MORGAT: A Digital Simulator for EHV Relaying Scheme Tests

摘要

The evolution of EHV system relays compels to bring up to date protection testing facilities. This is because analog or digital relays are getting faster and faster, and use an extended signal frequency range. To qualify them, submit them to routine tests, analyze defective operation or study new principles, one needs to use a tool able to generate correct short-circuit voltage and current waveforms within a large bandwidth. To meet these requirements, the EDF designed simulator computes (off-line) instantaneous electrical quantities, by integration of system evolution equations and the use of Bergeron's method applied to polyphase lines. In a second stage, the computed values are sent to the tested equipment through a digital-to-analog conversion system. The simulator simultaneously samples the logical inputs coming from the relay for an automatic analysis. As the digital simulator is intensively used by people without particular knowledge in the field of numerical analysis and computer science, a special care was taken in the design of a high quality man-machine interface, just as in the verification of stability and self checking of numerical methods used. The object of the presentation is to state the system modelization principles, computation algorithms and implemented hardware. (ERA citation 11:053875)