• Proceedings of the KIPE Conference
• /
• 2001.07a
• /
• pp.252-255
• /
• 2001

In this paper, a mathematical model of permanent magnet synchronous motor (PMSM) fed by inverter with Direct Torque Control (DTC) Dynamic and steady state characteristics of PMSM is simulated and analyzed: electro-magnetic torque response, speed response, locus of the stator flux linkage. It is mathematically proven that the increase of electromagnetic torque in a permanent magnet motor is proportional the increase of the angle between the stator and rotor flux linkages, and, therefore, the fast torque response can be obtained by adjusting the rotating speed of the stator flux linkage as fast as possible. The simulation results verify the proposed control and also show that the torque response under DTC is much faster than the PWM current controlled drive.

• Proceedings of the KIEE Conference
• /
• 1993.07b
• /
• pp.1051-1053
• /
• 1993

In this paper, the new flux weakening contol algorithm for the drive system of Interior Permanent Magnet Synchronous Motor(IPMSM) is proposed which includes the feedback of torque and current The torque error is used in order to control the current phase angle in the field weakening control. The proposed control method is compared with the stator flux oriented vector control method. Through the simulation the prominence of the proposed control method is verified.

• Journal of Power Electronics
• /
• v.19 no.4
• /
• pp.956-967
• /
• 2019

This paper introduces a virtual signal injected maximum torque per ampere (MTPA) control strategy for direct-torque-controlled five-phase interior permanent magnet synchronous motor (IPMSM) drives. The key of the proposed method is that a high frequency signal is injected virtually into the stator flux linkage. Then the responding stator current is calculated and regulated to compensate the amplitude of the flux linkage. This is done according to the relationship between the stator current and the stator flux linkage. Since the proposed method does not inject any real signals into the motor, it does not cause any of the problems associated with high-frequency signals, such as additional copper loss and extra torque ripple. Simulation and experimental results are offered to verify the effectiveness of the proposed method.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2006.10a
• /
• pp.187-188
• /
• 2006

• Journal of Electrical Engineering and Technology
• /
• v.10 no.3
• /
• pp.1025-1034
• /
• 2015

This paper presented an improved analytical method for calculating the open-circuit magnetic field in the surface-mounted permanent magnet machines accounting for slots and eccentric magnet pole. Magnetic field produced by radial and parallel permanent magnet is equivalent to that produced by surface current according to equivalent surface-current method of permanent magnet. The model is divided into two types of subdomains. The field solution of each subdomain is obtained by applying the interface and boundary conditions. The magnet field produced by equivalent surface current is superposed according to superposition principle of vector potential. The investigation shows harmonic contents of radial flux density can be reduced a lot by changing eccentric distance of eccentric magnet poles compared with conventional surface-mounted permanent-magnet machines with concentric magnet poles. The FE(finite element) results confirm the validity of the analytical results with the proposed model.

• 제어로봇시스템학회:학술대회논문집
• /
• 2000.10a
• /
• pp.402-402
• /
• 2000

MFL(Magnetic Flux Leakage) methods are used extensively for inspection of ferromagnetic materials. As an example, pipelines that are buried underground are inspected using MFL methods. By the MFL methods, ferromagnetic pipelines are magnetized by a permanent magnet or an electromagnet and then flux leakage is detected at the defection position. In this paper, we perform modeling of the magnetized pipelines. Also we propose the method localization of th defected areas. The effectiveness of the proposed method is verified experimentally.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.15 no.10
• /
• pp.6270-6275
• /
• 2014

The paper reports an improvement method on torque ripples of multi-pole interior permanent magnet synchronous motor (IPMSM) applied to a traction motor for hybrid electric vehicles. In the case of multi-pole IPMSM, the magnetic flux generated by a permanent magnet tends to leak through the bridge of the rotor without a link with stator windings. The slit design on the rotor surface was proposed to reduce torque rippling and increase the output power by reducing the leakage flux. Two design parameters for the slit are suggested for optimal design using the response surface method. As an analysis method, the 2D finite element method (FEM) was applied to consider magnetic saturation effect.

• Proceedings of the KIEE Conference
• /
• 2006.04b
• /
• pp.127-129
• /
• 2006

In this paper, a synchronous permanent magnet planar motor (SPMPM) with Halbach array is proposed for its high energy density. The magnetization and flux density distribution are obtainedby magnet scalar potential the characteristics such as inductance, back-EMF and thrust are evaluated. It can be concluded that the analysis of SPMPM with Halbach magnet array is credible and feasible.

• Proceedings of the KIEE Conference
• /
• 1997.07a
• /
• pp.319-321
• /
• 1997

This paper deals with multipolar magnetizing process which can exert a considerable influence on the final performance of permanent magnet machine. In combination with impulse discharge magnetizer, the analysis and design of magnetizing fixture using finite element method is required to obtain the accurate characteristics of permanent magnet for small-size step motor. Simulated result of flux density shows good agreement with measured one.

• Proceedings of the KIEE Conference
• /
• 1997.07a
• /
• pp.67-73
• /
• 1997

A magnet for urban transit Maglev is designed, analyzed and experimented to evaluate and to improve its characteristic. FEM is also used to calculate magnetic field density, magnetic force, leakage flux and losses. Seven cases of magnets are analyzed and tested for verifying the calculated characteristics and for optimizing the shape. Using the results, an improved levitation magnet is proposed for the vehicle.