Wind Turbine Power Reference Limiting During Grid Frequency Deviation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Wind turbines in power plants increase power production during over frequency events due to changes in available wind power, contradicting the required reduction in power output, which can exacerbate grid frequency instability.
Innovation Solution
A method for controlling power plants with wind turbines involves memorizing a power level during a grid frequency event, setting a power limit based on this level, and gradually adjusting power output to prevent unintended fluctuations, using a central controller to manage power references and limits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If wind turbines are controlled to produce power according to available wind power, then power production follows wind availability, but power production increases during over frequency events when power reduction is required
Solution Approach 1:
The system performs preliminary action by memorizing the power level at the time of frequency event detection before the event fully develops. This allows the control system to reference the pre-event power level and prevent unintended increases during the frequency event, ensuring power reduction is maintained even when wind availability changes.
Solution Approach 2:
The control system implements feedback by continuously monitoring grid frequency, comparing current power production against the memorized power level, and adjusting the power reference accordingly. This closed-loop feedback ensures that power production responds appropriately to frequency events while accounting for changes in wind availability.
2Power
If power reference is reduced during over frequency events, then power production should decrease, but available wind power changes can cause unintended power increases
Solution Approach 1:
The system applies preliminary anti-action by setting a power limit based on the memorized power level before unintended increases can occur. This preemptive constraint prevents the power reference from increasing even when wind availability improves, counteracting the potential harmful effect before it manifests.
Solution Approach 2:
The control system dynamically adjusts the power reference by combining the reduced power reference (in response to frequency events) with the power limit constraint (based on memorized levels). This dynamic adjustment ensures power production remains stable and follows the intended reduction trajectory despite changes in wind conditions.
3Speed
If power reference changes rapidly in response to frequency events, then grid frequency response is improved, but power production fluctuations increase
Solution Approach 1:
The system performs preliminary action by memorizing the power level at the moment of frequency event detection. This captured reference point enables rapid response to frequency changes while providing a stable baseline that prevents erratic fluctuations, balancing speed and smoothness in the power reference adjustment.
Data Source
Figure 1
Figure 2A~2B
Figure 3A~3B
AI summary
The invention relates to a method for controlling a power plant during an event which requires a change of the power produced by the power plant, wherein the power plant comprises a plurality of power generating units including at least one wind turbine generator, the method comprises determining the power reference dependent on an available power (Pava), changing the power reference to a modified power reference (Pref_mod) by a power variation (ΔP) in response to detecting a first event, memorizing a power level relating to the actual power production at a time occurrence of the first event, setting a maximum power limit (Pmax) to the memorized power level, limiting the modified power reference (Pref_mod) to the maximum power limit (Pmax), and controlling the power produced by the wind turbines in accordance with the limited modified power reference.