• 제목/요약/키워드: Phase Estimation

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커패시터 구동형 단상유도전동기의 손실분리에 대한 연구 (Study on Losses Segregation for Capacitor-Run Single Phase Induction Motor)

  • 김광수;김기찬;이성구;고성철;전연도;이철규;이주
    • 전기학회논문지
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    • 제57권9호
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    • pp.1546-1551
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    • 2008
  • This paper is concerned with the problems of accurate losses segregation in capacitor-run single phase motor. Segregation of losses in single phase induction motor is more complicated than that in three phase induction motor, because of the backward magnetic field component in the motor. Generally there are two methods for losses segregation of single phase induction motor. The one is relatively complicated method based on parameter estimation of single phase induction motor. By the way, the other one is simplified method based on IEEE Standard 114. All of the methods for the experimental determination of single phase induction motor losses are studied in this paper. Since the IEEE Standard is not possible to be applied for all type of single phase induction motors, we modified that method to apply for losses segregation of capacitor-run single phase induction motor as unifying the method based on parameter estimation.

3상 AC-DC 승압형 컨버터를 이용한 SOC 추정 기반의 효율적 배터리 충전 알고리즘 (An Efficient Battery Charging Algorithm based on State-of-Charge Estimation using 3-Phase AC-DC Boost Converter)

  • 이정효;원충연
    • 조명전기설비학회논문지
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    • 제29권9호
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    • pp.96-102
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    • 2015
  • This paper presents battery charging method using 3-phase AC-DC boost converter. General battery charging method is that charging the battery voltage to the reference voltage according to the constant current(CC) control, when it reaches the reference voltage, charging the battery fully according to the constant voltage(CV) control. However, battery chaging time is increased because of the battery impedance, constant current charging section which shoud take the large amount of charge is narrow, and constant voltage charging section which can generate insufficient charge is widen. To improve this problem, we proposes the method to reduce the charging time according to the SOC(State of Charge) estimation using battery impedance.

브러시리스 직류전동기의 안전성을 고려한 Hall Sensor 신호 추정 알고리즘 설계 (The Estimation Algorithm Design of Hall Sensor Signal Considering Safety of BLDC Motor)

  • 윤용호
    • 전기학회논문지
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    • 제65권11호
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    • pp.1894-1899
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    • 2016
  • In this paper, because the position sensor represents the important factor in BLDC (Brushless DC) motor drives, BLDC motor is necessary that the three Hall-sensors evenly be distributed around the stator circumference in case of the 3 phase motor. The Hall-sensor is set up in this motor to detect the main flux from the rotor. So the output signal from Hall-sensor is used to drive IGBT to control the stator winding current. However, in case of breakdown Hall sensor, we research that the estimation algorithm of Hall sensor signal to detect rotor position and for the speed feedback signals with BLDC motor whose six stator and two rotor designed. In addition, this paper presents a sensorless speed control of BLDC Motor using terminal voltage of the one phase. Rotor position information is extracted by indirectly sensing the back EMF from only one of the three terminal voltages for a three-phase BLDC motor.

제1상 임상시험에서 곡선적합을 이용한 MTD 추정법 (Maximum Tolerated Dose Estimate by Curve Fitting in Phase I Clinical Trial)

  • 허은하;김동재
    • Communications for Statistical Applications and Methods
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    • 제18권2호
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    • pp.179-187
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    • 2011
  • 제 1상 입상시험의 주된 목적은 신약의 최대허용용량(Maximum tolerated dose; MTD)의 추정이다. 본 논문에서는 실험으로 얻어진 Dose-toxicity data를 S자 모형에 적합 시켜 MTD를 추정하는 방법을 제안하였다. 멈춤 규칙(stopping rule)에 의해 MTD가 결정되는 방법과 미리 정해진 표본수에서 실험을 종료하고 MTD를 추정하는 기존의 추정방법을 본 논문에서 제안한 방법과 모의실험을 통하여 비교하였다.

가상자속관측기를 이용한 3상 AC/DC PWM PFC 컨버터의 입력전압 센서리스 제어 개선 (Improved Input Voltage Sensorless Control of Three-Phase AC/DC PWM PFC Converter using Virtual Flux Observer)

  • 김영삼;소상호
    • 한국군사과학기술학회지
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    • 제16권4호
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    • pp.566-574
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    • 2013
  • In this paper, direct power control system for three-phase PFC AC/DC converter without the source voltage sensors is proposed. The sinusoidal input current and unity effective power factor are realised based on the estimated flux in the observer. Both active and reactive power calculated using estimated flux. The estimation of flux is performed based on the reduced-order virtual flux observer using the actual currents and the command control voltage. Moreover, source voltage sensors are replaced by a estimated flux. DC output voltage has been compensated by DC output ripple voltage estimation algorithm. The active and reactive powers estimation are performed based on the estimated flux and Phase angle. The proposed algorithm is verified through simulation and experiment.

