
27-1
27.1 Introduction
Drive systems with AC machines are designed for applications with dierent requirements for a
rotor speed control. In the closed-loop control systems, usually a torque has to be controlled and
machine currents have to be limited. A general idea of designing the controlled drives is based on
the application of a controller, which ensures required dynamical properties for the torque. In case
of AC machines, the torque is generated as the result of mutual interaction between currents and
uxes formed by three-phase, or more general, multiphase systems. Models of AC machines derived
as dierential equations for ...