MORGAT: digital simulator used for industrial qualification of protective relays

Electricite de France decided that a new tool needed to be developed for efficiency testing relays. The required tool had to accurately simulate a wide range of transient electric phenomena for a wide range of varied network topologies and be easy to use. To fulfil these requirements, a digital simulator, MORGAT, has been designed to reproduce transient electric phenomena. MORGAT basically consists of a program which computes electric system transients and of a real-time input/output facility delivering these transients to actual protection and control equipment. The system is made available using a sophisticated man-machine interface. Testing a protection is performed in two stages: first, the electric transients are computed then the results of computation are applied in real time to the tested relays, using an analog-to-digital converter associated with voltage and current amplifiers