Substation design
AC substation design from 11 kV to 400 kV.
Complete FEED and detailed design for air-insulated and gas-insulated substations — primary plant, secondary systems, civil interfaces and HV cables — produced to the technical specifications of the network operator who will own it.
We take a substation from single line diagram to a construction-ready package, and we do it as one co-ordinated design rather than a primary set and a secondary set that meet for the first time on site. Clearances, cable routes, earthing, protection and civil guide drawings are developed together so the contractor inherits a scheme that fits.
Packages are produced to DNO and TSO standards and formatted for their design approval processes. Where a client has its own drawing conventions or CAD standards we adopt them; where it does not, we bring ours.
Primary design
- Single line diagrams and operational diagrams
- Electrical equipment layouts, elevations and sections
- Safety clearance and phase-spacing checks
- Plant and equipment specifications to DNO / TSO standards
- Earthing design — CDEGS soil and grid studies, step and touch assessment, earth grid layouts
- Short-circuit force and wind-load calculations for busbars and structures
- Lightning protection and shielding drawings
- AC and DC auxiliary load estimates with LVAC and DC single line diagrams
- Ducting, trench and cable route layouts
- Lighting, small power and CCTV layouts
- Oil containment, fire separation and blast wall drawings
- Civil guide drawings, including overhead line interfaces and terminal tower positions
Secondary, protection & control
- Key line diagrams and protection philosophy
- Interlocking diagrams and trip logic matrices
- Signal lists and I/O schedules for RTU and SCADA
- Control and protection scheme schematics
- CT and VT sizing with stability and saturation checks
- Relay selection and ordering code specification
- Protection co-ordination studies and relay setting calculations
- Multicore and fibre-optic cable schedules
- Termination schedules and wiring diagrams
- Substation automation architecture, including IEC 61850 configuration
- Telecoms, SCADA and RTU interface design
Civil interfaces & HV cables
- Civil guide drawings, plinth and foundation loads
- HV and MV cable sizing, rating and pulling-tension checks
- Cable schedules, joint bay and sealing-end arrangements
- Containment, duct bank and trench design
BIM & 3D modelling
- Revit and BIM models of the substation to agreed level of detail
- Clash detection between plant, structures, cabling and civils
- 3D visualisation for stakeholder and safety reviews
- Model handover in native and IFC formats
Common questions
What voltage levels do you design substations for?
From 11 kV distribution substations to 400 kV transmission sites, air-insulated, gas-insulated and hybrid, for FEED and detailed design.
Do you produce both primary and secondary design?
Yes, and as one co-ordinated package. Layouts, earthing, cable routes, protection schematics and civil guide drawings are developed together so the contractor receives a scheme that fits.
Can you work to our DNO or National Grid standards and approval process?
Yes. Packages are produced to the operator’s technical specifications and formatted for their design approval process, and we can provide design assurance roles under National Grid TP141.
Do you provide BIM models?
Yes. Revit and BIM models to an agreed level of detail, with clash detection and handover in native and IFC formats.
Related capabilities
Ready when you are.
Bring us a single line diagram and a connection offer, and we will tell you what the design package needs to contain.