• Journal of Electrical Engineering and Technology
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• 제8권6호
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• pp.1345-1351
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• 2013

Variable iron loss as function of current phase angle of Interior Permanent Magnet Synchronous Motor(IPMSM) was calculated through Curve Fitting Method(CFM). Also, a magnetic flux density distribution of iron core according to current phase angle was analyzed, and an iron loss calculation was performed including harmonic distortion. The experiment was performed by production of non-magnetizing model for the separation of mechanical loss, and the iron loss was calculated by the measurement of input using power analyzer and output power using dynamometer. Some error was generated between experimental results and calculation value, but an iron loss diminution according to current phase angle followed a same pattern. So, errors were generated by measurement, vibration, noise, harmonic distortion loss, etc.

• 조명전기설비학회논문지
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• 제25권1호
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• pp.78-84
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• 2011

Using sensors to detect current or voltage of motors is disadvantaged because motor is exposed to vibration, impacts, corrosion, high temperature and humidity in the machinery structure like HEV. In the case of IPMSM, position information is included not only in the flux or EMF term but also in the rotator inductance because of its saliency. To solve this problem, a new mathematical model of IPMSMs on fixed frame is proposed and an extended EMF includiing rotating position information is defined to estimate extended EMF. A strong low-pass filter through the variable cut-off frequency using velocity function was proposed. This makes it is possible to estimate extended EMF by least order disturbance observer. The proposed method was proved through the experiment.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2014년도 추계학술대회 논문집
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• pp.131-134
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• 2014

PMSM(Permanent Magnet Synchronous Motor)은 가공기, 로봇, 공장 자동화 등 현재까지도 산업 시스템 전반에 널리 쓰이고 있으며, 그에 대한 연구도 활발히 진행되고 있다. 하지만 PMSM에 부하를 인가하거나 혹은 기계 몸체와의 결합 과정에서 기구부가 가지고 있는 고유진동 주파수에 의해 동력 전달 부분에 있어 기계계의 응답 특성은 불안정해지고, 떨림 현상이 발생된다. 본 논문에서는 PMSM을 이용한 회전 운동 시스템에서 출력되는 전류에 기구부가 가지고 있는 특정 영역의 고유진동 주파수를 제거한 전류를 적응 노치필터를 통해 내보낸다. 그 결과 기계부의 떨림 현상을 제거하고, 안정적인 제어 시스템을 제안한다. 이 제어알고리즘을 가상실험으로 필터 통과 전과 후의 결과를 비교 및 분석하도록 한다.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제55권4호
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• pp.209-215
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• 2006

Recently Permanent Magnet Linear Synchronous Motors(PMLSMs) are widely used for many linear transportation applications. The PMLSM has many advantages such as simple structure, high speed and thrust. However, especially in short primary type PMLSM, there exists very large detent force, which makes the thrust force ripple, undesired vibration and noise. The detent force is composed of the Cogging force and the End force. The Cogging force comes from the interaction between the permanent magnets and interior teeth of the stator. And the End force acts on the exterior teeth of the stator by the permanent magnets. Usually End force is larger than Cogging force, so the detent force is drasically reduced only by reducing the End force. This paper shows the End force is minimized by optimizing the stator length and chamfering the shape of the exterior teeth of the stator.

• Journal of Magnetics
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• 제20권3호
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• pp.258-264
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• 2015

In this paper, an adequate B-H curve extrapolation method is proposed and its reliability is verified through experiments. A method is developed to estimate the magnetic saturation induction from the density of the lamination core and electrical resistivity. The magnetic saturation induction of electrical steels measured using a vibration sample magnetometer are compared with the analytical results to validate the accuracy of the proposed estimation method. It is found that the predicted error in the magnetic saturation induction of the electrical steels are approximately 1.2% when the proposed method is used. The performance of interior permanent magnet synchronous motors that applies the proposed method are evaluated via 2D nonlinear finite element analysis and through experiments. Based on the obtained results, the extrapolated B-H curves from the estimated saturation induction can be used for various analyses in saturation region.

• 소음진동
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• 제2권3호
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• pp.213-222
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• 1992

The effect of cavitation on the synchronous steady state response of a single rotor supported on cavitated squeeze film dampers executing a circular orbit is investigated theoretically. The Swift-Stieber boundary conditions and a long bearing approximation are utillized to evaluate the direct and the cross coupled damping coefficients of a cavitated squeeze film damper. For typical design parameters, frequency response curves are presented here to exhibit the effect of cavitation on the imbalance response and transmissibilities for both a flexible rotor and a rigid rotor. Investigations show that cavitation occured in a squeeze film damper produces bistable jump phenomena and deteriorates the performance of a squeeze film damper. This arises from that the large cavity causes substantial increment of the cross coupled damping which has radial stiffening effect. Furthermore, the large cavity causes the decrement of the direct damping which has pure damping effect. It is also observed that in the absence of cavitation, both rotor excursion amplitude and imbalance transmissibilities are very well damped.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2015년도 제46회 하계학술대회
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• pp.810-811
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• 2015

In this paper, we investigate the optimization design for a spoke type motor with the characteristics of high torque density and high-efficiency. This motor has a high output per unit volume. In order to reduce noise and vibration caused by a high cogging torque, optimization design of the rotor and stator have been conducted using both Response surface method (RSM) and Finite elements method (FEM). In this paper, we show the potential for this motor to efficiently replace existing interior permanent magnet synchronous motors (IPMSM) in a wide range of industries.

• 음성과학
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• 제7권3호
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• pp.153-165
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• 2000

During the phonation of voiced sounds, instants exist where the glottis is opened or closed, due to the periodic vibration of the vocal cord. When closed, this is called the glottal closure instant(GCI) or epoch.. The correct detection of the GCI is one of the important problems in speech processing for pitch detection, pitch synchronous analysis, and so on. Recently, it has been shown that the local maxima points of the wavelet transformed speech signal correspond to the GCIs of speech signal. In this paper, we investigate the accuracy of Gels estimated from this wavelet transformed speech signal. For this purpose we compare them with the negative peak points of the differentiated EGG signal that represents the actual GCIs of speech signal.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2005년도 춘계학술대회 논문집
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• pp.97-102
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• 2005

This paper presents feed rate optimizaton of a PMLSM driven feed-slide for mininum vibrations by smoothing velocity curve with finite jerk. First of all, the PMLSM was designed and made to reduce detent force. Next, a PMLSM driven feed-slide system was mathematically modeled as a 4-degree-of-freedom lumped parameter model. The key idea of our vibration minimization method is to find out the most appropriate smooth velocity curve with finite jerk. The validity of our proposed method has been verified by comparing computer simulation results of the feed-slide model with experimental ones.

• 전력전자학회논문지
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• 제7권1호
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• pp.91-100
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• 2002

본 논문에서는 매입형 영구자석 동기전동기의 전자기 토크의 맥동저감에 관하여 기술하였다. 일반적으로 토크 맥동은 전동기의 진동과 소음을 유발하는 중요한 원인이 된다. 제안된 방법에서는 비정현적인 역기전력을 가진 IPMSM에서 토크 맥동을 저감하기 위해 단위전류당 최대토크 제어를 할 수 있는 최적의 전류 형상을 고려하여 도출하였다. 그리고 이를 전동기에 인가했을 때 토크 맥동이 개선될 수 있음을 시뮬레이션과 실험을 통해서 입증하였다.