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Protective Devices


Protective devices are intrinsic components of the power system as they are essential in case of incident, and therefore, they have to be modelled correctly. FAST provides an extended set of relays:


  • pic3334_03.225.11_MEDIUM.JPGGenerator loss of synchronism relays.
  • Generator minimum and maximum voltage protection relays.
  • Generator over- and under-speed protection relays.
  • Generator over-current protection relays
  • Frequency load shedding relays
  • Static distance protection relays
  • Line and transformer over-current protection relays
  • Line and transformer power protection relays
  • Line directional over-current relays
  • Line differential relays
  • Transformer biased differential relays
  • Under load tap changer controller
  • Breaker failure protection relays
  • Breaker automatic re-closure relays


The logic of each relay is checked at each integration step, thus typically every 10 ms. If the tripping conditions are met, relays send control actions to the related equipment, namely the circuit breakers. For instance, if a fault occurs on a line, detection of the fault by the relays takes about 20 to 40 ms and breaker openings take another 40 ms.


To strengthen a scenario and “cause” large scale incidents, protective devices can be disabled by a special event.


Protective devices also facilitate the development of the training scenarios because they react spontaneously to all unforeseen situations. Consequently, there is no need to pre-programme all the consequences of all possible actions in the scenario files. Actually, protective devices ensure that training sessions remain within the physical domain of the modelled system.


Additional relays can be customized to meet your individual need.



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