• 조명전기설비학회논문지
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• 제24권9호
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• pp.118-123
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• 2010

The selection of flux level in the maximum torque control of stator flux-oriented induction motor drives in the field weakening region is dependent on stator resistance and inductances. This paper presents parameter detuning effects of stator flux-oriented control drives in the field weakening region. The detuning effects of stator resistance and rotor leakage inductance are analyzed. The decrease of torque and the flux control lost by the detuning of inductance are shown in the simulation results.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제48권8호
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• pp.408-416
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• 1999

The characteristics of permanent magnet synchronous motor are defined by airgap flux and circuit parameters. Interior Permanent Magnet Synchronous Motor(IPMSM) has a nonlinear characteristics due to structural speciality of rotor, so it is difficult to analyze circuit parameters and field-weakening characteristics of IPMSM. This paper presents the calculation of circuit parameters by using Finite Element Method(FEM) taken into consideration of nonlinear characteristics. Using the circuit parameters by FEM, IPMSM is analyzed to field-weakening characteristics and is compared with the Equivalent Magnetic Circuit(EMC) in which lumped parameter is consideration.

• 대한전기학회논문지
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• 제45권1호
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• pp.74-80
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• 1996

This paper describes current controlled PWM technique of PM synchronous motors for a wide variety of speed control applications. They are however limited in their ability to operate in the power limited regime where the available torque is reduced as the speed is increased above its base value. This paper reviews the operation of the PMSM drives when they are constrained to be within the permissible envelope of maximum inverter voltage and current to produce the rated power and to provide this with the highest attainable rotor speed. The optimal field-weakening control algorithm is the use of phase current and d-axis current feedback to reduce of error between the d-axis current command and real current and to improve the torque characteristics. The improved torque characteristics of speed control strategy with optimal field weakening control algorithm is analyzed and the performance is investigated by the computer simulation and experimental results. (author). refs., figs.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1993년도 하계학술대회 논문집 B
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• pp.1051-1053
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• 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.

• 전기학회논문지P
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• 제59권4호
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• pp.351-357
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• 2010

In this paper, a vector control of the IPMSM drives for the next generation domestic high speed railway system is presented. The applied control method uses one pulse mode field weakening control in constant power region, and maximum torque control per ampere control in constant torque region considering current and voltage limits. An overmodulation control interval is inserted to improve the transient characteristics during transition period of the control modes. Simulation programs based on Matlab/Simulink are developed. Finally the designed system is verified by simulation and their characteristics are analyzed by the simulation results.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 A
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• pp.28-30
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• 1996

In the paper the authors deal with inverter fed induction motors design criteria for having a wide constant power range. In particular, the flux weakening operation is the main feature considered. The design target concerns the possibility of having a wide flux weakening region avoiding or limiting, at the same time, to oversize the motor and the inverter.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 Proceedings ICPE 01 2001 International Conference on Power Electronics
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• pp.779-784
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• 2001

For electrical vehicles, switched reluctance drives present a promising alternative-compared to asynchronous and synchronous (permanent magnet) concepts. For these applications, a very wide field weakening range is a key issue. Other requirements include high torque output from a small machine and low current ripple at the DC-side without the use of bulky filters - when powered from fuel cells or advanced Lithium-Ion-batteries. A new converter and control strategy according to these requirements is presented and compared to existing designs. The comparison is done for a drive system with a continuous power rating of 30 to 40 kW.

• 전력전자학회논문지
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• 제16권2호
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• pp.152-161
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• 2011

영구자석 매립형 동기전동기는 고효율, 소형화 및 넓은 가변속운전 등의 특성으로 인해 전기자동차에 적용되고 있다. 본 논문에서는 유기전압이 고조파를 함유하고 있는 영구자석 동기전동기에 대하여 고속운전 시 약자속 운전 영역의 해석에 대해 제안한다. 유기전압의 고조파가 전동기 속도와 최대토크에 미치는 영향을 해석하고 전압제한 및 전류제한 조건에서 최대토크 운전을 위한 dq 전류에 대해 분석한다. 약자속 운전영역에 대한 기존 및 제안된 해석결과를 비교하고 최대토크-속도 특성의 실험을 통하여 해석결과를 검증한다.

• 한국지진공학회논문집
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• 제24권5호
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• pp.219-232
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• 2020

The slip-weakening model developed by Ohnaka and Yamashita is extended over the breakdown zone by equating the scaling relationships for the breakdown zone and the whole rupture area. For the extension, the study uses the relationship between rupture velocity and radiation efficiency, which was derived in the theory of linear elastic fracture mechanics, and the definition of f_max given in the specific barrier model proposed by Papageorgiou and Aki. The results clearly show that the extended scaling relationship is governed by the ratio of rupture velocity to S wave velocity, and the velocity ratio can be determined by the ratio of characteristic frequencies of a Fourier amplitude spectrum, which are corner frequency, f_c, and source-controlled cut-off frequency, f_max, or vice versa. The derived relationship is tested by using the characteristic frequencies extracted from previous studies of more than 130 shallow crustal events (focal depth less than 25 km, M_W 3.0~7.5) that occurred in Japan. Under the assumption of a dynamic similarity, the rupture velocity estimated from f_max/f_c and the modified integral timescale give quite similar scale-dependence of the rupture area to that given by Kanamori and Anderson. Also, the results for large earthquakes show good agreement to the values from a kinematic inversion in previous studies. The test results also indicate the unavailability of the spectral self-similarity proposed by Aki because of the scale-dependent rupture velocity and the rupture velocity-dependent f_max/f_c; however, the results do support the local similarity asserted by Ohnaka. It is also remarkable that the relationship between the rupture velocity and f_max/f_c is quite similar to Kolmogorov's hypothesis on a similarity in the theory of isotropic turbulence.

• 전력전자학회논문지
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• 제12권4호
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• pp.318-323
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• 2007

본 논문에서는 영구자석형 5상 전동기(Five-phase permanent magnet motor)의 약계자 제어에 대한 연구를 수행한다. 제안된 전동기는 집중권 방식의 권선분포를 가지고 있고 사다리꼴 형태의 역기전력을 나타내고 있으며, 사다리꼴 형태의 전류를 인가하기 위하여 사인파의 기본파 성분에 3고조파 성분을 첨가하였다. 따라서 BLDC 전동기(Brushless dc motor)와 등가적으로 같은 평균토크를 발생시키면서 BLDC 전동기의 단점을 극복할 수 있었다. 전동기 전류의 토크성분과 자속성분은 다중 레퍼런스 프래임을 이용하여 분리할 수 있었으며, 결과적으로 쉽게 벡터제어가 이루어질 수 있었다. 사용된 전동기는 고속영역에서부터 저속영역까지 BLDC 전동기와 같이 높은 토크 밀도를 가지며, 약계자 영역이나 고속영역에서 영구자석형 전동기와 같이 제어의 용이함을 가진다는 장점을 가지고 있으며 실험결과를 통하여 제안된 전동기와 알고리즘을 검증하였다.