Analytical calculations of electromagnetic quantities for wound rotor salient-pole synchronous machines

Purpose This paper aims to present an analytical electromagnetic model for wound rotor synchronous machines with a salient-pole rotor structure based on the two-dimensional subdomain technique. Design/methodology/approach The machine is divided into five active sub-regions: stator slots, stator slot openings, air gap, rotor slots and rotor slot openings. For each sub-region, the governing partial differential equations are derived and solved analytically. Findings The magnetic flux density distributions in all active sub-regions are analytically computed and other quantities such as back-emf, inductances, electromagnetic torque and unbalanced magnetic forces are also analytically calculated. The results of the analytical model are compared to those obtained from the finite element analysis to show the accuracy of the proposed model. Originality/value The two-dimensional analytical model of a wound rotor salient-pole synchronous machine using the sub-domain technique is the main contribution of the research.