Cezary Jedryczka, Wojciech Szelag and Zbigniew Jerry Piech
The purpose of this paper is to investigate advantages of multiphase permanent magnet synchronous motors (PMSM) with fractional slot concentrated windings (FSCW). The…
Abstract
Purpose
The purpose of this paper is to investigate advantages of multiphase permanent magnet synchronous motors (PMSM) with fractional slot concentrated windings (FSCW). The investigation is based on comparative analysis and assessment of FSCW PMSM wound as 3, 6, 9 and 12 phase machines suited for low speed applications.
Design/methodology/approach
The investigations are focussed on distortions of back electromotive (emf) and magnetomotive force (mmf) with the torque ripples and motors’ performance taken into account. The finite element models with the aid of customized computer code have been adopted for motor winding design and back emf, mmf and motor performance analyses.
Findings
The novel multiphase winding layouts were found to offer lower content of sub-harmonics in the mmf waveforms compared with the traditional three-phase machine designs. Moreover, the investigated multiphase machines exhibited higher average value of the electromagnetic torque, while the multiphase PMSM machines with FSCW were further characterized by significantly lower torque pulsations.
Originality/value
The analyses presented in this paper demonstrate that PMSM with FSCW are advantageous to their counterpart three-phase machines. Specifically, they offer higher performance and are more suitable to work with multiple drives supplying segmented winding system. This ability of using multi-drive supply for one motor offers flexibility and cost reduction while increasing fault tolerant power train system.
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Mariusz Baranski, Wojciech Szelag and Wieslaw Lyskawinski
This paper aims to elaborate the method and algorithm for the analysis of the influence of temperature on back electromotive force (BEMF) waveforms in a line start permanent…
Abstract
Purpose
This paper aims to elaborate the method and algorithm for the analysis of the influence of temperature on back electromotive force (BEMF) waveforms in a line start permanent magnet synchronous motor (LSPMSM).
Design/methodology/approach
The paper presents a finite element analysis of temperature influence on BEMF and back electromotive coefficient in a LSPMSM. In this paper, a two-dimensional field model of coupled electromagnetic and thermal phenomena in the LSPMSM was presented. The influence of temperature on magnetic properties of the permanent magnets as well as on electric and thermal properties of the materials has been taken into account. Simulation results have been compared to measurements. The selected results have been presented and discussed.
Findings
The simulations results are compared with measurements to confirm the adequacy of this approach to the analysis of coupled electromagnetic-thermal problems.
Originality/value
The paper offers appropriate author’s software for the transient and steady-state analysis of coupled electromagnetic and thermal problems in LSPMS motor.
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Cezary Jedryczka, Wojciech Szelag, Michal Jan Gwozdz and Michal Krystkowiak
The purpose of this paper is to present the electromagnetic phenomena in permanent magnet synchronous generator (PMSG) suited for wind turbines with uniquely designed system of…
Abstract
Purpose
The purpose of this paper is to present the electromagnetic phenomena in permanent magnet synchronous generator (PMSG) suited for wind turbines with uniquely designed system of two windings. The machine’s windings allow for application of a reliable and low-cost power electronic converter.
Design/methodology/approach
The 2D field-circuit model has been developed and used in comparative analysis between reference design PMSG with concentrated three-phase winding and two-windings PMSG to facilitate application of a low-cost and reliable AC/DC power electronic converter. The paper focuses on comparison of radial force density, core losses and torque waveforms in the proposed and reference machine with sinusoidal load currents.
Findings
The usefulness of the proposed approach for analysis of the two-winding PMSG performance by means of the field-circuit model has been proved. The obtained results show practically no drop off of performance of proposed machine in relation to reference PMSG. Moreover, it has been shown that both machines are characterized by the same level of radial force density. Therefore, the lower cost and reliable power electronic converts can be applied in the wind power energy systems (WPES) by slightly more complex design of the stator winding.
