• Proceedings of the KIEE Conference
• /
• 2006.07b
• /
• pp.653-654
• /
• 2006

This paper proposes a new linear magnetic damper for absorbing shock from a crash accident involving high speed vehicles. The magnetic damper is composed of a conductive plate, a yoke and permanent magnets which are constructed to a Halbach array to improve the damping force. In order to calculate the damping force, finite element analysis(FEA) using J-Mag, a commercial FEA tool, is performed and the results are validated by the experiment. Also, the design optimization of the plate generating the eddy current causing the damping force performed to obtain the most efficient damping force. Finally, the specifications and the performance of the proposed magnetic damper are represented.

• Journal of Electrical Engineering and Technology
• /
• v.6 no.2
• /
• pp.202-207
• /
• 2011

Numerous methodologies have been developed in an effort to reduce cogging torque. However, most of these methodologies have side effects that limit their applications. One approach is the optimization methodology that determines an optimized design variable within confined conditions. The response surface methodology (RSM) and the genetic algorithm (GA) are powerful instruments for such optimizations and are matters of common interest. However, they have some weaknesses. Generally, the RSM cannot accurately describe an object function, whereas the GA is time consuming. The current paper describes a novel GA and RSM hybrid algorithm that overcomes these limitations. The validity of the proposed algorithm was verified by three test functions. Its application was performed on a surface-mounted permanent magnet.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.7 no.6
• /
• pp.517-523
• /
• 2002

A sensorless control of a PM synchronous motor with the compensation of the motor parameter variation is presented. The rotor position is estimated by using the d-axis and q-axis current errors between the real system and motor model of the position estimator. The stator resistance is measured at low speeds when the motor changes its rotating direction and the variation of the stator resistance and back emf constant caused by the temperature variation is compensated. The gains in the position estimator are also adapted according to the motor speeds.

• Proceedings of the KIPE Conference
• /
• 2000.07a
• /
• pp.615-619
• /
• 2000

This paper presents an implementation of digital motion control system of Surface Permanent-Magnet Synchronous Motor(SPMSM) vector drives with a direct torque control(DTC) using the 16bit DSP TMS320F240 The DSP controller enable enhanced real time algorithm and cost-effective design of intelligent control for motors which can be yield enhanced operation fewer system components lower system cost increased efficiency and high performance The system presented are stator flux and torque observer of stator flux feedback model that inputs are current and voltage sensing of motor terminal and angle for a low speed operating area two hysteresis band controllers an optimal switching look-up table and IGBT voltage source inverter by using fully integrated control software. The developed control system are shown a good motion control response characteristic results and high performance features using 1.0Kw purposed servo drive SPMSM.

• Proceedings of the KIEE Conference
• /
• 2003.04a
• /
• pp.116-118
• /
• 2003

The Slotless Permanet-magnet linear synchronous motors (PMLSM) have been developed for factory automation, transportation applications, wafer steppers, conveyance system, and so on[1]. The current analysis and design are treated in air-cored PMLSM. The main purpose of this paper is to provide a general design and analysis framework for the iron-cored linear permanent-magnet machines. Based on field solution using two dimensional analytical technique the magnetic field required magnet volume size, optimal winding thickness size, winding flux linkage and thrust will be discussed.

• Journal of Power Electronics
• /
• v.8 no.1
• /
• pp.23-34
• /
• 2008

This paper deals with a Direct Torque Control (DTC) of an Interior Permanent Magnet Synchronous Motor (IPMSM) for the Electric Vehicle (EV) propulsion system using a Neural Network (NN). The Conventional DTC with optimized switching lookup table and three level torque controller generates relatively large torque ripples in an electric vehicle motor drive. For reducing the torque ripples, a three level torque controller is hereby replaced by the five level torque controller. Furthermore, the switching lookup table of the five level torque controller based DTC is replaced with a Neural Network. These DTC schemes of an IPMSM drive are simulated using MATLAB/SIMULINK. The simulated results are compared with the conventional DTC and it is found that the ripples in the torque, as well as in the stator current, are reduced drastically.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.19 no.5
• /
• pp.463-469
• /
• 2014

This paper proposes a maximum torque operation strategy for the direct torque control of a surface-mounted permanent-magnet synchronous motor (SPMSM). The proposed method analyzes the available operation region of the stator flux of the SPMSM under voltage and current constraints. Based on this analysis, the optimal stator flux trajectory that yields the maximum torque is obtained across the entire operation region, including constant torque and constant power regions. The proposed strategy is also applicable in the flux-weakening region II operation of the SPMSM, which has no speed limit. The validity of the proposed method is verified through experiments conducted on an 800 W SPMSM drive system.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.23 no.4
• /
• pp.240-246
• /
• 2018

In this paper, a sensorless V/f control based on maximum torque per ampere (MTPA) operation for PMSMs is proposed. Given that the MTPA operation is not considered in the conventional sensorless V/f control, efficient PMSM drives cannot be achieved. Therefore, this paper proposes an improved technique based on the d-axis current control to enable the MTPA operation in the V/f control for PMSMs. A stabilization technique is also proposed to improve the dynamic characteristics and stability against load variation. The effectiveness of the proposed technique is verified by conducting experiments with a 250 W SPMSM for driving a blower.

• Proceedings of the KIPE Conference
• /
• 2017.11a
• /
• pp.57-58
• /
• 2017

This paper proposes a high efficiency hybrid generator which has a winding and PM(Permanent Magent) field together. The PM field can supply the enough flux to generate the no-load output voltage, and the field winding current can supply the flux to compensate the voltage drop from the load. Furthermore, the PM exciter can supply the enough power for the field of the generator. The detailed design and the FEM analysis are presented to verify the proposed hybrid generator. Then the experimental results shows the effectiveness of the proposed system.

• The Journal of the Korea Contents Association
• /
• v.14 no.11
• /
• pp.154-163
• /
• 2014

This paper has examined the current status of Korea's welfare policy and asserts the necessity of artist classification by types of employment, dividing them into those who have irregular jobs and those who are in permanent positions, focusing on filmmakers. Furthermore, it has looked into the certification policy for artist welfare support that is currently in action. In conclusion, this paper discusses the certification and suggests implementation methods for "Artist Welfare Card" in expectation of future activation of Artist Welfare Support Project.