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The Euro-style prefabricated substation for renewable energy is a three-room package that puts the high voltage switchgear, the step-up transformer and the low voltage distribution in one weatherproof enclosure. It is applied to solar and wind farms, biomass and hydro plants and battery parks where the collection network has to be built quickly and the land take kept small. The unit is wired, interlocked and routine tested in the factory before it ships.
Inside the Euro-style prefabricated substation for renewable energy, the high voltage room, transformer room and low voltage room are separated by steel partitions, and the enclosure is a structural frame with insulated wall panels. The transformer may be oil-immersed with a sealed tank, or dry-type with vacuum-cast resin windings, cooled by ONAN or ONAF oil circulation, or by air in the dry version. Cable entry is from below through a trench, and the unit bolts to a level concrete platform.
| Electrical & Standards | Rated capacity | New-energy step-up: 630–3150 kVA and above |
Voltage combination (HV–LV) | HV 6/10/20/35 kV (Um 7.2/12/24/40.5 kV); | |
Vector group | Dyn11/Ynd11 etc. for step-up per earthing & protection | |
Tapping | ±5% or ±2×2.5%; | |
Rated frequency | 50 Hz /60 Hz | |
Cooling | ONAN / ONAF (oil) or AN / AF (dry) | |
Noise | Transformer sound level approx. ≤55–70 dB | |
Protection / IP & environment | Enclosure IP23D–IP54; service −40/+45 °C; | |
Standards & certification | GB、CE、IECEE CB、KEMA、ISO | |
| Structure & Materials | Enclosure & shell | Structural Frame/ Wall Panels / Thermal Insulation/ Corrosion Protection & Coating/ Auxiliary Parts |
Compartment layout | HV room/ transformer room/LV room | |
Core | Cold-rolled grain-oriented silicon steel; amorphous core optional for ultra-low no-load loss | |
Windings | copper / aluminum | |
Insulation system | Oil-immersed: oil-paper composite dry-type: epoxy vacuum-cast resin with silica filler and glass fiber | |
Insulating oil | Mineral oil / vegetable oil | |
Transformer tank | fully sealed or with conservator | |
Bushings & terminations | Porcelain or composite silicone-rubber bushings; cast-in terminals for dry-type; HV cable bottom-entry standard, overhead bushing entry can be reserved | |
Corrosion / coating | Outdoor weatherable / salt-fog coating; stainless steel enclosure or C5 heavy anti-corrosion coating with stainless fasteners for coastal projects | |
Mounting & base | Bolted to pre-embedded parts of a level concrete platform rated for unit weight; lift by base lugs only; earthing busbar and terminals; cable chamber / trench below base |
The core is built from CRGO Hi-B silicon steel with fully mitered joints, which keeps no-load loss and sound level down over the long operating hours of a generation asset. An amorphous metal core is available on request where no-load loss is the deciding factor.
On the inverter side the winding carries a high current at a low voltage, so the low voltage winding is produced as electrolytic copper foil. Foil construction gives a uniform current distribution, a low stray loss and a good withstand against the harmonic currents that inverter duty imposes.
The high voltage winding is wound from electrolytic copper wire and insulated for a system voltage of 10 kV or 35 kV, with an aluminium winding offered as an option where the project specifies it.
Oil-immersed units use an oil-paper composite insulation system with PCB-free mineral oil, and ester oil where the project is environmentally sensitive. Where oil is not acceptable, the transformer is supplied as a dry-type unit with epoxy cast-resin insulation.
The tank is fabricated from Q235 corrugated or plain plate and is fully sealed, with no conservator. Cooling is by oil circulation to the tank walls and radiators for oil-immersed units, or by air for dry-type units, with forced cooling applied where the rating requires it.
The enclosure is a double-layer sandwich construction in steel or composite board with a fireproof thermal-insulation filling and a rain-shed roof. Natural ventilation is combined with forced ventilation so that heat is rejected from the transformer room under full load.
