CASE STUDY 10 - WINDMILLS

In the Windmills of Your Mind…how EDC Scotland and DART brought a wind turbine back to life after six months of downtime.

When a wind turbine stops turning, it isn't just energy that's being lost — it's revenue. And when ageing drive technology, electrical failures and challenging environmental conditions combine, getting those blades turning again requires more than a quick fix.

For one wind turbine operator, persistent electrical and control system problems had resulted in more than six months of lost generation. Despite numerous attempts to restore operation, the turbine remained stubbornly stationary.

It was time for a more comprehensive engineering solution — and that's where the combined expertise of EDC Scotland's drive specialists and DART engineers came into play.

The challenge: More than just a drive failure.

The turbine had experienced reliability issues from the outset, with several underlying problems contributing to its prolonged downtime.

At the heart of the installation was an ageing ABB ACSM1 drive, a legacy product with limited support and no readily available replacement spares. This created a significant risk to long-term reliability and maintainability.

But the drive itself was only part of the problem.

A detailed assessment identified several additional concerns:

· Obsolete drive technology: The existing ABB ACSM1 drive was no longer a practical long-term solution, with replacement parts unavailable.

· Deteriorating electrical infrastructure: The general condition of the control cabinet and associated components required substantial remedial work.

· Failed filtering components: The existing ABB filter had suffered significant damage, with failed capacitors leaking material into the enclosure.

· Inadequate surge protection: The installation lacked suitable protection against lightning-induced and transient overvoltages.

· Environmental exposure: Condensation, humidity and weather ingress were compromising conditions inside the electrical cabinet.

· Incorrect ventilation design: An oversized extraction fan was creating excessive negative pressure, drawing moisture-laden external air into the cabinet during wet weather.

These issues presented a combination of electrical, environmental and operational risks. Simply replacing the failed drive would not have addressed the conditions that could cause future failures.

The objective was clear: restore generation, improve reliability and create an installation capable of being monitored and maintained for the long term.

The solution: Engineering reliability back into the system!

EDC Scotland and DART engineers worked together to deliver a comprehensive electrical and drive system overhaul.

Rather than treating individual faults in isolation, the team addressed the complete installation — from drive technology and electrical protection through to enclosure integrity, environmental control and remote monitoring.

1. Modernising the drive system

The obsolete ABB ACSM1 drive was replaced with a modern ABB ACS880-11 regenerative drive, providing a more supportable platform for the turbine's power conversion requirements.

The new drive was configured and commissioned to operate with the turbine's existing control system, ensuring compatibility with the established operating sequence and control requirements.

2. Improving cabinet protection and environmental conditions

To address the persistent moisture-related problems, a new weatherproof enclosure was installed over the existing electrical cabinet, providing additional protection against the elements.

The team also upgraded the internal heating, lighting and ventilation arrangements, addressing the previous excessive extraction and helping to maintain more suitable operating conditions for the electrical equipment.

These improvements were particularly important given the turbine's exposed location and the sensitivity of power electronics to moisture, contamination and temperature extremes.

3. Restoring electrical integrity

Damaged and defective electrical components were replaced, and the cabinet wiring and internal equipment arrangement were refurbished.

A new surge protection device was installed to provide additional protection against transient over-voltages associated with lightning activity and electrical disturbances.

Following completion, the installation underwent electrical inspection and testing, with a comprehensive NICEIC electrical testing report produced.

4. Adding intelligence with DART remote monitoring

With the electrical infrastructure restored and the new drive commissioned, the final stage was to provide the operator with improved visibility of the turbine's ongoing performance.

A DART remote monitoring device was installed to provide access to key operating and environmental information without the need for routine site attendance.

The monitoring arrangement enables the operator to:

· Track energy export: Review the amount of electrical energy exported by the turbine, including month-on-month performance.

· Monitor cabinet temperature: Identify changes in enclosure temperature that could affect drive operating conditions.

· Monitor humidity: Observe moisture levels inside the cabinet and identify potentially problematic environmental trends.

· Review operating conditions remotely: Gain greater visibility of site conditions to support maintenance planning and fault investigation.

For an installation that had already suffered significant moisture-related problems, the ability to monitor environmental conditions remotely provides an additional layer of operational insight.

DART helps turn the refurbished installation from a purely reactive maintenance challenge into an asset whose operating conditions can be reviewed and assessed over time.

The result: From prolonged downtime to renewed generation.

After more than six months out of service, the turbine was finally returned to operation.

But the project delivered more than simply getting the blades turning again.

The obsolete drive technology was replaced, damaged electrical infrastructure was refurbished, environmental protection was improved and remote monitoring was introduced to support ongoing operation.

The result is a more maintainable, better-protected installation, with improved visibility of the conditions that can influence its reliability.

For the turbine operator, that means renewed generation capability and a stronger foundation for long-term asset performance.

For EDC Scotland and DART, it demonstrates the value of combining specialist drive engineering, electrical refurbishment and intelligent remote monitoring in one integrated solution.

Keeping the blades turning — and the power flowing.

Because in wind generation, every hour of avoidable downtime is an hour of lost opportunity.