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To obtain reliable operating of HTS cable system, temperature and pressure are commonly used as condition monitoring parameters. However, the sensors for the parameters are attached only at the terminals or joints of the HTS cable; therefore, the conventional parameters are not suitable to detect the inward change of the HTS cable. In this paper, tangent distance-based template matching (TDTM) coefficient is proposed to monitor the condition of the HTS cable. TDTM technique is applied to time-frequency domain reflectometry (TFDR) which is an advanced fault localization technique, and the TDTM coefficient is calculated during the template matching. A single phase HTS cable is utilized to verify the performance of the TDTM coefficient, and baseline results are measured at 300 K and 77 K in the test bed. It is expected that the proposed TDTM coefficient can be used for stable operation and monitoring of the HTS cable system.
Gu-Young Kwon; Yong-June Shin. Condition Monitoring Technique of HTS Cable via Tangent Distance-Based Template Matching Coefficient. IEEE Transactions on Applied Superconductivity 2021, 31, 1 -5.
AMA StyleGu-Young Kwon, Yong-June Shin. Condition Monitoring Technique of HTS Cable via Tangent Distance-Based Template Matching Coefficient. IEEE Transactions on Applied Superconductivity. 2021; 31 (5):1-5.
Chicago/Turabian StyleGu-Young Kwon; Yong-June Shin. 2021. "Condition Monitoring Technique of HTS Cable via Tangent Distance-Based Template Matching Coefficient." IEEE Transactions on Applied Superconductivity 31, no. 5: 1-5.
The demand for cable diagnostics and monitoring techniques has increased significantly in recent decades. Various diagnostic tests such as partial discharge, dielectric loss, and elongation-at-break tests are available in real-world applications. Among the cable diagnostic methods, reflectometry can be used to detect the location of a fault according to the reflected signal at the impedance-discontinuity point. Because it is a nondestructive method and can be applied regardless of the cable type, reflectometry is commonly used for monitoring real-world applications. Time–frequency domain reflectometry, an improved type of reflectometry, is more accurate than conventional reflectometry and employs time–frequency localized signals that are robust to noise. To compensate for the errors occurring in the time–frequency domain reflectometry, several algorithms have been reviewed. In the past, because the signal of time-frequency domain reflectometry contains both time and frequency information, a high-specification signal generator and measurement sensors were required, which made practical application of the method difficult. However, with recent developments in instrumentation and sensing technology, reduction in the instrumentation size and cost facilitates the use of time–frequency domain reflectometry in various industrial applications, e.g., control and instrumentation cables in nuclear power plants, superconducting cables, and submarine cables. This work reviews the use of time-frequency domain reflectometry for cable diagnostics and monitoring in real-world applications. The purpose and results of the experiments on industrial applications are introduced and analyzed. This study also suggests directions for further research to make time–frequency domain reflectometry a diagnostic standard.
Hyeong Min Lee; Geon Seok Lee; Gu-Young Kwon; Su Sik Bang; Yong-June Shin. Industrial Applications of Cable Diagnostics and Monitoring Cables via Time–Frequency Domain Reflectometry. IEEE Sensors Journal 2020, 21, 1082 -1091.
AMA StyleHyeong Min Lee, Geon Seok Lee, Gu-Young Kwon, Su Sik Bang, Yong-June Shin. Industrial Applications of Cable Diagnostics and Monitoring Cables via Time–Frequency Domain Reflectometry. IEEE Sensors Journal. 2020; 21 (2):1082-1091.
Chicago/Turabian StyleHyeong Min Lee; Geon Seok Lee; Gu-Young Kwon; Su Sik Bang; Yong-June Shin. 2020. "Industrial Applications of Cable Diagnostics and Monitoring Cables via Time–Frequency Domain Reflectometry." IEEE Sensors Journal 21, no. 2: 1082-1091.
The characteristics of the HTS cable including conductivity, permittivity and insulation characteristics vary depending on the conditions of temperature and pressure during operation. We propose a diagnostic method that estimate the propagation constant of the HTS cable and detect the location and the degree of the fault using stepped frequency waveform reflectometry (SFWR). The performance of proposed method is verified by the HTS cable experiment regarding the propagation constant estimation and the fault detection. The results of HTS cable cooled by the liquid nitrogen are also compared to the results at the room temperature to analyze the insulation characteristics change according to the state. The proposed method is expected to be further applied to monitor the condition of HTS cable system regarding temperature and pressure.
