Flux Permanent Magnet Brushless Research Articles

Performance optimisation of axial flux permanent magnet brushless DC motor for electric vehicle application with the genetic algorithm (GA) approach

This paper presents the multi-objective performance optimisation of an axial flux permanent magnet brushless dc motor for electric vehicle application. An axial flux brushless motor is designed for direct drive application in electric two-wheelers. It is quite important to improve the efficiency and weight simultaneously, hence multi-objective optimisation is performed. The efficiency and weight of the motor are two opposite performance parameters hence it is a challenging task to improve both simultaneously. The main contribution of the present work is to propose the best combination of design variables obtained using the genetic algorithm optimisation technique. The proposed technique is validated with finite element analysis. The proposed optimisation technique is effective in performance improvement of axial flux brushless dc motors and practically implementable. The novelty of the proposed work is performance improvement without increasing manufacturing complexity – cost and adopting new materials. The proposed optimisation technique can be useful for multi-objective performance improvement of any nonlinear design involving various design variables.

Multi-Objective Optimization of an Axial Flux Permanent Magnet Brushless DC Motor with Arc-Shaped Magnets

To get a better electromagnetic performance of an axial flux permanent magnet brushless DC motor (AFPMBLDC), an AFPMBLDC with arc-shaped magnets and its multi-objective optimization design are researched. Firstly, the main design parameters of the AFPMBLDC are proposed, and the initial designs are carried out according to the given requirements. Furthermore, the pole arc coefficient, permanent magnet thickness, permanent magnet arc radius, and air-gap length are selected as optimization factors. Then, an orthogonal experiment table is established, in which the flux density, no-load back EMF, harmonic distortion rate, and output torque ripple are selected as optimization targets. The Taguchi optimization method is adopted to optimize the performance indexes and the optimal parameters are obtained. Finally, the optimized model is constructed, and some simulations are carried out to verify the optimal design. The research results have shown that the air-gap flux density of the optimized AFPMBLDC is reduced to 31.8%, the total harmonic distortion rate of no-load back EMF is less than 7.5%, and the torque ripple is reduced to 4.3%.

Reduction of cogging torque of radial flux permanent magnet brushless DC motor by magnet shifting technique

Introduction. In spite of many advantages of radial flux permanent magnet brushless DC motors it suffers from the distinct disadvantage of high cogging torque. The designer must emphasize to reduce the cogging torque during the design stage. This paper introduces magnet shifting technique to mitigate cogging torque of surface mounted radial flux brushless DC motor. Methodology. Initially 200 W, 1000 rpm surface mounted radial flux permanent magnet brushless DC motor is designed with symmetrical placement of permanent magnets with respect to each other on rotor core. Cogging torque profile of this initial motor is obtained by performing finite element modelling and analysis. Originality. This design has been improved by shifting the position of permanent magnets with respect to adjacent permanent magnets. The effect of magnet shifting on cogging torque has been analyzed by performing finite element analysis. Results. It has been examined that the peak to peak cogging torque is decreased from 1.1 N×m to 0.6 N×m with shifting of permanent magnets respectively.

Optimization of Power Density of Axial Flux Permanent Magnet Brushless DC Motor for Electric Two-Wheeler

The main objective of this work is to optimize the power density of axial flux permanent magnet brushless dc (PMBLDC) motor based on genetic algorithm (GA) technique for performance improvement of electric 2-wheeler. Power density is one of the important performance parameter of motor as it significantly influences overall performance of electric 2-wheeler. Firstly, the rating of electric motor is determined according to the application requirements and vehicular dynamics. Axial flux PMBLDC motor of 250 W, 150 rpm is designed to fit in to the rim of electric 2-wheeler based on assumption of various design variables. The salient contribution of this work is to suggest the best combination of design variables with the application of GA optimization technique for power density optimization. Comparative performance analysis is carried out between initially designed motor and optimized motor. Finally, 3 dimensional (3-D) finite element analysis (FEA) is performed to verify the results obtained from design optimization. Results obtained from FEA fairly validates the initial design and optimized design. It is analyzed that the power density of motor is enhanced by 42.85 % with the proposed optimization technique. The proposed technique is implementable and complexity free. It may further be applied to the performance improvement of a non-linear design comprising different design variables.
 HIGHLIGHTS
 
