Development of Graphical User Interface for the PT relays
Computer relaying has played an important role in power system protection as technology advances. Due to the great flexibility of computer-based relays, it will be applicable to design a general user programmable relay to meet the various relaying applications in the utilities. The power group in University of Manitoba has successfully implemented such kind of distance relay prototype based on Digital Signal Processor (DSP), in which different applications adopted a generic piece of hardware capable of implementing all of the relaying functions but with a capability to expand as the need arises. However, the configuration/modification of custom relay algorithms still remain difficult for the relay engineers since a thorough understanding of C/Assembly language and hardware knowledge is required. In this thesis, a Graphical User Interface (GUI) for the DSP-based distance relay was developed, which would assist the relay engineer to design a suitable algorithm for the application and then configure a general purpose relay hardware to run algorithms. The key part of the developed Graphical User Interface is a graphical block library of basic functions for distance relaying. Based on the developed GUI, a Graphical DSP-based Distance Relay (GDDR) was implemented. In addition, evaluation of the GDDR relay performance was carried out using laboratory tests, and the effects of System Impedance Ratio (SIR), fault types, and fault location on the fault pick-up time were investigated.