Chun-Kwon Lee; Gu-Young Kwon; Yeong Ho Lee; Geon Seok Lee; Su Sik Bang; Yong-June Shin. Insulation Characteristics and Fault Analysis of HTS Cable via Stepped Frequency Waveform Reflectometry. IEEE Transactions on Applied Superconductivity 2019, 29, 1 -5.
AMA StyleChun-Kwon Lee, Gu-Young Kwon, Yeong Ho Lee, Geon Seok Lee, Su Sik Bang, Yong-June Shin. Insulation Characteristics and Fault Analysis of HTS Cable via Stepped Frequency Waveform Reflectometry. IEEE Transactions on Applied Superconductivity. 2019; 29 (5):1-5.
Chicago/Turabian StyleChun-Kwon Lee; Gu-Young Kwon; Yeong Ho Lee; Geon Seok Lee; Su Sik Bang; Yong-June Shin. 2019. "Insulation Characteristics and Fault Analysis of HTS Cable via Stepped Frequency Waveform Reflectometry." IEEE Transactions on Applied Superconductivity 29, no. 5: 1-5.
Load forecasting is a key issue for efficient real-time energy management in smart grids. To control the load using demand side management accurately, load forecasting should be predicted in the short term. With the advent of advanced measuring infrastructure, it is possible to measure energy consumption at sampling rates up to every 5 min and analyze the load profile of small-scale energy groups, such as individual buildings. This paper presents applications of deep learning using feature decomposition for improving the accuracy of load forecasting. The load profile is decomposed into a weekly load profile and then decomposed into intrinsic mode functions by variational mode decomposition to capture periodic features. Then, a long short-term memory network model is trained by three-dimensional input data with three-step regularization. Finally, the prediction results of all intrinsic mode functions are combined with advanced measuring infrastructure measured in the previous steps to determine an aggregated output for load forecasting. The results are validated by applications to real-world data from smart buildings, and the performance of the proposed approach is assessed by comparing the predicted results with those of conventional methods, nonlinear autoregressive networks with exogenous inputs, and long short-term memory network-based feature decomposition.
Seon Hyeog Kim; Gyul Lee; Gu-Young Kwon; Do-In Kim; Yong-June Shin. Deep Learning Based on Multi-Decomposition for Short-Term Load Forecasting. Energies 2018, 11, 3433 .
AMA StyleSeon Hyeog Kim, Gyul Lee, Gu-Young Kwon, Do-In Kim, Yong-June Shin. Deep Learning Based on Multi-Decomposition for Short-Term Load Forecasting. Energies. 2018; 11 (12):3433.
Chicago/Turabian StyleSeon Hyeog Kim; Gyul Lee; Gu-Young Kwon; Do-In Kim; Yong-June Shin. 2018. "Deep Learning Based on Multi-Decomposition for Short-Term Load Forecasting." Energies 11, no. 12: 3433.
In this paper, new time-frequency-based anomaly detection methodology is proposed for the condition monitoring of high-temperature superconducting (HTS) cable systems. The time-frequency-based anomaly detection methodology includes two indices, which are obtained via cross Wigner-Ville distribution and scattering parameter. For the validation of the proposed methodology, the methodology is applied to an ac 22.9-kV/50-MVA HTS cable system connected to the real power grid network. Furthermore, the changes in dielectric properties of the HTS cable system during the cooling process and the current imbalance failure are monitored. The proposed anomaly detection indices are shown to be able to detect the heat and the current imbalance caused by the malfunction of the joint box. For the application of the two validated indices, new anomaly detection procedure for HTS cable systems is also presented.
Geon Seok Lee; Su Sik Bang; Gu-Young Kwon; Yeong Ho Lee; Song-Ho Sohn; Sang-Chul Han; Yong-June Shin. Time–Frequency-Based Condition Monitoring of 22.9-kV HTS Cable Systems: Cooling Process and Current Imbalance. IEEE Transactions on Industrial Electronics 2018, 66, 8116 -8125.
AMA StyleGeon Seok Lee, Su Sik Bang, Gu-Young Kwon, Yeong Ho Lee, Song-Ho Sohn, Sang-Chul Han, Yong-June Shin. Time–Frequency-Based Condition Monitoring of 22.9-kV HTS Cable Systems: Cooling Process and Current Imbalance. IEEE Transactions on Industrial Electronics. 2018; 66 (10):8116-8125.
