A digital TNA for testing relays

The authors describe the design and performance of a digital transient network analyzer (DTNA) for testing relays. The DTNA uses a parallel processing architecture to run power system simulations in real time with a time setup of 50-100 mu s. Relays can be fed with the appropriate signals from the DTNA, and the output from the relay trip circuit can be fed back into the simulation. Examples are given of tests on a commercial distance relay.<
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