• Proceedings of the KSR Conference
• /
• 2011.10a
• /
• pp.2310-2316
• /
• 2011

In order to apply Interior Permanet Magnet Synchronous Motor(IPMSM) to the propulsion system of the railway transit, 110 (kW) class IPMSMs with high-power density are designed as a concentrated winding model and a distributed winding model in this study. The concentrated winding model designed in this study is 6 poles/9 slots and the distributed winding model is 6 poles/36 slots. In general, the eddy current losses in the permanent magnets of IPMSM are caused by the slot harmonics. The thermal demagnetization of the magnet by the eddy current losses at high rotational speed often becomes one of the major problems in the IPMSM with a concentrated windings especially. A design to reduce eddy current losses in permanent magnets design is important in IPMSM for the railway vehicle propulsion system which requires high-speed operation. Therefore, a method to devide the permanent magnet is proposed to reduce the eddy current losses in permanent magnet in this study. Authors analyze the variation characteristics of the eddy current losses generated in permanent magnet of the concentrated winding model by changing the number of the division of the permanent magnets.

• Journal of Electrical Engineering and Technology
• /
• v.10 no.2
• /
• pp.545-550
• /
• 2015

High Temperature Superconducting (HTS) synchronous generators can be designed with either an air-core type or iron-core type. The air-core type has higher efficiency under rated rotating speed and load than the iron-core type because of the iron losses which may produce much heat. However, the total length of HTS wire in the air-core type is longer than the iron-core type because the generated magnetic flux density of the air-core type is low. This paper deals with designs of 10 MW air-core and iron-core HTS wind power generators for wind turbines. Fully air-core, partially iron-core, and fully iron-core HTS generators are designed, and various stator winding methods in the three HTS generators are also considered, such as short-pitch concentrated winding, full-pitch concentrated winding, short-pitch distributed winding, and full-pitch distributed winding. These HTS generators are analyzed using a 3D finite elements method program. The analysis results of the HTS generators are discussed in detail, and the results will be effectively utilized for large-scale wind power generation systems.

• Proceedings of the KIEE Conference
• /
• 2005.07b
• /
• pp.1104-1107
• /
• 2005

This paper presents a comparison of core losses for the four cases of Switched Reluctance Motors (SRM) with different winding method and switching sequence. With concentrated winding SRM, two kinds of switching sequence are considered for one-phase exciting and two-phase simultaneously exciting driving. With both distributed winding and toroidal winding, two-phase exciting driving is considered. The ratio of calculated core losses to input power is able to be used a guide or reference for deciding the winding method and switching sequence of in the initial design stage of SRM.

• Proceedings of the KIEE Conference
• /
• 2003.07b
• /
• pp.1012-1014
• /
• 2003

This paper deals with the characteristic Analysis of synchronous reluctance motors (SynRMs) using coupled Preisach modeling & FEM. The focus of this paper is the characteristic Analysis relative to Inductances and losses on the basis of stator slot number, winding in SynRMs. The coupled Finite Elements Analysis (FEA) & Preisach model has been used to evaluate the nonlinear solution. Comparisons arc given with characteristics of normal distributed winding SynRM and those according to stator slot number, winding in concentrated winding SynRM, respectively.

• Proceedings of the KIEE Conference
• /
• 2006.04b
• /
• pp.83-86
• /
• 2006

A grid-connected distributed generation system which consists of engine generator, dc link with multiple energy sources and inverter is proposed. All six of the stator leads of the generator, which is a surface mount permanent magnet machine, are brought out to the terminal of the generator. Three leads are connected to the inverter and the others are connected to the utility grid. In this proposed system the power from the engine-generator and the power from dc link can be controlled simultaneously by only one three-phase power converter. A control algorithm for the system is developed and verified by experiment results.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
• /
• 2003.02a
• /
• pp.58-61
• /
• 2003

A typical HTS power transmission cable has multi-layer conductor structure to increase the current capacity. The current distribution among the conductor tapes is controlled mainly by pitches and winding directions of the layers, because the inductance of the layer is determined by the pitch and the winding direction. However, usually the current is not evenly distributed among the layers. This paper describes a method to make the current distribution more uniform and hence reduce the AC loss. If we choose a good combination we can find the optimal pitches and make an even current distribution. We studied the effect of the winding direction on a 2-layer cable by a statistical way. Calculation results and discussions will be presented.

• Proceedings of the KIEE Conference
• /
• 2006.07b
• /
• pp.785-786
• /
• 2006

Performance comparison of IPMSMs with distributed and concentrated winding is presented in this papcr. Two IPMSMs have been designed and fabricated with identical rotor dimension, air-gap length, series turn number, stator outer radius, and axial length except winding configuration. Basic parameters and machine performance, such as resistances, back emf, output torque, and efficiency, are compared. From the comparison results, motor design considering winding configuration is discussed.

• Journal of Magnetics
• /
• v.18 no.1
• /
• pp.65-73
• /
• 2013

In this paper, design and performance analysis of robust and inexpensive permanent magnet-assisted synchronous reluctance generators (PMa-SynRG) for tactical and commercial generator sets is studied. More specifically, the optimal design approach is investigated for minimizing volume and maximizing performance for the portable generator. In order to find optimized PMa-SynRG, stator winding configurations and rotor structures are analyzed using the lumped parameter model (LPM). After comparisons of stator windings and rotor structure by LPM, the selected stator winding and rotor structure are optimized using a differential evolution strategy (DES). Finally, output performances are verified by finite element analysis (FEA) and experimental tests. This design process is developed for the optimized design of PMa-SynRG to achieve minimum magnet and machine volume as well as maximum efficiency simultaneously.

• Proceedings of the KIEE Conference
• /
• 1994.11a
• /
• pp.104-106
• /
• 1994

In this study, electrical stress of the steep-fronted surge voltage which is distributed into motor winding in switching has been analyzed by multiple-conductor transmission equation. We see that the greatest electrical stress appears at the last turn of the first coil of motor.

• Proceedings of the KIEE Conference
• /
• 2006.07b
• /
• pp.765-766
• /
• 2006

Interior Permanent Magnet Synchronous Motor(IPMSM) have many advantages such as high power density, wide speed range and so on. With the IPMSM, miniaturization and energy efficient design can be achieved in comparison with Surface Permanent Magnet Synchronous Motor(SPMSM). In order to secure miniaturization and manufacturing efficiency of the motor, it has concentrated winding, because concentrated winding can reduce the motor volume and make manufacturing to be simple compared with the distributed winding. However, according to the pole-slot combinations motor parameters can be changed and unexpected normal force can be generated. Especially, unbalanced normal force in airgap can cause serious vibration and acoustic problem. Accordingly, in this paper, normal force and parameters variation of concentrated winding IPMSM are investigated according to the pole-slot combinations.