The synchronous machine with a divided winding rotor

The stability limitations of an alternator with a ‘conventionally-wound-rotor’ (cwr) can be overcome by using an alternator with a 'divided-winding-rotor, (dwr) with suitable control. The development of the dwr machine is reviewed and the physical aspects of winding arrangement, selection of control gear, synchronization and control of the power factor of the dwr machine, are discussed. The two-axis theory is used to analyse the machine behaviour and typical performance curves are presented. The cwr and dwr machine performance are compared with one another and future manufacturing and operating problems are considered.