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.

Optimizing converter protection for wind turbine generators

Abstract: An integrated fault and personnel protection system (5) and method for a multi-thread converter 20-1, 20-2, 20-3, 20-4 in a wind turbine power system is provided The structure and method provide for system optimization, as well as, arc flash protection Fault sensing (182), (183) with means of removing power applied to the converter minimizes the energy available to produce an arc flash event Sensing and disconnects devices (125), (135), (145), (155) for the protections are provided close to the source of energy to protect more of the system (5) Converter controls (25) detect, identify and isolate faults selecting the best combinations of novel specific fault isolation devices Components are distributed into separate physical to enhance protection

Transmission-Line Fault Analysis Using Synchronized Sampling

Abstract: An automated analysis approach, which can automatically characterize fault and subsequent relay operation, is the focus of this paper. It utilizes synchronized samples captured during transients from both ends of the transmission line to detect, classify, and locate transmission-line faults and can verify that the tripped line has indeed experienced a fault. The proposed method is tested for several faults simulated on an IEEE 118-bus test system and it has been concluded that it can detect and classify a fault using prefault and postfault recorded samples within 7 ms of fault inception and can accurately locate a fault with 3% accuracy. This time response performance is highly desirable since with the increasing use of modern circuit breakers, which can open the faulty line in less than two cycles, the time window of the captured waveforms is significantly reduced due to the unavailability of measurement signals after breakers open.

High-speed fault identification and protection for HVDC line using wavelet technique

Abstract: This paper describes a new high-speed HVDC line protection using wavelet technique. Based on the representation of the travelling waves through wavelet modulus maxima, the protection criteria for HVDC fine are proposed. Simulations are carried out for testing the criteria. The influences of similar faults are discussed. The protection can detect the HVDC line fault well and identify the HVDC line fault clearly from the similar transients, such as commutation failure and AC single phase fault.

Adaptive Transformer Thermal Overload Protection

Abstract: This paper is based on a report of the same title, prepared by Working Group K3 of the Substation Protection Subcommittee of the Power System Relaying Committee of the Power Engineering Society of the IEEE. The paper begins with background information on the causes, measurement techniques, and consequences of overheating in mineral-oil-immersed power transformers. Then techniques for adaptive transformer thermal overload protection based on the real-time solution of the transient heating equations are presented. An adaptive overcurrent protection implementation, and the related functional requirements, are discussed. The equations of Clause 7 of the 1995 IEEE Guide for Loading Mineral-Oil-Immersed Transformers are used in the analysis, with a slight modification to allow for continuously varying ambient temperature.

Optimal Robustness in Power Grids From a Network Science Perspective

Abstract: In recent years, the frequent occurrences of large-scale blackouts highlight the necessity of enhancing the robustness of power grids. In this brief, based on the cascading failure model which considers both the network topology and electrical characteristics running in power grids, we study how the topological metrics affect the robustness of power grids. The topological metrics considered include both the connectivity of the network and the distribution of generators. We compare the results in typical complex network models and an IEEE 118-bus network. Moreover, by using the simulated annealing method, we find the optimal network topology to achieve the best network robustness, and compare the topological metrics before and after the optimization to verify our findings. The results show that, in order to enhance the robustness of power grids, it is better to make the network sparsely connected, and place the generators as hubs and decentralize these generators.