Renewable energy projects have unique transformer requirements. Solar and wind farms need equipment that can handle variable power flows, harsh outdoor environments, and increasingly stringent grid codes. This guide covers the key considerations.
Solar Farm Transformers
Inverter Step-Up Transformer
Each central inverter or group of string inverters requires a step-up transformer to raise voltage from the inverter output (typically 400-690V) to the medium voltage collection network (typically 33-35kV).
Key specifications:
- Capacity: 1,000 – 5,000 kVA (matched to inverter block size)
- Impedance: 5-6% (critical for fault current management)
- Winding configuration: Dyn11 (standard for solar applications)
- Harmonic tolerance: K-factor rated or oversized for inverter harmonics
- Cooling: ONAN with solar-compatible thermal management
Grid Connection Transformer
The main transformer at the point of grid connection handles the full solar farm output:
- Capacity: 20,000 – 200,000 kVA
- Voltage: 33/110kV, 33/220kV, or as required by grid operator
- OLTC: On-load tap changer for voltage regulation
- Must comply with grid code requirements for reactive power and fault ride-through
Wind Farm Transformers
Turbine Transformer
Located at the base of each wind turbine tower:
- Capacity: 2,000 – 8,000 kVA (matched to turbine rating)
- Must withstand vibration and variable loading
- Compact design for nacelle or tower base installation
- Lightning and surge protection critical
Offshore Wind Challenges
Offshore wind farms add additional complexity:
- C5-M corrosion protection for marine environment
- Hermetically sealed construction
- Higher reliability requirements (limited maintenance access)
- Submarine cable interface considerations
Prefabricated Substations for Renewables
VoltBridge's YB□ prefabricated substations are ideal for renewable energy collection points:
- All-in-one design: HV switching, transformation, and LV distribution
- Weatherproof: IP33/IP43 for outdoor installation
- Quick deployment: Factory-assembled, reducing on-site construction time
- Containerized option: 20ft/40ft shipping container format for remote locations
Environmental Considerations
- Biodegradable ester-filled transformers available for environmentally sensitive sites
- Oil containment bunding designed to local environmental regulations
- Noise levels compliant with rural planning requirements
- Low-loss designs to maximize overall plant efficiency
VoltBridge Renewable Energy Track Record
We have supplied transformers and substations to solar and wind projects across:
- Southeast Asia (Vietnam, Thailand, Philippines)
- Middle East (UAE, Saudi Arabia, Oman)
- Africa (Kenya, Nigeria, South Africa)
- South America (Brazil, Chile, Colombia)
Every project receives dedicated engineering support from specification through commissioning.