Wind Turbine Controller Reference Adjustment for Smooth Load Transitions
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Solution Overview
Problem
Existing wind turbine control systems face challenges in achieving smooth transitions between partial load and full load regions, leading to potential instability, increased loads, and inefficiencies due to late switching between controllers, which can result in oscillations and energy loss.
Innovation Solution
The method involves continuously adjusting the power controller speed reference value based on pitch conditions and the pitch controller speed reference value based on power conditions, allowing both controllers to be active simultaneously, thereby avoiding interference and enabling smooth transitions without the need for discrete switching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If discrete switching between speed-power controller and speed-pitch controller is used, then controller simplicity is maintained, but transition smoothness deteriorates causing bumps and oscillations
Solution Approach 1:
The patent merges the speed-power controller and speed-pitch controller into a unified control structure where both controllers operate simultaneously. The power controller and pitch controller work together in a coordinated manner, eliminating the need for discrete switching between controllers while maintaining transition smoothness and system stability.
Solution Approach 2:
The patent implements preliminary action by having the pitch controller anticipate upcoming transitions and begin adjusting pitch angles before the actual transition occurs. This proactive approach prevents bumps and oscillations by preparing the system in advance for load changes, ensuring smooth transitions between partial and full load regions.
2Device complexity
If late switching between controllers occurs, then switching complexity is reduced, but energy production deteriorates due to suboptimal operating points
Solution Approach 1:
The patent implements feedback mechanisms that continuously monitor operating conditions and provide real-time information to both controllers. This feedback enables the controllers to detect approaching transitions and adjust their control actions accordingly, ensuring the turbine operates at optimal points and maximizing energy production without late switching delays.
Solution Approach 2:
The patent employs dynamic control where the controllers continuously adapt their behavior based on current operating conditions. The power controller and pitch controller dynamically adjust their reference values and control actions in response to changing wind conditions and load demands, maintaining optimal performance throughout transitions and eliminating the energy losses associated with late switching.
3Speed
If aggressive pitch changes are made to control speed in transition zone, then speed control responsiveness is improved, but structural loads increase due to rapid thrust changes
Solution Approach 1:
The patent applies the counterweight principle by having the pitch controller generate opposing pitch changes that compensate for the thrust variations caused by power controller actions. When the power controller adjusts power to control speed, the pitch controller simultaneously adjusts pitch angles to counterbalance the resulting thrust changes, thereby reducing tower and blade loads while maintaining speed control responsiveness.
Solution Approach 2:
The pitch controller acts as an intermediary between the power controller and the mechanical system. It mediates the interaction between power changes and structural loads by adjusting pitch angles to smooth out rapid thrust variations, allowing speed control to remain responsive while protecting the structure from excessive loads during transitions.
Data Source
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AI summary
There is described a method of controlling operation of a power controller (220) and a pitch controller (230) in a wind turbine. The described the method comprises (a) obtaining a pitch value, (b) determining whether a first pitch condition is fulfilled, and if so, increase a power controller speed reference value (n1, 211) by a first incremental value, (c) determining whether a second pitch condition is fulfilled, and if so, decrease the power controller speed reference value (n1, 211) by a first decremental value, (d) obtaining a power value, (e) determining whether a first power condition is fulfilled, and if so, decrease a pitch controller speed reference value (n2, 212) by a second decremental value, and (f) determining whether a second power condition is fulfilled, and if so, increase the pitch controller speed reference value (n2, 212) by a second incremental value. Furthermore, there is described a corresponding device and system as well as a computer program and a computer program product.