Wind Turbine Power Control via Grid Frequency Proportional Adjustment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Wind energy installations struggle to effectively react to variations in grid frequency, leading to potential instability in the electrical grid, as their output power control mechanisms often include large 'dead bands' that delay responses to frequency deviations, causing power losses and instability.
Innovation Solution
A method and system for controlling wind energy installation output power that reduces power as soon as the grid frequency deviates from the nominal frequency, eliminating the dead band and allowing for quicker reactions to frequency changes, with optional threshold-based or non-linear power reduction strategies to balance reaction speed and power loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a dead band is used in output power control, then the wind energy installation maintains constant output power over a frequency range, but the reaction to frequency deviations is delayed
Solution Approach 1:
The patent changes the control parameter from a step-function dead band approach to a continuous function where output power is reduced proportionally to the frequency deviation. This allows the system to respond immediately to any frequency deviation while maintaining grid stability through proportional control rather than threshold-based control.
Solution Approach 2:
The patent introduces dynamic control where the output power reduction varies continuously with the magnitude of frequency deviation. The control mechanism adapts its response based on the actual frequency condition, providing faster reaction to deviations while maintaining stability through proportional adjustment rather than fixed dead band thresholds.
2Speed
If the dead band is reduced or eliminated, then the reaction to frequency deviations becomes faster, but the output power loss due to control increases
Solution Approach 1:
The patent applies partial action by reducing output power proportionally to the frequency deviation rather than eliminating it completely or using fixed threshold reductions. This allows the system to respond quickly to deviations while minimizing unnecessary power loss when deviations are small, and only reducing power significantly when frequency deviations become large.
Solution Approach 2:
The patent changes the control strategy from fixed dead band thresholds to continuous proportional control, where the degree of power reduction varies with the magnitude of frequency deviation. This enables faster reaction to any deviation while optimizing energy loss by applying minimal control action when frequency is close to nominal.
3Reliability
If output power is reduced immediately upon frequency deviation, then grid instability is prevented, but the wind turbine experiences increased wear from frequent power adjustments
Solution Approach 1:
The patent implements dynamic proportional control where the rate and magnitude of power reduction adapt to the frequency deviation. This smooths the control action compared to abrupt dead band switching, reducing mechanical stress and wear on turbine components while maintaining grid stability through continuous adjustment.
Solution Approach 2:
The patent changes from threshold-based step control to continuous proportional control, where the control parameter (power reduction) varies smoothly with frequency deviation. This reduces the number and magnitude of abrupt adjustments, thereby minimizing wear on wind turbine components while preventing grid instability.
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 enables earlier and more responsive adjustments to grid frequency changes, reducing the risk of grid instability and power losses, while minimizing the impact on wind turbine wear by varying the rate of power reduction based on frequency deviation.
Implementation Method 1
a wind driven generator
Implementation Method 2
generator electronics
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A method of controlling the output power from a wind energy installation to a utility grid (7) having a specified nominal frequency (fN) is provided, in which the output power (P) is controlled depending on the actual grid frequency (f) in the utility grid (7) such that the output power (P) is reduced when the grid frequency (f) exceeds a predetermined value. The predetermined value is at most two per mill higher than the nominal frequency (fN) of the grid (7) and the output power (P) is reduced as soon as any increase of the grid frequency (f) above the predetermined value is detected.