ABSTRACT

The chapter introduces phasor analysis, a powerful and very useful methodology that extends to the sinusoidal steady state all the concepts, theorems, and procedures applied to resistive circuits under dc conditions. The key underlying concept is the transformation of linear differential equations describing the behavior of circuits involving capacitors and inductors under steady-state sinusoidal conditions to algebraic equations involving the imaginary unit j. Appendix D provides an introduction to complex quantities. The v–i phasor relations for resistors, capacitors, and inductors are derived, leading to the concept of impedance. The chapter considers representation of circuits in the frequency domain including several illustrative examples. Analysis of the sinusoidal steady state is the derivation of the currents and voltages in a circuit after a sinusoidal excitation has been applied for a sufficiently long time. The chapter ends with a discussion of phasor diagrams.