The module reviews the concepts of modern high-voltage (HV) Electrical Power Systems and their operation. Including: Planning: electrical power system, including generating sources, storage, security and reliability. Operation and Control: Decentralised control; excitation systems, synchronous machines, substation automation. Centralised control, Reactive Power Plant and FACTS Controllers. Shunt and series compensations, VAR compensation. Power Transformers: Review, construction, oil systems, nameplate, specifications. Single and three-phase transformers. Short circuit and inrush currents, surge protection. Control of Power and Frequency: Automatic Voltage Regulators (AVRs), Control Loops, Division of Load, Power-Frequency Characteristic, Computer Control of Load, Frequency & Stability. Control of Voltage and Reactive Power: Review of Reactive Power, Voltage Control, Injection of Reactive Power, Tap-Changing Transformers. Reactive Power Compensation: Shunt Capacitors, Static VAR Control, Series Compensation, Subsynchronous Resonance. HVDC: Review of HVDC converters. Converter station design. HVDC thyristor valves, harmonic filters, Reactive power considerations. Control of HVDC.