 Axial flux permanent magnet motors are the most compatible in electric vehicle applications
 Power density is one of the important performance parameters of axial flux permanent magnet motors
 Optimization of power density improves drive range and overall performance of electric vehicle
 Influential design variables are identified based on parametric analysis and its optimization is carried out with an GA based optimization technique with an objective of power density optimization
 Proposed optimization technique is validated with finite element analysis
 
 GRAPHICAL ABSTRACT

Design of 6S8P axial flux permanent magnet brushless DC motor with double-sided rotor

Electric motors developed rapidly in this decade. That is because electric motors have many advantages over conventional engines. The types of electric motors also vary, from low rated power to high rated power. Electric motors become an essential part of many sectors, such as industry and transportation. Brushless Direct Current Motor (BLDC) is one of the electric motors that has been developed because it has advantages compared to BDC motors. Low-power BLDC motors are widely used in several fields, such as computer construction, robots, and aviation. Research on the form of BLDC motor construction needs to be done to find out the maximum performance of a BLDC motor. Testing of a small motor axial flux permanent magnet brushless direct current with the double-sided rotor (AFPM BLDC DR) was carried out to determine the values of rotational speed, torque, mechanical power, and efficiency. Based on the test, a maximum rotational speed of 2365 rpm, the torque of 0.055 Nm, and the effectiveness of 70.34% are obtained.

Optimization of Specific Power of Surface Mounted Axial Flux Permanent Magnet Brushless DC Motor for Electrical Vehicle Application

Optimization of specific power of axial flux permanent magnet brushless DC (PMBLDC) motor based on genetic algorithm optimization technique for an electric vehicle application is presented. Double rotor sandwiched stator topology of axial flux permanent magnet brushless DC motor is selected considering its best suitability in electric vehicle applications. Rating of electric motor is determined based on vehicular dynamics and application needs. Double rotor sandwiched stator axial flux PMBLDC motor is designed considering various assumed design variables. Initially designed axial flux PMBLDC motor is considered as a reference motor for further analysis. Optimization of the specific power of electric motor for electric vehicle applications is a very important design issue. The Genetic Algorithm (GA) based optimization technique is proposed for optimization of specific power of axial flux permanent magnet brushless DC motor. Optimization with an objective of maximum specific power with the same torque rating is performed. Three-dimensional finite element analysis is performed to validate the proposed GA based specific power optimization. Close agreement between results obtained from finite element analysis and analytical design establishes the correctness of the proposed optimization technique. The performance of the improved motor is compared with the initially designed reference motor. It is analyzed that the specific power of axial flux PMBLDC motor is enhanced effectively with the application of GA based design optimization technique.

Optimized design of permanent magnet brushless DC motor for ceiling fan applications

The objective of this research to design a compact electrical motor for a ceiling fan to save more electric power. Presently, single phase induction motor is used for ceiling fan application. Losses generated by single phase induction are more and hence efficiency is lower. In addition, overload is not handled by single phase induction motor whereas DC models can handle a lot of overload quite easily. In induction motor, the rotor frequency is lesser than stator frequency i.e rotor frequency is slip times the stator frequency. AC induction motor uses capacitor in anyone of its phases to excite and rotate the machine, so it is larger in size. In this paper, the axial flux type of permanent magnet machine configuration is selected to propose the optimum design of ceiling fan machine. The proposed configuration has single stator and single rotor for the axial flux permanent magnet Brushless Direct current Motor (BLDC) machine. By using the magnet software, the analysis of proposed machine has been done in terms of various aspects such as the induced voltage, phase current and air gap flux density.

