CoreGrid Engineering

Infrastructure sector

AIS/GIS Substation & Switchyard Engineering

Electrical, civil and structural design for air-insulated and gas-insulated substations and switchyards, AC up to 765 kV: new stations, bay extensions, interconnecting transformer yards and line bays.

Generic switchyard arrangement plan with bays, transformer and control building
Generic illustration of a switchyard arrangement plan.

Who needs it

EPC contractors

Awarded substation packages that need the electrical or civil design, or both, developed to the utility’s specification and taken through approval.

Renewable and industrial connections

Pooling, evacuation and dedicated grid-connection substations where the station is part of a larger plant.

Owners’ engineers and reviewers

Teams that need vendor documents, calculations or drawings checked against the specification.

Station types and arrangements

An illustrative 765/400/220 kV arrangement is shown on the home page.

TypeWhat drives the designTypical engineering focus
AIS (air-insulated)Phase and ground clearances, bus arrangement and yard areaYard GA and sections, flexible or rigid bus, SCF and sag-tension, gantries, DSLP, earthing
GIS (gas-insulated)The supplier’s equipment layout and the building that houses itHall layout and interfaces, cable and bus-duct entries, building, crane and floor loads, earthing of enclosures
Extensions and hybridExisting station data and the interface with operating equipmentInterface drawings, matching of bus levels and earthing, outage-aware sequencing of drawings
Bus schemesReliability and switching needs set by the utilityBreaker-and-a-half at 765 kV and 400 kV, double main and transfer at 220 kV, and other schemes as specified

Scope by discipline

The contract and MDL decide what a given package contains.

Electrical

  • System SLD, bus arrangement, bay list and electrical key diagram
  • Switchyard GA, plot plan, bay sections and clearances
  • Conductor and busbar selection, sag-tension, short-circuit forces
  • Earthing (GPR, step and touch) and direct stroke lightning protection
  • CT, CVT, LA, CB, isolator and earth switch rating checks; NGR sizing
  • LTAC and DC systems, battery and charger sizing, cables, illumination
  • Protection, control and SCADA interface documents, where in scope

Electrical design & engineering

Civil & structural

  • Site grading and plot plan from survey and geotechnical data
  • Gantries, equipment support structures and lightning masts
  • Equipment, transformer and reactor foundations with oil containment
  • Control room, relay and GIS buildings
  • Cable trenches, duct banks, drainage, roads and fencing
  • Reinforcement drawings, bar bending schedules and BOQ

Civil & structural engineering

Inputs the design depends on

InputTypically fromUsed for
Single-line diagram, bay list, utility criteriaClient or utilityBus scheme, ratings and arrangement
Fault level and system dataClient or system studyEquipment ratings, earthing, conductor and SCF design
Equipment GTP and vendor drawingsSuppliersDimensions, weights, terminal loads, clearances
Survey and geotechnical reportClient or surveyorGrading, foundations, earthing soil model
Specification and MDLClientDeliverables, formats, codes and revision convention

Interfaces we coordinate

InterfaceWhat is coordinated
Transformer and reactor yardPlinth, oil pit, firewall, bushing clearances, NGR and neutral connections
Line entriesGantry position, tension and swing, line-side equipment, shield wire termination
GIS buildingEquipment loads, openings, crane, cable and bus-duct entries, earthing
Control buildingPanel layout, cable entries, auxiliary supplies, lighting and earthing
Equipment suppliersGTP, outline drawings, terminal loads and mounting details

Representative substation assignments

Client is the company that awarded CoreGrid the work. Owners and locations are not shown.

Substation

400 kV Substation

Client
Hartek Power Pvt. Ltd.
Scope
Earthing design and calculation using CDEGS
Detailed engineeringElectricalStudies
Substation

220 kV Substation

Client
Hartek Power Pvt. Ltd.
Scope
Civil detailed design and engineering support
Detailed engineeringCivil & structural
Substation

132/33 kV Substation

Client
Hartek Power Pvt. Ltd.
Scope
Civil detailed design and engineering support
Detailed engineeringCivil & structural
Substation

66/11 kV Substation

Client
Hartek Power Pvt. Ltd.
Scope
Complete civil engineering consultancy
Detailed engineeringCivil & structural
Substation

Substation Detailed Engineering

Client
Powerica Limited
Scope
Detailed engineering support
Detailed engineering
GIS substation

400/220 kV GIS Substation

Client
Stelmech
Scope
Electrical design support: 400 kV line reactor neutral grounding resistor (NGR) sizing
Detailed engineeringElectricalStudies
GIS substation

400/220 kV GIS Substation

Client
Jakson Infra
Scope
Pre-bid civil engineering
Pre-bidCivil & structural

Share your SLD, technical specification or MDL for an engineering proposal

Send us the tender extract, single-line diagram, master deliverable list or the specific calculation you need. We will confirm scope, inputs and a realistic submission sequence before any work starts.