Ming Cheng

Design and analysis of a new doubly salient permanent magnet motor

This paper presents the design and analysis of a new doubly salient permanent magnet (DSPM) motor. The corresponding output power equation is analytically derived. The initial calculation of motor dimensions and parameters, namely, the core diameter, stack length, permanent magnet size, and winding turns, are also discussed. An 8/6-pole DSPM motor is designed and built for exemplification. Moreover, finite element analysis of this motor is carried out to investigate the magnetic field distribution at different rotor positions and load currents, in which the leakage flux outside the stator circumference of the DSPM motor is firstly taken into account. Hence, the characteristics of the proposed motor are deduced. Experimental results of the prototype are given to verify the theoretical analysis and to confirm its high efficiency.

Nonlinear varying-network magnetic circuit analysis for doubly salient permanent-magnet motors

In this paper, a nonlinear varying-network magnetic circuit (VNMC) modeling method is developed for doubly salient permanent-magnet (DSPM) motors. The method is used to analyze the static characteristics of DSPM motors by specific performance calculations, in which the interaction between the permanent-magnet field and the armature current field, as well as magnetic saturation, are taken into account. Two newly proposed DSPM motors (12/8-pole and 6/4-pole) are used as examples. There is good agreement between the results of the nonlinear VMMC modeling method and finite-element analysis. Moreover, the nonlinear VNMC method offers the advantage of calculating, effectively and efficiently, the static characteristics of DSPM motors having different dimensions, parameters, and conditions. Finally, the proposed method is verified by experimental testing of a 6/4-pole prototype.

Nonlinear magnetic circuit analysis for a novel stator-doubly-fed doubly-salient machine

Summary form only given. The doubly-salient permanent-magnet (DSPM) machine takes the advantages of high power density and high efficiency, but still suffers from limited constant-power speed range and high PM material cost. We propose a novel topology, namely the stator-doubly-fed doubly-salient (SDFDS) machine, which not only solves the problems of the DSPM machine, but also offers the flexibility to on-line optimize the efficiency. In order to effectively analyze and efficiently optimize the proposed machine, a new nonlinear magnetic circuit (NMC) analysis approach is also proposed.

Control and operation of a new 8/6-pole doubly salient permanent-magnet motor drive

This paper proposes a new 8/6-pole doubly salient permanent-magnet (DSPM) motor drive, which offers the advantages of higher power density, higher efficiency, and wider speed range. The corresponding control and operation of the motor drive are presented. A variable proportional-integral (PI) controller combined with bang-bang control for the DSPM motor drive is developed. Two operation modes, namely, four-phase and two-phase operation modes, are proposed for the 8/6-pole DSPM motor drive. The drive system is implemented and tested. The results show that the developed control scheme can operate the DSPM motor properly, and the DSPM motor drive offers high efficiency over wide power range and good dynamic performance. Furthermore, the two-phase operation mode of the 8/6-pole DSPM motor offers the possibility of eliminating the torque ripple of the motor drive.

Performance Analysis of 8/6-Pole Doubly Salient Permanent Magnet Motor

In this paper, a new 8/6-pole doubly salient permanent magnet (DSPM) motor is proposed and analyzed. The key is to analytically derive the output power density of the DSPM motor in terms of the rotor-to-stator pole ratio. Hence, the analytical design, finite element analysis, and computer simulation of the proposed 8/6-pole DSPM motor are presented. Compared with the well-known 6/4-pole DSPM motor, the proposed 8/6-pole offers higher power density, wider speed range, less torque ripple, and less phase current magnitude.

New split-winding doubly salient permanent magnet motor drive

A new split-winding doubly salient permanent magnet (DSPM) motor drive is proposed. This DSPM motor drive offers the advantages of high power density, high efficiency, and wide speed range. The corresponding operation, analysis, implementation, and experimentation are successively presented. Finally, experimental results are used to confirm that the proposed DSPM motor drive offers high efficiency over a wide output power range, exhibits good dynamic performance, and extends the constant-power operation range significantly.

Performance Analysis of Split-Winding Doubly Salient Permanent Magnet Motor for Wide Speed Operation

In this paper, various flux-weakening techniques available for wide speed operation of the doubly salient permanent magnet (DSPM) motor are reviewed. A new split-winding topology capable of widening the speed range is proposed, which is valid not only for the DSPM motor with stationary PMs, but also for that with rotary PMs. Based on the parameters obtained by finite element analysis, the performance of the proposed DSPM motor is analyzed. The results show that this motor combines the features of wide speed range, high efficiency, simple structure, and low cost.In this paper, various flux-weakening techniques available for wide speed operation of the doubly salient permanent magnet (DSPM) motor are reviewed. A new split-winding topology capable of widening the speed range is proposed, which is valid not only for the DSPM motor with stationary PMs, but also for that with rotary PMs. Based on the parameters obtained by finite element analysis, the performance of the proposed DSPM motor is analyzed. The results show that this motor combines the features of wide speed range, high efficiency, simple structure, and low cost.

A new doubly salient permanent magnet motor

In this paper, a new 8/6-pole doubly salient permanent magnet (DSPM) motor is proposed and analyzed. The key is to analytically derive the output power density of the DSPM motor in terms of the rotor-to-stator pole ratio. Hence, the analytical design, finite element analysis and computer simulation of the proposed 8/6-pole DSPM motor are presented. The results show that this DSPM motor has following major features: it can achieve higher power density than an induction motor; its power density is proportional to the ratio of rotor pole and stator pole numbers; there is a maximum speed limitation which is proportional to the voltage but inversely proportional to the phase winding turns and the rate of change of PM flux; at high speed, the distribution of phase current is asymmetric and current regulation is needed in the negative stroke. Compared with the well known 6/4-pole DSPM motor, the proposed 8/6-pole one offers higher power density, wider speed range and less phase current magnitude.