Wind Turbine Throttle-Point Control for Rapid Reserve Power
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Solution Overview
Problem
Existing wind turbine control methods struggle to efficiently manage transitions between reduced and increased power output while minimizing wear and maximizing speed potential without exceeding technical limits, particularly in partial load conditions.
Innovation Solution
A method for controlling a wind turbine with adjustable blade angles, selecting a throttle operating point with a higher tip speed ratio and negative gradient iso-characteristic curve, allowing quick transitions to a reserve operating point with minimal blade adjustments, leveraging kinetic energy for immediate power increase.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the wind turbine operates at the optimal operating point with maximum Cp value to maximize power output, then power generation efficiency is improved, but the ability to quickly increase power output in response to grid frequency changes is reduced
Solution Approach 1:
The wind turbine is deliberately operated at a throttle operating point below the optimal Cp value during normal partial load operation. This preliminary reduction in power output creates a reserve capacity that can be quickly activated when grid frequency changes occur, eliminating the need for time-consuming transitions from optimal operation
Solution Approach 2:
The control system dynamically adjusts the operating point between the throttle operating point and the optimal operating point based on grid frequency conditions. When frequency drops below the threshold, the system transitions to the optimal operating point to maximize power output, and returns to the throttle operating point when frequency stabilizes
2Object-affected harmful factors
If the wind turbine operates at reduced speed to minimize noise, then noise levels are reduced, but the time required to increase power output to maximum capability is extended
Solution Approach 1:
The rotor is maintained at a higher rotational speed at the throttle operating point than would be selected solely for noise minimization. This preliminary speed maintenance ensures that the rotor is already close to its maximum speed capability, enabling rapid power increase when grid frequency changes occur without requiring extended acceleration time
Solution Approach 2:
The control system changes the operating parameters (blade pitch angle and rotational speed) to select a specific throttle operating point that balances noise reduction with the ability to quickly increase power. The blade pitch angle is adjusted to a value that reduces power output while maintaining higher rotational speed compared to noise-optimized operation
3Productivity
If the wind turbine frequently adjusts blade pitch angle to optimize operation at varying wind speeds, then power generation efficiency is improved, but wear on the blade adjustment drives increases
Solution Approach 1:
The blade pitch angle is pre-adjusted to a throttle position suitable for the current wind speed range, allowing the turbine to operate at reduced power without requiring frequent pitch adjustments. This preliminary positioning reduces the frequency of blade adjustments while maintaining the ability to respond to wind speed changes
Solution Approach 2:
Instead of continuously optimizing the blade pitch angle for maximum power extraction, the system applies a partial adjustment to a fixed throttle position that is adequate for the prevailing wind conditions. This reduces the frequency and magnitude of pitch adjustments, thereby reducing wear on the adjustment drives while maintaining acceptable power generation efficiency
4Adaptability or versatility
If the wind turbine maintains a reserve operating point with higher output power capability, then the ability to respond to sudden power demand increases is improved, but the complexity of the control system increases
Solution Approach 1:
The control system pre-defines a reserve operating point with specific blade pitch angle and rotational speed parameters that correspond to higher power output capability. This preliminary configuration allows the system to quickly transition to maximum power output when grid frequency drops, without requiring complex real-time calculations or multiple reserve operating points
Solution Approach 2:
The control system uses parameter changes in the blade pitch angle to define and transition between the throttle operating point and the reserve operating point. By utilizing the existing blade pitch mechanism and its associated sensors and actuators, the system achieves reserve capacity without adding complex control hardware or multiple independent control systems
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
Facilitates rapid power output adjustments with reduced wear and minimal blade adjustments, ensuring immediate power availability during grid frequency changes and other demand fluctuations.
Implementation Method 1
a wind turbine having a rotor with adjustable blade angles θ, wherein the rotor can be operated at a variable speed
Implementation Method 2
the rotor is connected to an electrical generator
Data Source
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AI summary
The invention relates to a method for controlling a wind turbine (100), wherein the wind turbine (100) is operated in a partial load range and can be operated at a variable, predefinable operating point (302, 308, 310) which can be represented in a λθ diagram in which the tip speed ratio (λ) is plotted against the blade angle (θ), and several operating points (302, 308, 310) with the same Cp value can be represented as an iso-characteristic curve in the λθ diagram.A change in the operation of the wind turbine from the throttled operating point (308) to a reserve operating point (310) with higher output power is provided, in response to a power increase request, wherein the throttled operating point (308) has an increased tip speed ratio compared to the reserve operating point (310) and the iso-characteristic curve in the throttled operating point (308) has a negative characteristic curve slope, in which the tip speed ratio decreases with increasing blade angle, wherein a derivative of the power coefficient (CP) of the throttled operating point (308) or of the reserve operating point (310) with respect to the blade angle exceeds a predetermined minimum derivative value in magnitude.