In this paper, the magnetic coupling between an induction cooker and a metallic pot is studied for various winding topologies. Effects of the winding orientation on the power transfer capability and on the emitted magnetic field under the cooker are discussed and compared. A novel topology inspired by permanent magnet Halbach array is proposed. This consists in coupling in both horizontal and vertical directions and to create an asymmetric field in order to reduce the emission under the cooker.

Application of linear electric motors to automation of manufacturing processes, gantry robots, machining processes, machining centers, additive manufacturing and laser scribing has been discussed. The paper focuses on replacement of ball lead screw mechanisms with linear electric motors, linear motor driven positioning stages, linear motor driven gantries, machining centers, machining of large objects and industrial lasers. The best linear electric motors for application to machining processes are permanent magnet (PM) linear synchronous motors (LSMs), especially those without PMs in the reaction tail, e.g., high thrust density linear (HDL) LSMs and PM flux switching (FS) LSMs.

In this paper, we proposed how the V-skew applied of the rotor to inprove the characteristics of cogging torque in large PMSM. Large PMSM is difficult to apply a pitch of the diagonal magnetic skew because of the motor's structure and making. In addition, the force in the direction of z-axis occurs when the diagonal skew is applied. So we are applying the optimal v-skew to reduce torque ripple and cogging torque because this reduces the noise and vivration on the motor. Throug FEM dD analysis, we studied to find the optimal v-skew angle for reducing torque ripple.

This paper presents output characteristics of a linear switched reluctance motor (LSRM) with excitation windings wound by using high-temperature superconducting (HTS) tapes. In a double-sided LSRM, Bi-2223 or YBCO tape conductors are used for the excitation windings. The characteristics of the LSRM are obtained by a finite element method analysis. We can obtain large thrust compared with a conventional LSRM by using YBCO tape conductors. Also, the effect of a configuration of the YBCO coil on the thrust is calculated. We discuss a suitable coil configuration for the average thrust upgrading.

The rotor overhang is used to enhance air-gap flux and improve power density. Due to asymmetry in the axial direction caused by the overhang, the time consuming 3D analysis is necessary to design the motor with overhang. To solve this problem, this paper proposes the equivalent magnetic circuit model (EMCM) that can consider overhang effects without the 3D analysis by using effective air-gap length. The analysis time can be reduced significantly via the proposed EMCM. The reduction of the analysis time is essential for the preliminary design of the motor. In order to verify the proposed model, the 3-D finite-element method (FEM) analysis is adopted. 3-D FEM results confirm the validity of the proposed EMCM.

This paper includes new protection concepts and practices to avoid mechanical damage of three-phase transformer by asynchronous operation of synchronous generator. this failure is often caused just after synchronous generator was connected to the grid because of a malfunction of the controller or misconnections of the synchronous devices. The results of the studies on the analyzing the phenomenon of asynchronous operation experienced in Korea and rapidly detecting asynchronous state are descrived.

This paper includes the results of the electromagnetic finite element analysis with regard to overheating problem of the power cable tray due to asymmetric magnetic flux density. This phenomenon was experienced in the utility power plant, Korea. The influences of the power cable arrangements and material of the tray were analyzed to find the best solutions using the eddy current-thermal coupled analysis.

This paper describes analysis of journal bearings lubricated with ferrofluid, which are very suitable for high speed machines. Comparing to conventional lubricants, the coupling of hydrodynamic, thermal and magnetic properties of ferrofluid adds to the complexity in analysis. Modified Reynolds equation and energy equation are derived and solved numerically using finite volume method. Pressure distribution is got which takes temperature effect into consideration. Static characteristics are then discussed. One optimal scheme is also got according to analysis results.

This paper proposes a sensorless speed control based on a novel extension of the torque producing flux (active flux) observer for the surface mounted permanent magnet synchronous machines (SPMSM) without additional high frequency signal injection. From the estimated torque producing flux, the rotor position and speed can be calculated at low speed due to their independency. Therefore, no rotor position sensor is required. Two approaches of the torque producing flux observer are presented and compared. The results show the stability and robustness of the expansion of the torque producing flux observer at low speed for the SPMSM.

An haptic tactile interface (HTI) is presented with its modeling. Its design is dedicated to perform friction coefficient measurement to characterize reachable feelings with that kind of interface. Friction measurements are presented and discussed.

A thermal model of power modules based on the physical dimension and thermal properties is proposed in this paper. The heat path in the power module is considered as a one-dimensional heat transfer in the model. The method of the parameters extraction for the model is given in the paper. With high speed and accuracy, the thermal model is suit for electrothermal simulation. The proposed model is verified by experimental results.

