Permanent magnet (PM) excited synchronous machines used in modern drives for electro-mobiles suffer in high speed regions from the limited battery-voltage. The field weakening requires designing machines with reduced power conversion properties or increasing the size of the power converter. A new concept of such a machine features PM excitation, single-tooth winding and an additional circumferential excitation coil fixed on the stator in the axial center of the machine. By the appropriate feeding of this coil, the amplitude of the voltage effective excitation field can be varied from zero to values above those of the conventional PM-machines. The capability of reducing the excitation field to zero is an important safety aspect in case of failing of the feeding convertor.

In the paper a novel mathematical model of electromechanical actuator is presented. It is based on application of Hamiltonian equations in the description of electromechanical energy conversion. It results in employment of flux linkages as state variables in the state space equations. For simplicity only a 3-phase wye connected stator winding without a neutral wire is considered in detail. The procedure can be generalised to any number of phases. Topology-based approach is used in the model implementation. Procedures for evaluation of all quantities (currents, energy/coenergy, electromagnetic torque) present in model equations are described. Eddy currents and hysteresis phenolmenon are neglected in formulation of the model to enable application of state-space description.

In the paper a novel mathematical model of electromechanical actuator is presented. It is based on application of Hamiltonian equations in the description of electro-mechanical energy conversion. It results in employment of flux linkages as state variables in the state space equations. For simplicity only a 3-phase wye connected stator winding without a neutral wire is considered in detail. The procedure can be generalised to any number of phases. Topology-based approach is used in the model implementation. Procedures for evaluation of all quantities (currents, energy/coenergy, electro-magnetic torque) present in model equations are described. Eddy currents and hysteresis phenolmenon are neglected in formulation of the model to enable application of state-space description.