Chicago/Turabian StyleGeon Seok Lee; Su Sik Bang; Gu-Young Kwon; Yeong Ho Lee; Song-Ho Sohn; Sang-Chul Han; Yong-June Shin. 2018. "Time–Frequency-Based Condition Monitoring of 22.9-kV HTS Cable Systems: Cooling Process and Current Imbalance." IEEE Transactions on Industrial Electronics 66, no. 10: 8116-8125.
Fault localization is one of the most significant aspects in the maintenance of high-voltage direct current (HVDC) submarine cables that have unconventional installation characteristics such as long cable lengths and underwater installation locations. In order to protect and diagnose the cable, an improved fault localization technique, i.e., time-frequency domain reflectometry (TFDR) and tangent distance pattern recognition are proposed in this paper. The fault location information of the HVDC submarine cables can be obtained from the tangent distance, to support the results of TFDR. To verify the performance of the proposed method, a commercial HVDC submarine cable is used in the experiments. A test bed is constructed for creating a similar environment with that of submarine cable and filled with sea water. Both low- and high-impedance faults are emulated in this experiment by local insulation faults with iron, sea water, and air. The theoretical concepts and experimental results of the proposed method are presented. It is expected that the proposed method can improve the reliability of real-world HVDC power systems.
Gu-Young Kwon; Chun-Kwon Lee; Geon Seok Lee; Yeong Ho Lee; Seung Jin Chang; Chae-Kyun Jung; Ji-Won Kang; Yong-June Shin. Offline Fault Localization Technique on HVDC Submarine Cable via Time-Frequency Domain Reflectometry. 2018 IEEE Power & Energy Society General Meeting (PESGM) 2018, 1 -1.
AMA StyleGu-Young Kwon, Chun-Kwon Lee, Geon Seok Lee, Yeong Ho Lee, Seung Jin Chang, Chae-Kyun Jung, Ji-Won Kang, Yong-June Shin. Offline Fault Localization Technique on HVDC Submarine Cable via Time-Frequency Domain Reflectometry. 2018 IEEE Power & Energy Society General Meeting (PESGM). 2018; ():1-1.
Chicago/Turabian StyleGu-Young Kwon; Chun-Kwon Lee; Geon Seok Lee; Yeong Ho Lee; Seung Jin Chang; Chae-Kyun Jung; Ji-Won Kang; Yong-June Shin. 2018. "Offline Fault Localization Technique on HVDC Submarine Cable via Time-Frequency Domain Reflectometry." 2018 IEEE Power & Energy Society General Meeting (PESGM) , no. : 1-1.
Fault detection and localization of an electrical cable are essential to prevent a serious accident of cable system originated from the cable failure. Despite the outstanding performance in fault detection and localization, time-frequency domain refletometry (TFDR) faces an important issue of reliability of the diagnostic result. In this paper, skewness of time-frequency cross-correlation is used as the additional index to examine the existence of the unrevealed fault. In order to verify the validity of the proposed method, simulation is carried out with various types of fault occurrence circumstances. The analytic discussion on the simulation results is presented, and it is found to support effectiveness of the proposed method. It is expected that the proposed method will contribute to enhance the diagnostic performance of TFDR.
Gyeong Hwan Ji; Geon Seok Lee; Chun-Kwon Lee; Gu-Young Kwon; Yeong Ho Lee; Yong-June Shin. A Statistical Approach in Time-Frequency Domain Reflectometry for Enhanced Fault Detection. 2018 IEEE 2nd International Conference on Dielectrics (ICD) 2018, 1 -4.
AMA StyleGyeong Hwan Ji, Geon Seok Lee, Chun-Kwon Lee, Gu-Young Kwon, Yeong Ho Lee, Yong-June Shin. A Statistical Approach in Time-Frequency Domain Reflectometry for Enhanced Fault Detection. 2018 IEEE 2nd International Conference on Dielectrics (ICD). 2018; ():1-4.
Chicago/Turabian StyleGyeong Hwan Ji; Geon Seok Lee; Chun-Kwon Lee; Gu-Young Kwon; Yeong Ho Lee; Yong-June Shin. 2018. "A Statistical Approach in Time-Frequency Domain Reflectometry for Enhanced Fault Detection." 2018 IEEE 2nd International Conference on Dielectrics (ICD) , no. : 1-4.
