Analyze Of A New Dual-Redundancy PMSM With Weak Thermal Coupling And No Electromagnetic Coupling

Electromechanical actuator has been widely used for its advantages such as simple,reliable, cheap and easy to control. In advanced aircrafts like airplanes, spaceships andmissiles, in order to make the electromechanical actuator to meet the high reliabilityrequirements, people generally use redundancy technology. And permanent magnetsynchronous motor has high power density and high reliability, so dual-redundancyPMSM is being widely and deeply researched. However, there usually existselectromagnetic coupling and thermal coupling between the two channels in traditionaldual-redundancy PMSMs. Therefore, doing research on dual-redundancy PMSM withweak electromagnetic coupling and thermal coupling has important meaning.The paper proposed a new dual-redundancy PMSM with weak thermal coupling andno electromagnetic coupling. Basing on12-slots10-poles PMSM with double layerfractional-slot concentrated windings, we added a small tooth in the middle of each slotthat has windings of two different phases in it, and then put a heat shield on both sides ofthe small teeth. This not only isolated the windings of each phase physically andelectrically, but also made mutual inductance between phase windings to be zero. Sothere’s no electromagnetic coupling among phases, and normal armature current or faultcurrent from any phase won’t affect windings of other phases. Besides, since there existssmall teeth and heat shields, heat generated by the fault current won’t transfer too muchto the other side of the small teeth, so the windings there can still work normally, and thesystem reliability gets improved.The paper first analyzed the structure and principle of the new proposed motor, thenbuilt a electromagnetic fields model of the motor with the finite element method forsimulation and analysis, to choose its physical parameters, like size of stator and rotor,rotor structure, shape and angle of the new designed small teeth, permanent magnet pole-arc coefficient and so on, to improve the electromagnetic properties of the motor. At lastthe paper built a temperature field model of the motor for simulation and analysis as well,which showed that the thermal coupling between different windings is low. Throughtheoretical analysis and simulation, it’s proved that the proposed motor can achieve thedesired goals, and meet high reliability requirements.