Assessment of Losses in a Brushless Doubly-Fed Reluctance Machine

The brushless doubly-fed reluctance machine is attracting attention because it has no brushes and a reduced converter drive requirement. It has a reluctance type of rotor of p pole pairs. The stator will have two sets of 3-phase windings with p plusmn 1 pole pairs. Previous studies have concentrated on the control of the machine. The machines used usually have axial rotor laminations; this is a modification from the synchronous reluctance machine. However, in the doubly-fed application the rotor experiences rotating flux waves which can produce lamination eddy currents which could cause excess losses. This paper seeks to investigate this and compare to a radial laminated rotor using a 2/6 pole arrangement, (with 2 pole power and 6-pole control windings).