Failures on power cable system lead to severe damage to power grid and tremendous repairing cost. Therefore, various techniques for monitoring and diagnosing cable system have been actively utilized. Most of diagnostic techniques are off-line systems, since they are limited to cables which are disconnected from power sources. In this paper, a method for online diagnosis of power cables that are connected to power grid is proposed using a state of art cable diagnostic technique, time-frequency domain reflectometry (TFDR) and inductive couplers. The performance of the proposed diagnostic technique for live cables is verified with two different live conditions: DC and AC. It is expected that the proposed diagnostic system will become an effective solution for ensuring reliability and safety of power grid in the future.
Yeong Ho Lee; Su Sik Bang; Chun-Kwon Lee; Gu-Young Kwon; Gyeong Hwan Ji; Yong-June Shin. Application of Inductive Coupler for Diagnosis of Live Cable System. 2018 IEEE 2nd International Conference on Dielectrics (ICD) 2018, 1 -3.
AMA StyleYeong Ho Lee, Su Sik Bang, Chun-Kwon Lee, Gu-Young Kwon, Gyeong Hwan Ji, Yong-June Shin. Application of Inductive Coupler for Diagnosis of Live Cable System. 2018 IEEE 2nd International Conference on Dielectrics (ICD). 2018; ():1-3.
Chicago/Turabian StyleYeong Ho Lee; Su Sik Bang; Chun-Kwon Lee; Gu-Young Kwon; Gyeong Hwan Ji; Yong-June Shin. 2018. "Application of Inductive Coupler for Diagnosis of Live Cable System." 2018 IEEE 2nd International Conference on Dielectrics (ICD) , no. : 1-3.
Fault detection and localization of an electrical cable are essential to prevent a serious accident of cable system originated from the cable failure. Despite the outstanding performance in fault detection and localization, time-frequency domain refletometry (TFDR) faces an important issue of reliability of the diagnostic result. In this paper, skewness of time-frequency cross-correlation is used as the additional index to examine the existence of the unrevealed fault. In order to verify the validity of the proposed method, simulation is carried out with various types of fault occurrence circumstances. The analytic discussion on the simulation results is presented, and it is found to support effectiveness of the proposed method. It is expected that the proposed method will contribute to enhance the diagnostic performance of TFDR.
Gyeong Hwan Ji; Geon Seok Lee; Chun-Kwon Lee; Gu-Young Kwon; Yeong Ho Lee; Yong-June Shin. A Statistical Approach in Time-Frequency Domain Reflectometry for Enhanced Fault Detection. 2018 IEEE 2nd International Conference on Dielectrics (ICD) 2018, 1 -4.
AMA StyleGyeong Hwan Ji, Geon Seok Lee, Chun-Kwon Lee, Gu-Young Kwon, Yeong Ho Lee, Yong-June Shin. A Statistical Approach in Time-Frequency Domain Reflectometry for Enhanced Fault Detection. 2018 IEEE 2nd International Conference on Dielectrics (ICD). 2018; ():1-4.
Chicago/Turabian StyleGyeong Hwan Ji; Geon Seok Lee; Chun-Kwon Lee; Gu-Young Kwon; Yeong Ho Lee; Yong-June Shin. 2018. "A Statistical Approach in Time-Frequency Domain Reflectometry for Enhanced Fault Detection." 2018 IEEE 2nd International Conference on Dielectrics (ICD) , no. : 1-4.
Failures on power cable system lead to severe damage to power grid and tremendous repairing cost. Therefore, various techniques for monitoring and diagnosing cable system have been actively utilized. Most of diagnostic techniques are off-line systems, since they are limited to cables which are disconnected from power sources. In this paper, a method for online diagnosis of power cables that are connected to power grid is proposed using a state of art cable diagnostic technique, time-frequency domain reflectometry (TFDR) and inductive couplers. The performance of the proposed diagnostic technique for live cables is verified with two different live conditions: DC and AC. It is expected that the proposed diagnostic system will become an effective solution for ensuring reliability and safety of power grid in the future.
Yeong Ho Lee; Su Sik Bang; Chun-Kwon Lee; Gu-Young Kwon; Gyeong Hwan Ji; Yong-June Shin. Application of Inductive Coupler for Diagnosis of Live Cable System. 2018 IEEE 2nd International Conference on Dielectrics (ICD) 2018, 1 -3.
