352 Electrotechnical Systems
input Wind, and at the input Trip the logical signal can be sent that, being equal to1,
disconnects WG from the grid. The option “External mechanical torque” can be
selected in the dialog box; at that point, the input Wind is replaced by the input T
m
.
This option gives the opportunity to use WG model with the other, developed by the
User model of WG. Both models operate only in the Phasor mode.
The rst model consists of the previously described turbine model and the squirrel-
cage IM model, whose stator connects to the grid with the help of breaker. An only
controller in the model is the β controller that is active when IG output power exceeds
nominal value.
The output vector m contains eight internal signals: