Amin Mahmoudi

AXIAL-FLUX PERMANENT-MAGNET MOTOR DESIGN FOR ELECTRIC VEHICLE DIRECT DRIVE USING SIZING EQUATION AND FINITE ELEMENT ANALYSIS

The design process of a double-sided slotted TORUS axial- ∞ux permanent-magnet (AFPM) motor suitable for direct drive of electric vehicle (EV) is presented. It used sizing equation and Finite Element Analysis (FEA). AFPM motor is a high-torque-density motor easily mounted compactly onto a vehicle wheel, fltting the wheel rim perfectly. A preliminary design is a double-sided slotted AFPM motor with 6 rotor poles for high torque-density and stable rotation. In determining the design requirements, a simple vehicle-dynamics model that evaluates vehicle performance through the typical cruising trip of an automobile was considered. To obtain, with the highest possible torque, the initial design parameters of the motor, AFPMs fundamental theory and sizing equation were applied. Vector Field Opera-3D 14.0 commercial software ran the FEA of the motor design, evaluating and enhancing accuracy of the design parameters. Results of the FEA simulation were compared with those obtained from the sizing equation; at no-load condition, the ∞ux density at every part of the motor agreed. The motors design meets all the requirements and limits of EV, and flts the shape and size of a classical-vehicle wheel rim. The design process is comprehensive and can be used for an arbitrary EV with an arbitrary cruising scenario.

Design, Analysis, and Prototyping of a Novel-Structured Solid-Rotor-Ringed Line-Start Axial-Flux Permanent-Magnet Motor

This paper presents the design process, detailed analysis, and prototyping of a novel-structured line-start solid-rotor-based axial-flux permanent-magnet (AFPM) motor capable of autostarting with solid-rotor rings. The preliminary design is a slotless double-sided AFPM motor with four poles for high torque density and stable operation. Two concentric unilevel-spaced raised rings are added to the inner and outer radii of the rotor discs for smooth line-start of the motor. The design allows the motor to operate at both starting and synchronous speeds. The basic equations for the solid rings of the rotor of the proposed AFPM motor are discussed. Nonsymmetry of the designed motor led to its 3-D time-stepping finite-element analysis (FEA) via Vector Field Opera 14.0, which evaluates the design parameters and predicts the transient performance. To verify the design, a prototype 1-hp four-pole three-phase line-start AFPM synchronous motor is built and is used to test the performance in real time. There is a good agreement between experimental and FEA-based computed results. It is found that the prototype motor maintains high starting torque and good synchronization.

A Comprehensive Review of Axial-Flux Permanent-Magnet Machines

This paper presents a state-of-the-art review of axial-flux permanent-magnet (AFPM) machines in the aspects of construction, features, electromagnetic and thermal modeling, simulation, analysis, design, materials, and manufacturing. Some key references on the above-mentioned aspects pertaining to the machine are discussed briefly. Particular emphasis is given on the design and performance analysis of AFPM machines. A comparison among different permanent magnet machines is also provided. Thus, this paper makes a bridge between the currently used permanent magnet machines in industry and the recent developments of AFPM machines.

Improvement to performance of solid-rotor-ringed line-start axial-flux permanent-magnet motor

This paper presents two design-and-analysis cases of a line- start axial-∞ux permanent-magnet motor: with solid rotor and with composite rotor. For a novel structure of the motor, two concentric unilevel spaced raised rings are added to the inner and outer radii of its rotors to enable auto-start capability. The composite rotor was coated by a thin (0.05mm) layer of copper. The basic equations for the solid rotor ring were extracted. The motors lack of symmetry necessitated 3D time-stepping flnite element analysis, conducted via Vector Field Opera 14.0, which evaluated the design parameters and predicted the motors transient performance. Results of the FEA show the composite rotor signiflcantly improving both starting torque and synchronization capability over solid rotor.

A comparison between the TORUS and AFIR axial-flux permanent-magnet machine using finite element analysis

This paper presents a comparison between TORUS and AFIR, the two topologies for double-sided axial-flux permanent-magnet machines. Their slotted and non-slotted topologies were investigated and compared in terms of power density and torque quality. The critical field analysis of the topologies was by finite element method. Results show TORUS topologys high power-density in high current-density and low electrical-loading. AFIR topology has high power in low current-density and high electrical-loading. Non-slotted TORUS and AFIR AFPM machines have negligible cogging torque and lower ripple torque than their slotted counterparts.

On line trained fuzzy logic and adaptive continuous wavelet transform based high precision fault detection of IM with broken rotor bars

This paper presents an online trained fuzzy logic and adaptive wavelet based high precision fault detection of broken rotor bars for squirrel cage induction motor (IM). Motor faults which consist of broken rotor bars, bearing decay, eccentricity, etc. appears as different frequencies in the stator current signals. The winding function is used to obtain stator current and speed signals at different fault and load conditions. These signals are analysed through the adaptive continuous wavelet transform (CWT) to detect the amplitudes and frequency components corresponding to different fault and load conditions. The coefficients of CWT are adapted online based on the harmonics amplitude, which are the output of CWT. These amplitudes and frequencies are applied to train a fuzzy logic controller (FLC) in simulation. Then the adaptive CWT and trained FLC are applied to detect the fault condition of a large size motor in both simulation and realtime. The experimental results found that the proposed adaptive CWT and FLC based fault detection method can detect the motor fault conditions accurately. Thus, the proposed method could be a potential candidate to detect the motor fault, especially for large size industrial motors.

DESIGN OPTIMIZATION AND ANALYSIS OF AFPM SYNCHRONOUS MACHINE INCORPORATINGPOWER DENSITY, THERMAL ANALYSIS,AND BACK-EMF THD

This paper presents the design and analysis of an inside-out axial-∞ux permanent-magnet (AFPM) synchronous machine optimized by genetic algorithm (GA) based sizing equation, flnite element analysis (FEA) and flnite volume analysis (FVA). The preliminary design is a 2-pole-pair slotted TORUS AFPM machine. The designed motor comprises sinusoidal back-EMF waveforms, maximum power density and the best heat removal. The GA is used to optimize the dimensions of the machine in order to achieve the highest power density. Electromagnetic fleld analysis of the candidate machines from GA with various dimensions is then put through FEA in order to obtain various motor characteristics. Based on the results from GA and FEA, new candidates are introduced and then put through FVA for thermal behavior evaluation of the designed motors. Techniques like modifying the winding conflguration and skewing the permanent magnets are also investigated to attain the most sinusoidal back-EMF waveform and reduced cogging torque. The performance of the designed 1kW, 3-phase, 50Hz, 4-pole AFPM synchronous machine is tested in simulation using FEA software. It is found that the simulation results fully agree with the designed technical speciflcations. It is also found from FVA results that the motor temperature reaches

GENETIC ALGORITHM AND FINITE ELEMENT ANALYSIS FOR OPTIMUM DESIGN OF SLOTTED TORUS AXIAL-FLUX PERMANENT-MAGNET BRUSHLESS DC MOTOR

This paper presents an inside-out axial-∞ux permanent- magnet brushless DC motor optimized by Finite Element Analysis (FEA) and Genetic Algorithm (GA) that uses sizing equation. The double-sided slotted-stator designed TORUS motor has sinusoidal back EMF waveform and maximum power density. The GA obtained the dimensions that gave the motor its highest power density. Field analysis of the dimensions was then put through FEA, to obtain and re-optimize the motors characteristics. Possible design parameters were investigated via use of Commercial Vector Field Opera 14.0 software used in three-dimensional FEA simulation and of MATLAB 2010a in GA programming. Techniques such as modifying winding conflguration and skewing the permanent magnets were explored to achieve the most-sinusoidal back-EMF waveform and minimized cogging torque. The desired technical speciflcations were matched by simulation results of the 3D FEA and the GA. The FEA and the GA simulation results comparison of the ∞ux density in difierent parts of the designed motor at no-load condition agreed well.

Design and performance improvement of a line-start PMSM

This paper presents the design and performance analysis of a line-start permanent-magnet synchronous-motor (LSPMSM) to overcome the efficiency and power factor deficiencies of induction motors. Proper start-up and synchronization are obtained through the design. An optimization algorithm is applied to improve the rotor bar resistance for the smooth line start of the motor. Dynamic d-q modeling and finite element analysis (FEA) are performed to predict the transient and steady state performance of the motor.

Sizing equation and Finite Element Analysis optimum design of axial-flux permanent-magnet motor for electric vehicle direct drive

This paper presents the design process of a slotted TORUS axial-flux permanent-magnet motor suitable for direct drive of an electric vehicle through sizing equation and Finite Element Analysis. AFPM motor is a high torque density motor which can be easily and compactly mounted into the automobiles wheel fitting the rim perfectly. A double-sided slotted AFPM motor with 6 rotor poles for high torque density and stable rotation is the preliminary design. In order to determine the design requirements, a simple vehicle dynamic model evaluating the vehicle performance considering an automobiles typical-trip cursing scenario is considered. Axial-flux permanent-magnet machines fundamental theory and sizing equation are applied to obtain the initial design parameters of the motor with the highest possible torque. The FEA of designed motor was conducted via commercial Vector Field Opera-3D 14.0 software for evaluation and accuracy enhancement of the design parameters. FEA simulation results are compared with those results obtained from sizing equation showing a good agreement of flux density values in various parts of the designed motor at no-load condition. The motor meets all the requirements and limitations of the electric vehicle fitting the shape and the size of a classical rim of the vehicle wheel.