Pitch system design
Electrical or hydraulic pitch design?
Looking for electrical or hydraulic pitch system ? DEIF Wind Power Technology is supplier of the entire solution design.
For electrical pitch designs, we supply the entire system including battery or ultracap module charger, sensors, encoders, pitch motor drive ( pitch servo drive ), pitch motors, etc. A complete and proven system ready to implement into your design. If you chose to use a hydraulic pitch system, we customise the pitch design perfectly tailored to your wind turbine design in collaboration with our supplier.
Pitch system design approach
The primary functions of the pitch system are to optimise the power production and to stop the wind turbine in maintenance and emergency situations. DEIF designs the pitch system to individually match the specific wind turbine design in order to optimise the operation under the following conditions; high, medium, low wind and extraordinary situations like LVRT (Low Voltage Ride Through) conditions and emergency stop. Our R&D teams base their system design on the load data and aerodynamic characteristics of the turbine.
The main system design consist of a complete component package that can be individually customized to your needs. The basic design package consists of the following related components:
The pitch boxes are customized to match the physical size of the hub. Metal, coating and colour are specified by the customer. Two preferred metals are available; construction steel and stainless steel.
The cabinets have an important function not only for enclosure but also for damping electrical noise (EMI), an increased demand stipulated by IEC 61400. Our R&D team design the cabinets and interconnection with reference to the specific lightning zones inside the HUB.
The system can be delivered in different variants, from 3 to 7 box solutions, depending on the space inside the hub. The choice of energy storage affects the required number of boxes and the possibilities you have. Batteries are to be placed in separate battery boxes for each blade due to the explosive gases they generate during charging.
The inverter, pitch controller and the remaining system components are placed in other boxes. In the 7 box solution, for instance, a centre box contains the pitch motion controller, the over voltage protection and the grid connection point, and for each blade there will be identical battery boxes and pitch drive boxes – three of each.
Another example is a 4-box Ultra -Cap solution where a centre box contains the pitch motion controller and three other identical boxes contain Ultra-Caps and power inverters for each blade.
In all our design we consider carefully the environment for the pitch cabinet. This is why all DEIF products are designed and tested with the highest level of EMC and surgeprotections - and an a market leading temperature range
The pitch motion controller is based on our advanced wind turbine controller platform. Being the centre of the system, it collects all inputs from other components such as sensors, chargers and drives. The pitch motion controller works by command from the wind turbine controller, or independently if communication to the controller is lost.
The application comprises sensors for monitoring of the pitch system itself and for monitoring the need of service of the wind turbine. The control system further comprises monitoring of the battery lifetime and the grid connection. The pitch system is self-protected – undetected system faults cannot occur.
Main features of the pitch motion controller software
- Individual pitch control/pitch SW
- RS485/CAN/Profibus interface for nacelle
- Battery voltage monitoring and lifetime estimation
- We can supply you a .dll file for load and performance evaluation
Integrated pitch drive to optimise design efficiency
The Integrated Motor Drive (IMD) is developed with offset in decades of accumulated knowhow about the entire wind turbine and its pitch systems. With its integrated motor solutions, the IMD reduces cabling in your system and provides maximum reliability at minimum cost. Engineered to your application, the IMD is bound to become your preferred choice for pitch and yaw control.
The IMD is an all-in-one solution and comes with components such as I/O, ballast resistor, EMC filters, charger, power supply, motor brake control, choke and safety chain designed in accordance with the Machinery Directive.
Safety is a vital function in electric pitch systems, and the IMD are the main part controlling the blade angle during turbine operation and in safe stop situations. In modern wind turbines ranging from kW to MW, the pitch system is the only brake capable of stopping the wind turbine during operation. This makes the pitch drive a safety-critical component. The IMD complies with the ISO 13849 functional safety standards due to the failsafe hardware resulting in a high MTTFd and high performance level PL=d