Originality/value
The proposed 2D field-circuit numerical model makes it possible to analyze the performance of the star-delta winding PMSG dedicated to be loaded by the AC to DC converter specially designed to achieve high reliability and efficiency of the system. Presented comparative studies on generator performance show that proposed modulated synchronous flux generator characterize with the same output torque at given supply current and core losses level like conventional PMSG with sinusoidal load.
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Wojciech Szelag, Andrzej Demenko and Lech Nowak
The time‐stepping finite method of transient analysis in permanent magnet synchronous machines has been presented. This method has been used for determining the steady‐state and…
Abstract
The time‐stepping finite method of transient analysis in permanent magnet synchronous machines has been presented. This method has been used for determining the steady‐state and dynamic performance of the permanent magnet self‐starting synchronous motor. The movement of the rotor, the saturation of the ferromagnetic core, the properties of permanent magnet and eddy currents in the solid bars of the cage winding have been taken into account.
Deals with coupled electromagnetic, hydrodynamic, thermodynamic and mechanical motion phenomena in magnetorheological fluid brake. Presents the governing equations of these…
Abstract
Deals with coupled electromagnetic, hydrodynamic, thermodynamic and mechanical motion phenomena in magnetorheological fluid brake. Presents the governing equations of these phenomena. The numerical implementation of the mathematical model is based on the finite element method and a step‐by‐step algorithm. In order to include non‐linearity, the Newton‐Raphson process has been adopted. The method has been successfully adapted to the analysis of the coupled phenomena in the magnetorheological fluid brake. Present the results of the analysis and measurements.
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This paper deals with coupled electromagnetic, hydrodynamic and mechanical motion phenomena in magnetorheological fluid devices. The governing equations of these phenomena are…
Abstract
This paper deals with coupled electromagnetic, hydrodynamic and mechanical motion phenomena in magnetorheological fluid devices. The governing equations of these phenomena are presented. The numerical implementation of the mathematical model is based on the finite element method and a step‐by‐step algorithm. In order to include non‐linearity, the Newton‐Raphson process has been adopted. A prototype of an electromagnetic brake has been built at the Poznań University of Technology. The method has been successfully adapted to the analysis of this brake. The results of the analysis are presented.
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Cezary Jędryczka, Piotr Sujka and Wojciech Szeląg
The purpose of this paper is to elaborate upon the mathematical model of coupled electromagnetic, fluid dynamic and motion phenomena that will allow for investigation of the…
Abstract
Purpose
The purpose of this paper is to elaborate upon the mathematical model of coupled electromagnetic, fluid dynamic and motion phenomena that will allow for investigation of the magnetic hysteresis influence on the axial symmetry magnetorheological fluid (MRF) clutch operation.
Design/methodology/approach
To solve the partial differential equations describing magnetic vector and fluid velocity potential distributions in axial symmetry MRF electromechanical transducers the finite‐element methods have been applied. To solve model equations in the time domain, the time stepping method have been adopted. To introduce magnetic hysteresis phenomenon to presented approach the Jiles‐Atherton model have been applied. The physical properties of MRFs have been modeled by means of the Bingham model. Owing to high nonlinearity of the considered problem to solve obtained matrix equations systems the iterative Newton‐Raphson combined with the block over relaxation method have been applied.
Findings
The proposed model of coupled phenomena and the elaborated algorithm for solving the nonlinear model equations can be successfully applied in the analysis of transients in the MRF transducers taking fluid dynamics and magnetic hysteresis into account. Comparison of the measured and calculated clutch characteristics proves the model accuracy. Moreover, it has been shown that the residual magnetic flux density of the ferromagnetic core has significant impact on both to yield stresses forming in MRFs as well as the torque in disengagement clutch operation.
Originality/value
Development of the method for analysis of transients electromagnetic and fluid flow phenomena in MRF transducers taking magnetic hysteresis, electric circuits and motion into account. The presented approach is universal and can be successfully applied in other types of MRF electromechanical transducers such as clutch, brakes, rotary and linear dampers.
