The Experts below are selected from a list of 13167 Experts worldwide ranked by ideXlab platform
Edward Choi - One of the best experts on this subject based on the ideXlab platform.
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Analysis and design of an Overcurrent protection scheme based on parasitic inductance of SiC MOSFET power module
2018 IEEE Applied Power Electronics Conference and Exposition (APEC), 2018Co-Authors: Rolando Burgos, Yonghan Kang, Dushan Boroyevich, Edward ChoiAbstract:This paper presents an Overcurrent protection scheme based on parasitic inductance between the power source and the Kelvin source of the power module. A complete design process and comprehensive analysis of the Overcurrent protection scheme, which can be applied generally, to any power module containing Kelvin source is shown. The protection circuit can be used to detect both very intense short-circuit fault (SC) and relatively slow Overcurrent fault (OC), fault out of load for example. A 1.2 kV SiC MOSFET gate driver prototype with integrated Overcurrent protection circuit is designed to verify the functionality of the protection method.
Benjamin J. Blalock - One of the best experts on this subject based on the ideXlab platform.
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Design and Performance Evaluation of Overcurrent Protection Schemes for Silicon Carbide (SiC) Power MOSFETs
Ieee Transactions on Industrial Electronics, 2014Co-Authors: Zhong Quan Wang, X. J. Shi, Yuncan Xue, Laren M. Tolbert, F. Wang, Benjamin J. BlalockAbstract:Overcurrent protection of silicon carbide (SiC) metal-oxide-semiconductor field-effect transistors (MOSFETs) remains a challenge due to lack of practical knowledge. This paper presents three Overcurrent protection methods to improve the reliability and overall cost of SiC MOSFET-based converters. First, a solid-state circuit breaker (SSCB) composed primarily by a Si IGBT and a commercial gate driver IC is connected in series with the dc bus to detect and clear Overcurrent faults. Second, the desaturation technique using a sensing diode to detect the drain-source voltage under Overcurrent faults is implemented as well. Third, a novel active Overcurrent protection scheme through dynamic evaluation of fault current level is proposed. The design considerations and potential issues of the protection methods are described and analyzed in detail. A phase-leg configuration-based step-down converter is built to evaluate the performance of the protection schemes under various conditions, considering variation of fault type, decoupling capacitance, protection circuit parameters, etc. Finally, a comparison is made in terms of fault response time, temperature-dependent characteristics, and applications to help designers select a proper protection method.
E. Vazquez - One of the best experts on this subject based on the ideXlab platform.
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Functional Structure for Performance Improvement of Time Overcurrent Relays
Electric Power Components and Systems, 2007Co-Authors: A. Conde, E. VazquezAbstract:Abstract In this article, we recommend a functional structure for time Overcurrent relays. This type of relay has a higher sensitivity and reduced back-up times compared to other types of relay using only the information available at the relay's site. We describe the functional structure of time Overcurrent adaptive relays for phase protection. The results obtained from time Overcurrent adaptive relays are collated, and the results from analysis of negative sequence relays and conventional time Overcurrent relays are also presented.
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Operation Logic Proposed for Time Overcurrent Relays
IEEE Transactions on Power Delivery, 2007Co-Authors: A. Conde, E. VazquezAbstract:This paper presents a new logic of operation for time Overcurrent relays. With the application of the proposed technique, the sensitivity of time Overcurrent relays is increased. In order to obtain this, the relay operates with a dynamic pickup setting, such as load current. Additionally, fast operation of Overcurrent relays is obtained. The functional structure is described and the logic of Overcurrent relay is evaluated under different operative states. We describe the functional structure of the proposed relay and its implementation in laboratory tests.
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Operation logic proposed for time Overcurrent relays
2006 IEEE Power Engineering Society General Meeting, 2006Co-Authors: A. Conde, E. VazquezAbstract:This paper presents a new logic of operation for time Overcurrent relays. With the application of the proposed technique, the sensitivity of time Overcurrent relays is increased. In order to obtain this, the relay operates with a dynamic pickup setting like load current. Additionally a fast operation of Overcurrent relays is obtained. The functional structure is described and the logic of Overcurrent relay is evaluated under different operative states. We describe the functional structure of the proposed relay and its implementation in laboratory test.
A. Conde - One of the best experts on this subject based on the ideXlab platform.
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Mitigation of DOCR miscoordination through distance relays and non-standard Overcurrent curves
Electric Power Systems Research, 2018Co-Authors: C. Castillo, A. Conde, Erika FernandezAbstract:Abstract This article presents the application of non-standardized inverse-time curves and distance relays to solve the lack of sensitivity of relays during Overcurrent relay coordination. The inclusion of distance relays to replace the insensitive Overcurrent is proposed, the effect of underreaching by infeed is considered. Directional Overcurrent relays very frequently act as backup protection in sub-transmition networks when line differential relays or pilot protection are used as primary protection. Thus, the directional Overcurrent relays (DOCR) coordination application should be evaluated not only in small electrical systems but also in large and meshed networks. The model used of Overcurrent relay considers five adjustable settings to enhance the coordination when distance relays are considered. The proposed method reduces the number of relays that do not coordinate, this allows to obtain results with better implementation. The results show a performance improvement in Overcurrent relay coordination in several highly interconnected IEEE systems.
