EHV substation EPC
A substation is a sequence of devices that must coordinate exactly. Get the ratings or the grading wrong and one fault takes the whole station out.
EPC · In short
EHV substation EPC covers the design, supply, civil construction, erection, testing and commissioning of an extra-high-voltage substation. Enersys Engineers has delivered design, engineering and PMC for a 132/11 kV 2 × 25 MVA substation and a 220/33 kV 2 × 37.5 MVA substation, with scope including electrical works, civil construction, control room building and fire fighting systems, and is qualified for substation projects up to 400 kV and 765 kV.
What sits inside a bay
The isolator provides visible isolation. The circuit breaker interrupts fault current within cycles. The current transformer feeds the protection relays. The power transformer steps voltage between systems. Each is sized from the fault level study, and each has to grade correctly against the next.
- Isolators and earth switches
- Circuit breakers, rated from the fault MVA study
- Current and voltage transformers for protection and metering
- Surge arresters
- Power transformers with OLTC, and their protection
- Bus configuration — single, double or main-and-transfer, selected against reliability requirement
Full EPC scope
- Design and detailed engineering, including the fault level and relay coordination studies
- Supply contracts for major equipment and auxiliary systems
- Civil construction — foundations, structures, gantries, cable trenches, roads and drainage
- Control room building, including cable spreader room and battery room
- Fire fighting system
- Complete earthing grid with step and touch potential verified against permissible limits
- Protection, control, metering and SCADA panels — manufactured in our own shop
- Erection, testing and commissioning as EPC contractor
Delivered substation projects
Frequently asked
What substation voltages has Enersys delivered?
Design, engineering and PMC have been delivered for 132/11 kV (2 × 25 MVA) and 220/33 kV (2 × 37.5 MVA) substations. The company is qualified for EHV substation projects up to 400 kV and 765 kV.
Is the control room civil work included?
Yes. The EPC scope covers electrical works together with civil construction including the control room building and fire fighting system.
Who manufactures the protection and control panels?
Enersys manufactures them in-house, to the same protection scheme our engineers drew. This removes the interface between the study and the equipment that most often delays substation commissioning.
What is the difference between AIS and GIS?
Air-insulated switchgear uses air as the insulating medium and occupies a large outdoor footprint. Gas-insulated switchgear uses SF6 in a sealed enclosure and is far more compact, at higher capital cost. AIS is the norm where land is available; GIS is used where space or environment demands it.
What usually goes with this
These are the adjacent scopes clients most often need alongside it.
Transmission line EPC
Six trades in sequence, each dependent on the one before it. This is the work behind the kilometre figure.
Read more →ManufacturingRelay & metering panels
The panel and the grading study come from the same team, so the settings that were calculated are the settings that get applied.
Read more →ConsultancyEnergy design & system studies
The analytical work that decides whether a plant runs smoothly or trips on its own faults.
Read more →ApprovalsDISCOM approval & connection
The distribution licensee decides your supply voltage, your metering arrangement and your connection date. Those are engineering questions before they are administrative ones.
Read more →Need substations? Tell us the scope.
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