3.3.2. Considered Events

The event block allows the controller to simulate the events required by the current industry standards for a full load calculation [21]. Table 3 presents and explains all the events that the controller is able to perform. All of the listed events are controlled by a set of parameters passed to the controller.

**Table 3.** Events included in the event block.


Both the normal stop and the emergency stop events require two parameters: a flag to indicate if the event will be triggered and the time at which the maneuver is triggered.

The pitch runaway to feather/fine fault simulates an error in one or several pitch actuators. In this event, one or several blades suddenly pitch with a given pitch rate to the respective extreme value. The pitch rate is one of the parameters for this event. The sign of the pitch rate defines if the event is a pitch-to-feather (positive rate) or a pitch-to-fine (negative rate) fault event. There is one activation flag and one activation time parameter for each blade. This gives the flexibility to simulate the single pitch fault events and the collective pitch fault events with a limited set of parameters.

The pitch transducer fault simulates an error in the measurement of the generator speed. Instead of the actual speed, the transducer measures a constant value and passes it to the pitch and torque controller. The parameters for this event are a flag to enable the event, the time at which the event starts and the constant generator speed passed to the controller once the fault occurs.

The grid loss event simulates a sudden loss of the electrical grid. As a consequence, the generator cannot feed the generated power to the grid and the torque drops to 0 Nm. This event also raises the grid loss flag so that the alarm block recognizes the event and triggers the appropriate maneuver. The parameters that control this event are a flag that enables it and the time at which the grid loss event happens.

Finally, the yaw runaway event simulates a malfunction in the yaw system that causes the yaw motor to activate. The parameters for this event are an activation flag, a time to start yawing, a yaw rate and a time to stop yawing.
