• Title/Summary/Keyword: Phase Estimation

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

  • Kim, Kwang-Soo;Kim, Ki-Chan;Lee, Sung-Gu;Go, Sung-Chul;Chun, Yon-Do;Lee, Chul-Kyu;Lee, Ju
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.57 no.9
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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.

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

  • Lee, Jung-Hyo;Won, Chung-Yuen
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.29 no.9
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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.

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

  • Yoon, Yong-Ho
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.65 no.11
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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.

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

  • Heo, Eun-Ha;Kim, Dong-Jae
    • Communications for Statistical Applications and Methods
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    • v.18 no.2
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    • pp.179-187
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    • 2011
  • The purpose of a Phase I clinical trial is to estimate the maximum tolerated dose, MTD, of a new drug. In this paper, the MTD estimation method is suggested by curve fitting the dose-toxicity data to an S-shaped curve. The suggested MTD estimation method is compared with established MTD estimation procedures using a Monte Carlo simulation study.

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

  • Kim, Young-Sam;So, Sang-Ho
    • Journal of the Korea Institute of Military Science and Technology
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    • v.16 no.4
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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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    • v.13 no.2
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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.

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

  • Rha, Sa-Kyun;Lee, Youn Seoung
    • Journal of the Korean Ceramic Society
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    • v.49 no.5
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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.

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

  • 김형주;최정희
    • Proceedings of the IEEK Conference
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    • 2000.11a
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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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    • v.56 no.1
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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%.

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

  • Chong, Da-Hae;Lee, Byeong-Yun;Kim, Sang-Hun;Joung, Young-Bin;Song, Iick-Ho;Yoon, Seok-Ho
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.32 no.3A
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    • pp.281-289
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    • 2007
  • In this paper, a novel pseudo noise (PN) code acquisition scheme called the phase-shift-network-based differential sequential estimation (PDSE) is proposed, in the presence of data modulation in code division multiple access (CDMA) systems. The PDSE has even less complexity compared with that of the dual correlating sequential estimation (DCSE), and the reduction in complexity becomes more significant as the period of PN code increases. Numerical results demonstrate that the PDSE performs equivalently to the DCSE with less complexity.