Equivalent circuit modelling of new brushless synchronous alternator

A new type of brushless synchronous machine has been described in the companion paper ‘New brushless synchronous alternator’ (Brown, N.L. and Haydock, L.: IEE Proc., Electr. Power Appl. 2003, 150, (6), pp. 629–635.) The machine combines permanent magnet and wound coil excitation to provide a single-stage brushless alternator. The simple construction conceals a difficult magnetic circuit that displays complex interactions between excitation sources in the presence of saturation and leakage fields. A design procedure for such a machine using equivalent circuit models is described and the theoretical results are compared with measured values.