Dynamic performance analysis of electrified propulsion system in electric vehicle

High speed can be achieved by choosing compact size of propulsion system in an electric vehicle (EV). The cost of the propulsion system is one of the major design considerations which fall on the type of motor and controller. The choice of pancake shape Axial Flux Permanent Magnet Brushless DC Motor (AFPM BLDC) reduces the size of the propulsion system and improves the on board space of the EV. The intermittent periodic duty class has been considered to choose the power rating of the AFPM. A new type of Zeta converter is proposed here to regulate the input side DC voltage. The dynamic performance of the EV has been compared with and without Zeta converter which will be useful for the researchers in future.

Selection of Motor foran Electric Vehicle: A Review

In this study, five kinds of drive train systems of the electric motor drives for EVs are discussed. Furthermore, the requirements of EVs on electric motor drives are presented. Hence, a review on motor types and their drives used in EV has been made. The comparative investigation on the efficiency, cost, maximum speed, and reliability is carried out for switched reluctance motor, induction motor, permanent magnet motor, DC motor and axial flux permanent magnet brushless dc motor, in order to find out most appropriate electric motor drives for electric vehicle applications. According to these researches, some conclusions have been obtained. The study shows that axial flux permanent magnet brushless dc motor drives are the prior choice for electric vehicles.

Cogging Torque Reduction of Sandwiched Stator Axial Flux Permanent Magnet Brushless DC Motor using Magnet Notching Technique

Cogging torque reduction of axial flux permanent magnet brushless dc (PMBLDC) motor is an important issue which demands attention of machine designers during design process. This paper presents magnet notching technique to reduce cogging torque of axial flux PMBLDC motor designed for electric vehicle application. Reference axial flux PMBLDC motor of 250 W, 150 rpm is designed with 48 stator slots and 16 rotor poles of NdFeb type permanent magnet without notching. Three dimensional finite element modeling and analysis is performed to obtain cogging torque profile of initially designed reference machine. Notches are created on permanent magnets and its influence on cogging torque is analyzed with 3-D finite element modeling and analysis. It is analyzed that magnet notching is an effective technique to reduce cogging torque of axial flux PMBLDC motor.

Axial flux PM BLDC motor design methodology and comparison with a radial flux PM BLDC motor

The aim of this paper is to develop a methodology to design an axial flux permanent magnet brushless direct current (AFPM) motor for a washing machine and compare the results with a conventional radial flux permanent magnet brushless direct current (RFPM) motor with the same power ratings. The AFPM motor is designed based on the maximum power density for an optimum inner-to-outer diameter ratio by using the reference RFPM motor constraints, such as the same rated torque at the rated speed. Both motors use the same materials in terms of lamination, permanent magnet, and conductor. They both use ferrite magnets; however, the AFPM motor has a surface-mounted structure and the RFPM motor has a buried one. The algorithm is used to determine the motor dimensions such as motor diameters, lengths, and the number of turns. The optimum number of poles considered for the design is chosen. Both motors are analyzed by finite element method (FEM) to verify the analytical approach and are compared in terms of power density, torque density, total weight and volume, torque ripple, and efficiency.

Parametric analysis of axial flux HUB motor for electric vehicles in rural areas

Heavy vehicle transportation in rural areas decreases the load factor and the transportation efficiency because of the size of the vehicle. Transportation efficiency in rural areas can be improved by reducing the size of the propulsion system in the electric vehicle. A pancake-shaped axial flux permanent magnet brushless DC motor is proposed here which has the compact size. The finite element method (FEM) and the Matlab/Simulink models have been developed to analyse its performance. A 2.75 kW motor has been designed using Ansys Maxwell to extract the machine parameters such as armature resistance, armature inductance, weight of the stator, rotor and density. The torque-speed characteristics of the motor have been analysed by varying the motor parameters, snubber parameters and load. Optimum performance of the AFPM motor has been obtained at the value of 2.4 Ω of armature resistance and the moment of inertia of 20.8 e-3 kg m2.

