Yong-June Shin

Yonsei University, Sŏul, Seoul, South Korea

Are you Yong-June Shin?

Claim your profile

Publications (41)22.34 Total impact

  • Article: b

    No preview · Article · Feb 2015
  • Source
    Dataset: iecon

    Full-text · Dataset · Jan 2015
  • [Show abstract] [Hide abstract]
    ABSTRACT: Based on cross-bispectrum, quadratic-nonlinearity coupling between two vibration signals is proposed and used to assess health conditions of rotating shafts in an AH-64D helicopter tail rotor drive train. Vibration data are gathered from two bearings supporting the shaft in an experimental helicopter drive train simulating different shaft conditions, namely, baseline, misalignment, imbalance, and combination of misalignment and imbalance. The proposed metric shows better capabilities in distinguishing different shaft settings than the conventional linear coupling based on cross-power spectrum.
    No preview · Article · Oct 2014 · IEEE Transactions on Aerospace and Electronic Systems
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: A new method to estimate the average dielectric constants of cable sections that have undergone aging is proposed. By comparing the experimental Joint Time-Frequency Domain Reflectometry waveform signatures from a new and an aged cable of the same type, it is demonstrated that the change in the average dielectric constant of the insulation material due to aging can be estimated. For example, for a cable containing Cross-Linked Polyethylene insulation, accelerated aging tests based on the modified Arrhenius equation that simulate 120 years of aging at 50 °C operating temperature show that the dielectric constant of the insulation decreases by more than 34.5%. The same tests performed on another cable containing Ethylene-Propylene Rubber insulation show that the average dielectric constant of the insulation decreases by 10.4%. The efficacy of the method is further demonstrated by estimating the increase in the average dielectric constant of a wedge section of a cable that contained water intrusion.
    Full-text · Article · May 2014 · Journal of Electromagnetic Waves and Applications
  • Hossein Ali Mohammadpour · Yong-June Shin · Enrico Santi
    [Show abstract] [Hide abstract]
    ABSTRACT: This paper investigates the sub-synchronous resonance (SSR) phenomenon in a series compensated doubly-fed induction generator (DFIG) based wind farms. A detailed linear state space model of a fixed-series compensated DFIG wind farm is presented for different operating point conditions. The model of the system includes a wind turbine aerodynamics, a 6th order induction generator, a 3rd order two-mass shaft system, a 4th order series compensated transmission line, an 8th order rotor and generator side converter controllers, and 1st order DC link model. The 22nd order system is modeled in Matlab/Simulink, and modal analysis is performed on the modeled DFIG wind farm, and eigenvalues of the system are calculated. The eigenvalue analysis and time-domain simulation results show that SSR can potentially occur in the fixed-series compensated DFIG-based wind farm even at realistic levels of series compensation. The fixed-series capacitor is replaced with a gate-controlled series capacitor (GCSC), which is a series flexible ac transmission system (FACTS) device composed of a pair of gate-commutated switches in parallel with a capacitor that enables one to control impedance and power flow of transmission lines, for series compensation and SSR damping. The root-locus analysis is employed to design a SSR damping controller (SSRDC) for the GCSC. It is shown than a well-designed SSRDC for the GCSC can alleviate the SSR in DFIG-based wind farms. The IEEE first benchmark model adapted with a DFIG-based wind farm is employed as a case study.
    No preview · Conference Paper · Mar 2014
  • Source

