Woodward HighPROtec MCDLV4, Manual, Page: 668 / 1275

Protective Elements
Trip-Trans
–
Transfer of Trip Decisions over Protection Communication
Available elements:
Trip-Trans
The line differential protection is based on two protection devices that constantly communicate one with another via
a dedicated ProtCom protection communication interface. The module Trip-Trans (“Transfer of Trip Decisions over
Protection-Communication”) is comparable with the Sig-Trans module because it allows for sending trip decisions
from one protective device to the other via the ProtCom connection. The main difference between these two
modules is that Trip-Trans generates trip decisions and is therefore some kind of protection function. The tripping
commands of the Trip-Trans module can be handled like those of any other protection function; in particular, the
Trip Manager can be used to assign the tripping commands to a circuit breaker, and the tripping commands are
logged by the Fault Recorder.
Whether or not such a direct transfer of tripping commands is required for a given application, depends on the
configuration of the line differential protection. The values of differential and restraining current are transmitted over
the ProtCom interface anyway, so that both protective devices share the same values and make the same tripping
decisions in case of identical settings. In this case, a transfer of tripping commands is obviously not required,
contrast to an application that uses different settings. Whenever both devices might make their tripping decisions in
different ways (due to different settings), a tripping transfer can be required.
Independent of this, the Trip-Trans module is also available for further types of tripping transfers. In general, it can
be used whenever it has to be made sure that an electrical circuit is isolated in a controlled way, by two circuit
breakers opening in a synchronized manner.
If the protection communication should fail then of course no tripping commands are transferred. This means that in
this case, the respective tripping signals simply keep the value 0 (inactive).
Functionality of the Trip-Trans module. The sub-routine “Eval. Trip” is detailed in the following diagram.
668 MCDLV4 DOK-HB-MCDLV4-2E