Key Components of MV Metal Enclosed Substations

1. Switchgear

   • Circuit Breakers: Used for interrupting and isolating electrical circuits during faults or maintenance. Types include vacuum, SF6, and air circuit breakers.
   • Disconnectors (Isolators): Ensure a visible break in the circuit for safe maintenance.
   • Load Break Switches: Used to interrupt current under normal load conditions.

2. Busbars

   • Material: Typically made of copper or aluminum.
   • Configuration: Can be single bus, double bus, or sectionalized for flexibility and reliability.

3. Transformers

   • Types: Power transformers or distribution transformers.
   • Cooling: Oil-filled or dry-type, with cooling methods such as ONAN (Oil Natural Air Natural) or ONAF (Oil Natural Air Forced).

4. Protective Relays

   • Function: Monitor electrical parameters and trip circuit breakers during faults to protect equipment and ensure safety.
   • Types: Overcurrent, earth fault, differential, and distance protection relays.

5. Current Transformers (CTs) and Voltage Transformers (VTs)

   • CTs: Measure current and provide isolation between high voltage circuits and measurement devices.
   • VTs: Step down high voltage to a lower level for metering and protection.

6. Meters and Monitoring Equipment

   • Function: Measure electrical parameters such as voltage, current, power, and energy.
   • Types: Analog or digital meters, power quality analyzers, and event recorders.

7. Control and Communication Systems

   • SCADA (Supervisory Control and Data Acquisition): For remote monitoring and control.
   • PLC (Programmable Logic Controllers): Automate control processes within the substation.
   • IEDs (Intelligent Electronic Devices): Provide advanced protection, control, and automation functions.

8. Auxiliary Systems

   • Battery Systems: Provide backup power for control and protection systems.
   • Battery Chargers: Maintain battery health and ensure continuous operation.
   • AC/DC Distribution Boards: Distribute power to auxiliary equipment.

9. Enclosures

   • Construction: Made of metal, providing mechanical protection and shielding from environmental factors.
   • Types: Indoor or outdoor, with ratings for ingress protection (IP) against dust and moisture.

10. Grounding and Bonding Equipment

    • Grounding Grid: Ensures safe dissipation of fault currents into the earth.
    • Bonding Conductors: Connect various metal parts to prevent potential differences.