Design optimization and efficiency analysis of 12slot-10pole wound field flux switching machine

Abstract

Over the last decade, many Flux switching machines (FSM) topologies have been introduced for various application i.e. automotive, domestic appliances, aerospace etc. FSM can be classified into three groups that are Permanent magnet (PM) FSM, Field Excitation (FE) FSM and Hybrid Excitation (HE) FSM. Permanent magnet and field winding are the main sources of flux in PMFSM and FEFSM while in HEFSM, both field winding and permanent magnet produces the flux. A wound field flux switching motor (WFFSM) is an alternative candidate of non-PM machine for HEV drives. The stator of proposed machine is composed of laminated iron core, armature coils and DC-field excitation coils (FECs) as the only field mmf source. The rotor is made of only laminated iron core similar with Switch reluctance motor(SRM). However, since this machine is operated by 3-phase sinusoidal voltage/current, the acoustic noise is not concerns different from SRM. Several electric motors have investigated for Electric Vehicles such as dc motor, induction motor, interior permanent magnet synchronous motor (IPMSM), wound field segmented rotor (WFSegR) FSM [1], wound field salient rotor (WFSalR) FSM [2] and switched reluctance motor. Based on the exhaustive review on state of the art of electric-propulsion systems, investigations on WFSegR FSM with non-overlap windings and WFSalR FSM with overlap windings are highly dominant due to no permanent magnet which reduced the cost. In spite of their good performances, both machines have certain drawbacks. WFSegR FSM has high efficiency due to less iron and copper losses but has less value of electromagnetic torque. WFSegR FSM cannot be used for high speed applications because of low rotor mechanical stress. WFSalR FSM has robust rotor structure but overlap armature and field windings increased the copper consumption, raised the weight and copper losses of machine and thus reduced the efficiency.