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Lech Nowak, Andrzej Demenko and Wojciech Szeląg
This paper deals with a coupled field‐circuit simulation of transients in a three‐phase, three‐limb power transformer taking non‐linearity into consideration. A comparative…
Abstract
This paper deals with a coupled field‐circuit simulation of transients in a three‐phase, three‐limb power transformer taking non‐linearity into consideration. A comparative analysis of the results obtained from the application of 3D and 2D field models has been carried out. Owing to core saturation and the non‐periodic components of the magnetic fluxes, the magnetic field exists also within the space surrounding the core. Hence, three‐dimensional description is necessary. It has been proved that assuming the 2D model significantly overstated peak values of currents are obtained.
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Andrzej Demenko, Ernest Mendrela and Wojciech Szeląg
The aim of the paper is to find the simple and accurate model for the analysis of a drive with a tubular linear permanent magnet machine (TLPMM). Attention is paid to the models…
Abstract
Purpose
The aim of the paper is to find the simple and accurate model for the analysis of a drive with a tubular linear permanent magnet machine (TLPMM). Attention is paid to the models that take into account the saturation effects and is useful in the calculations of electromagnetic forces.
Design/methodology/approach
A circuit model and a field‐circuit model (FCM) are considered. The FCM includes finite element (FE) formulation for the axisymmetric electromagnetic field, equations which define the connections of windings and converter elements, and expressions that describe the control system. The FE method is used to determine the parameters of the circuit model. In order to simplify the circuit model, saturation effects caused by armature reaction are ignored. The electromagnetic force calculation is based on the virtual work principle and uses an approximate expression for the derivative of system co‐energy. The results obtained for the proposed models have been compared.
Findings
The proposed FE method of force calculation conforms with the applied method of movement simulation. For the rotor position when the cogging force is equal to zero the calculated cogging force is “almost” zero within seven‐decimal‐place accuracy. The effects of armature reaction on the performance of a TLPMM machine are similar to those which occur in a classical DC machine; in particular the demagnetising effect caused by saturation is observed.
Originality/value
The paper shows the influence of the saturation effects on the electromagnetic force of a TLPMM. In the case of “strong saturation”, the classical circuit model may be inappropriate for engineering calculations.
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Mariusz Baranski, Andrzej Demenko, Wieslaw Lyskawinski and Wojciech Szelag
The purpose of this paper is to elaborate the method and algorithm for the analysis of electromagnetic and thermal transients in a squirrel cage induction motor.
Abstract
Purpose
The purpose of this paper is to elaborate the method and algorithm for the analysis of electromagnetic and thermal transients in a squirrel cage induction motor.
Design/methodology/approach
The paper presents the special software for transient finite element (FE) analysis of coupled electromagnetic‐thermal problems in a squirrel cage induction motor. The software has been prepared and is successfully applied in the design of special squirrel cage motors, e.g. the motors working in cryogenic conditions. A time‐stepping FE method and transients analysis of an induction motor has been applied. The nonlinearity of the magnetic circuit, the movement of the rotor and the skewed slots have been taken into account. The results of computations have been compared with measurements.
Findings
The method presented and the elaborated specialised software for FE analysis of electromagnetic and thermal transients are used to determine the dynamic performance of the squirrel‐cage induction motor. The results of simulations compared with measurements confirm the adequacy of this approach to the analysis of coupled electromagnetic‐thermal problems.
Research limitations/implications
3D effects have only been taken into account by quasi‐3D techniques (e.g. the multi‐slice for the skewed rotor slots).
Practical implications
The software developed can be useful in the analysis and design of squirrel cage motor, especially motors working in cryogenic conditions.
Originality/value
The paper offers appropriate software for transient analysis of coupled electromagnetic and thermal problems in squirrel cage motors with skewed slots.