ABSTRACT
This chapter is one of several providing a very basic review of those major concepts of electrical circuits that we need in order to understand electrical power systems. In this chapter, we review basic electrical quantities and circuits, introducing Ohm’s law and the fundamentals of circuit analysis methods including Kirchhoff’s voltage and current laws, nodal and mesh analysis, and Thévenin and Norton theorems. In preparation for understanding power transfer, we cover modeling of voltage and current sources and the basics of maximum power transfer. In this chapter, we will focus on direct current (DC) circuits, and later, in Chapter 5, we introduce alternating current (AC) circuits. This topic is expanded in Chapter 8 discussing AC circuit analysis and power calculation for AC circuits, and in Chapter 10 when we introduce transformers and three-phase circuits. Basic DC circuit analysis is covered in many textbooks used in introductory circuit analysis courses and can serve as supplementary material [1-3]. Reviews are also available in textbooks devoted to renewable energy [4,5].
Electrical charge is a fundamental property of matter that can both generate and interact with electromagnetic fields. Charge can be positive or negative; at the subatomic level, protons represent positive charge, whereas electrons have negative charge. The unit of charge is the coulomb or C, where 1 C is the equivalent charge of 6.2 × 1018 electrons. In a conductor, free electrons can flow and represent a movement of negative charge.
