Understanding Grid Substation Components
A grid substation is a key part of the power system that helps in transmitting and distributing electricity. It adjusts voltage levels and ensures system safety.
🔧 Main Parts and Their Uses:
⚡ Surge Arrester with Counter – Protects equipment from high voltage (lightning or switching) by diverting it to the ground. The counter shows how many surges happened.
🔋 CVT (Capacitive Voltage Transformer) – Reduces high voltage to safe levels for protection and metering.
🧲 3-Phase Disconnecting Switch with Earthing Blades – Isolates parts of the circuit for maintenance with a clear visible gap.
🔌 CT (Current Transformer) – Converts high current to measurable values for meters and protection systems.
🛑 Circuit Breakers – Stop electricity flow during faults like short circuits or overloads:
🌫️ SF6 Circuit Breaker
💨 Air Circuit Breaker
🧪 Vacuum Circuit Breaker
🔷 Bus Bar – Carries electricity within the substation, connecting equipment like transformers.
🔧 Auxiliary Transformer – Steps down voltage for substation internal needs (lights, control panels, etc.).
🔋 Power Transformer – Converts 132kV transmission voltage to 33kV distribution level. (31.5 MVA, ONAN cooling)
🛡️✅ Power Transformer Protection
The differential protection and restricted earth fault (REF) protection.
safety devices like the pressure relief valve and Buchholz relay.
🧰✅ Transformer & OLTC Maintenance
The routine transformer health checks (oil testing, insulation resistance).
OLTC (On Load Tap Changer) operation for voltage regulation.
🔎✅ Transmission Line Protection Relays
The distance, overcurrent, and directional relays.
The way relays detect faults in real time and improve grid stability.
🦺✅ Safety in High Voltage Work
🏷️ LOTO (Lock Out Tag Out)
🥽 PPE (Personal Protective Equipment)
🔐 Interlocks and 📝 work permits
Understood how safety systems protect technicians and reduce risk.
🔋✅ DC System in the Substation
The setup of battery banks, chargers, and DC panels.
The role of DC systems in relay protection and emergency operations.
The maintenance to ensure long-term DC system performance.
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