Applied Mechanics and Materials Vols. 416-417

Abstract: In this paper, two novel structures of linear double salient permanent magnet (LDSPM) motor having magnets and armature windings in primary are proposed and compared. Firstly, the design principles of both motors are presented. Then, for a fair comparison, two motors are designed based on the same primary dimensions including the slot area, teeth number, pole pitch, permanent magnet volumes and coils number per phase, while the stator pole pitch and the primary structure are different. Finally, the configurations and static characteristics of both motors are critically compared based on finite element (FE) analysis. The results indicate that the proposed topology can avoid the asymmetry of back-EMF waveforms and reduce cogging force and thrust force ripple. Also, the proposed primary permanent magnet linear motors are suitable for the longer stator application such as urban rail transit (URT).

Abstract: This paper proposes a linear sandwiched switched flux permanent magnet (LSSFPM) machine and two double-sided linear switched flux permanent magnet (LSFPM) machines havingtoroidal windings. Bothmachines are optimized and then compared with the conventional 6-slot/5-pole LSFPM machine. It is found that the proposed machines exhibithigher magnet usage efficiencies than the conventional LSFPM machine, and the double-sided machines show shorter end-windings, which are benefited from toroidal windings. The performance, including back-EMF, cogging force and average thrust force, are analyzedby two-dimensional (2-D) finite element analysis (FEA).

Abstract: With the increasing requirements for driving comfort and reliability of electric vehicles, the multi-phase fault-tolerant permanent-magnet synchronous machines (PMSMs) have drawn more and more attention. A 40-slot/42-pole five-phase outer-rotor PMSM is investigated. The electromagnetic structure is designed, and the winding configurations, pole-arc coefficient, magnetization direction, and the structure of slot notch are optimized to obtain better machine performance.

Abstract: In this paper, the cogging torque, airgap flux density, back-emf, and losses of a surface-mounted and a hybrid magnetization interior brushless machines with the same stator, airgap width, armature core length, material, permanent magnet consumption, speed and copper loss are compared. The analysis reveals that the loss in rotor back iron of interior motor is higher than that in surface-mounted motor due to the skin effect while the eddy current losses in sleeve and magnets of surface-mounted motor are significant, causing the total losses of surface-mounted motor are higher than that of interior motor.

Abstract: Permanent magnet linear synchronous motors (PMLSMs) is the best driving motor for rope-less hoist system because of the advantages of simple structure, small volume, high force, unlimited hoisting height and speed. In this paper, the finite element method (FEM) is adopted to design a PMLSM with 16-pole 15-slot as a unit for rope-less hoist system. Through the FEM analysis, the EMF constant K_e and the force constant K_f of unit motor were got. Then a direct driving elevator prototype drove by the proposed PMLSM was built. Experimental results show the stable operation performance of the experimental device, having good prospects for the development and application.

Abstract: This paper discusses the design of a fault-tolerant Permanent-Magnet Synchronous Machine (PMSM) for electric vehicles. The investigated machine is a five-phase in-wheel machine with 40 slots and 42 poles. The electromagnetic performance of double layer and single layer windings are compared based finite element analysis. The magnetic isolation abilities of the two winding types are also compared. Finally, a 12kW five-phase fault-tolerant machine which is able to meet the demand of electric drive system is designed and evaluated.

Abstract: This paper proposes an ironless permanent magnet linear synchronous motor (ILPMLSM) with a novel Halbach array. The magnetic flux density distribution of the Halbach array is solved analytically by using the equivalent magnetization intensity method. The expressions of no-load back-EMF and electromagnetic thrust are obtained. All of the results are verified by finite element method and they are coincide very well.

Abstract: Based on the requirement of high-power linear propulsion system, a novel twelve-phase linear induction motor (LIM) with double-sided long stators was designed, and the winding construction of twelve-phase LIM was presented in this paper. On the basis of this, the mathematical model of ABC coordinates for this novel motor was derived, and the rule of the asymmetry of end-winding leakage inductance of the twelve-phase LIM with double-sided long stators, which is determined by the relative space position of the each phase end-winding in the motor, and then this rule was compared with the law of the asymmetry of end-winding leakage inductance of the multi-phase rotating motor. Simulation model of the motor was established, and the electromagnetic properties of the motor is calculated.

Abstract: Long primary double sided linear motor drive technology is applied in electromagnetic aircraft launch application. Due to the structure of the secondary board, there is a great room for the improvement of electromagnetic thrust for the long primary double sided linear motor. This paper studies mainly the secondary structures of the long primary double sided linear motor. The results of this paper lead to a better performance of the motor by the transformation of the structural design of the secondary board.

Abstract: To the problem of Linear motors temperature rise , and according to the basic theory of heat transfer, the heat conduction model of stator slot was established, the thermal conductivity of stator slot and the convection coefficient between the stator and rotor were determined .Based on this , the simulation model of motor transient temperature field operating at the polymorphism was established by using the finite element analysis software such as MagNet and ThemNet. Then the temperature field of the linear motor that work under the long-trem and periodic duty was calculated. Through the contrast and analysis between the simulation results and experimental data, the rationality of the simulation model and the correctness of calculation method were verified, which has effective help to design, manufacture and apply such kinds of special linear motor.