Results 251 to 260 of about 5,009,115 (304)

Variable Tripping Time Differential Protection for Microgrids Considering DG Stability

IEEE Transactions on Smart Grid, 2019
Coordination between protective device fault clearing times and distributed generation (DGs) stability is essential to avoid nuisance tripping of DG. In this paper, a multi-agent protection scheme based on a variable tripping time differential protection
T. Aghdam, H. Kazemi Karegar, H. Zeineldin   +2 more
semanticscholar   +1 more source

Countermeasure to Prevent the Incorrect Blocking of Differential Protection Applied to Converter Transformers

IEEE Transactions on Power Delivery, 2020
Harmonic blocking is usually applied by converter transformer differential protection to prevent protection mal-operation during an inrush condition, but it may incorrectly block the protection during an internal fault. This paper first makes an in-depth
Yucong Zhao, P. Crossley
semanticscholar   +1 more source

Syntheses of differentially protected isocoumarins

Tetrahedron, 2010
Syntheses of an isocoumarin subunit suitable for the completion of purpuromycin are outlined. Specifically, work targeting an orthogonally protected isocoumarin (eventually 12% yield over 12 steps) and an improved synthesis of a symmetrically protected isocoumarin (18% over 10 steps) are described.
Andrew N. Lowell, Philip D. Wall, Stephen P. Waters, Marisa C. Kozlowski   +3 more
openaire   +1 more source

Impact of DC bias on differential protection of converter transformers

, 2020
Converter transformers in high-voltage direct current (HVDC) systems are often subjected to DC bias induced by earth return currents (ERCs) from HVDC systems or by geomagnetically induced currents (GICs).
Yucong Zhao, P. Crossley
semanticscholar   +1 more source

Novel differential protection using model recognition and unsymmetrical vector reconstruction for the transmission line with wind farms connection

, 2020
The large-scale integration of different kinds of wind farms (WFs) in a transmission grid can bring special adaptability issues to the traditional phasor-based line differential protection in both the transient and steady states.
Kaiqi Ma, Zhe Chen, C. Bak, Zhou Liu, M. Castillo, R. Torres-Olguin, Nan Qin   +6 more
semanticscholar   +1 more source

Ratios-based universal differential protection algorithm for power transformer

Electric power systems research, 2020
For safe operation of power systems, it is essential that the transformer protection operate reliably if a fault occurs. There are many challenges in developing a fast and accurate differential protection scheme that not only disconnects the transformer ...
E. Ali, Om P. Malik, A. Knight, S. Abdelkader, A. A. Helal, H. Desouki   +5 more
semanticscholar   +1 more source

Modifications of the Algorithm of Differential Protection

Power Technology and Engineering, 2020
Algorithms based on differential protection for comparing the instantaneous values of two currents, and the segmentation and recovery of a distorted current, are considered from unified positions. A key position is localization of that subset of observed modes that is alternative to modes of a fault of the object being protected.
A. B. Atnishkin, Yu. Ya. Lyamets
openaire   +1 more source

A novel algorithm for improving the differential protection of power transmission system

, 2020
Current differential protection is simple in principle and is immune to power swings, load encroachment and mutual coupling problems. It provides simultaneous tripping at both ends of the transmission line and multi phase auto reclosing can be easily ...
Hema Latha Adharapurapu, R. Bhimasingu
semanticscholar   +1 more source

Testing the Performance of a $dq0$ Phaselet Transform Based Digital Differential Protection for $3\phi$ Converter Transformers

IEEE transactions on industry applications, 2020
This article presents and tests the performance of a digital differential protection for three-phase ($3\phi$) converter transformers. The proposed digital differential protection is developed to comply with the ANSI 87T protection procedure.
S. Saleh, E. Ozkop, X. F. St-Onge, Chistian Richard   +3 more
semanticscholar   +1 more source

Instantaneous bus-differential protection

Electrical Engineering, 1949
CURRENT TRANSFORMER core saturation has contributed largely to the difficulty of obtaining satisfactory bus differential relaying in the past. The scheme here proposed uses differentially connected standard bushing current transformers, and is supported by test data permitting wide application.
H. T. Seeley, F. Von Roeschlaub
openaire   +1 more source