• 전력전자학회논문지
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• 제6권6호
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• pp.506-513
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• 2001

SRM의 토크는 상전류와 인덕턱스의 기울기에 따라 달라진다. 그러나 자기회로의 포화로 인하여 원하는 토크를 제어하기 어렵다. 원하는 토크를 발생시키기 위해 SRM 드라이브는 스위치-온각, 스위치-오프각 그리고 인가 접압에 의해 제어된다. 스위치-온, 오프 각 에의해 원하는 전류와 토크를 제어할수있다. 본 논문은 스위치 온, 오프각을 제어하는 최적제어방식을 제안하였다. 스위치 오프 각은 시뮬레이션과 실험을 통하여 효율을 기준으로 결정하였으며, 스위치 온각은 부하에 의해 결정되었다. 도통각은 토크제어와 속도제어를 위해 GA-신경회로망을 이용하여 제어하였다.

• 한국초전도ㆍ저온공학회논문지
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• 제11권1호
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• pp.30-34
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• 2009

This paper deals with charging and persistent-current mode operating characteristics of BSCCO magnet load using high-temperature superconducting (HTS) power supply. The HTS power supply consists of two heater-triggered switches, an iron-core transformer with the primary copper winding and the secondary BSCCO solenoid, and a BSCCO magnet load. The magnet load was fabricated by double pancake winding and its inductance is about 21 mH. A hall sensor was installed at the middle of the magnet load to measure the current in the load. In order to investigate the efficient pumping characteristics, operating tests of heater-triggered switch with respect to dc heater current were carried out, and the electromagnet current was determined by considering saturation characteristics of its iron core. The saturation characteristics of charged current in the magnet load were observed with respect to various pumping periods: 12 s, 14 s, 24 s and 32 s. After charging the magnet load, the persistent current was measured. The operating characteristics of the persistent current mode were mainly determined by joint resistance and magnet load.

• 전기학회논문지
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• 제56권3호
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• pp.519-523
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• 2007

In this paper, we propose a precise parameter extraction of interior permanent magnet (IPM) motors based on finite element analysis. For the calculation of the two-axis inductances Ld and Lq, the slotting effect and cross magnetization due to torque angle are considered. It is examined that back electro-motive force (BEMF) constant is affected by the magnetic saturation in different ways dependent on motor types. Numerical analyses and some measurements are performed for a spoke type and a flux barrier type IPM motors

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제53권10호
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• pp.585-596
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• 2004

In this paper, finite element analysis for a PMASynRM is presented and the characteristic analysis of inductance and torque is performed under the effect of saturation. The focus of this paper is characteristic analysis of d and q-axis inductances and torque according to magnetizing quantity of interior permanent magnet for PMASynRM. The d and q-axis current component ratios, load angles of a PMASynRM are investigated quantitatively on the basis of the proposed analysis method and the experimental test. Comparisons are given with output characteristic curves of normal SynRM and those according to the load in PMASynRM, respectively And it is confirmed that the proposed model results in high output power performance.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제54권10호
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• pp.470-476
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• 2005

In this paper PU control scheme is presented. The proposed scheme has following features. The one is oft-starting method which is used for preventing to flow large current in motor phase winding when motor starts. The ther is the selection of the level of the over current. The first feature is implemented by increasing the PWM duty lowly, the second feature is implemented by limiting the magnitude of the phase current level by which the over heat f motor by copper losses and magnetic saturation decreases. By the analysis using FEM considering load condition, the peed of mode transition from PW to single pulse control is selected and confirmed by simulation that there is no ver current occurs during the mode transition. For the verification of proposed scheme, the simulation using MATLAB Simulink with considering non-linearity of inductance profile from FEM analysis is performed and the experiment with SRM drive system which has the DSP controller and single Phase SRM are peformed.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 B
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• pp.801-803
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• 2001

On this study the motor design method with fairly good characteristics and control capability as well as cooling capability is presented with considering the magnetic effect due to ventilation hole, which is installed to prevent the temperature rise. When the input voltage rises due to critical variation in traction power supply system, the final ventilation hole is presented by checking the inductance parameter with clarifying the relation between saturation of the motor core and the ventilation hole.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1989년도 추계학술대회 논문집 학회본부
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• pp.180-185
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• 1989

In the current source type active power filter, the DC current source is implemented using an inductor with large inductance by maintaining the inductor current constantly. In this case, to compensate the loss of the switching devices of the power converter and the inductor, some real power should be supplied to the filter from the source. This process is analyzed through the equivalent circuit which expresses the loss of the switching devices and the inductor with the equivalent resistor R. This work discusses the validation of this DC side equivalent circuit and points out the problems, through the experiments using the experimental active power filter with 220V, 10KVA ratings, and suggests a more accurate equivalent circuit which puts the saturation voltage of the power transistors and the threshold voltage of the diodes into consideration.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 학술대회 논문집 전문대학교육위원
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• pp.152-156
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• 2000

A Switched Reluctance Motor(SRM) has been widely studied for practical use due to recent development on technology of power electronics. Because of its advantage that are high speed driving, simple structure and easy variable-speed control, it is expected for applications to automo biles and others. However, it has some problems that are, for examples, relatively high torque ripples and electromagnetic noise. In this paper, a simple theory is presented to represent characteristic of a SRM and theoretical results are compared with experimental ones. In the theory, the inductance variations of a SRM are approximated as linear and winding resistances and the magnetic saturation are ignored. With these approximations, we derived some equations expressing load characteristics of a SRM. Also, the torque ripple was removed by applying a variable hysteresis band control.

• Journal of Advanced Marine Engineering and Technology
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• 제23권6호
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• pp.738-747
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• 1999

Vector controlled induction motor have been widely used in high performance applications. How-ever the performance is sensitive to the variations of motor parameters especially the rotor time constant which varies with the temperature and the saturation of the magnetizing inductance. In this paper the authors propose new identifying method for time-varying parameters of an induction motor which is based on adaptive vector control with serial block algorithm. Vector con-trol system realized on synchronous frame and parameter identification system realized on sta-tionary frame are not easily affected by the vector control frame. Parameter mismatch in the control system results in heavy transient variation in speed and torque response. In order to compensate degradation of the responses at the middle and low speed region adaptive identifier is introduced. To verify the feasibility of this technique compute simu-lations carried out.

• 산업기술연구
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• 제34권
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• pp.15-20
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• 2014

Recently, PMSMs(Permanent Magnet Synchronous Motors) have become increasingly popular in various high-performance motor drive applications. However, the high-performance drive of PMSMs needs a position sensor such as a resolver, which increases not only the price of the system but also reduces the system reliability. This paper is on the implementation of sensorless control of a SPMSM, which drives a fan for cooling in appliances. In this paper, the rotor position for high-performance drive of a SPMSM is derived from back electromotive force (EMF) information proportional to the rotor speed. Also, the initial rotor position information for start-up is estimated from a saturation phenomenon of inductance. The validity of the proposed sensorless drives was confirmed by the experiment on the SPMSM drive systems for cooling fans of refrigerators and laptop computers.