Mohd Fairoz Omar

Performances comparison of various design slot pole of Field Excitation Flux Switching Machines with segmental rotor

Single-phase Field Excitation Flux Switching Machines (FEFSMs) are increasingly considered as suitable candidate for high speed applications due to their variable flux capability and single piece structure of rotor. However, most of existing FEFSMs have overlap windings between armature and field excitation coil (FEC) which lead to increased size of motor, copper losses as well as material costs. This paper describes the performance comparison of four topologies of FEFSMs, with particularly emphasis on the segmental rotor and non-overlap armature and FEC windings placed on the stator. The performances, including coil arrangement test, back-EMF, flux strengthening, cogging torque, flux line, flux distribution of machines are analyzed and compared by 2D finite element analysis (FEA). The results obtained show that the appropriate combination of stator slot-rotor pole configurations is 12S-6P which provide high torque and power.

New Topology of Single-Phase Segmented Rotor Field Excitation Flux Switching Machine for High Density Air-Condition

Various topologies of 3 phase and single phase Field Excitation Flux Switching Machines (FSMs) have been develop recently due to the advantages of veriable flux capability of DC Field Excitation coil located on the stator as well as robust single piece rotor structure suitable for high speed applications. However, the fundamantel principles of the develop machine with salient pole rotor, requires overlap winding between armature and FEC, creating the problems of high end coil, huge size of motor as well as high copper losses. Therefore, in this paper, a new topology of single phase segmented rotor FEFSM with 12S-6P configuration is presented with the advantage of non overlap armature and FEC windings, a smaller machine with low copper loss is designed. In this study, the principle of single phase 12S-6P with segmental is an investigated using 2D-FEA finite element analysis to validate the torque, speed and power characteristics. As conclusion, the proposed design is suitable for high density air-conditioner because 1kW power generated at 1.8Nm and the corresponding speed of 4977r/min.

Performance Comparison and Analysis of (HEFSM) and (FEFSM) Using Segmental Rotor Structure

This paper presents a new structure of hybrid excitation flux switching motor (HEFSM) using segmental rotor and the comparison of HEFSM and FEFSM using segmental rotor is performed to find the best candidate for hybrid electric vehicles (HEV). (HEFSM) using segmental rotor contains both the FEC and PM on the stator to produce maximum flux linkages. Initially, the coil arrangement tests are examined to validate the operating principle of the (HEFSM) using segmental rotor. Moreover the profile of flux linkage, cogging torque, and torque characteristics at various armature current densities of both the (HEFSM) and (FEFSM) using segmental rotor are observed based on 2D-finite element analysis (FEA). Initially performances show that HEFSM using segmental rotor produces torque of 18 Nm with low cogging torque and sinusoidal flux waveform. Thus by further design optimization the proposed motor will effectively achieve the target performances.

Magnetic Flux Analysis of a New Field-Excitation Flux Switching Motor Using Segmental Rotor

Recently, a three-phase field-excitation flux switching motor (FEFSM) with salient rotor structure has been introduced with their advantages of easy rotor temperature removal and controllable field excitation coil (FEC) magnetic flux particularly suitable for high torque, high power, and high-speed diverse performances. Nevertheless, the salient rotor structure is found to lead a longer magnetic flux path between stator and rotor producing weak flux linkage along with low torque performances. Besides, the overlap armature coil and FEC windings yield high coil end length, producing much high copper loss and large motor size. In this paper, a new FEFSM using segmental rotor with non-overlap armature coil and FEC windings is proposed. The shorter magnetic flux path of the proposed segmental rotor is noticeably more focused to produce much higher torque while the non-overlap armature and FEC will reduce the copper loss and motor weight. Both FEFSMs with salient and segmental rotors are designed using 2-D-FEA JMAG Designer version 14.1 for comparison. As a result, magnetic flux of the segmental rotor design is 11 times higher than the salient rotor structure mainly due to shorter magnetic flux linkage between two stator teeth and single rotor segment. The torque and power of 0.91 Nm and 293 W, respectively, are obtained from the new FEFSM which are much higher than salient rotor design. In addition, the simulation and experimental results show a good agreement in back-electromotive force amplitude and waveform at various speeds, as well as similar increment of torque versus FEC current characteristics. As the conclusion, the proposed FEFSM with non-overlap and segmental rotor structure has produced much higher flux, with significant improvement of torque and power performances compared with existing FEFSM with salient rotor.

Development of a novel permanent magnet flux switching machine prototype for light weight electric vehicles

Increasing transportation efficiency is the best place to start efforts to reduce emission of carbon dioxide (CO2), which is a primary culprit in global warming. This has gained an interest in electric vehicles (EVs) instead of conventional internal combustion engine from automakers, governments and customers to make it as more attractive research. Since electric motors are the core of EVs, it is a pressing need for researchers to develop advanced electric motors. As one of the candidates, flux switching machine (FSM) is introduced in order to cope with the requirement. This paper outlines an investigation and prototype development of a novel FSM employing alternate circumferential and radial flux (AlCiRaF) permanent magnet (PM) configurations. At first stage, the machine general construction, operating principle and design concept of proposed machine is portrayed. Subsequently, coil arrangement test, 3-phase flux linkage, back emf, cogging torque, output torque and power are analyzed by two-dimensional finite element analysis (2D-FEA) using JMAG solver while Solidwork software is utilized for the fabrication process. Accordingly, the simulated result shows that the proposed AlCiRaF PMFSM machine attains its highest output torque performances of 46.55 Nm and output power of 18.5kW at maximum Ja of 30Arms/mm2, respectively suitable for light weight EV.