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Functional Structure for Performance Improvement of Time Overcurrent Relays
Electric Power Components and Systems, 2007Co-Authors: A. Conde, E. VazquezAbstract:Abstract In this article, we recommend a functional structure for time Overcurrent relays. This type of relay has a higher sensitivity and reduced back-up times compared to other types of relay using only the information available at the relay's site. We describe the functional structure of time Overcurrent adaptive relays for phase protection. The results obtained from time Overcurrent adaptive relays are collated, and the results from analysis of negative sequence relays and conventional time Overcurrent relays are also presented.
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Operation Logic Proposed for Time Overcurrent Relays
IEEE Transactions on Power Delivery, 2007Co-Authors: A. Conde, E. VazquezAbstract:This paper presents a new logic of operation for time Overcurrent relays. With the application of the proposed technique, the sensitivity of time Overcurrent relays is increased. In order to obtain this, the relay operates with a dynamic pickup setting, such as load current. Additionally, fast operation of Overcurrent relays is obtained. The functional structure is described and the logic of Overcurrent relay is evaluated under different operative states. We describe the functional structure of the proposed relay and its implementation in laboratory tests.
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Operation logic proposed for time Overcurrent relays
2006 IEEE Power Engineering Society General Meeting, 2006Co-Authors: A. Conde, E. VazquezAbstract:This paper presents a new logic of operation for time Overcurrent relays. With the application of the proposed technique, the sensitivity of time Overcurrent relays is increased. In order to obtain this, the relay operates with a dynamic pickup setting like load current. Additionally a fast operation of Overcurrent relays is obtained. The functional structure is described and the logic of Overcurrent relay is evaluated under different operative states. We describe the functional structure of the proposed relay and its implementation in laboratory test.
Richard Hunt - One of the best experts on this subject based on the ideXlab platform.
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current transformer saturation effects on coordinating time interval
IEEE Transactions on Industry Applications, 2013Co-Authors: Terrence Smith, Richard HuntAbstract:The primary function of protective devices is to remove faulted equipment from the electrical system. It is typically very advantageous for these devices to isolate as small of a section of the electrical system as possible. Overcurrent protection is the most common protection function used, as faulted equipment typically results in a large short circuit current. When Overcurrent protection is employed, the Overcurrent protection is typically coordinated with time so that the devices closest to the fault will operate and isolate only that section of equipment before devices farther from the fault operate and isolate larger pieces of the system. These time Overcurrent devices must also be coordinated with damage curves for equipment such as buses and cables to clear the fault before the Overcurrent can cause damage to the equipment. This concept of time coordination of Overcurrent is well understood, and there are general guidelines applied to account for measurement error and other inaccuracies. The reduced signal levels provided to relays due to current transformer (CT) saturation are normally not considered during coordination studies. This reduced signal level will result in slower than desired operation of protective relays. Feeder relays could trip slower than upstream devices, isolating more of the power system than intended, or could allow primary equipment to be damaged before tripping. This paper will review the concept of coordinating time Overcurrent relays and then discuss the concept of loss of coordination associated with CT saturation. This paper will model CT saturation from actual installations using the IEEE Power System Relaying Committee CT Saturation Calculator tool. This model data will be used to estimate the performance of protective relays. This paper will discuss methods to improve the coordination of Overcurrent relays when faced with significant CT saturation.
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current transformer saturation effects on coordinating time interval
Conference for Protective Relay Engineers, 2011Co-Authors: Terrence Smith, Richard HuntAbstract:The primary function of protective devices is to remove faulted equipment from the electrical system. It is typically very advantageous for these devices to isolate as small of a section of the electrical system as possible. Overcurrent protection is the most common protection function used, as faulted equipment typically results in a large short circuit current. When Overcurrent protection is employed, the Overcurrent protection is typically coordinated with time so that the devices closest to the fault will operate and isolate only that section of equipment before devices farther from the fault operate and isolate larger pieces of the system. These time Overcurrent devices must also be coordinated with damage curves for equipment such as buses and cables to clear the fault before the Overcurrent can cause damage to the equipment. This concept of time coordination of Overcurrent is well understood, and there are general guidelines applied to account for measurement error and other inaccuracies. The reduced signal levels provided to relays due to current transformer saturation is normally not considered during coordination studies. This reduced signal level will result in slower than desired operation of protective relays. Feeder relays could trip slower than upstream devices, isolating more of the power system than intended, or could allow primary equipment to be damaged before tripping. This paper will review the concept of coordinating time Overcurrent relays, and then discuss the concept of loss of coordination associated with current transformer saturation. The paper will model current transformer saturation from actual installations using the IEEE PSRC CT Saturation Calculator tool. This model data will be used to estimate the performance of protective relays. The paper will discuss methods to improve coordination of Overcurrent relays when faced with significant CT saturation.
