International Journal of Applied Electromagnetics and Mechanics - Volume 59, issue 3

Authors: Baloch, Noman | Khaliq, Salman | Kwon, Byung-il

Article Type: Research Article

Abstract: This paper presents an axial flux dual stator flux modulating synchronous machine, referred to here as axial flux modulating synchronous machine (AFMSM) for simplicity. The proposed machine has dual stators with a non-overlapped concentrated armature winding on the upper stator and field winding on the lower stator. The recently developed radial flux modulation synchronous machine (RFMSM) employs both field winding and armature winding on a single stator. Due to separate winding on different stators in the proposed AFMSM, the armature winding has more freedom of fill factor compared to single stator RFMSM. The surface current density of the proposed machine …can also be doubled compared to the RFMSM due to individual winding on separate stators. Moreover, due to dual stator and axial flux topology, the rotor does not need back iron and the torque to volume ratio of the machine is rather better than single stator radial flux machine. The electromagnetic characteristics of the proposed machine are investigated using 3D finite element analysis (FEA). Two types of rotor pole shapes i.e. general shape and sinusoidal shape have been studied to improve the cogging torque and torque ripple. The performance with both kind of rotor pole shapes have been compared. The variable speed characteristics of the machine are investigated, and it is observed that the speed of the machine can be increased by adjusting the field current. Show more

DOI: 10.3233/JAE-171040

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 59, no. 3, pp. 785-796, 2019

Authors: Ishikawa, Takeo | Watanabe, Taiki | Suzuki, Yuichiro

Article Type: Research Article

Abstract: The authors designed a rotor structure of permanent magnet synchronous machine (PMSM) to develop a large output power by the proposed topology optimization method. As the obtained magnet shape is complex and less practical, this paper proposes a rotor topology of PMSM considering ease of manufacturing. Finite element simulation confirms that the average output power of the designed machine is higher than that of a generator used in Prius under the condition of the same stator, the same weight of rotor and the same permanent magnet volume.

Keywords: Topology optimization, permanent magnet synchronous machine, asymmetrical rotor

DOI: 10.3233/JAE-171030

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 59, no. 3, pp. 797-804, 2019

Authors: Lombard, Patrick | Fireteanu, Virgiliu | Constantin, Alexandru-Ionel

Article Type: Research Article

Abstract: Based on the scalar 3D formulation and the step by step in time domain finite element solution of the electromagnetic field in a squirrel-cage induction motor, the time dependence and harmonics of the electromagnetic torque and rotor unbalanced force are computed. The results for different faulty states of motor operation are compared with those for the healthy motor. In comparison with the healthy state, when the imposed speed motion model for loaded motor operation is considered, only the broken bar fault has a consistent influence on the mean value of the motor torque. Important influences on the mean values …of the rotor unbalanced force are in decreased order the broken bar fault, the rotor eccentricity fault and the stator short-circuit fault. All the three faults generate specific harmonics of the motor torque and of the rotor force. Show more

Keywords: Squirrel-cage induction motor, finite element analysis, broken bar, short-circuit, eccentricity, torque, rotor force

DOI: 10.3233/JAE-171136

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 59, no. 3, pp. 805-815, 2019

Authors: Lee, Ho-Hyun | Woo, Kyung-Il | Park, Han-Seok | Jeon, Hee-Deuk

Article Type: Research Article

Abstract: This paper proposes an evaluation method for the efficiency uncertainty of a three-phase induction motor using the finite element method (FEM). The motor efficiency was calculated by the loss separation method through FEM as in the actual test. The type-A standard uncertainty in FEM was calculated from the RMS values of voltage and current and average values of angular speed and torque during separate periods in the steady state. The type-B standard uncertainty in the FEM was assumed to be zero. In addition, the efficiency uncertainty of the three-phase induction motor analyzed by FEM was compared with that obtained by …the actual test. The results validated the proposed method to evaluate the efficiency uncertainty of the three-phase induction motor. Show more

Keywords: Efficiency, FEM, loss separation method, three-phase induction motor, uncertainty

DOI: 10.3233/JAE-171055

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 59, no. 3, pp. 817-823, 2019

Authors: Sathyan, Sabin | Aydin, Ugur | Lehikoinen, Antti | Belahcen, Anouar | Vaimann, Toomas | Kataja, Juhani

Article Type: Research Article

Abstract: This paper presents the vibration analysis and results of an induction motor through two kinds of magneto-mechanical coupling methods. The computation results are validated by comparing them with the vibration measurements of the motor. The role of both the magnetic forces and magnetostriction are examined and distinguished based on their contribution to the vibration behavior of the machine. It was found that the pole pair number of an induction machine can affect the way the vibrations caused by magnetostriction and magnetic forces either add up or oppose each other.

