Power Transmission and Distribution

What Will You Learn?

• Describe the structure of a power system from generation through transmission to distribution and the standard voltage levels used at each stage.
• Explain why electrical power is transmitted at high voltage and calculate how raising voltage reduces line current and I-squared-R losses.
• Identify the main components of an overhead line — conductors (ACSR), insulators, cross-arms, earth wire and towers — and state the job of each.
• Explain sag and tension in conductors, the factors that affect them, and why correct sag matters for safety and clearance.
• Select the correct type of insulator (pin, suspension, strain) for a given voltage and describe corona and string efficiency.
• Explain the purpose and main equipment of a substation and how step-up and step-down transformers change voltage levels.
• Compare radial and ring-main distribution systems and overhead versus underground options, and size the role of feeders and distribution transformers.
• Describe distribution feeder protection (fuses, auto-reclosers, sectionalisers) and the meaning of voltage drop, voltage regulation and power-factor correction.

Requirements

• Fundamentals of Electricity and Electronics (Level 1) or equivalent knowledge of voltage, current, resistance and AC power.
• Protective Devices and Safety (Level 3) or a working understanding of electrical hazards and safe isolation.
• Basic numeracy and algebra for power, current and voltage-drop calculations.
• Strict adherence to high-voltage safety rules: students never work on live HV equipment, only on de-energised training rigs and models.