Three-phase Flux Reversal Machine Research Articles

Modelling and performance of three‐phase 6/14 pole flux reversal machine

A three-phase flux reversal machine (FRM) is modelled using the d–q theory. A fictitious ‘electrical gear’ concept is used to simplify modelling and analysis of this machine. The d–q equivalent circuits are proposed based on this gear ratio. A power density of the machine is improved with full pitch winding. The torque obtained with full pitch winding is twice that of concentrated stator pole winding for same input current. FRM with full pitch winding (FPFRM) is compared with the conventional concentrated stator pole winding FRM (CSPFRM). The results obtained using the proposed d–q circuits are compared with those obtained from FEM analysis. A steady-state performance of FPFRM and CSPFRM is evaluated with proposed d–q circuits. To validate the modelling based on d–q equivalent circuits, a 6/14 pole FRM is fabricated with the conventional concentrated stator pole winding and full pitch winding for wind power application. The analytical results are compared with finite element method (FEM) analysis results and experimental results.

Analysis of Flux-Reversal Machine Based on Fictitious Electrical Gear

This paper proposes a concept of fictitious “Electrical Gear” to analyze the flux pattern in the three-phase flux-reversal machine (FRM). The rotating-flux pattern of FRM has either two or four poles depending on the number of stator poles. FRM can be analyzed on similar lines as permanent magnet synchronous machine with the concept of this gear. The flux-density distribution in FRM is analyzed with Fourier analysis. The magnitude of various space harmonics and their contribution to the winding-flux linkages are determined. The procedure for finding the rms value of air-gap flux density from machine dimensions is described. In order to verify the aforementioned analysis, a 6/14 pole FRM with distributed and concentrated windings is designed and fabricated. The experimental results are compared with those obtained from finite-element method simulation studies and analytical results.

Design and analysis of full pitch winding and concentrated stator pole winding three-phase flux reversal machine for low speed application

The flux reversal machine (FRM) is a doubly-salient stator permanent magnet machine with flux linkage reversal in the stator concentrated winding. The existing machines at low speed, low power (2·4 kW, 300 rpm) range are not economical. FRM topology is best suited for this application. An attempt has been made to improve the power density of machine by introducing full pitch winding. Full pitch winding FRM (FPFRM) has higher power density than the conventional concentrated stator pole winding FRM (CSPFRM).Design and comparative analysis of FPFRM and CSPFRM are made. Both machines are designed for 88·58 Nm and 300 rpm. Design details of both machines are presented. Finite Element Method (FEM) analysis is carried out to evaluate and compare the performance of CSPFRM and FPFRM. Series capacitive compensation is provided for better voltage regulation of both machines.

Cost-effective three-phase FRM drive with four switches and bootstrap gate control circuitry

A cost-effective three-phase flux reversal machine (FRM) drive topology, which consists of four main switches with bootstrap gate control circuitry, is proposed. A design guide for a proper profile of bootstrap charging and discharging voltages is proposed by considering the switching sequence for four-switch drives. The proposed design scheme, which considers the switching sequence of a four-switch drive, is verified by a laboratory prototype 100 W FRM.

A Study of the Design for the Flux Reversal Machine

The three-phase flux reversal machine (FRM) is a doubly-salient stator-permanent magnet machine with flux linkage reversal in the stator three-phase concentrated windings. It can operate in both motoring and generating modes. In this paper, we identify stator/rotor geometrical design variables that influence the cogging, interaction torques, and winding flux linkage using a two-dimensional finite-element method and the flux-magnetomotive force diagram technique. Also, the novel design to improve the performance of the FRM is studied both theoretically and experimentally.

Vector Control of Three-Phase Flux Reversal Machine

Three-phase flux reversal machine (FRM) is a novel electric machine which can operate in either generating mode or motoring mode. In this paper, the study of vector control of a three-phase FRM is presented. The machine under study is based on the improved design of the prototype machine which has been built and tested. Encouraging results have been achieved in terms of the feasibility of vector control to the three-phase FRM, the torque smoothness, and the speed transients. It is shown that the three-phase FRM, when properly designed and controlled, is a competent candidate of high-profile industrial drive applications and servo systems.

Design of a Three-Phase Flux Reversal Machine

A comprehensive design of a novel doubly-salient, stator-permanent magnet (PM) three-phase flux reversal machine (FRM) is presented in this paper. FRM has a robust and easy-to-build structure and is suitable for high-speed applications. Detailed design procedures and formulae are given. All of the dimensions of the FRM are derived. Basic parameters are calculated. The most important aspect of this design is to consider the wide operating speed range. The work presented may serve as a guideline for the general principle of design on three-phase FRM. Furthermore, the methodology and formulae introduced in this paper are also applicable to other types of PM and/or reluctance machine.

Three-phase flux reversal machine (FRM)

A flux reversal machine (FRM) is a doubly-salient stator-permanent magnet (PM) machine with a windingless rotor, where the flux reverses polarities in the stator concentrated coils. The FRM may be built in single- or multiple-phase configurations. The three-phase FRM is studied in terms of magnetic field distribution, cogging and interaction torque and self and mutual inductances through finite element analysis (2-D FEA). Rotor/stator geometrical variables that influence the cogging and interaction torques are identified. Rotor skewing to reduce the cogging torque is successfully demonstrated. A suboptimised configuration based on an initial-geometry prototype is documented. Other potential two-, three- and five-phase pole combinations with adequate rotor skewing angle are also given. Low electrical time constant. Low torque ripple and good torque density in a rugged, easily manufactured, novel machine (the 3 phase machine) are proved through FEA. The encouraging results obtained through FEA constitute a strong foundation for the optimal design, and for the analysis of FRM transients and control.