Efficiency Improvement of an Axial Flux Permanent Magnet Brushless DC Motor for LVAD Application

This paper presents the Finite Element Analysis (FEA) based design, optimization and development of an axial flux permanent magnet brushless DC motor for Left Ventricular Assist Device (LVAD). With the design objective of improving the existing motor's efficiency , different topologies of AFPM machine has been examined. Selection of optimal magnet frac-tion, Halbach arrangement of rotor magnets and the use of Soft Magnetic Composite (SMC) material for the stator core results in a novel motor with improved efficiency and torque profile. The results of the 3D Finite element analysis for the novel motor have been shown.Thermal analysis for the existing motor has also been done and the FEA results are compared with the analytical and experimental results.Finally the test results for the novel motor and the general conclusions are also discussed.

Optimization and Comparison of Novel E-Core and C-Core Linear Switched Flux PM Machines

Linear flat switched flux permanent magnet (SFPM) brushless machines have significant potential for many applications including transportation, automobile and aerospace. Novel E-core and C-core linear SFPM machines are proposed and optimized by individual parameter optimization, when the copper loss and volume is fixed, in this paper by finite element (FE) analysis. Then, the results of the individual parameter optimizations are examined by a global optimization with genetic algorithm. Furthermore, the magnet thickness of all the machines and the middle teeth of the E-core machines are analyzed individually. Finally, the electromagnetic performance of the novel machines are analyzed and compared with the conventional machine. It shows that both E-core and C-core machines require significantly smaller magnet volume since only about half the number of permanent magnets is required. Furthermore, the C-core machines have the largest back-EMF and force density due to the largest slot area, and the E-core machines are suitable for fault-tolerant operations while the 6/11 mover/stator pole E-core SFPM machine has the smallest cogging force.

Design and Parametric Analysis of Axial Flux PM Motors With Minimized Cogging Torque

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> This paper deals with analysis and experiment of an axial flux permanent magnet (AFPM) brushless direct current (BLDC) motor with minimized cogging torque. Recently, many optimal designs for the AFPM motor have been done by finite-element (FE) analysis, but such analysis generally is time-consuming. In this study, the equation of magnetic flux lines existing between PMs and cores is assumed mathematically and the minimum cogging torque is calculated theoretically and geometrically without FE analysis. The form of equation is assumed to be a second-order polynomial in this paper. The skew angle that makes the cogging torque minimized is calculated theoretically, and the value of minimum cogging torque is confirmed by FE analyses and experiments. In the theoretical analysis, the maximum cogging torque of a proposed AFPM motor has the smallest value approximately at a skew angle of 4<formula formulatype="inline"> <tex Notation="TeX">$^\circ$</tex></formula> and that value is about the same as those of FE analyses and experiments. Compared with the nonskewed motor, the cogging torque of the skewed motor can be decreased to over 90%, which has a value of 5% of the rated torque. Two types of stator cores, with the skew angle of 0<formula formulatype="inline"><tex Notation="TeX">$^\circ$</tex> </formula> (nonskewed) and 4<formula formulatype="inline"><tex Notation="TeX">$^\circ$</tex> </formula>(skewed optimally), are analyzed, manufactured, and tested experimentally in this paper. </para>

Analysis and experimental validation of performance for an axial flux permanent magnet brushless DC motor with powder iron metallurgy cores

A small axial flux permanent magnet (AFPM) brushless DC servomotor with powder iron metallurgy cores has been designed and built and its results are presented in this paper. To predict the motor performance, 2-D and 3-D finite element analyses have been performed respectively, and the results are compared in terms of computations of the no-load field and the cogging torque. Finally, the computed results and the predicted characteristics are validated by measurements on a prototype AFPM motor.

The design and development of an axial flux permanent magnet brushless DC motor for wheel drive in a solar powered vehicle

This paper presents the development of a weight-power trade-off applicable to high-performance, power limited vehicles. The theory is then applied to the electric vehicle case to justify the pursuit of an the motor design. The singular benefits of axial flux geometry are discussed with reference to the particular requirements of electric motors for vehicular applications. The basic design process, construction, and test results for a motor fitted in a 26 inch wheel to drive a 260 kg all up weight vehicle are presented. At an output power of 1 kW, the attainable vehicle speed is 72 km/h, corresponding to a motor/wheel speed of 578 r/min and torque of 16.5 Nm, at an estimated motor efficiency of 94%. >