Introduction
Substations are critical nodes within the electrical grid. They regulate voltage, provide switching and protection functions, and serve as transition points between generation, transmission, and distribution. Understanding different substation types helps stakeholders design efficient and safe power systems.
Types of substations
1. Transmission Substation
Handles voltages above 110kV, reduces transmission voltage from power stations, and manages large-scale power flow with robust protection systems and high-voltage transformers.
2. Distribution Substation
Reduces voltage from transmission to usable levels (e.g., 33kV to 11kV or 11kV to 0.4kV), delivering electricity to residential and industrial areas.
3. Pole-Mounted Substation
Common in rural and low-load areas, mounted on utility poles. Ideal for 11kV/0.4kV transformation with compact footprint and fast deployment.
4. Underground Substation
Fully enclosed substations in urban spaces. Used where land is scarce or aesthetics are important. Higher cost, but efficient and secure.
5. Mobile Substation
Portable substations on trailers or skids. Used for emergency backup, maintenance bypass, or temporary power supply.
Common Substation Components
- Power Transformers
- Circuit Breakers & Disconnectors
- Busbars
- Surge Arresters
- Instrument Transformers (CTs/VTs)
- Protection Relays
- SCADA and Monitoring Units
Factors Influencing Substation Selection
- Required voltage levels
- Location (urban, rural, industrial)
- Load demand and distribution
- Environmental and space constraints
- Cost, redundancy, and regulatory compliance
PREGUNTAS FRECUENTES
Q1: What’s the difference between transmission and distribution substations?
A: Transmission substations operate at higher voltages to move electricity over long distances, while distribution substations step the voltage down for local delivery.
Q2: Can substations be mobile?
A: Yes. Mobile substations are portable, used during emergencies, planned maintenance, or temporary projects.
Q3: Why use underground substations?
A: They save space in dense urban areas, minimize visual clutter, and offer better protection—ideal for metro systems and CBDs.