The high voltage and low voltage rooms are fully separated, and the transformer is mounted externally or semi-externally so that its heat does not load the switchgear rooms. Door interlocks prevent access to a live compartment in service.
Porcelain or composite bushings are fitted for the high voltage connections, and the cables enter from below through a bottom entry with cable seals, which suits the buried cable practice used on most PV and wind sites.
Vector group Dyn11 is the common connection, with Ynd11 applied where the grid and earthing arrangement calls for it; the delta low voltage winding suppresses third harmonic currents. Off-circuit taps of plus or minus 2 x 2.5 percent are standard, and an on-load tap changer can be specified where the grid voltage moves during the day.
Base lifting lugs allow the complete unit to be lifted in one piece onto its foundation, and the footprint follows the factory datasheet. For coastal or offshore sites a C4 or C5 anti-corrosion coating system, silicone seals, anti-condensation heating and rodent-proof mesh are applied.
Every renewable energy transformer is routine tested as a transformer and, where the scope includes the enclosure and switchgear, function tested as a complete assembly before shipment.
Core steel, foil and wire conductor, tank plate and insulating oil are inspected against the approved specification on receipt, and traceability records are kept for every batch used in the active part.
Winding, core stacking, tanking and oil filling are checked stage by stage, so that every Euro-Style Prefabricated Substation for Renewable Energy is verified against its design before it moves to final testing.
Routine testing follows IEC 60076 and covers winding resistance, ratio and vector group, no-load and load loss, impedance, insulation resistance, applied and induced voltage withstand, and oil tightness on sealed units. Where the supply includes the enclosure, the assembly is checked to IEC 62271-202 practice and against the applicable PV or wind grid-code requirements.
The unit is shipped with a routine test report and a certificate of conformity, recording the measured values against the nameplate data.
Euro-Style Prefabricated Substation for Renewable Energy is configured around the generation asset it serves: the inverter or turbine output voltage, the collection network voltage and the grid connection requirements come first, and the transformer, enclosure and protection follow from them.
Capacity is built from 1000 kVA to 3150 kVA and above, with higher ratings engineered for larger blocks. The high voltage side is normally 10 kV or 35 kV, and the low voltage side follows the inverter, typically 0.27 kV, 0.315 kV, 0.4 kV or 0.8 kV, with 0.8 kV used for large central inverters.
Cooling is oil-immersed ONAN or ONAF, or dry-type AN or AF where no oil is permitted. Insulation is oil-paper composite with mineral oil, or ester oil for environmentally sensitive projects; vector group Dyn11 or Ynd11, off-circuit taps or an on-load tap changer, CRGO Hi-B or amorphous core, and aluminium windings are all selectable.
For the enclosure and site conditions, the double-layer shell, compartment layout and C4 or C5 anti-corrosion coating are matched to the location, with silicone seals, anti-condensation heating and rodent-proof mesh for humid, coastal or desert sites.
Renewable energy transformers are packed for long-distance transport to generation sites, which are often remote and have limited handling equipment on arrival.
Secure Packaging: Bushings, accessories and control cabinets are protected and braced against vibration and impact, and openings are sealed against moisture and dust.
One-piece Lifting: Base lifting lugs allow the complete assembly to be lifted in one piece, so no reassembly is needed at the site.
Reliable Transport: Road, rail or sea freight is arranged to the project schedule, with the route and handling method agreed for oversized units.
Complete Documentation: Routine test report, certificate of conformity, drawings, manuals and shipping documents travel with the unit.
Installation Support: Guidance on foundation, cable entry, earthing, protection settings and energisation is available through commissioning.
Inverter-fed and turbine-fed plants impose harmonic currents and load swings on the transformer, and the design accounts for that duty rather than treating the unit as a plain distribution transformer.
The unit is routine tested before shipment and leaves the factory with the records that the project needs for commissioning and for the grid operator.
Off-circuit taps are standard on the high voltage side, and an on-load tap changer can be specified where the network voltage varies during the day.
