Goga Cvetkovski

Improved design of a novel PM disc motor by using soft magnetic composite material

Summary form only given. We present some aspects of soft magnetic composite (SMC) material application in electrical machines. The object applied in the research is an inverter fed double sided axial field permanent magnet disc motor having two stators with 36 slots each and a centred rotor with 8 skewed neodium-iron-boron permanent magnets. Although the SMC materials have low permeability and high iron loss at low frequencies they are still very attractive for manufacturing the stator cores of permanent magnet motors in general. We present not only the construction procedure improvement of the permanent magnet disc motor (PMDM), but also an improvement of the PMDM parameters, magnetic field and magnetic characteristics when SMC material is used as a magnetic material for the stator construction. The complex analysis of the electromagnetic characteristics will also be performed.

Efficiency maximisation in structural design optimisation of permanent magnet synchronous motor

In this paper a topology optimal design of a permanent magnet synchronous motor (PMSM) based on efficiency maximisation is performed. In the design procedure performed on the PM synchronous motor, genetic algorithm, as an optimisation tool is used. The optimal design of the PMSM is based on previously performed 2D FEM magnetic field calculation and analysis of the motor. Comparative values of the efficiency improved motor parameters in relation to the basic model, as well as the results of the 2D FEM magnetic field calculation for both models are presented.

Cogging torque minimisation of PM synchronous motor using genetic algorithm

The minimization of the torque ripple in permanent magnet synchronous motors (PMSM) is generally achieved by a special motor design which in the design process involves a variation of many geometrical motor parameters. In this paper a new approach is introduced where genetic algorithm is used as an optimization tool where the maximum value of the cogging torque is used as an objective function. Therefore a proper mathematical presentation of the cogging torque for the analyzed synchronous motor is developed. Finally the initial motor and the optimized motor model are modeled in FEMM software which is based on finite element method. The cogging torque is analytically and numerically calculated and the results for both models are presented.

Genetic Algorithm Applied in Optimal Design of PM Disc Motor Using Specific Power as Objective

In general the optimal design of electrical machines is a constrained maximization/minimization problem with a big number of optimization parameters and variety of constraints. This makes it a difficult problem to solve for the deterministic methods, but on the other hand quite an easy task for the stochastic methods, especially for the Genetic Algorithms (GAs). When optimizing an electric motor, there are multiple choices of the objective function available. The objective function is the specific property of the machine to be optimized, for example efficiency, torque, volume or cost. The application of the permanent magnet disc motor (PMDM) is in electric vehicle and therefore there are several objectives that should be tackled in the design procedure, such as an increased efficiency, reduced total weight of the motor or increased power/weight ratio (specific power). In this work an optimal design of a PMDM using specific power as objective function is performed. In the design procedure performed on the PM disc motor, genetic algorithm, as an optimization tool is used. Comparative analysis of the optimal motor solution and its parameters in relation to the initial model is presented.

Hybrid analytical - FEM analysis of single phase Permanent Magnet Synchronous Motor

Self-starting single-phase Permanent Magnet Synchronous Motors (PMSM) are widely accepted as low-power motors in many domestic appliances. In the paper a hybrid analytical-FEM approach for full performance analysis of a PMSM is presented. At the beginning, the magnetic circuit theory as an essential approach and Finite Element Method (FEM) as a powerful numerical approach are employed for determination of the most important parameters and steady-state characteristics. After, the calculated results are implemented in a simulation approach based on a MATLAB/Simulink environment. The final results are the dynamic characteristics, developed for variety of the motor starting conditions. On the basis of the determined characteristics, the full performance analysis, including steady-state and transient operation of the studied motor is carried out.

Specific power as objective function in GA optimal design of permanent magnet disc motor

Purpose – The application of the analysed permanent magnet disc motor (PMDM) is in electric vehicle and therefore there are several objectives that could be tackled in the design procedure, such as an increased efficiency, reduced total weight of the motor or increased power/weight ratio (specific power). The purpose of this paper is to perform an optimal design of a PMDM using specific power as objective function. In the design procedure performed on the PMDM, genetic algorithm (GA), as an optimisation tool is used.Design/methodology/approach – The created optimal design programme genetic algorithm for optimal design of electrical machines is using the GA as an optimisation tool. According to the design characteristics of PMDM, some of the parameters are chosen to be constant and some variable. A comparative analysis of both motor models based on the values of some specific parameters is performed.Findings – From the comparative data analysis of both motor models, it can be concluded that the main object...

