21,454 research outputs found

    International White Book on DER Protection : Review and Testing Procedures

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    This white book provides an insight into the issues surrounding the impact of increasing levels of DER on the generator and network protection and the resulting necessary improvements in protection testing practices. Particular focus is placed on ever increasing inverter-interfaced DER installations and the challenges of utility network integration. This white book should also serve as a starting point for specifying DER protection testing requirements and procedures. A comprehensive review of international DER protection practices, standards and recommendations is presented. This is accompanied by the identiïŹ cation of the main performance challenges related to these protection schemes under varied network operational conditions and the nature of DER generator and interface technologies. Emphasis is placed on the importance of dynamic testing that can only be delivered through laboratory-based platforms such as real-time simulators, integrated substation automation infrastructure and ïŹ‚ exible, inverter-equipped testing microgrids. To this end, the combination of ïŹ‚ exible network operation and new DER technologies underlines the importance of utilising the laboratory testing facilities available within the DERlab Network of Excellence. This not only informs the shaping of new protection testing and network integration practices by end users but also enables the process of de-risking new DER protection technologies. In order to support the issues discussed in the white paper, a comparative case study between UK and German DER protection and scheme testing practices is presented. This also highlights the level of complexity associated with standardisation and approval mechanisms adopted by different countries

    Effects of Load Magnitude on Diagnosing Broken Bar Faults in Induction Motors Using the Pendulous Oscillation of the Rotor Magnetic Field Orientation

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    The effects of load level on the ability to diagnose broken bar faults in squirrel-cage induction motors are studied in this paper. The pendulous oscillation of the rotor magnetic field orientation is implemented as a fault signature for rotor fault diagnostic purposes at steady-state operations. Moreover, the effects of load level on the low-side band component of the stator current spectrum, and associated diagnostic difficulties in this approach particularly in the presence of motor operation from pulsewidth-modulation drives, are reported as well. These investigations were performed through testing 2-hp and 5-hp induction motors over a wide range of load levels and control drives. The results of these tests and investigations demonstrate the efficacy of the pendulous oscillation signature as a diagnostic means that can be used for a wide range of motor operating conditions

    Great East Japan Earthquake, JR East Mitigation Successes, and Lessons for California High-Speed Rail, MTI Report 12-37

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    California and Japan both experience frequent seismic activity, which is often damaging to infrastructure. Seismologists have developed systems for detecting and analyzing earthquakes in real-time. JR East has developed systems to mitigate the damage to their facilities and personnel, including an early earthquake detection system, retrofitting of existing facilities for seismic safety, development of more seismically resistant designs for new facilities, and earthquake response training and exercises for staff members. These systems demonstrated their value in the Great East Japan Earthquake of 2011 and have been further developed based on that experience. Researchers in California are developing an earthquake early warning system for the state, and the private sector has seismic sensors in place. These technologies could contribute to the safety of the California High-Speed Rail Authority’s developing system, which could emulate the best practices demonstrated in Japan in the construction of the Los Angeles-to-San Jose segment

    Service continuity in complex power systems: safety, operation and maintenance

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    The research aims to define electrical architectures based on the rationalization of the distribution structure and of power sources with the achievement of the primary objectives of service continuity, power quality, safety and safe maintenance. The thesis consists of two parts: the first part deals with the architecture impact on a complex system analyzing the system configuration and operational safety aspects. New developments and methodologies are presented in the study of critical systems. A theory of complex systems for safety, operation and maintenance aspects is defined that enables to assist the management of the system throughout its whole life cycle and allows an implementation of programming languages. The second part refers to specific issues of mission critical power systems, data centers and hospitals especially. Several measurements were performed in laboratory and on field to analyze sneaky critical cases for the service continuity and the integrity of these strategic power systems.The research aims to define electrical architectures based on the rationalization of the distribution structure and of power sources with the achievement of the primary objectives of service continuity, power quality, safety and safe maintenance. The thesis consists of two parts: the first part deals with the architecture impact on a complex system analyzing the system configuration and operational safety aspects. New developments and methodologies are presented in the study of critical systems. A theory of complex systems for safety, operation and maintenance aspects is defined that enables to assist the management of the system throughout its whole life cycle and allows an implementation of programming languages. The second part refers to specific issues of mission critical power systems, data centers and hospitals especially. Several measurements were performed in laboratory and on field to analyze sneaky critical cases for the service continuity and the integrity of these strategic power systems

    CIRSS vertical data integration, San Bernardino study

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    The creation and use of a vertically integrated data base, including LANDSAT data, for local planning purposes in a portion of San Bernardino County, California are described. The project illustrates that a vertically integrated approach can benefit local users, can be used to identify and rectify discrepancies in various data sources, and that the LANDSAT component can be effectively used to identify change, perform initial capability/suitability modeling, update existing data, and refine existing data in a geographic information system. Local analyses were developed which produced data of value to planners in the San Bernardino County Planning Department and the San Bernardino National Forest staff
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