Introduction to Electric Power Systems

Summary

The electric power system consists of power generation, transmission and distribution system. Power is generated from two main sources, namely conventional energy sources and non‐conventional energy sources. Three wires are required for powering the three‐phase loads without neutral like motor loads and four wires are required for three‐phase loads with neutral like UPS systems. The three‐phase power supply connections are classified into two types: Star connection or wye connection and the Delta connection. Electrical power is classified into three forms: Real power (W), Reactive power (VAr), and Apparent power (VA). Power factor is the effective usage of real power converted into useful work from apparent power. The electrical loads are classified into two types based on the voltage and current relationship: Linear loads and Non‐linear loads. The power plant or power station, power transmission and power distribution systems are the main parts of an electrical power system.