Compensating characteristics of a voltage sag/swell compensator utilizing single-phase matrix converter is examined. First, system configuration and operation for both voltage sag and swell are described. Next, in order to suppress pulsations of the source voltage, a countermeasure using low pass filter and all pass filter is introduced. Then, compensating characteristics of the compensator are investigated for R-L load by simulation. Finally, the validity of the simulated results is confirmed by the experimental results.

The authors study a novel type of elevator emergency stop device which enables to soften impact force at an emergency halt. A new structure of emergency stop devices has been already proposed by our laboratory and also its characteristics has been already proposed by our laboratory and also its characteristics has been shown by digital simulations[1]. In order to confirm the actual effects of our proposed emergency stop device, we have made up a simulator having the same characteristics as the conventional emergency stop device to accomplish the experiments from now on. In this paper, this process is introduced.

Electrical equipments of nuclear power plant are divided into class 1E and non-class 1E. Electrical equipment and systems that are essential to emergency reactor shutdown, containment isolation, reactor core cooling, and containment and reactor heat removal, are classified as class 1E. batteries of nuclear power plant are divided into four channels, which are physically and electrically separate and independent. The battery bank of class 1E DC power system of the nuclear power plant use lead-acid batteries in present. The lead acid battery, which has a high energy density, is the most popular form of energy storage. Kt factor of lead-acid battery is used to determine battery size and it is one of calculatiing coefficient for capacity. this paper analyzes Kt factor of lead-acid battery for the DC power system of nuclear power plant. In addition, correlation between Kt parameter and peukert's exponent of lead-acid battery for nuclear plant are discussed. The analytical results contribute to optimize of determining size Lead-acid battery bank.

The paper presents a novel DC grid connection topology and control strategy for doubly-fed induction generator (DFIG) based wind power generation system. In order to achieve the wind power conversion, the stator side converter and the rotor side converter is used to implement the DFIG control based on the indirect air-gap flux orientation, and a DC/DC converter is used for the DFIG system to DC grid connection. The maximum power point tracking and DC voltage droop control can also be implemented for the proposed DFIG system. Finally, a 4-terminal DFIG-based multi-terminal DC grid system is developed by Matlab to validate the availability of the proposed system and control strategy.

The railway developed countries in Europe, Japan such as ERTMS Regional, FFB, COMBAT, it is the stage of development or testing the train control system for the signal system of branch interval of low density. Similar to the signal system used by the mainline and branch sections of low density domestic portions not suitable in terms of maintenance operational efficiency in accordance with the installation and operation in many cases. Therefore these low-density branch railway lines required that oriented train control system of wireless communication to improve the operation efficiency and line side equipment controlled on board the train. In this paper, We was published a route on setting is the operation of the new on-board oriented train control system for controlling a line converter of the train so that it is possible to improve the operational efficiency of the branch of the low density.

This paper focuses on the design and control of a new concept for wind turbines with a planetary gearbox to realize a power split. This concept, where the generated wind power is split into two parts, is to increase the utilization of the wind power and may be particularly suitable for large scale off-shore wind turbines. In order to reduce the cost of the power electronic devices, a synchronous generator, which is driven by the planetary gear, is directly connected to the power grid without electronic converter. A servo drive, which functions as the control actuator, is connected to the power grid by a power electronic converter. With small scale power electronic device, the current harmonics can also be reduced. The speed of the main shaft is controlled to track the optimal tip speed ratio. Meanwhile the speed of the synchronous generator is controlled to stay at the synchronous speed. The minimum rated power of the servo motor and the converter, is studied and discussed in this paper. Different variants of the wind turbine with a planetary gear are also compared. The controller for optimal tip speed ratio and synchronous speed tracking is given.

A defect which is axially oriented with small size is hard to detect in conventional system. CMFL(Cricumferential Magnetic Flus Leakage) type PIG(Pipelines Inspection Gauge) in the NDT(Nondestructive Testing), is operated to detect this defect called axially oriented cracks in the pipe. It is necessary to decompose the size and shapes of cracks for the manintenance of underground pipelines. This article is focused on the decomposing method of the size and shape of the axially oriented cracks by using inspection signal data for defect.

This paper introduces the high efficiency operation of switched reluctance generator (SRG). The proposed SRG operates under the rated speed. The high efficiency can be obtained by the optimal current shape which can make the total losses minimum. For this purpose, theoretical analysis of the copper and core loss is done. In addition, a modified angle position control (MAPC) method which can get the optimal current shape over wide speed condition is presented. In order to verity the theory, the experimental platform is set up. The feasibility of the theory is verified by the simulation and experimental results. The proposed method is simple, reliable and easy to achieve.