AMA StyleYeong Ho Lee, Su Sik Bang, Chun-Kwon Lee, Gu-Young Kwon, Gyeong Hwan Ji, Yong-June Shin. Application of Inductive Coupler for Diagnosis of Live Cable System. 2018 IEEE 2nd International Conference on Dielectrics (ICD). 2018; ():1-3.
Chicago/Turabian StyleYeong Ho Lee; Su Sik Bang; Chun-Kwon Lee; Gu-Young Kwon; Gyeong Hwan Ji; Yong-June Shin. 2018. "Application of Inductive Coupler for Diagnosis of Live Cable System." 2018 IEEE 2nd International Conference on Dielectrics (ICD) , no. : 1-3.
A nuclear power plant (NPP) depends on instrumentation and control (I&C) systems to ensure its safe and efficient operation. In particular, I&C cables take on the pivotal role of measuring and controlling the critical equipment of the NPP. Thus, it is indubitable that the diagnostic technology of I&C cables for detecting faults and accurately assessing their health status is required for ensuring the safety and reliability of the NPP operation. We propose a diagnostic method that combines fault detection and evaluation algorithm for the I&C cables with stepped-frequency waveform reflectometry with signal propagation and reflection modeling. The signal modeling allows the assessment of the fault with an estimated reflection coefficient by separating the propagation and reflection effects of the measured signal. In short, cable faults are differentiated and quantified regardless of distance. The proposed algorithm is verified by characteristic impedance measurement, various fault detection/evaluation experiments, and the fault evaluation of local accelerated thermal aging cable.
Chun-Kwon Lee; Gu-Young Kwon; Yong-June Shin. Condition Assessment of I&C Cables in Nuclear Power Plants via Stepped-Frequency Waveform Reflectometry. IEEE Transactions on Instrumentation and Measurement 2018, 68, 215 -224.
AMA StyleChun-Kwon Lee, Gu-Young Kwon, Yong-June Shin. Condition Assessment of I&C Cables in Nuclear Power Plants via Stepped-Frequency Waveform Reflectometry. IEEE Transactions on Instrumentation and Measurement. 2018; 68 (1):215-224.
Chicago/Turabian StyleChun-Kwon Lee; Gu-Young Kwon; Yong-June Shin. 2018. "Condition Assessment of I&C Cables in Nuclear Power Plants via Stepped-Frequency Waveform Reflectometry." IEEE Transactions on Instrumentation and Measurement 68, no. 1: 215-224.
Fault diagnosis has been studied actively across the electrical industry to help maintain the stability of electrical equipment. Among these equipment, shielded cables, which are widely used in various industrial sectors, require careful and periodic diagnosis, owing to their poor installation environments and potential for creating huge economic losses. Reflectometry is a representative solution to locate the cable faults; however, conventional reflectometry techniques require prior knowledge about the cable under test, such as the reference wave velocity, total length of the cable, etc. Moreover, the degree of failure cannot be determined using conventional methods. In this paper, a novel reflectometry technique is proposed to locate and evaluate the faults in a cable, without requiring any prior knowledge. General regression neural network (GRNN) based on kernel density estimation are utilized with special feature extraction procedures. The proposed method is tested in an actual test bed with two types of emulated faults, and is found to estimate both the fault location and reflection coefficient successfully. It is expected that the proposed method can improve the stability of industrial equipment.
Gu-Young Kwon; Chun-Kwon Lee; Yong-June Shin. Diagnosis of Shielded Cable Faults via Regression-Based Reflectometry. IEEE Transactions on Industrial Electronics 2018, 66, 2122 -2131.
AMA StyleGu-Young Kwon, Chun-Kwon Lee, Yong-June Shin. Diagnosis of Shielded Cable Faults via Regression-Based Reflectometry. IEEE Transactions on Industrial Electronics. 2018; 66 (3):2122-2131.
Chicago/Turabian StyleGu-Young Kwon; Chun-Kwon Lee; Yong-June Shin. 2018. "Diagnosis of Shielded Cable Faults via Regression-Based Reflectometry." IEEE Transactions on Industrial Electronics 66, no. 3: 2122-2131.
In this paper, we propose a new time-frequency based analysis method that monitors the state of the high temperature superconducting (HTS) cable system in a real-time manner and detects the current imbalance of HTS cable system. The new time-frequency-based method utilizes the cross Wigner–Ville distribution to analyze the time-frequency localized phase difference of the reflected signal, which varies depending on the insulation characteristics of the HTS cable system. Also, a real-world AC 22.9 kV 50 MVA HTS cable system and a current source are used to validate the performance of the new monitoring method in order to detect current imbalance phenomenon.
