APPLICATION OF MODAL TRANSFORMATION FOR FAULT ANALYSIS AND DIGITAL DISTANCE RELAYING

Transmission lines are usually protected by distance relays that measure the apparent distances of faults and compare them with the relay settings to determine if the fault is inside the protected zone. The information required for setting relays is generally obtained from fault analysis studies. Presently, electromechanical and solid state components are used for implementing distance relay schemes. During the past 15 years, the development of digital processor based relays has received considerable attention. The symmetrical and Clarke components are generally used for the analysis of faulted power systems. Fault conditions derived from these transformations have been used in digital distance relays. The symmetrical components transformation includes phase shifting operators and can only be used in conjunction with steady state phasors. The Clarke components transformation is composed of real elements and can be applied to instantaneous voltages and currents. However, this transformation includes irrational numbers and its use in on-line application requires multiplications that are time consuming This thesis describes the application of a real transformation, called the Modal Transformation, for the analysis of faulted power systems and application in digital distance relays. Conditions describing shunt faults and open circuits on transmission lines are derived. Modal networks and their inter-connections representing faults are described. A fault analysis program that uses the modal transformation is described. A distance relaying criterion for shunt faults is derived and a relay scheme based on this criterion is developed. The design and software simulation of the relay scheme is described. The performance of the relay was tested using fault data obtained from the EMTP program for shunt faults on a six bus model of the SPC system. Test results are also included in the thesis.

Name thesis:degree_name

Master of Science (M.Sc.)

Level thesis:degree_level

Masters

Grantor

University of Saskatchewan

Year dc:date.issued

1985

Author dc:creator

• Kolla, Sri Rsmsnjaneyulu

Advisor dc:contributor.advisor

• Sachdev, M. S.

Handle dc:identifier.uri

https://hdl.handle.net/10388/15721

OAI identifier oai:identifier

oai:harvest.usask.ca:10388/15721