Document Type
Thesis
Date of Award
1-31-1985
Degree Name
Master of Science in Electrical Engineering - (M.S.)
Department
Electrical Engineering
First Advisor
K. Denno
Second Advisor
Edwin Cohen
Third Advisor
W. H. Warren Ball
Abstract
An analytical investigation has been conducted on a three-phase three-machine network power system to determine the optimum Scheme of Connections of the three-phase three-element power directional relay in which the torques of the three independent dynamometer operate on a common axis providing mechanical summation of torques proportional to the power components at the terminals of different phases.
The operation of three-phase, three-element power directional relay is determined by the summation of current and voltage systems having the same phase sequences which is governed by the form of power expression that is proportional to the resulting torque for the various combinations of voltages and currents to the optimum mode of connection of three-phase, three-element power directional relay taking into consideration the field of application of various schemes with phase starting.
The mechanism is made up of two kinds of network reduction techniques aimed at the identification of positive, negative and zero sequence impedances. In both cases their numerical values are found to be identical with almost negligible differences on the part of the zero sequence impedances hence providing consistent and unique methodologies. Currents and voltages based on the impedances following each technique are computed for the following respective faults:
- Symmetrical three-phase
- Line-to-Line
- Single line-to-ground
- Double line-to-ground
On provision of torque expressions, the Analysis are centred on establishment of selectivity tables of optimum mode of relay connection and the graphical determination of the limiting angles at which the three-phase three-element power directional relays operate under the above-mentioned fault conditions.
Recommended Citation
Dakogol, Fidelis Wagoela, "Design criteria of three-phase three-element power directional relay under asymetrical faults" (1985). Theses. 3644.
https://digitalcommons.njit.edu/theses/3644