    Full-text · Conference Paper · Nov 2013
  • [Show abstract] [Hide abstract]
    ABSTRACT: The increasing deployment of wind power generation is leading to the integration of large wind farms into the power distribution grid. Given the remote geographic location of wind farms, series capacitive compensation is commonly used to ensure stable power transmission over long distances. However, the sub-synchronous resonance (SSR) phenomenon presents potential risks in a series compensated wind farm. Although the SSR problem in traditional power systems is well-known and has been extensively studied in the literature, the SSR problem in series-compensated wind farms requires more study and analysis. This paper investigates the application of the gate-controlled series capacitor (GCSC), a new series FACTS device consisting of a fixed capacitor in parallel with a pair of anti-parallel GTOs, for series compensation in fixed-speed wind turbine generator (FSWTG) systems. The GCSC enables fast control of series impedance of the transmission line, which can be used for SSR damping. The power system studied in this paper is the IEEE First Benchmark Model. Extensive simulations are carried out using PSCAD/EMTDC to validate the result. Simulation results show that the GCSC can effectively damp the SSR in wind farms. Therefore, the GCSC is an effective solution to provide series compensation and SSR damping for the FSWTG. Index Terms—Flexible AC transmission systems (FACTS), fixed-speed wind turbine, gate-controlled series capacitor (GCSC), modeling and simulation, PSCAD/EMTDC, sub-synchronous resonance.
    No preview · Conference Paper · Jul 2013
  • [Show abstract] [Hide abstract]
    ABSTRACT: The increasing deployment of wind power generation is leading to the integration of large wind farms into the power distribution grid. Given the remote geographic location of wind farms, series capacitive compensation is commonly used to ensure stable power transmission over long distances. However, the sub-synchronous resonance (SSR) phenomenon presents potential risks in a series compensated wind farm. Although the SSR problem in traditional power systems is well-known and has been extensively studied in the literature, the SSR problem in series-compensated wind farms requires more study and analysis. This paper investigates the application of the gate-controlled series capacitor (GCSC), a new series FACTS device consisting of a fixed capacitor in parallel with a pair of anti-parallel GTOs, for series compensation in fixed-speed wind turbine generator (FSWTG) systems. The GCSC enables fast control of series impedance of the transmission line, which can be used for SSR damping. The power system studied in this paper is the IEEE First Benchmark Model. Extensive simulations are carried out using PSCAD/EMTDC to validate the result. Simulation results show that the GCSC can effectively damp the SSR in wind farms. Therefore, the GCSC is an effective solution to provide series compensation and SSR damping for the FSWTG. Index Terms—Flexible AC transmission systems (FACTS), fixed-speed wind turbine, gate-controlled series capacitor (GCSC), modeling and simulation, PSCAD/EMTDC, sub-synchronous resonance.
    No preview · Conference Paper · Jul 2013
  • [Show abstract] [Hide abstract]
    ABSTRACT: The increasing deployment of wind power generation is leading to the integration of large wind farms into the power distribution grid. Given the remote geographic location of wind farms, series capacitive compensation is commonly used to ensure stable power transmission over long distances. However, the sub-synchronous resonance (SSR) phenomenon presents potential risks in a series compensated wind farm. Although the SSR problem in traditional power systems is well-known and has been extensively studied in the literature, the SSR problem in series-compensated wind farms requires more study and analysis. This paper investigates the application of the gate-controlled series capacitor (GCSC), a new series FACTS device consisting of a fixed capacitor in parallel with a pair of anti-parallel GTOs, for series compensation in fixed-speed wind turbine generator (FSWTG) systems. The GCSC enables fast control of series impedance of the transmission line, which can be used for SSR damping. The power system studied in this paper is the IEEE First Benchmark Model. Extensive simulations are carried out using PSCAD/EMTDC to validate the result. Simulation results show that the GCSC can effectively damp the SSR in wind farms. Therefore, the GCSC is an effective solution to provide series compensation and SSR damping for the FSWTG. Index Terms—Flexible AC transmission systems (FACTS), fixed-speed wind turbine, gate-controlled series capacitor (GCSC), modeling and simulation, PSCAD/EMTDC, sub-synchronous resonance.
    No preview · Conference Paper · Jul 2013
  • [Show abstract] [Hide abstract]
    ABSTRACT: Wind energy is an important contributor to the evolution of the smart grid, but the power electronics necessary to interface a wind turbine generator (WTG) to the grid can have a negative impact on the power quality (PQ) of the grid if the effects are not well understood. In this paper, the wind energy conversion system is reviewed with models of the two most common types of WTGs: a doubly-fed induction generator (DFIG) and a synchronous generator (SG). Time-frequency analysis is introduced as a unique, advantageous way of quantifying and comparing the time-varying disturbances introduced by these generators, which can not be accomplished from the existing PQ indices published by International Electrotechnical Commission (IEC). Time-frequency distributions and metrics are employed to analyze the PQ effects of the DFIG and SG under two case studies: a three-phase-to-ground fault and a generator trip and recovery. The analysis of these studies reveals time-varying frequency information that can be used to properly compensate for such events in the future depending upon the type of generator employed and improve the quality of power these types of WTGs inject onto the grid.
