• Zhejiang Zhilu Transmission and Distribution Equipment Co., Ltd

Special Environmental Adaptation Solutions for Photovoltaic Prefabricated Substations on Islands

1. Introduction

2. Key Environmental Challenges on Islands

2.1 Corrosive Atmosphere

• Salt - Fog Corrosion: High - concentration salt particles in sea breezes cause electrochemical corrosion on metal surfaces (e.g., steel enclosures, electrical contacts).

• Humidity and Condensation: Persistent high humidity (≥85% RH) and temperature fluctuations promote mold growth, insulation degradation, and electrical short - circuits.

2.2 Extreme Weather Conditions

• Typhoons and Strong Winds: Islands are prone to typhoons with wind speeds exceeding 200 km/h, posing risks of structural damage to substation enclosures and external components.

• Storm Surges and Flooding: Coastal islands may face inundation during extreme weather, threatening substation grounding systems and low - voltage equipment.

2.3 Limited Resources and Maintenance

• Remote Location: Islands often lack immediate access to replacement parts and professional maintenance teams, necessitating long - lasting and self - sufficient substation designs.

• Power Grid Instability: Weak or isolated island grids require PV substations to support grid stability during power outages or fluctuations.

3. Adaptation Solutions for Island PV Substations

3.1 Anti - Corrosion Design

• Material Selection:

• Enclosures: Use corrosion - resistant materials such as marine - grade stainless steel (e.g., 316L), aluminum alloy, or fiber - reinforced plastics (FRP).

• Internal Components: Coat electrical contacts, busbars, and connectors with anti - corrosion compounds (e.g., silver - plated copper, tin - plating with anti - oxidation additives).

• Surface Treatment:

• Apply multi - layer coatings, including zinc - rich primer (zinc content ≥95%), epoxy intermediate coat, and fluorocarbon topcoat for long - term protection.

• Use powder coating for enclosures, providing a durable, scratch - resistant finish.

3.2 Structural Reinforcement for Extreme Weather

• Wind Resistance:

• Design substation structures to withstand wind loads equivalent to typhoon - level speeds (e.g., IBC 2018 Wind Load Category D).

• Anchor substations with deep - foundation bolts or concrete slabs, ensuring a safety factor of ≥1.5 against uplift forces.

• Flood and Moisture Protection:

• Elevate substations at least 1.5 meters above the highest predicted storm - surge level.

• Seal all penetrations (cable entries, ventilation holes) with waterproof gaskets and epoxy resin, maintaining IP66/IP67 protection.

3.3 Enhanced Thermal and Humidity Management

• Ventilation and Dehumidification:

• Install forced - air ventilation systems with moisture - resistant fans and air filters to prevent condensation.

• Integrate desiccant dehumidifiers or Peltier - effect cooling units to maintain internal humidity below 60% RH.

• Heat Dissipation:

• Use heat - dissipating fins or liquid - cooling systems for high - heat - generating components (e.g., transformers, inverters).

• Apply heat - reflective coatings on enclosure exteriors to reduce solar heat absorption.

3.4 Robust Electrical and Protection Systems

• Insulation Enhancement:

• Upgrade insulation materials to high - performance types (e.g., silicone rubber, cross - linked polyethylene) with improved moisture resistance.

• Conduct regular insulation resistance tests (e.g., monthly) to detect early degradation.

• Surge Protection:

• Install multiple - stage surge arresters (e.g., gas - discharge tubes, metal - oxide varistors) to protect against lightning strikes and grid transients.

• Ground substations with low - resistance grounding grids (≤2 Ω) and corrosion - resistant grounding rods (e.g., copper - clad steel).

3.5 Smart Monitoring and Autonomous Maintenance

• IoT - Enabled Sensors:

• Deploy sensors for real - time monitoring of humidity, temperature, corrosion levels, and electrical parameters.

• Use predictive analytics to detect potential failures (e.g., corrosion - induced electrical shorts) and trigger alerts.

• Self - Healing and Remote Management:

• Incorporate self - healing materials (e.g., microcapsule - based coatings that release repair agents upon damage).

• Enable remote control and firmware updates via satellite communication, reducing dependence on on - site maintenance.

4. Case Study: PV Substation on a Coastal Island

4.1 Project Background

• Location: A subtropical island with average humidity of 88%, annual typhoon frequency of 3 - 4, and salt - fog density of 5 mg/m³.

• PV System: 2MW capacity with a 10/0.4kV prefabricated substation.

4.2 Adaptation Measures

• Enclosure: FRP enclosure with UV - resistant, anti - corrosion coating; IP67 - rated for dust and water ingress.

• Electrical Components: Silver - plated copper busbars and connectors; double - insulated cables.

• Monitoring: IoT sensors for humidity, temperature, and insulation resistance; data transmitted via LoRaWAN to a mainland control center.

• Structural Design: Substation elevated 2 meters above sea level; anchored with 12 - mm - diameter stainless - steel bolts.

4.3 Performance Results

• After 3 - year operation:

• Zero corrosion - related electrical failures.

• Substation withstood two category 4 typhoons without structural damage.

• Remote monitoring reduced maintenance trips by 70%.

5. Conclusion