Geon Seok Lee; Gyeong Hwan Ji; Gu-Young Kwon; Su Sik Bang; Yeong Ho Lee; Song-Ho Sohn; Kijun Park; Yong-June Shin. Monitoring Method for an Unbalanced Three-Phase HTS Cable System via Time-Frequency Domain Reflectometry. IEEE Transactions on Applied Superconductivity 2018, 28, 1 -5.
AMA StyleGeon Seok Lee, Gyeong Hwan Ji, Gu-Young Kwon, Su Sik Bang, Yeong Ho Lee, Song-Ho Sohn, Kijun Park, Yong-June Shin. Monitoring Method for an Unbalanced Three-Phase HTS Cable System via Time-Frequency Domain Reflectometry. IEEE Transactions on Applied Superconductivity. 2018; 28 (4):1-5.
Chicago/Turabian StyleGeon Seok Lee; Gyeong Hwan Ji; Gu-Young Kwon; Su Sik Bang; Yeong Ho Lee; Song-Ho Sohn; Kijun Park; Yong-June Shin. 2018. "Monitoring Method for an Unbalanced Three-Phase HTS Cable System via Time-Frequency Domain Reflectometry." IEEE Transactions on Applied Superconductivity 28, no. 4: 1-5.
High temperature superconducting (HTS) cables are drawing attention as transmission and distribution cables in future grid, and related researches on HTS cables have been conducted actively. As HTS cables have come to the demonstration stage, failures of cooling systems inducing quench phenomenon of the HTS cables have become significant. Several diagnosis of the HTS cables have been developed but there are still some limitations of the experimental setup. In this paper, a non-destructive diagnostic technique for the detection of the local temperature change point is proposed. Also, a simulation model of HTS cables with a local temperature change point is suggested to verify the proposed diagnosis. The performance of the diagnosis is checked by comparative analysis between the proposed simulation results and experiment results of a real-world HTS cable. It is expected that the suggested simulation model and diagnosis will contribute to the commercialization of HTS cables in the power grid.
Su Sik Bang; Geon Seok Lee; Gu-Young Kwon; Yeong Ho Lee; Gyeong Hwan Ji; Songho Sohn; Kijun Park; Yong-June Shin. Detection of Local Temperature Change on HTS Cables via Time-Frequency Domain Reflectometry. Journal of Physics: Conference Series 2017, 871, 012100 .
AMA StyleSu Sik Bang, Geon Seok Lee, Gu-Young Kwon, Yeong Ho Lee, Gyeong Hwan Ji, Songho Sohn, Kijun Park, Yong-June Shin. Detection of Local Temperature Change on HTS Cables via Time-Frequency Domain Reflectometry. Journal of Physics: Conference Series. 2017; 871 (1):012100.
Chicago/Turabian StyleSu Sik Bang; Geon Seok Lee; Gu-Young Kwon; Yeong Ho Lee; Gyeong Hwan Ji; Songho Sohn; Kijun Park; Yong-June Shin. 2017. "Detection of Local Temperature Change on HTS Cables via Time-Frequency Domain Reflectometry." Journal of Physics: Conference Series 871, no. 1: 012100.
Fault localization is one of the most significant aspects in the maintenance of high-voltage direct current (HVdc) submarine cables that have unconventional installation characteristics, such as long cable lengths and underwater installation locations. In order to protect and diagnose the cable, an improved fault localization technique, that is, time-frequency domain reflectometry (TFDR) and tangent distance pattern recognition are proposed in this paper. The fault location information of the HVdc submarine cables can be obtained from the tangent distance, to support the results of TFDR. To verify the performance of the proposed method, a commercial HVdc submarine cable is used in the experiments. A test bed is constructed for creating a similar environment with that of the submarine cable and filled with sea water. Both low- and high-impedance faults are emulated in this experiment by local insulation faults with iron, sea water, and air. The theoretical concepts and experimental results of the proposed method are presented. It is expected that the proposed method can improve the reliability of real-world HVdc power systems.
Gu-Young Kwon; Chun-Kwon Lee; Geon Seok Lee; Yeong Ho Lee; Seung Jin Chang; Chae-Kyun Jung; Ji-Won Kang; Yong-June Shin. Offline Fault Localization Technique on HVDC Submarine Cable via Time–Frequency Domain Reflectometry. IEEE Transactions on Power Delivery 2017, 32, 1626 -1635.
