Predictive Control of Power Converters and Electrical Drives

9.1 Introduction

Permanent magnet synchronous motors (PMSMs) present several characteristics that make them very attractive for drive applications, such as high torque, high power density and efficiency, and excellent dynamic response. Because of these characteristics, PMSMs are suitable for a wide variety of applications including general purpose industrial drives, high-performance servo drives, and several specific applications where size and weight are restricted, as in automotive and aerospace applications.

PMSMs are composed, in general, of three-phase stator windings and an iron rotor with permanent magnets attached to it. The permanent magnets can be mounted on the rotor surface or inside the rotor core. In this way, the magnetic field is fixed to the rotor position. Due to its construction, the rotor's speed is rigidly related to the stator frequency and for variable speed operation a voltage source inverter is required.

Several control schemes have been proposed for the PMSM. Well-established methods are field-oriented control (FOC) [1] and direct torque control (DTC) [2, 3]. The quality of the FOC scheme depends on the performance of the current controllers, the most common being the use of PI controllers with PWM. Other control schemes like hysteresis and deadbeat-based controllers [4, 5] have also been proposed. The use of MPC for current control in a PMSM is presented in this chapter, based on similar control schemes that were reported in [6, 7].

A very different approach ...