RUBIX extending the life of wind turbines

Across the industry, there is a mix of maturing equipment alongside brand-new machinery that is a result of continued investment to support expansion. For operators managing maturing equipment, turbines are approaching – or even exceeding – their original design life, leading to increased pressure to maximise uptime, manage costs and reduce reliance on fragmented global supply chains to keep operations running smoothly.

In the face of these challenges, turbine and equipment maintenance has evolved to become a critical strategic function.

The challenge of ageing assets

As wind turbines age, the risk of failure becomes greater, and when they occur, the typical response is replacement – often via the original equipment manufacturer. The benefits of this approach are clear to see, providing a straightforward way of getting operations back on track.

However, this route doesn’t always address the underlying issues that have triggered the failure. Replacing components like-for-like restores equipment to its original design specification, including any limitations. In practice, that means machinery can be back up and running but still have the same inherent risks long-term, leaving operators open to unexpected failure and unplanned, costly downtime.

Instead of straightforward replacement, some operators are now focussing on engineering-led maintenance solutions that are designed to find the cause of the failure, rather than just recommending replacements. This approach requires a deep understanding of operating conditions, machine design and component materials to support targeted upgrades that can restore performance and even extend it beyond the original specification.

This approach has been adopted by an offshore[PM1]  operator who experienced a 2.3 MW generator failure without any prior indication. On the surface, everything looked normal – no unusual vibrations, no rising temperatures and no anomalies in the SCADA data. Right up until the point of failure, everything was going smoothly.

Instead of opting for a direct replacement through the OEM, however, the operator chose to lean into to the support of Rubix to investigate the failure and find a lasting solution.

In practice: how engineering insight enhances reliability

Working collaboratively with the clients engineering team, Rubix conducted a full teardown and analysis of the generator at its Aberdeen facility.

With the generator fully dismantled and the rote rotor carefully removed, the nature of the failure began to reveal itself. Deep within the stator, at a single slot position, a magnetic wedge had failed. Around 100mm of that wedge was missing and later recovered from the opposite end of the casing, having been struck by the rotor and carried through the air gap.

That missing wedge had been doing a critical job, securing the stator coils and preventing movement under electromagnetic forces. With the wedge gone, the coil beneath was no longer fully restrained. Over time, it was free to flex, vibrate and rub against the slot walls. Eventually, the insulation system could no longer cope, allowing coil movement that ultimately led to insulation breakdown and a localised winding failure.

Crucially, the wider condition of the machine remained strong, with no evidence of systematic degradation, widespread ageing, thermal degradation or contamination. That confirmed that the machine wasn’t at the end of its service life, but the victim of a very specific mechanical failure.

On closer inspection, a felt packer was identified on top of the coil and the magnetic wedge that had been installed during manufacture to compensate for a dimensional gap.

In theory, the vacuum pressure impregnation (VPI) process should flood this area with resin, locking everything together into a solid structure. In practice, however, it hadn’t. The felt had distorted, creating voids beneath the wedge which left localised weaknesses in what should have been a rigid insulation system. Over the years of operation, vibration and thermal cycling gradually exploited those voids, and the wedge loosened, lifted into the air gap, and was eventually struck by the rotor.

At this point, the failure was understood and, crucially, Rubix recognised it as a known issue and proposed a technical solution.

The value of this exercise extended far beyond the repair of a single asset. With multiple turbines built to the same specification, the operator now had an understanding of the risks posed across its essential equipment. Now, instead of responding to failures as they occur, they are able to implement targeted upgrades to address known issues before they lead to further downtime.

Engineering impact at scale

This approach to asset management has clear operational and commercial benefits for operators who are under pressure to maximise performance and uptime. Particularly in the wind sector where operations are becoming more complex, the ability to lean into the expertise and support of engineering-led supply partners is becoming more important.

Operators are under greater pressure to deliver performance, extend asset life and manage costs within increasingly strained operational environments. Responding to these demands requires a shift in approach – away from reactive maintenance and towards engineering-led optimisation.

Rubix is spearheading this approach within the wind sector to give operators greater control over their repair and upgrade processes. Providing hands-on technical expertise and in-house capabilities – including the ability to manufacture its own coils and perform full stator rewinds – Rubix delivers solutions that are tailored to operators’ specific needs.

To get in touch, please call 0121 508 6000 or contact your local  Service Centre, who will be happy to discuss your options.
 

#Renewables #Reliability #Engineering #TechnicalKnowHow