    No preview · Conference Paper · Jan 2013
  • David Coats · Md Nazmul Alam · Qiu Deng · Mohammod Ali · Yong-June Shin
    [Show abstract] [Hide abstract]
    ABSTRACT: In this paper, we present a time-frequency based reflectometry solution that focuses on the practical implementation of in-situ and non-destructive cable diagnostic tests. Towards this ideal health monitoring approach, we have explored the implementation of alternative monitoring techniques using surface wave injection for monitoring of cable insulation health toward nondestructive tests. Through use of surface wave propagation, a diagnostic signal can be injected in control, instrumentation, and power cable without removing installed samples under test. However, in practical implementation of surface wave tests through antenna, problems are presented in the form of dispersive media distorting the response of the frequency sweeping reference signal in either frequency or time-frequency domains. We present an optimal reference signal and time-frequency cross correlation diagnostic and prognostic algorithm to allow for implementation of joint time-frequency domain reflectometry (JTFDR) in minimal bandwidth to reduce attenuation in surface wave reflectometry.
    No preview · Conference Paper · Jul 2012
  • [Show abstract] [Hide abstract]
    ABSTRACT: This paper introduces a quadratic-nonlinearity powers-index spectrum (QNLPI(ƒ)) measure that describes quantitatively how much of the mean square power at certain frequency ƒ is generated by nonlinear quadratic interaction between different frequencies inside signal spectrum. The proposed index QNLPI(ƒ) is based on the bicoherence spectrum, and the index can be simply seen as summary of the information contained in the bicoherence spectrum in two dimensional graph which makes it easier to interpret. The proposed index is studied first using computer generated data and then applied to real-world vibration data from a helicopter drive train to characterize different mechanical faults. This work advances the development of health indicators based on higher order statistics to assess fault conditions in mechanical systems.
    No preview · Article · May 2012 · Conference Record - IEEE Instrumentation and Measurement Technology Conference
  • Source
    Lingyu Yu · Bin Lin · Yong-June Shin · Jingjiang Wang · Zhenhua Tian
    [Show abstract] [Hide abstract]
    ABSTRACT: This paper presents a novel ultrasonic guided wave based inspection methodology for detecting and evaluating gas accumulation in nuclear cooling pipe system. The sensing is in-situ by means of low-profile permanently installed piezoelectric wafer sensors to excite interrogating guided waves and to receive the propagating waves in the pipe structure. Detection and evaluation is established through advanced cross time-frequency analysis to extract the phase change in the sensed signal when the gas is accumulating. A correlation between the phase change and the gas amount has been established to provide regulatory prediction capability based on measured sensory data.
    Full-text · Conference Paper · Apr 2012
  • [Show abstract] [Hide abstract]
    ABSTRACT: In order to properly suppress the harmonic current in a power system, the harmonic similarity metric is developed in this paper and used to establish an efficient strategy for harmonic filter placement. To validate the strategy, an industrial distribution system is analyzed under two harmonic current injection scenar- ios. It is demonstrated that the proposed strategy has a robust ability to successfully determine the most efficient and effective location for placing a harmonic filter bank based upon the desired objectives. The two harmonic current injection scenarios serve to validate the proposed strategy regardless of the power distribution level at which harmonic current is injected. Index Terms—Filtering, harmonic similarity (HS), industrial distribution system, power quality, power-system harmonics.
    No preview · Article · Feb 2012 · IEEE Transactions on Industrial Electronics
  • [Show abstract] [Hide abstract]
    ABSTRACT: For efficient maintenance of a diverse fleet of aging air- and rotorcraft, effective condition based maintenance (CBM) must be established based on rotating components monitored vibration signals. Traditional linear spectral analysis techniques of the vibration signals, based on auto-power spectrum, are used as common tools of rotating components diagnoses. Unfortunately, linear spectral analysis techniques are of limited value when various spectral components interact with one another due to nonlinear or parametric process. In such a case, higher order spectral (HOS) techniques are recommended to accurately and completely characterize the vibration signals. Since the nonlinearities result in new spectral components being formed with coherency in phase, the detection of such phase coherence may be carried out with the aid of higher order spectra. In this paper, we use the bispectrum as a higher order spectral analysis tool to investigate nonlinear wave-wave interaction in vibration signals. Accelerometer data has been collected from baseline tests of accelerated conditioning in tail rotor drive-train components of an AH-64 helicopter drive-train research test bed simulating drive-train conditions. Through bispectrum analysis, we compare the harmonics interaction patterns contained in vibration signals from different physical setting of helicopter drive train and compare that with classical power spectral density plots. The analysis advances the development of higher order statistics and two dimensional frequency health indicators in order to qualify health conditions in mechanical systems.