A Position Sensorless Control of Switched Reluctance Motors Based on Phase Inductance Slope

  • Cai, Jun;Deng, Zhiquan
    • Journal of Power Electronics
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    • 제13권2호
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    • pp.264-274
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    • 2013
  • A new sensorless position estimation method for switched reluctance motor (SRM) drives is presented in this paper. This method uses the change of the slope of the phase inductance to detect the aligned position. Since the aligned positions for successive electrical cycle of each phase are apart by a fixed mechanical angle $45^{\circ}$ in the case of 12/8 SRM, the speed of the machine can be calculated to estimate the rotor position. Since no prior knowledge of motor parameters is required, the method is easy for implementation without adding any additional hardware or memory. In order to verify the validity of this technique, effects such as changes in the advanced angle and phase lacking faults are examined. In addition, an inductance threshold based sensorless starting scheme is also proposed. Experimental results demonstrate the validity of the proposed method.

XRD와 XAS에 의한 TiO2 분말의 상분율 결정 (Estimation of Phase Ratio for TiO2 Powders by XRD and XAS)

  • 나사균;이연승
    • 한국세라믹학회지
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    • 제49권5호
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    • pp.469-474
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    • 2012
  • The crystallinity and phase ratio of anatase to rutile in $TiO_2$ were estimated by x-ray diffraction (XRD) and x-ray absorption spectroscopy (XAS). Traditionally, the structural characterization of $TiO_2$ powders has been carried out by XRD techniques, which are comparatively easy in use and analysis. However, materials with amorphous phase, nano-sized or nano-structured crystallinities cannot be fully characterized by XRD because XRD analysis has a limit for abnormal contributions of the nano-crystal such as the surface contribution. From the comparison with the experimental and calculated Ti K-edge XAS spectra, we found the possibility of efficient estimation in the crystalinites and the phase ratio of anatase to rutile for nano-sized $TiO_2$ mixture.

SAR(Synthetic Aperture Radar)Imaging 시스템에서 제안 알고리즘의 반복수행을 통한 위상오차의 기울기 추정기법 연구 (The estimation of first order derivative phase error using iterative algorithm in SAR imaging system)

  • 김형주;최정희
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2000년도 추계종합학술대회 논문집(1)
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    • pp.505-508
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    • 2000
  • The success of target reconstruction in SAR(Synthetic Aperture Radar) imaging system is greatly dependent on the coherent detection. Primary causes of incoherent detection are uncompensated target or sensor motion, random turbulence in propagation media, wrong path in radar platform, and etc. And these appear as multiplicative phase error to the echoed signal, which consequently, causes fatal degradations such as fading or dislocation of target image. In this paper, we present iterative phase error estimation scheme which uses echoed data in all temporal frequencies. We started with analyzing wave equation for one point target and extend to overall echoed data from the target scene - The two wave equations governing the SAR signal at two temporal frequencies of the radar signal are combined to derive a method to reconstruct the complex phase error function. Eventually, this operation attains phase error correction algorithm from the total received SAR signal. We verify the success of the proposed algorithm by applying it to the simulated spotlight-mode SAR data.

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Development of a one-dimensional system code for the analysis of downward air-water two-phase flow in large vertical pipes

  • Donkoan Hwang;Soon Ho Kang;Nakjun Choi;HangJin Jo
    • Nuclear Engineering and Technology
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    • 제56권1호
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    • pp.19-33
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    • 2024
  • In nuclear thermal-hydraulic system codes, most correlations used for vertical pipes, under downward two-phase flow, have been developed considering small pipes or pool systems. This suggests that there could be uncertainties in applying the correlations to accident scenarios involving large vertical pipes owing to the difference in the characteristics of two-phase flows, or flow conditions, between large and small pipes. In this study, we modified the Multi-dimensional Analysis of Reactor Safety KINS Standard (MARS-KS) code using correlations, such as the drift-flux model and two-phase multiplier, developed in a plant-scale air-inflow experiment conducted for a pipe of diameter 600 mm under downward two-phase flow. The results were then analyzed and compared with those based on previous correlations developed for small pipes and pool conditions. The modified code indicated a good estimation performance in two plant-scale experiments with large pipes. For the siphon-breaking experiment, the maximum errors in water flow for modified and original codes were 2.2% and 30.3%, respectively. For the air-inflow accident experiment, the original code could not predict the trend of frictional pressure gradient in two-phase flow as / increased, while the modified MARS-KS code showed a good estimation performance of the gradient with maximum error of 3.5%.

CDMA 시스템에서 부호 획득을 위한 위상 변이 네트워크 기반의 차동 순차 추정 기법 (Phase-Shift-Network-Based Differential Sequential Estimation for Code Acquisition in CDMA Systems)

  • 정다해;이병윤;김상훈;정영빈;송익호;윤석호
    • 한국통신학회논문지
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    • 제32권3A호
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    • pp.281-289
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    • 2007
  • 본 논문에서는 부호 분할 다중 접속 (code division multiple access: CDMA) 시스템에서 의사 잡음 부호 및 반전된 의사 잡음 부호의 획득이 가능하고 데이터 복조도 가능한 위상 변이 네트워크 기반의 차동 순차 추정 기법을 제안하였다. 모의실험을 통해 제안한 기법의 성능이 이제까지의 이중 상관 순차 추정 기법에 비해 낮은 복잡도를 가지면서도 동일한 성능을 지니고 있음을 보였다.