Figure 17 Turbine control panel, courtesy of Mita Technik.
Function
The control system provides supervisory control (including health monitoring) and active power and load control in order to optimise wind turbine life and revenue generation, while meeting externally imposed requirements.
What it costs*
The control system costs vary significantly for different nacelle layouts.
Who supplies them
Bachmann, DEIF, KK-Electronic and Mita Teknik.
Key facts
The control system carries out regular health checking using hundreds of sensors monitoring key components and sub systems. In response to unexpected data, it takes decisions to curtail operation and provides regular reporting to the Supervisory Control and Data Acquisition (SCADA) system.
The control system also takes control input from the SCADA system, for example to derate wind turbines in response to utility customer requests. Increasing turbines have a power boost capability where they will generate at higher powers in benign conditions when parameters such as temperature and wind shear are in acceptable ranges.
Key control parameters for active power and load control are rotor speed, output power and the pitch angle of each blade.
Control intelligence may be distributed around the turbine, including in the hub. Control panels contain in-in-house designed and standard panel hardware to interface with sensors and auxiliary systems and combined may weigh up to 750 kg.
In parallel to the control system, a safety system protects the turbine from control system or operator error. Key sensors for this overriding safety system include speed and vibration sensors. An emergency system with physical press-button and/or chord inputs is provided to bring the rotor to a halt in the event of risk to maintenance personnel.
Each wind turbine can operate independently from external intervention, starting and stopping in response to changing wind conditions. Control at a wind farm level is used to optimise energy production and minimise loading, for example by avoiding turbines sitting in the wake of turbines immediately upwind.
What’s in it
- Control panels, control system hardware and software
- Sensors: Accelerometers, load cells, power meters, strain gauges, thermocouples, and tachometers
- Safety and emergency systems