Gareth Devine, Head of Development Engineering at EA Technology
Surface partial discharge (PD) makes up over 70% of the PD cases in the UK, costing the owners of critical high voltage assets millions of pounds every year in maintenance and unplanned outages.
These failures can be devastating for critical infrastructure, and as we become increasingly more reliant on electricity for everything from heating to transport, keeping our electrical assets healthy is paramount.
Fortunately, modern monitoring technology means that it’s more affordable and efficient than ever before to check for partial discharge, requiring minimal training to deploy effectively.
Despite this, PD monitoring is often overlooked by asset owners, with many still viewing it as a ‘should do’ rather than a ‘must do’.
With the stakes this high, PD monitoring needs to become commonplace in asset owner operations, no matter the sector. It’s simply a matter of national resilience.
Understanding partial discharge
Partial discharge is a strong indicator of electrical infrastructure health and occurs in network assets when electrical insulation has become compromised. It creates tiny sparks that erode material over time, and if left undetected, the degradation can result in catastrophic equipment failures such as transformer explosions, switchgear faults, and cable failures.
The problem is that PD rarely gives obvious outward signs until it’s too late. A substation or cable might appear to be operating normally while its insulation is steadily deteriorating. When failure does occur, the consequences are immediate and costly – unplanned outages, damage to surrounding equipment, safety risks to personnel, and expensive emergency repairs.
A new monitoring era
Historically, monitoring for PD was considered too complex and too costly to roll out widely, often requiring site visits from specialist engineers who would undertake complicated data analysis. Fortunately, this is no longer the case, and over the past decade especially advances in technology have revolutionised monitoring for anyone looking after high-voltage assets.
Sensor technology and data analytics have come a long way, and portable handheld instruments now allow front-line engineers to carry out fast and accurate surveys without specialist training. Always-on systems can provide continuous asset monitoring, alerting remote operators to early signs of PD before they escalate.
All of these advancements have culminated in devices that asset owners can easily deploy on-site to check for partial discharge. EA Technology’s own device – the UltraTEV® Plus² – was designed to incorporate the best of all of these advancements and means that engineers no longer need to be experts to understand the readings.
Prevention, prevention, prevention
Having that level of visibility means that owners of critical high-voltage assets are no longer forced into a reactive posture, preventing failures instead of dealing with them as they occur. A reactive approach isn’t just expensive, it’s dangerous. Unplanned outages put engineers at risk and it’s common that vital services are disrupted when there’s a critical network failure.
With PD monitoring, they’re on the front foot, shifting to a proactive model of asset management and identifying at-risk equipment months before failure. As a result, scheduling repairs becomes easier and more cost effective, and investment can be prioritised based on real-world condition data rather than assumptions.
The cost of installing PD monitoring is dwarfed by the savings from avoiding a single major asset failure. More importantly, it bolsters reliability – a benefit that extends far beyond balance sheets.
Conclusion
Ultimately, PD monitoring is about keeping the lights on. High-voltage asset owners should be doing everything in their power to prevent catastrophic switchgear failures and extend the life of network-critical transformers. Homes, businesses and public services all rely on the steady supply of electricity, and as the country transitions to net zero, reliability becomes even more essential.
Preventing high-voltage asset failures is an operational priority, which is why partial discharge monitoring is no longer simply a nice to have. It’s the key to preventing catastrophic failures, reducing costs, and ensuring engineer safety. It’s time the industry turned PD monitoring from a ‘should’ to a ‘must.’