Power-system protection

About: Power-system protection is a research topic. Over the lifetime, 6353 publications have been published within this topic receiving 117961 citations.

Arcing fault detection for distribution feeders: security assessment in long term field trials

Abstract: A downed conductor, arcing fault detection system has been designed using multiple protection algorithms. An intelligent analysis system processes the outputs from several algorithms to determine the "confidence" that a fault exists. The design includes careful attention to discriminating arcing faults from normal system activity to ensure system security. Key to the acceptance of this system is testing under actual field conditions. The results of long term tests on five utilities are presented. The behavior of the prototype systems to staged faults, naturally occurring faults, and normal system disturbances is described. Conclusions are drawn concerning the practical viability of this system. >

A generic real-time computer Simulation model for Superconducting fault current limiters and its application in system protection studies

Abstract: A model for the SCFCL suitable for use in real time computer simulation is presented. The model accounts for the highly nonlinear quench behavior of BSCCO and includes the thermal aspects of the transient phenomena when the SCFCL is activated. Implemented in the RTDS real-time simulation tool the model has been validated against published BSCCO characteristics. As an example for an application in protection system studies, the effect of an SCFCL on a utility type impedance relay has been investigated using a real time hardware-in-the-loop (RT-HIL) experiment. The test setup is described and initial results are presented. They illustrate the effect of how the relay misinterprets the dynamically changing SCFCL impedance as an apparently more distant fault location. It is expected that the new real-time SCFCL model will provide a valuable tool not only for further protection system studies but for a wide range of RT-HIL experiments of power systems.

Operating MicroGrid Energy Storage Control during Network Faults

Abstract: A MicroGrid is expected to operate both as a sub system connected to the main grid or as an islanded system. However the provision of fault currents, in an islanded MicroGrid consisting only of micro-generation interfaced with relatively low-current power electronics, is a serious system protection issue. This paper presents the novel concept of using the central energy storage system (flywheel) as the main fault current source in islanded mode. The three-phase MicroGrid test rig used at University of Manchester, and the flywheel control system are described. The importance of accurate systems modeling of the whole microgrid and energy storage unit is shown. A fault study is carried out on the test rig and in PSCAD. The flywheel inverter system is shown to contribute enough fault current for a sufficient duration to cause the system protective device to clear the fault.

A Numerical Formulation for Grounding Analysis in Stratified Soils

Abstract: The design of safe grounding systems in electrical installations is essential to assure the security of the persons, the protection of the equipment and the continuity of the power supply. In order to achieve these goals, it is necessary to compute the equivalent electrical resistance of the system and the potential distribution on the earth surface when a fault condition occurs. In this paper we present a formulation for the analysis of grounding systems embedded in stratified soils, on the basis of the boundary element method (BEM). Suitable arrangements of the final discretized equations allow us to use the highly efficient analytical integration techniques derived by the authors for grounding systems buried in uniform soils. The feasibility of this approach is demonstrated by applying the BEM formulation to the analysis of a real grounding system with a two-layer soil model.

Power Engineering Letters Transient Stability Analysis of a Distribution Network With Distributed Generators

Abstract: This letter describes the transient stability analysis of a10-kVdistributionnetworkwithwindgenerators,microturbines, and CHP plants. The network being modeled in Matlab/Simulink takesintoaccountdetaileddynamicmodelsofthegenerators.Fault simulations at various locations are investigated. For the studied cases, the critical clearing times are calculated. Results obtained from several case studies are presented and discussed. Index Terms—Critical clearing time, distributed generation, dis- tribution network, power system protection.