A.c. circuit analysis

Abstract

Publisher Summary This chapter presents the alternating circuit analysis. Circuit theory and analysis of alternating circuits is invariably achieved using complex numbers (otherwise known as symbolic or j). The effect of multiplying a phasor by j is to rotate it in a positive direction on an Argand diagram through 90° without altering its length. There are a number of circuit theorems that have been developed for solving problems in alternating current electrical networks. These include: (1) the superposition theorem, (2) Thevenin's theorem, (3) Norton's theorem, and (4) the maximum power transfer theorem. As a preliminary to using circuit theorems, star-delta and delta-star transformations may be used. Any network containing one or more current or voltage sources and linear impednaces can be reduced to a Thevenin equivalent circuit. When a load is connected to the terminals of this equivalent circuit, power is transferred from the circuit to the load. Sometimes networks are complicated and may be transformed using delta-star or star-delta transformations as a preliminary to using a circuit theorem.