DREAMS in Windpower use case

ALSTOM engineers and maintains the GALILEO Supervisory System, which supervises and controls the distributed subsystems of a wind turbine. Strict real-time constraints apply to the core of the Supervisory System. It also supports functionality with no real-time requirements such as the Human Machine Interface (HMI) or the communication with the SCADA. In DREAMS the supervisory system is to be combined with a new safety-critical application: the protection system in charge of maintaining the wind turbine in a safe state.

For this functionality to be included into the Supervisory System platform, a third partition needs to be created by using the DREAMS solution. It needs certification according to the standard IEC 61400-1. The requirements of this third partition are very different from the rest of the system, since the computational power required is much lower and a simpler architecture to ease certification would be very valuable. Heterogeneity support would allow the use of a simpler and easier to certify core for the safe partition, while using a more powerful and extended core for the implementation of the other functionalities.

The protection functions shall be activated as a result of a failure of the control function (running in the Supervisory System) or of the effects of an internal or external failure or dangerous event. It should be activated is cases such as:

· Overspeed

· Generator overload or fault

· Excessive vibration

· Abnormal cable twist (due to nacelle rotation by yawing)

Currently, the Protection System is implemented in a battery-powered external module integrated in the EtherCAT ring. This solution lacks of the flexibility to implement complex logics since it is only able to handle digital inputs and outputs, and it is mainly a commercial-HW-based system.