PM synchronous machine drives

The purpose of this chapter is to discuss techniques for analyzing and controlling the electrical performance characteristics of permanent magnet (PM) synchronous machines (PMSMs) based on electrical equivalent circuit models for the machine derived in the synchronously rotating reference frame. Representation of the d- and q -axes components of the key machine variables as complex vectors provides a powerful means of graphically illustrating the amplitudes and spatial orientations of these key variables in the machine. This complex-plane representation of the machine-phase currents will be used to investigate the performance limits of the machine at high speeds when operating from a source that is restricted by maximum voltage and current limits.