2.0 System Description | 11 |
2.2Control System Description
The following parameters are monitored by the wind turbine’s control system. It initiates shutdowns when faults have been detected to protect the wind turbine from mechanical and electrical damage.
UTILITY NETWORK:
∙Over/under voltage
∙Phase loss
∙Phase reversal
∙Over/under frequency (optional)
TURBINE:
∙Generator temperature
∙Rotor speed
∙Power (derived from rotor speed)
∙Parking brake current
SYSTEM:
∙Wind speed (redundant anemometers)
∙Ambient temperature switch (optional)
2.3Operation Description
The AOC 15/50 is a downwind turbine, i.e. its blades rotate downwind of the drive train assembly. Furthermore, it has no active yaw control and depends on its blades to track the wind. In winds outside of the required wind band, the PLC (Programmable Logic Controller) disconnects the wind turbine from the grid and parks it; the wind turbine is brought to a complete stop. The parking brake remains applied, thereby preventing the blades from rotating. However, they will still track the wind and the wind turbine will pivot about its yaw bearing accordingly.
The AOC 15/50 has three main modes of operation: test, off and on. The setting of the TEST/OFF/ON switch determines the parameters monitored by the PLC and which other switches can be activated. When the turbine TEST/OFF/ON switch is set to OFF, the PLC only monitors grid faults.
Once the turbine TEST/OFF/ON switch is set to ON, the PLC starts evaluating the wind speed data which, together with the generator rotor speed, is the most important source of input data to the PLC; grid related parameters and thermal relays play a secondary role.
The wind speed is measured using two cup anemometers. For the wind turbine operation the wind speed has to fall within the specified speed band of
NOTICE: Use of the material contained in this document is subject to the warning on page Iv and the disclaimer on page v of this document.
DOC012R02 | AOC 15/50 User Manual | Nov 2001 |
