Polyphase Systems

Abstract

A polyphase system is one having many phases or voltages, each being phase displaced from the next. In its simplest form, a polyphase supply can be thought of as several alternators mounted on the same shaft and whose outputs are electrically connected, but whose voltages are phase displaced from one another. Examples of phasor diagrams of a two-phase, a three-phase, and a six-phase supply are shown in diagrams (a), (b) and (c), respectively, of Figure 12.1. Since the three-phase supply is the one most widely used, we will pay special attention to it.