A real time digital simulator for testing relays

The structure and performance of a real-time digital simulator (RTDS) for testing relays are described. The RTDS uses parallel processing architecture based on a state-of-the-art digital signal processor (DSP) to run power system simulations in real time with a time step of 50-100 mu s. Physical devices such as relays, energy monitors for MOVs, or power system stabilizers can be fed with the appropriate signals from the RTDS and the output from the physical device can be fed back into the simulation. Examples are given of tests on a commercial distance relay.<
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