energy weekly — enough to power a city the size of Inverness.
The station experienced operational challenges due to fluctuations in reactive power (MVAr), which led to intermittent tripping of one of the hydrogenerators.
Due to a surge in reactive power, the operator was forced to take the unit offline, otherwise the AVR would have tripped the system. These fluctuations resulted in an excursion of 4.05 MVAr, causing instability. If not properly resolved, this overexcitation could have led to non-compliance with grid code and machine damage.
To investigate the source of this issue, EES conducted a series of site visits. However, after a lack of conclusive results, a chart recorder was installed on site to capture further data for a deeper understanding of the fault’s behaviour.
Through detailed analysis, EES confirmed that the root cause of the problem was a faulty DC current transformer, which was providing incorrect measurements to the programmable logic controller and triggering the protection function in the AVR. While a permanent solution was sourced, EES implemented a temporary fix that allowed the power station to continue operating as usual, minimising downtime and ensuring continued power generation.
“We were faced with an unusual fault, but by employing a methodical and collaborative approach, we were able to pinpoint the root cause and ensure operations continued with minimal disruption,” explained Ling Li Li, graduate engineer at EES, who presented the findings at the STGUG event. “The presentation at the STGUG provided valuable insights into how engineering solutions can address unique challenges, and the importance of ensuring system reliability in critical infrastructure.”
To learn how excitation systems work and about EES and its generator excitation system design visit Excitation Engineering’s commissioning page.
