Fundamental Concepts in Power System Analysis

In this chapter, the fundamental concepts discussed in power system studies are presented. In this regard, first, the sinusoidal signals and their representations in time and phasor domains are introduced, and then, active, reactive, apparent, and complex powers in a single-phase power system are formulated. Next, the power factor concept and different load types including purely resistive, inductive, purely inductive, capacitive, and purely capacitive are presented. After that, power factor correction for various goals, such as removing overloading or releasing the loading capacity of feeders, postponing installation of new power plants, improving the voltage profile of buses, decreasing power and energy losses of feeders, and minimizing the operation cost of an electrical system, is studied. Afterward, complex power generation-consumption balance and complex power flow are formulated and investigated. Subsequently, balanced three-phase power systems with star- and delta-connected loads are studied. Finally, the per-phase analysis of balanced three-phase power systems and three-phase powers are presented.