    No preview · Article · Jan 2012 · IEEE Aerospace Conference Proceedings
  • [Show abstract] [Hide abstract]
    ABSTRACT: A new concept of nonparametric signal detection and classification technique is proposed using mutual infor- mation measures in the time-frequency domain. The time- frequency-based self-information and mutual information are defined in terms of the cross time-frequency distribution. Based on time-frequency mutual information theory, this paper presents applications of the proposed technique to real-world vibration data obtained from a dedicated condition-based-maintenance experimental test bed. Baseline, unbalanced, and misaligned experimental settings of helicopter drivetrain bearings and shafts are quantitatively distinguished by the proposed techniques. With imbalance quantifiable by variance in the in-phase mutual infor- mation and misalignment quantifiable by variance in the quadra- ture mutual information developed and presented herein, machine health classification can be accomplished by use of statistical bounding regions.
    No preview · Article · Aug 2011 · IEEE Transactions on Instrumentation and Measurement
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Accelerometer data has been gathered from accelerated conditioning in grease lubricated and lubrication deprived gear meshes in AH-64 helicopter intermediate and tail rotor gearbox, which are commonly problematic components of the Apache helicopter platform. These tests were performed in a controlled drive-train research test bed, simulating drive-train conditions to improve diagnostic and prognostic capabilities of Condition Based Maintenance (CBM) practices in Integrated Vehicle Health Monitoring System - Health Usage Monitoring System (IVHMS-HUMS) and other comparable CBM packages, as monitored by a standardized Digital Source Collector (DSC) system. Time-frequency representations of vibration measurement collected from two spaced sensors are used to provide signature analysis of transient system harmonics. Furthermore, the time-frequency mutual information advanced signal processing technique is then proposed and validated using vibration data. The measure advances the development of mutual information health indicators to quantify degradation of the helicopter power train. The AH-64 test systems perform under stress in realistic loading conditions and lifetime accelerated aircraft aging is monitored using the proposed advanced signal processing techniques for baseline tests for comparison with faulted conditions.
    Preview · Conference Paper · Apr 2011
  • [Show abstract] [Hide abstract]
    ABSTRACT: Utilities are experiencing premature failures of power cables. In order to prevent electrical outages and to save on repair expenses, a nondestructive and nonintrusive condition assessment technique is highly desirable to evaluate the cable status and to predict the remaining life of a cable. In this paper, the capability of joint time-frequency domain reflectometry (JTFDR) as such a condition assessment technique is studied. The health status of three popular insulations in power system cables - cross-linked polyethylene, ethylene propylene rubber, and silicone rubber - is monitored using the JTFDR in a thermal accelerated aging test. The experimental results show that the JTFDR can successfully monitor the aging process of all three insulations. Then, the results from the JTFDR are compared with the results from the elongation at break (EAB); the results show that the JTFDR technique is comparable with the EAB and has a great potential as a nondestructive and nonintrusive condition assessment technique.
    No preview · Article · Apr 2011 · IEEE Transactions on Instrumentation and Measurement
  • Soo-Nam Kim · Philip Stone · Y. Zhang · Yong-June Shin · Roger Dougal
    [Show abstract] [Hide abstract]
    ABSTRACT: Recently, VTB has been developed as a naval electric ship evaluation program. However, the behind-the-source modeling level of the system generators is still not enough to realize the actual system. Especially, the results of harmonic analysis and fault analysis were not reliable because the ideal voltage source was used as a generation system due to the lack of a detailed model. For this reason, a more accurate generation model is needed to analyze the dynamic characteristics of the generation system. The work of this paper is featured by the applications of VTB for generation system modeling and simulation methods for electric ship power system design.
    No preview · Article · Jan 2011
  • [Show abstract] [Hide abstract]
    ABSTRACT: A new methodology for the evaluation of nonfailure operating time (NFOT) in the virtual test bed (VTB) environment is proposed. The proposed method is featured by the application of time-frequency analysis to estimate the parameters of reliability at the earliest stages of design based on the intercoupling of the 1/ f noise and the reliability of power system elements. The proposed approach enables one to directly quantify the reliability of the system by the investigation of the physical properties of the nonequilibrium fluctuations.
    No preview · Article · Aug 2010 · IEEE Transactions on Instrumentation and Measurement

Publication Stats

211 Citations
22.34 Total Impact Points

Institutions

  • 2014
    • Yonsei University
      • Department of Electrical and Electronic Engineering
      Sŏul, Seoul, South Korea
  • 2005-2012
    • University of South Carolina
      • Department of Electrical Engineering
      Columbia, South Carolina, United States
  • 2008
    • University of Texas at Austin
      • Department of Electrical & Computer Engineering
      Austin, TX, United States