Wind Turbine Pitch Feedback Control for Derated Power Output
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current wind turbine control systems face challenges in efficiently operating in derated modes, leading to increased load exposure and imprecise control of derated power output due to frequent shifts between full load and partial load control, and inaccuracies in pitch angle to output power correspondence.
Innovation Solution
A method for controlling wind turbines that involves setting a non-optimal blade pitch based on a power reference signal to capture wind power at a requested level, adjusting load torque to control power output, and using a pitch feedback control loop to compensate for any inaccuracies or drifts in the output power, thereby reducing load exposure and improving control precision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a wind turbine operates in derated mode by frequently shifting between full load and partial load control, then the requested power output level can be achieved, but the load exposure increases and control precision deteriorates
Solution Approach 1:
The control system dynamically adapts its operating mode based on real-time conditions. When operating in derated mode with available power above rated power, the system switches to a derated full load control mode that maintains stable operation without frequent transitions, thereby improving reliability while achieving the requested power output level
Solution Approach 2:
The system continuously monitors the difference between produced power and requested power, and adjusts the blade pitch angle accordingly. This feedback mechanism ensures precise control of derated power output by compensating for inaccuracies in the pitch angle to power correspondence, thereby improving control stability and reducing load exposure
2Power
If the blade pitch is set to non-optimal pitch value to capture wind power at requested level, then the power output can be reduced to derated level, but inaccuracies and drifts in output power control occur
Solution Approach 1:
A feedback control loop continuously monitors the actual produced power and compares it with the requested power level. The system adjusts the blade pitch angle based on the power difference to compensate for inaccuracies and drifts, ensuring precise control of derated power output
Solution Approach 2:
The control system pre-establishes the relationship between pitch angle and power output through calibration. This preliminary action creates a reference map that guides the pitch angle setting for desired power levels, improving the accuracy of power control before actual operation begins
3Productivity
If the wind turbine operates in partial load derated mode, then the requested power output can be achieved, but the frequency of control shifts increases leading to increased load exposure
Solution Approach 1:
The control system dynamically determines the appropriate operating mode based on the relationship between available power and rated power. By switching to derated full load control mode when available power exceeds rated power, the system reduces the frequency of control shifts and minimizes load exposure, thereby extending turbine lifespan while maintaining productivity
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach reduces the frequency of shifts between full load and partial load control, extends turbine lifespan, and ensures precise control of derated power output by compensating for pitch angle and output power discrepancies, enhancing operational efficiency and reliability.
Implementation Method 1
setting a blade pitch of a rotor of the wind turbine to a non-optimal pitch value based on the received power reference signal that causes the rotor to capture wind power
Implementation Method 2
controlling the produced power output power level of the wind turbine to the requested power output level by adjusting a load torque provided to the rotor by a generator coupled to the rotor
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
The present invention relates to control of the power output of wind turbine generator that operates in derated mode to generate a produced power output level lower than an available power level. A pitch system 48 sets the blade pitch of a rotor to a pitch value based on the received power reference signal 40. A power system 43 controls the produced power output power level of the wind turbine to the requested power output level. Moreover, the blade pitch of the rotor is further controlled by a pitch feedback control loop 47 that modifies the pitch value based on a difference between the produced power output level 46 and the requested power output level 40.