RW Energy Colombia PV Plant 35 kV Recloser Controller Project Case Study

01 Project Background

1.1 Project Background

Colombia is a core market for photovoltaic (PV) development in Latin America. However, its grid environment differs significantly from others. Solar irradiance fluctuations lead to highly stochastic PV output, resulting in low-inertia grid characteristics. Additionally, strong local electromagnetic interference and frequent frequency fluctuations pose extreme challenges for fault recovery and frequency stability control.

In the initial stages of a large-scale PV plant's connection, the existing recloser controllers were not adapted to the Colombian grid. Specifically, the core 81R frequency protection failed to meet local regulation requirements. Instead of identifying faults and optimizing reclosing sequences, it exacerbated frequency fluctuations, leading to frequent tripping on the PV side. This severely impacted generation efficiency and grid stability, causing significant financial losses and O&M pressure for the owner.

To resolve these challenges, the PV plant officially introduced RW Energy 35 kV recloser controllers in 2024. Leveraging RW Energy’s technical expertise in PV grid-tied protection and frequency stability control, a customized solution was provided to precisely adapt to the local 60 Hz grid, achieving rapid fault recovery and coordinated frequency regulation.

1.2 Core Product and Parameters

A total of 88 units of 35 kV recloser controllers, along with accessories and spare parts, were deployed.

1.3 Technical Drawings

The project utilized comprehensive electrical schematics for the RWK-352HBV 35 kV outdoor permanent magnet recloser controller. These drawings cover primary circuits, secondary control, 81R frequency protection logic, power supply, and communication interfaces including IEC 101/104, MODBUS, and RS485. The design precisely matches the 60 Hz frequency and 35 kV voltage requirements of the Colombian grid. Detailed wiring and control logic for permanent magnet actuators, CT/VTs, and remote control interfaces ensure stable operation under intense solar fluctuations and electromagnetic interference.

02 Technical Design and Quality Assurance

2.1 Core Technical Design

The RWK-352HBV recloser controller is tailored for low-inertia PV grid integration, with deep optimization of the 81R function:

• Algorithm Upgrade: Equipped with specialized frequency-slip locking and adaptive reclosing algorithms. It accurately identifies fault types and optimizes reclosing sequences to solve frequency fluctuations at the source.
• Adaptive Parameter Optimization: Supports a full cycle of "Parameter Rectification - Function Debugging - Scenario Testing - Optimization Iteration" to adapt to complex Colombian grid conditions.
• EMI/EMC Design: Utilizes high-strength electromagnetic shielding and anti-interference circuits to ensure stability under strong local interference.
• Integrated Architecture: Integrates fault detection, protection control, and reclosing execution, simplifying field installation and O&M.

2.2 Quality Certification

RW Energy is certified under ISO 9001, ISO 14001, and ISO 45001. All products have passed professional testing by international authoritative agencies, complying with IEC 60255 and other international protection standards.

03 Factory and Field Testing

All equipment underwent comprehensive factory acceptance tests (FAT) and field commissioning according to IEC standards and Colombian grid technical specifications:

• 81R Frequency Protection Test: Simulated Colombian grid fluctuations to verify frequency-slip locking accuracy. Verified via multi-round slope and pulse frequency tests, achieving a 100 % accuracy rate for 81R actions.

• Fault Recovery and Reclosing Sequence: Simulated short-circuits and grounding faults. Fault identification response time was ≤ 20 ms, with reclosing sequences perfectly matching grid requirements.
• EMC/EMI Testing: Simulated strong electromagnetic interference environments. Performance complied with IEC 61000 international standards with zero protection malfunctions.
• Dielectric and Reliability Tests: Completed 1 min power frequency withstand and impulse withstand tests with zero breakdown. Performed 72-hour continuous load operation with zero parameter drift.
• Field Commissioning: Technical teams performed multi-round parameter debugging on-site in Colombia, ensuring 100 % adaptation to the owner's and the local utility's requirements.

04 Packaging and Shipping

Equipment utilized heavy-duty export-grade moisture-proof and vibration-proof packaging. Core electronic boards were vacuum-sealed. Reinforced wooden crates were customized to withstand long-distance maritime and inland transport in Colombia. All components were clearly labeled in English and Chinese.

05 Installation and Operation Summary

5.1 Installation Implementation

RW Energy dispatched a professional technical team to the Colombian site to provide full-process technical services:

• Guided foundation construction, control box wiring, and grounding system installation.
• Performed insulation tests and wiring verification for 88 units.
• Conducted on-site energized commissioning and customized 81R parameter configuration.

• Final Acceptance: Successfully completed multiple rounds of on-site condition testing and optimization iterations, resolving parameter adaptation issues inherited from previous controllers and passing the final acceptance from both the project owner and the local utility.
• Training and Documentation: Conducted comprehensive operation and troubleshooting training for local O&M personnel and handed over a complete set of O&M manuals, technical drawings, and standard operating procedures (SOPs).

5.2 Operation Feedback

Since commissioning, the equipment has operated stably with zero downtime, exceeding the owner's expectations:

• Resolved Frequency Stability: The precise application of the 81R function suppressed frequency fluctuations and eliminated frequent tripping.
• Enhanced Fault Recovery: Fault recovery time was reduced by over 80 %, significantly minimizing generation loss.
• Improved Grid Stability: Grid-tied voltage and frequency now fully comply with Colombian national standards, receiving high praise from both the utility and the owner.
• Reduced O&M Costs: Stable operation reduced the need for site inspections and minimized downtime losses.

06 Full Lifecycle O&M Managed Services

RW Energy provides integrated full-lifecycle O&M services for the Colombia project, covering selection, installation, monitoring, regular inspection, maintenance, and status evaluation for recloser controllers, protection devices, and switchgear. Our professional team ensures long-term safety, extends equipment life, and reduces costs for renewable energy developers.

Contact us for customized PV grid-tied protection solutions in the Latin American market!