Skid-Mounted Substation provides a flexible, factory-integrated power distribution solution

Skid-Mounted Substation

A Skid-Mounted Substation is a factory-assembled modular electrical substation installed on a steel skid base frame for easy transportation, rapid installation, and simplified commissioning. It integrates major electrical equipment such as medium-voltage switchgear, transformers, low-voltage switchgear, protection systems, control panels, and auxiliary systems into a pre-engineered package.

Unlike conventional site-built substations, skid-mounted substations are manufactured, wired, tested, and commissioned in a controlled factory environment, then transported as a complete unit to the installation site.

They are widely used in oil & gas facilities, mining sites, renewable energy plants, industrial plants, offshore platforms, and temporary power installations.

Main Features
·Factory-built modular design
·Mounted on heavy-duty steel skid frame
·Pre-wired and factory tested
·Fast site installation
·Reduced civil construction requirements
·Easy transportation and relocation
·Compact footprint
·Suitable for remote locations
·Integrated protection and automation
·Expandable modular configuration

Typical Configuration
A skid-mounted substation may include:

1.) Medium Voltage Section
Equipment:
·MV switchgear (AIS/GIS)
·Vacuum circuit breakers (VCB)
·Load break switches
·Protection relays
·Current transformers (CT)
·Voltage transformers (VT)
·Metering units

Typical voltage levels:
·3.3kV
·6.6kV
·10kV
·12kV
·24kV
·35kV
·40.5kV

2.) Transformer Section
Transformer options:
·Oil-immersed transformer
·Dry-type transformer
·Cast resin transformer
Functions:
·MV/LV voltage conversion
·Electrical isolation
·Power distribution
Typical capacities:
·500 kVA
·1000 kVA
·2500 kVA
·5000 kVA
Higher ratings available

3.) Low Voltage Section
Includes:
·LV switchgear
·Motor Control Center (MCC)
·Distribution boards
·Soft starters
·Variable Frequency Drives (VFD)
·Metering systems
Typical LV voltages:
·400V
·415V
·480V
·690V

4.) Control and Auxiliary Systems
May include:
·Protection and control panels
·PLC systems
·SCADA communication
·UPS system
·DC power supply
·Battery charger
·HVAC system
·Fire detection system
·Lighting and socket outlets

Main Components
·Steel skid frame: Structural support and transportation base
·MV switchgear: Medium-voltage switching and protection
·Transformer: Voltage conversion
·LV switchgear: Low-voltage distribution
·MCC: Motor control
·Protection relay: Fault detection and isolation
·PLC/SCADA: Monitoring and automation
·UPS/DC system: Backup control power
·HVAC: Temperature control
·Cable system: Internal electrical connection

Typical Technical Specifications
·MV Rated Voltage: 3.3–40.5 kV
·LV Rated Voltage: 400–690 V
·Frequency: 50/60 Hz
·MV Current: 630–3150 A
·LV Main Bus Current: 1000–6300 A
·Transformer Capacity : 500 kVA–10 MVA+
·Short Circuit Level: 25–100 kA
·Protection Degree: IP54–IP66
·Ambient Temperature : -40°C to +50°C
·Installation: Indoor / Outdoor
·Service Life: 25–30 years

Types of Skid-Mounted Substations
1.) Open Skid Substation
Features:
·Outdoor installation
·Equipment exposed but protected by enclosure/canopy
·Suitable for industrial yards
Applications:
·Solar farms
·Mining sites
·Temporary power supply

2.) Enclosed Skid Substation
Features:
·Fully enclosed electrical room
·HVAC controlled
·Higher environmental protection
Applications:
·Oil & gas
·Offshore platforms
·Harsh environments

3.) Transformer Skid Substation
Features:
·Transformer mounted on skid
·Integrated MV/LV connection
·Compact design
Applications:
·Renewable energy
·Industrial plants

4.) Containerized Skid Substation
Features:
·Container-style electrical building
·High mobility
·Complete plug-and-play solution
Applications:
·Remote projects
·Emergency power systems

Working Principle
·MV incoming power enters through the MV switchgear.
·Protection devices monitor and control the incoming supply.
·The transformer reduces MV voltage to LV voltage.
·LV switchgear distributes power to plant loads.
·MCCs control motors and process equipment.
·Control systems monitor operation through PLC/SCADA.
·Backup DC and UPS systems maintain critical functions during power interruptions.

Advantages
Rapid Deployment
·Factory assembly minimizes site work
·Short installation period
·Reduced commissioning time
·Reduced Civil Construction
·Requires only foundation and cable connections
·Less building construction
High Quality
·Factory inspection and testing
·Controlled manufacturing environment
·Reduced installation errors
Mobility
·Can be relocated
·Suitable for temporary projects
·Harsh Environment Capability
Suitable for:
·Desert areas
·Offshore locations
·Mining sites
·Remote industrial facilities

Typical Applications
Renewable Energy
·Solar PV plants
·Wind farms
·Battery energy storage systems (BESS)
Industrial Facilities
·Mining operations
·Steel plants
·Cement plants
·Chemical factories
·Oil & Gas
·Refineries
·Offshore platforms
·LNG facilities
·Petrochemical plants
Infrastructure
·Railways
·Airports
·Water treatment plants
·Construction sites

Applicable Standards
·IEC 62271 – High-voltage switchgear and controlgear
·IEC 61439 – Low-voltage switchgear assemblies
·IEC 60076 – Power transformers
·IEC 60529 – Enclosure protection ratings
·IEC 60364 – Electrical installations
·IEEE / NFPA standards (where applicable)

Typical Ratings Summary
·MV Voltage: 3.3–40.5 kV
·LV Voltage: 400–690 V
·Transformer Rating: 0.5–10 MVA+
·MV Switchgear: AIS/GIS
·LV Switchgear: MCC/Switchboard
·Enclosure: Open skid / enclosed skid
·Protection: IP54–IP66
·Installation: Outdoor / Indoor
·Automation: PLC / SCADA
·Service Life: ≥25–30 years

A Skid-Mounted Substation provides a flexible, factory-integrated power distribution solution that combines mobility, rapid installation, and reliable electrical performance. It is particularly suitable for remote industrial projects, renewable energy facilities, offshore applications, and locations where traditional substation construction is difficult or time-consuming.