Brisbane, Australia – October 2025 – Queensland-based renewable energy developer SunConnect has successfully resolved persistent fault-related downtime at its 320MW Winton Solar Farm using ABB’s SPAJ140C highly integrated protection relays. The upgrade, completed in August 2025, replaced generic protection devices with 160 SPAJ140C units, reducing solar generation losses by 78% and improving grid compliance for inverter-connected power.
The Renewable Energy Challenge: Inverter Interference & Fault Misclassification
Winton Solar Farm, one of Queensland’s largest utility-scale solar projects, faced unique challenges with its original protection system:
- Inverter Compatibility Issues: Fluctuations in inverter output (common in solar generation) triggered frequent false overcurrent trips, halting production for 2–3 hours per incident.
- Earth Fault Misclassification: Traditional relays failed to distinguish between transient and permanent earth faults, leading to unnecessary shutdowns of entire solar arrays.
- Grid Compliance Risks: Slow fault response (1.2 seconds) violated Australia’s National Electricity Rules (NER), risking financial penalties of up to AUD 50,000 per non-compliant event.
- Limited Diagnostic Data: The original system provided no granular fault data, making it difficult to identify recurring issues in the farm’s 50km of underground cabling.
“Solar generation’s variability demands protection relays that can adapt to dynamic conditions,” said Mark Thompson, SunConnect’s Asset Manager. “Our old relays treated inverter fluctuations as faults, costing us 3–4% of annual generation capacity. We needed a solution that could differentiate between real threats and normal operational changes.”
ABB SPAJ140C: Tailored Protection for Renewable Integration
The SPAJ140C’s integrated design and renewable-specific features addressed SunConnect’s core challenges:
- Adaptive Protection Algorithms: The relay’s microprocessor-based logic dynamically adjusts to inverter output characteristics, ignoring transient current spikes while detecting genuine overcurrent events . Its IDMT overcurrent unit can be configured to match solar farm load profiles, preventing false trips.
- Precision Earth Fault Detection: Dual-setting earth fault protection (low-set IDMT for transient faults, high-set instantaneous for permanent faults) reduced unnecessary shutdowns by targeting only critical issues . The 50ms response time for high-set earth faults ensured compliance with NER’s 1-second fault clearance requirement.
- Comprehensive Fault Logging: Built-in event recording captures 100+ fault parameters (current magnitude, duration, phase angle), enabling SunConnect’s team to identify recurring fault points in cabling and inverters.
- Grid-Ready Integration: The relay’s IEC 61850 compatibility seamlessly connected to the farm’s SCADA system and ABB Ability™ platform, providing real-time visibility into protection events and performance metrics.
- Harsh Environment Durability: IP65-rated housing and operating temperature range of -30°C to +70°C withstood Winton’s extreme heat (summer temperatures exceeding 45°C) and dust storms .
Implementation & Quantifiable Outcomes
SunConnect’s engineering team installed the SPAJ140C relays across 40 inverter stations and 20 medium-voltage switchgears, with support from ABB’s renewable energy specialists. The project included custom configuration of protection curves to align with the farm’s 2MW string inverters and underground cable layout.
Three months post-deployment, the results exceeded expectations:
- Generation Loss Reduction: Fault-related downtime dropped from 182 hours annually to 39 hours—a 78% improvement, translating to AUD 1.2 million in recovered revenue.
- False Trips Eliminated: Monthly false trips decreased from 8 to 0, eliminating NER compliance penalties.
- Fault Resolution Speed: Diagnostic data from the SPAJ140C reduced fault localization time by 70%, cutting repair costs by AUD 180,000 annually.
- Grid Stability: The relay’s precise fault isolation prevented 2 potential grid disturbances, maintaining the farm’s reputation as a reliable power supplier.
“The SPAJ140C has transformed how we manage our solar farm,” Thompson said. “We’re no longer chasing false alarms—we’re addressing real issues quickly, and our generation capacity has never been more consistent. It’s a game-changer for renewable asset reliability.”
David Chen, ABB’s Asia-Pacific Renewable Protection Specialist, noted the relay’s broader impact: “As solar and wind penetration grows, grids need protection that bridges generation variability and reliability. The SPAJ140C’s integrated overcurrent and earth fault protection delivers that balance, helping renewable projects maximize output while meeting grid standards.”
SunConnect plans to deploy the SPAJ140C in its upcoming 500MW Emerald Solar Farm, set to come online in 2026, with a focus on leveraging the relay’s remote monitoring capabilities to optimize maintenance schedules.
