Search

A Dual three-phase winding configuration in a 12-slot 10-pole Brushless Alternative Current Synchronous Motor (BLAC) has been adopting in electrical power steering systems. The main aim of this winding configuration is to get a fault tolerance capability when the motor is a failure. Different arrangements of the coils of the windings are possible to separate the three-phase winding. In this paper, we investigate the effect of the various winding configurations for the fault tolerance on the iron losses of the BLAC motor. To calculate accurate iron losses, we use the instantaneous distribution of magnetic flux from a two-dimensional finite-element method. As a result, we suggest the most effective winding configuration to make the BLAC motor efficiency in the event of the fault.

Flux-reversal machine (FRM) is a new doubly salient stator-permanent magnet (PM) machine with flux linkage reversal in the stator concentrated windings. It can operate in both motoring and generating modes. Its simple structure makes it cost effective and suitable for mass production. However, there is notable permanent magnet flux leakage which deteriorates the torque ability of the FRM. In this paper, a novel design to improve the performance of an FRM is proposed. The proposed FRM has permanent magnets parallel to the stator magnet flux lines and thus is much more difficult to demagnetize. To analyze the characteristics of the proposed FRM, a two-dimensional finite-element method (2-D FEM) is used. The prototype FRM is also built to prove the advantage of the new design method. From the analysis and experimental results, it is shown that the proposed FRM has an improved performance.

A flux-reversal machine (FRM) is a new doubly salient stator-permanent magnet (PM) machine with flux linkage reversal in the stator concentrated windings. It can be driven by 120deg square-wave voltage and use pulse-width modulation (PWM) patterns in two-phase feeding schemes to control the speed of the machine. This paper introduces four PWM modes that used the FRM control system and analyzes the effects of four different PWM modes on the iron loss using a 2-D time-stepped voltage source finite-element method. The iron loss is calculated from the time variation of the magnetic field distribution

This paper describes the effect of pulsating current generated by back-electromotive force (BEMF) current of switch-off phase in flux-reversal machine (FRM) which is driven by 120deg square wave voltage sources. A two-dimension time-stepped voltage source finite element analysis using a direct convergence method is proposed to analyze an electromagnetic field and the BEMF current. To prove the propriety of the proposed analysis method, we build the prototype FRM and a digital signal processor (DSP) installed controller as a set for the experiment

The cogging torque of the flux-reversal machine (FRM) may cause some problems like noise and vibration of the motor. By FEM analysis of the cogging torque of FRM, a noticeable feature was found that the rotor teeth width increases, phase and magnitude of the cogging torque varies. So, the rotor teeth pairing method is proposed for reducing the cogging torque of FRM. In this method, we made a rotor which has two different tooth widths and measured the cogging torque of the motor. From the result, we can see that the simulation result is well matched with the measured result and the proposed method is feasible.

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.

Flux-reversal machine (FRM) is a new doubly-salient stator-permanent magnet (PM) machine with flux linkage reversal in the stator concentrated windings. The simple structure makes it cost effective and suitable for mass production. Also, the FRM has permanent magnets parallel to the stator magnet flux lines and thus is much more difficult to demagnetize. However, in actual application fields such as factory automation and a home appliance, the FRMs adopt permanent magnets with a low intrinsic coercivity and a narrow thickness. In this paper, we especially concentrate on the irreversible demagnetization characteristic of the permanent magnet. To analyze the characteristics of the FRM, a two-dimensional finite-element method (2D FEM) considering the nonlinear analysis of the permanent magnet is used.

Research interest in the switched reluctance motor (SRM) has grown significantly in recent years because of their apparent advantages such as simple construction, fault tolerance and mechanical robustness. In this paper, we deal with the effect of design variables on irreversible magnet demagnetization in the FRM using two-dimensional finite-element method (2-D FEM). The nonlinear characteristic of the permanent magnet is considered as well as that of a magnetic core on each B-H curve. From the analysis results, the most important geometrical dimensions are suggested in terms of irreversible magnet demagnetization.