AMA StyleGu-Young Kwon, Chun-Kwon Lee, Geon Seok Lee, Yeong Ho Lee, Seung Jin Chang, Chae-Kyun Jung, Ji-Won Kang, Yong-June Shin. Offline Fault Localization Technique on HVDC Submarine Cable via Time–Frequency Domain Reflectometry. IEEE Transactions on Power Delivery. 2017; 32 (3):1626-1635.
Chicago/Turabian StyleGu-Young Kwon; Chun-Kwon Lee; Geon Seok Lee; Yeong Ho Lee; Seung Jin Chang; Chae-Kyun Jung; Ji-Won Kang; Yong-June Shin. 2017. "Offline Fault Localization Technique on HVDC Submarine Cable via Time–Frequency Domain Reflectometry." IEEE Transactions on Power Delivery 32, no. 3: 1626-1635.
The maintenance of control and instrumentation (C&I) cables is crucial to safety of operating nuclear power plants. Therefore, when an accident occurs, there is a need for an accurate assessment of the impact on the cable's integrity. Unfortunately, most cable diagnostic methods are destructive and real-time assessment of the effect of accidents is not possible. Thus, in this paper, we present an analysis of a specific type of accident, a loss of coolant accident (LOCA), on C&I cables in real-time, based on time-frequency domain reflectometry (TFDR). Because the TFDR is sensitive to the signal-to-noise ratio and distortion of a reflected signal, we apply postprocessing techniques that compensate the dispersion based on the estimated propagation constant and a denoising method using singular value decomposition. The approach is verified by experimentally monitoring condition changes of localized LOCA hot spot in different C&I cables. The results are also validated by comparing with elongation at break test results.
Chun-Kwon Lee; Gu-Young Kwon; Seung Jin Chang; Moon Kang Jung; Jin Bae Park; Han-Soo Kim; Yong-June Shin. Real-Time Condition Monitoring of LOCA via Time–Frequency Domain Reflectometry. IEEE Transactions on Instrumentation and Measurement 2017, 66, 1864 -1873.
AMA StyleChun-Kwon Lee, Gu-Young Kwon, Seung Jin Chang, Moon Kang Jung, Jin Bae Park, Han-Soo Kim, Yong-June Shin. Real-Time Condition Monitoring of LOCA via Time–Frequency Domain Reflectometry. IEEE Transactions on Instrumentation and Measurement. 2017; 66 (7):1864-1873.
Chicago/Turabian StyleChun-Kwon Lee; Gu-Young Kwon; Seung Jin Chang; Moon Kang Jung; Jin Bae Park; Han-Soo Kim; Yong-June Shin. 2017. "Real-Time Condition Monitoring of LOCA via Time–Frequency Domain Reflectometry." IEEE Transactions on Instrumentation and Measurement 66, no. 7: 1864-1873.
A high-temperature superconducting (HTS) cable system with the 22.9 kV, 50 MVA, and 410 m length is installed and operated at 154 kV Icheon substation of Korea Electric Power Corporation (KEPCO). Unfortunately, it is a difficult task to diagnose and monitor electrical and thermal characteristics of the HTS cable system in a real-time manner. In order to protect operational failures of grid-connected HTS cable systems, this paper proposes time-frequency domain reflectometry (TFDR) and analysis techniques, i.e., time-frequency cross correlation and instantaneous frequency estimation. To verify the performance of the proposed method, the temperature is changed via the cryogenic refrigeration system and the status of the grid-connected HTS cable is monitored via TFDR in a real-time manner.
Geon Seok Lee; Gu-Young Kwon; Su Sik Bang; Yeong Ho Lee; Song-Ho Sohn; Kijun Park; Yong-June Shin. Monitoring Electrical and Thermal Characteristics of HTS Cable Systems via Time–Frequency Domain Reflectometry. IEEE Transactions on Applied Superconductivity 2017, 27, 1 -5.
AMA StyleGeon Seok Lee, Gu-Young Kwon, Su Sik Bang, Yeong Ho Lee, Song-Ho Sohn, Kijun Park, Yong-June Shin. Monitoring Electrical and Thermal Characteristics of HTS Cable Systems via Time–Frequency Domain Reflectometry. IEEE Transactions on Applied Superconductivity. 2017; 27 (4):1-5.
