On a solar project the substation sits between the inverters and the grid connection. It steps the inverter output up to the network voltage, carries the protection your grid operator requires, and provides the metering and the isolation point they will insist on before they energise.
Because the enclosure has to arrive on a site that is still being built, factory-assembled units are the normal choice. They are tested before delivery, which removes most of the commissioning risk from the critical path.
What a Solar Substation Has to Handle
- Step-up duty – from the inverter voltage, usually 400 V to 800 V, up to the MV collection voltage and then to the grid voltage.
- Intermittent loading – full output at midday, nothing at night, and a daily thermal cycle that the transformer insulation has to live with for decades.
- Harmonics – inverter output is not a pure sine wave, so the transformer and any capacitor banks have to be specified with that in mind.
- Grid compliance – the protection, the ride-through behaviour and the metering that your grid code and connection agreement require.
Typical Arrangement
| Stage | Equipment | Note |
|---|---|---|
| Inverter output | LV collection board | Per inverter station |
| Step-up | Transformer, 500 kVA to 8,000 kVA | Rating per block size |
| MV collection | MV switchgear, ring or radial | Per collector layout |
| Grid interface | Metering, protection, isolation | Per grid operator |
| Storage | Spare bay for the battery converter | Where BESS is included |
Storage and Hybrid Projects
When battery storage is part of the project, the substation needs a spare bay and the protection has to accommodate a source that can both import and export. We build units with the space and the provisions for the converter, so the battery can be added without replacing the substation.
What We Need From You
The inverter layout and output voltage, the block size, the grid voltage and fault level at the connection point, the grid code that applies, and the site conditions. With those we can propose an arrangement and price it. Where the project names a standard, we confirm the applicable clauses before production.
Solar and PV Substations in Our Range
Frequently Asked Questions
What size substation does a solar farm need?
It follows from the block size and the inverter layout. Small projects use a single unit in the 500 kVA to 2,000 kVA range; larger plants use several units feeding a collection network. We size it from your inverter layout rather than guessing.
Does the transformer need to be different for solar duty?
The transformer sees a daily thermal cycle and harmonic content from the inverters. Both are accounted for in the insulation specification and, where the harmonic level is significant, in the winding design. Send us the inverter data and we will specify it.
Can the substation accommodate battery storage?
Yes. We build units with a spare bay and the provisions for the battery converter, so storage can be added later without replacing the substation.
Who defines the protection settings?
Your grid code and connection agreement do. We build and wire to the scheme you specify, and the settings are confirmed at commissioning against the study.
How long does delivery take?
It depends on the rating, the configuration and the workshop load at the time of order. We give a programme with the quotation and confirm it when the drawings are approved.
Talk to Our Engineering Team
Send us your single-line diagram, load list and site conditions. We will come back with a proposed arrangement, the applicable standard set, and a quotation. Email info@xsdfftransformer.com or call +8615867897761.