Keywords: Finite element analysis, magnetic forces, magnetostriction, magnetomechanical coupling

DOI: 10.3233/JAE-171045

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 59, no. 3, pp. 825-834, 2019

Authors: Hong, Do-Kwan | Jeong, Yeon-Ho

Article Type: Research Article

Abstract: The ETC (Electric Turbo Charger) consists of high speed PMSM, ball or air foil bearings, impeller and controller. KERI (Korea Electrotechnology Research Institute) is developing a high speed surface permanent magnet (SPM) type of synchronous motor and a Pulsed Width Modulation (PWM)-driven inverter. This system operates at a power density of 3 kW/kg at 100,000 rpm and is intended to fit the 1,600 cc diesel vehicles to reduce turbo-lag within 0.5 s. The design and analysis of the PMSM for the ETC has been developed successfully considering the several losses and current overload rates using transient computational fluid dynamics (CFD).

Keywords: Electric turbo charger (ETC), high speed permanent magnet synchronous motor, multiphysics analysis, magnetic-forced vibration-acoustic analysis, transient computational fluid dynamics (CFD), thermal stability

DOI: 10.3233/JAE-171239

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 59, no. 3, pp. 835-843, 2019

Authors: Fuzhen, Xing | Zhao, Wenliang | Kwon, Byung-il

Article Type: Research Article

Abstract: This paper proposes a novel rotor strategy for the spoke-type IPM machine (STIPMM) with four surface-mounted ferrite magnets to increase torque density and decrease torque ripple. An asymmetrical rotor structure concept is used during the design process to increase the efficiency of the two torque compositions of the STIPMM, the reluctance torque and the magnetic torque. In this design, the torque is improved by ensuring that the maximum value points of the magnetic torque and the reluctance torque are closer to each other. In order to excavate the greatest potentiality of the initial model, the Kriging method and genetic algorithm …are used to obtain the optimized model. To verify the analysis result, the frozen permeability method (FPM) is employed to provide feasible insights into the separation of the torque components based on a 2-D finite element method (FEM). To highlight the superiority of the initial model, a conventional STIPMM with symmetrical rotor structure is adopted for comparison under the same magnet amounts, machine size and operating conditions. Show more

Keywords: Spoke-type IPM machine, finite-element method, magnetic torque, reluctance torque, Kriging method, genetic algorithm

DOI: 10.3233/JAE-171210

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 59, no. 3, pp. 845-854, 2019

Authors: Zhao, Wenliang | Shen, Haizhen | Chen, Dezhi | Wang, Xiuhe | Kwon, Byung-il

Article Type: Research Article

Abstract: This paper presents a dual-rotor permanent magnet synchronous reluctance machine (PM-SynRM) with toroidal windings to improve the magnetic torque and the utilization of two torque components, thus to obtain high electromagnetic performance, such as torque, efficiency, and power factor. To highlight the advantages of the proposed dual-rotor PM-SynRM, all of its machine characteristics, including airgap flux density, back electromotive force (EMF), torque, power, efficiency, and flux weakening capability are compared to those of a conventional PM assisted SynRM (PMA-SynRM) with the same machine size and operating conditions, with the aid of a finite element method (FEM) using the JMAG-Designer. Furthermore, …the proposed dual-rotor PM-SynRM is verified to have superior endurance against the magnet irreversible demagnetization within five times of the rated current excitation. Show more

Keywords: Dual-rotor, finite element method, permanent magnet synchronous reluctance machine, toroidal windings, torque

DOI: 10.3233/JAE-171185

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 59, no. 3, pp. 855-864, 2019

Authors: Kim, Hong-seok | Kwon, Jung-woo | Kwon, Byung-il

Article Type: Research Article

Abstract: In this paper, comparisons of the interior permanent magnet (IPM) BLDC motor characteristics considering the slot-pole combination and the magnetization direction simultaneously were done. The three directions of magnetization, radial, parallel and concentration were selected and analyzed for the same permanent magnet shape. No-load and load characteristics were compared. As a result, the motor efficiency of the combination of 6-slot and concentration directions was the best. Through analysis and comparisons, it was confirmed that the magnetization direction should also be considered as an important variable in initial design of the motor.

Keywords: Interior permanent magnet, slot-pole combination, magnetization direction, torque ripple, radial force

DOI: 10.3233/JAE-171126

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 59, no. 3, pp. 865-872, 2019

Authors: Bailly, Christophe | Guilly, Gildas | Mavrudieva, Diana | Lombard, Patrick

Article Type: Research Article

Abstract: This paper deals with a multi-physics shape optimization of a fuel pump permanent magnet motor implemented in an airplane wing. The goal is to reduce motor noise by working on both electromagnetic and vibration aspects. A challenge is to maintain the initial electromagnetic performances while reducing the noise. Coupling together EM simulations, vibro-acoustic analysis and optimization method, a noise average reduction of 1 dB and 15 dB for critical frequency has been obtained.

Keywords: Optimization, electromagnetic, vibro-acoustic

DOI: 10.3233/JAE-171115

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 59, no. 3, pp. 873-880, 2019