Load analysis of dual Rotor Hybrid Excitation Flux Switching Machine (DR-HEFSM)

Dual Rotor Hybrid Excitation Machine (DRHEFSM) idea mainly comes from the existing Hybrid Excitation Flux Switching Machine (HEFSM). HEFSM has been tested and obtain remarkably result. The machine rivaled the Interior Permanent Magnet Synchronous Machine (IPMSM) and produce high performance when compared to Field Excitation Flux Switching Machine (FEFSM) and Permanent Magnet Flux Switching Machine (PMFSM). The DRHEFSM operating principle has been tested and confirmed to follow the three phase operating machine principle. Further load analyses are conducted in order to examine the performance of the DRHEFSM. Through the test, the machine torque, speed and power are able to identify. Even though the machine supply equal flux sources to inner and outer rotor, the performance of the inner rotor higher than outer rotor.

Performance comparison of wound field flux switching machines

A flux switching machine (FSM) with a segmented rotor and non-overlap windings is an attractive alternative for driving high torque density applications. However, a rotor with segments makes the motor less robust as well as difficult to be assembled, whilst, FSMs with salient rotor and overlap windings inherit high copper losses and less efficiency due to high coil volume. In this paper, performance analysis of a novel structure of FSM with non-overlap windings and salient rotor are compared with 10Slot-8Pole segmental and salient rotors FSM. Deterministic optimization is adopted to enhance the characteristics of proposed machine. Using two-Dimensional Finite Element analysis, the proposed optimized machine are found to exhibit high torque and power than 10Slot-8Pole segmental and salient rotors FSM.

Performances comparison of 12S-14P field excitation flux switching motor with overlap and non-overlap windings for hybrid electric vehicles

Hybrid electric vehicles (HEVs), using combination of an internal combustion engine (ICE) and one or more electric motors, are widely considered as the most promising clean vehicles. The only machine that already installed for HEVs is interior permanent magnet synchronous machine (IPMSM) where it has developed to enhance power density of the machine. Despite of fine operated and superior performances, this machine do not miss approached by deficiency for instance IPMSM now have complex form and configuration that give difficulty to undertake the process of optimization. Moreover, the use of PM will result in a constant state of flux and cannot be controlled as well a burden because of expensive rare earth magnet prices. Therefore, a new candidate of field excitation flux switching machine (FEFSM), in which the uses of PM are totally excluded with rugged rotor structure suitable for high-speed operation and the ability to keep high torque and power density is proposed and examined in this paper. Under some design specifications, design principles and performances of 12S-14P FEFSMs with overlap and non-overlap FEC and armature coil windings are presented. The profile of flux linkage, induced voltage, cogging torque, torque and power characteristics are observed based on 2D finite element analysis (FEA).

Preliminary Design Analysis of a New Field Excitation Flux Switching Machine with Segmental Rotor and Non-overlap Winding

Recently, a three-phase Field Excitation Flux Switching Motor (FEFSM) with salient rotor structure has been introduced with their advantages of easy rotor temperature elimination and controllable FEC magnetic flux particularly meet for high torque, high power as well as high speed diverse performances. Nevertheless, the salient rotor structure is found to lead a longer magnetic flux path between stator and rotor producing weak flux linkage along with low torque performances. Therefore, a new structure of a single-phase FEFSM using segmental rotor with non-overlap windings is proposed. Segmental rotor and non-overlap windings are the clear advantages of these topologies as the copper losses gets reduce and rotor becomes less weight as well as more robust. Detailed analysis on winding arrangement test analysis, armature and FEC flux linkage, back-EMF and average torque characteristics have been performed by using 2D Finite Element Analysis (FEA) through JMAG version 15 software. The results show that the proposed motor with segmental rotor and non-overlap windings produce short flux path, high flux linkage and the highest torque capability achieved is 0.91 Nm.

Cogging Torque Reduction Technique on E-Core Hybrid Flux Switching Motor by Notching and Pole Pairing

Efficiency, reliability, high power quality and continuous operation are important aspects in electric vehicle attraction system. Therefore, quick fault detection, isolation and enhanced fault-tolerant control for open-switches faults in inverter driving systems become more and more required in this filed. However, fault detection and localization algorithms have been known to have many performance limitations due to speed variations such as wrong decision making of fault occurrence. Those weaknesses are investigated and solved in this paper using currents magnitudes fault indices, current direct component fault indices and a decision system. A simulation model and experimental setup are utilized to validate the proposed concept. Many simulation and experimental results are carried out to show the effectiveness of the proposed fault detection approach.The inverter with critical loads should be able to provide critical loads with a stable and seamless voltage during control mode change as well as clearing time. The indirect current control has been proposed for providing stable voltage with critical load during clearing time and seamless control mode transfer of inverters. However, the islanding detection is difficult since with the indirect current control the magnitude and frequency of voltage do not change when the islanding occurs. The conventional anti-islanding method based on the magnitude and frequency of voltage variation cannot apply to the indirect current control. This paper proposes an islanding detection method for the indirect current control. The proposed islanding detection method can detect the islanding using reactive power perturbation and observation when the frequency and magnitude of voltage don’t vary during clearing time. In order to verify the proposed anti-islanding method, the experimental results of a 600W three-phase inverter are provided.