Grid stations contain core equipment like power transformers, which change voltage, and switchgear, including circuit breakers and isolators, to control power flow. Busbars provide common connection points, while insulators prevent unintended current. Instrument transformers measure voltage and current, and protective devices like relays and lightning arresters safeguard against faults. Auxiliary equipment includes control rooms, battery systems, and SCADA systems for monitoring. 
Key Equipment and Functions

• Power Transformer:
  Changes high transmission voltages to lower distribution voltages or vice-versa. 
• Circuit Breaker:
  An automatic switch that interrupts fault currents to protect the system and can be operated manually. 
• Isolator (Disconnect Switch):
  Used to isolate a circuit from the power source after the circuit breaker has opened. 
• Busbars:
  Conductive bars that serve as a common connection point for distributing power to various components. 
• Insulators:
  Provide mechanical support and electrical insulation for conductors, preventing unwanted current paths. 
• Instrument Transformers (CTs and VTs):
  Safely reduce high currents and voltages to levels that can be measured by protective relays and meters. 
• Protective Relays:
  Detect faults and abnormal conditions, then signal the circuit breakers to open. 
• Lightning Arrester:
  Protects equipment from overvoltage caused by lightning strikes. 
• Capacitor Banks:
  Used to improve the power factor of the grid by supplying reactive power. 
• SCADA Systems:
  Supervisory Control And Data Acquisition systems monitor and control substation equipment remotely. 
• Control and Battery Rooms:
  House control panels, relays, and meters, with batteries providing essential DC power for protection systems. 
• Earthing System:
  Provides a safe path to the ground for fault currents. 

Equipment Arrangements
Grid stations are arranged with primary equipment located in the "yard" and control equipment in a "control building". 

• Yard Equipment:
  Transformers, circuit breakers, isolators, busbars, and other primary equipment are typically arranged in rows or sections to ensure safe clearance and efficient power flow. 
• Control Equipment:
  Control and relay panels are located inside a control room, where operators can monitor the status of the equipment in the yard, operate switches, and manage the system using the SCADA system. 
• Interconnections:
  Equipment is connected via high-voltage busbars and conductors, with insulators providing support and preventing short circuits. 
• Protection and Control:
  Relays, housed in control panels, are interconnected with current transformers (CTs) and voltage transformers (VTs) to provide the control logic for the circuit breakers. 
• Safety Features:
  Adequate clearances are maintained between equipment, and structures are designed to prevent lightning strikes from causing damage.