Investigation of an Intensifying-flux Variable Flux-leakage Interior Permanent Magnet Machine for Wide Speed Range

In this paper,a novel intensifying-flux variable flux-leakage interior permanent magnet(IFVF-IPM)machine is proposed,in which flux barriers were designed deliberately between the adjacent poles to obtain intensifying-flux effect and variable flux-leakage property.The rotor topology and design principles of the proposed machine are also introduced.Then,a multi-objective optimization method is adopted based on the sensitivity analysis,and some design variables of IFVF-IPM machine with strong sensitivity are selected to optimization progress by using the non-dominated sorting genetic algorithm-Ⅱ(NSGA-Ⅱ).Moreover,the electromagnetic characteristics of conventional IPM machine,conventional IFVF-IPM machine(CIFVF-IPM)and the novel IFVF-IPM machine are compared based on the finite element analysis(FEA)method which includes flux linkage,inductances characteristic,torque-speed envelops and power characteristic,as well as evaluation of the risk of irreversible demagnetization.Finally,the experiment results show that the IFVF-IPM machine has a better performance in flux weakening capability for wide speed range and a lower risk of irreversible demagnetization,which indicates the validity and feasibility of the proposed machine.

Wide Speed Range Permanent Magnet Synchronous Generator Design for a DC Power System

A wide speed range permanent magnet synchronous generator(PMSG)system is studied in this paper,including the PMSG design and comparative study on control strategies with a pulse width modulation(PWM)rectifier,the purpose of which is to regulate the DC-link voltage.It is of great importance to study the foregoing DC power system based on the PMSG and PWM rectifier,where vector control(VC)can be implemented and the corresponding field-weakening strategy can be realized by injecting a field-weakening current component without any auxiliary devices.Large machine inductance is desired in order to limit the short-circuit current and the loaded voltage drop.Different control strategies including VC,direct torque control(DTC)and direct voltage control(DVC)are studied and compared with both simulations and experiments.

Design and Analysis of Wide Speed Regulation of Variable Leakage Flux Reverse Salient-pole Motor

In this article, a new variable leakage flux reverse salient-pole motor(VLF-RSPM) is raised to widen the speed range. The innovation is to realize both reverse salient-pole characteristics and variable leakage flux characteristics by using a method of adding magnetic bridges and magnetic barriers. Firstly, the evolution of the topological structure and working principle of the motor are introduced. Secondly, based on 2D Finite Element Analysis(FEA), the electromagnetic properties and noise of the motor are analyzed in detail, and the electromagnetic properties are contrasted with that of the conventional V-type synchronous motor(CVTSM). The results show that VLF-RSPM has the advantages of small torque ripple, strong magnetic weakening ability, low noise, high efficiency, and low risk of permanent magnet demagnetization under different conditions. In addition, it is verified that the proposed motor extends the speed range.

Design and Optimization of Reverse Salient Permanent Magnet Synchronous Motor Based on Controllable Leakage Flux

In this paper,a controllable leakage flux reverse salient permanent magnet synchronous motor(CLF-RSPMSM)is designed,which has the advantages of wide speed range and low irreversible demagnetization risk.Firstly,the principle of controllable leakage flux and reverse saliency effect is introduced,and the design of the rotor flux barrier is emphatically discussed.Secondly,multiple design variables are stratified by the comprehensive sensitivity method,and the main variables are screened out.Then the relationship between the main variables and the optimization goal is discussed according to the response surface diagram.Thirdly,a sequential nonlinear programming algorithm(SNP)is used to optimize the three optimization objectives comprehensively.Finally,the electromagnetic performance of the proposed motor is compared with the initial IPM motor,the mechanical strength of the proposed rotor is analyzed,and the results verify the effectiveness of the design and optimization method of the proposed motor.