Chicago/Turabian StyleGeon Seok Lee; Gu-Young Kwon; Su Sik Bang; Yeong Ho Lee; Song-Ho Sohn; Kijun Park; Yong-June Shin. 2017. "Monitoring Electrical and Thermal Characteristics of HTS Cable Systems via Time–Frequency Domain Reflectometry." IEEE Transactions on Applied Superconductivity 27, no. 4: 1-5.
High temperature superconducting (HTS) cable operates under relatively low temperature and its unique operating condition brings new challenges in the area of maintenance and diagnostics of the cable. As an example, a temperature difference occurs on connection systems between instruments on room temperature and HTS cables which eventually leads to thermal energy loss. The thermal energy loss affects frequency characteristics of the cable which are critical aspects for simulation and maintenance of the HTS cable systems. In this paper, an attempt to reduce thermal loss is introduced with an improved connector applying a Peltier module. The performance of the designed connector is verified with analysis of electromagnetic wave propagation properties of HTS tapes and a cable. The investigation of S -parameters and the proposed connection method is expected to be further applied to various HTS systems in future.
Yeong Ho Lee; Su Sik Bang; Gu-Young Kwon; Geon Seok Lee; Gyeong Hwan Ji; Song-Ho Sohn; Kijun Park; Yong-June Shin. Analysis of Wave Propagation of HTS Cables for Compensation of Thermal Loss on Connectors. IEEE Transactions on Applied Superconductivity 2017, 27, 1 -5.
AMA StyleYeong Ho Lee, Su Sik Bang, Gu-Young Kwon, Geon Seok Lee, Gyeong Hwan Ji, Song-Ho Sohn, Kijun Park, Yong-June Shin. Analysis of Wave Propagation of HTS Cables for Compensation of Thermal Loss on Connectors. IEEE Transactions on Applied Superconductivity. 2017; 27 (4):1-5.
Chicago/Turabian StyleYeong Ho Lee; Su Sik Bang; Gu-Young Kwon; Geon Seok Lee; Gyeong Hwan Ji; Song-Ho Sohn; Kijun Park; Yong-June Shin. 2017. "Analysis of Wave Propagation of HTS Cables for Compensation of Thermal Loss on Connectors." IEEE Transactions on Applied Superconductivity 27, no. 4: 1-5.
Most of modeling and simulation of high temperature superconducting (HTS) cables are inadequate for high frequency analysis since focus of the simulation’s frequency is fundamental frequency of the power grid, which does not reflect transient characteristic. However, high frequency analysis is essential process to research the HTS cables transient for protection and diagnosis of the HTS cables. Thus, this paper proposes a new approach for modeling and simulation of HTS cables to derive the scattering parameter (S-parameter), an effective high frequency analysis, for transient wave propagation characteristics in high frequency range. The parameters sweeping method is used to validate the simulation results to the measured data given by a network analyzer (NA). This paper also presents the effects of the cable-to-NA connector in order to minimize the error between the simulated and the measured data under ambient and superconductive conditions. Based on the proposed modeling and simulation technique, S-parameters of long-distance HTS cables can be accurately derived in wide range of frequency. The results of proposed modeling and simulation can yield the characteristics of the HTS cables and will contribute to analyze the HTS cables.
Su Sik Bang; Geon Seok Lee; Gu-Young Kwon; Yeong Ho Lee; Seung Jin Chang; Chun-Kwon Lee; Songho Sohn; Kijun Park; Yong-June Shin. Modeling and simulation of HTS cables for scattering parameter analysis. Physica C: Superconductivity and its Applications 2016, 530, 142 -146.
AMA StyleSu Sik Bang, Geon Seok Lee, Gu-Young Kwon, Yeong Ho Lee, Seung Jin Chang, Chun-Kwon Lee, Songho Sohn, Kijun Park, Yong-June Shin. Modeling and simulation of HTS cables for scattering parameter analysis. Physica C: Superconductivity and its Applications. 2016; 530 ():142-146.
Chicago/Turabian StyleSu Sik Bang; Geon Seok Lee; Gu-Young Kwon; Yeong Ho Lee; Seung Jin Chang; Chun-Kwon Lee; Songho Sohn; Kijun Park; Yong-June Shin. 2016. "Modeling and simulation of HTS cables for scattering parameter analysis." Physica C: Superconductivity and its Applications 530, no. : 142-146.