Performance optimization of a permanent magnet synchronous motor by sampling based sensitivity analysis

In the paper the design optimization procedure of a permanent magnet synchronous motor (PMSM) based on the sensitivity analysis (SA) of selected samples of parameters is developed. Seeking for better operating characteristics of an existing permanent magnet synchronous motor the aim is, by easy-to-make changes in the motor topology, to improve its performance and to increase pull-up capabilities and stability. During the proposed procedure several constraints will be taken into consideration. Full performance analysis of the initial motor (original model) and the developed new one (optimal model), by using the results of magnetic field calculations is presented.

Study of the performance characteristics of a surface permanent magnet motor at various magnetization patterns

Purpose In the present paper the influence of the magnetization patterns of rotor magnets on the performance characteristics of a surface permanent magnet (SPM) motor has been investigated. The purpose of this paper is to show how the electromagnetic and electromechanical characteristics of this type of motor can be significantly changed by applying various magnetization patterns of permanent magnets (PM) on the rotor surface. Design/methodology/approach First, a survey of possible and most frequently used magnetization patterns for PM motors is presented. The research is focussed on the comparison of performance characteristics and is developed at three levels. The study starts with investigation of a conventional SPM motor having segmented PM, and two magnetization patterns are considered: parallel and radial. As there was no significant difference in motor performance at parallel and radial magnetization, for further investigation only radial magnetization, being more conventional, was considered. In the second step, the counterparts of SPM with two Halbach array configurations, under the constraint of fixed magnet volume, are studied. Finally, detailed comparative analyses of SPM at radial, Halbach 1, and Halbach 2 magnetic patterns are presented. The advantages and drawbacks of the suggested magnetic configurations are then discussed. Findings The authors have shown how the magnetization pattern of rotor PM can have a substantial impact on the SPM motor performance characteristics. From the analysis of magnetic field properties at various types of magnetization, it is observed that both the shape and the rates of the characteristics, for radial magnetization and Halbach 2 configuration, exhibit similar features. This is because the Halbach 2 array cancels the magnetic flux above the PM – that is, it strengthens the magnetic field in the rotor, and enhances the coupling between the rotor and stator magnetic field. It is worth emphasizing that, because of less saturation of the magnetic core and lower iron loss at Halbach 1 and Halbach 2 magnetization, it is possible to increase the armature current and consequently increase the electromagnetic torque. This finding could be an interesting for further research. Originality/value The paper presents an original comparative analysis of the performance characteristics of a surface permanent motor at various magnetization patterns. The novelty of the paper is seen in the introduction of two Halbach magnetization arrays for PM and improvement of the performance characteristics of the analysed motor.

Analysis of the stator topology impact on cogging torque for surface permanent magnet motor

Purpose – The purpose of this paper is to investigate the impact of the stator core design for a surface permanent magnet motor (SPMM) on the cogging torque profile. The objective is to show how the cogging torque of this type of motor can be significantly reduced by implementing an original compound technique by skewing stator slots and inserting wedges in the slot openings. Design/methodology/approach – At the beginning generic model of a SPMM is studied. By using FEA, for this idealised assembly, characteristics of cogging and electromagnetic torque are simulated and determined for one period of their change. Afterwards, actual stator design of the original SPMM is described. It is thoroughly investigated and the torque characteristics are compared with the generic ones. While the static torque is slightly decreased, the peak cogging torque is almost doubled and the curve exhibits an uneven profile. The first method for cogging torque reduction is skewing the stator stack. The second technique is to in...

Synthesis and analysis of a high‐performance low‐cost permanent magnet brushless DC motor

Purpose – The paper presents design development of a novel high‐performance low‐cost 6/4 pole permanent magnet brushless DC (PMBLDC) motor. The objective is to show how the cogging torque of this new design is minimised by determining the optimum stator pole arc length and the best shoe thickness.Design/methodology/approach – At the beginning a step‐by‐step design synthesis of a reference 6/4 pole PMBLDC motor with concentrated 3‐phase windings and asymmetric stator pole arcs is presented. It is followed by a full performance analysis of the reference motor. The FEM for electromagnetic field computation is employed. The characteristics of the motor are calculated and analysed. By simple variation of the stator pole geometry, two‐stage design optimisation for cogging torque minimisation is performed, and an optimised motor model is proposed. The comparative analyses of the reference and optimised motor models show the advantages of the proposed novel design.Findings – The focus is to show the sensitivity o...