Wind Turbine Control Device for Grid Frequency Stability
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Solution Overview
Problem
Existing wind turbine generator control systems are inadequate in responding immediately to frequency variations in utility grids during disturbances, leading to potential massive power failures.
Innovation Solution
A control device for wind turbine generators that measures grid frequency using moving averages and adjusts sampling periods and gains to generate instruction values for active power control, enabling immediate response to frequency variations by distinguishing between initial and later phases of disturbances.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If wind turbine generators continue operating during grid disturbances without immediate control response, then power supply capability is maintained, but grid frequency variation increases leading to potential massive power failures
Solution Approach 1:
The control device preliminarily determines the occurrence of grid disturbance by detecting frequency variation beyond a threshold before severe consequences occur. This preliminary detection triggers immediate active power control, allowing the wind turbine to respond proactively to grid disturbances rather than reactively, thereby maintaining grid stability while minimizing response time delay
Solution Approach 2:
The control device continuously monitors grid frequency and uses this feedback to dynamically adjust active power output. When frequency variation exceeds predetermined thresholds, the feedback mechanism triggers control actions that suppress frequency variation by adjusting power output, creating a closed-loop system that responds to real-time grid conditions
2Reliability
If wind turbine generators immediately suppress active power output in response to frequency variation, then grid frequency stability is improved, but power supply capability is reduced
Solution Approach 1:
The control device applies partial action by suppressing active power output only to the extent necessary to suppress frequency variation, rather than completely shutting down. The control suppresses power output during the period when frequency variation exceeds thresholds, and resumes normal operation when frequency stabilizes, achieving frequency stability while minimizing the reduction in overall power supply capability
Solution Approach 2:
The control system dynamically adjusts active power output based on real-time frequency conditions. The predetermined standards for frequency variation and the dynamic adjustment of power suppression levels allow the system to adapt its power output to match grid needs, maintaining optimal power supply while ensuring frequency stability
3Device complexity
If conventional control methods are used without phased sampling periods, then control system simplicity is maintained, but ability to distinguish between initial and later phases of disturbance is reduced
Solution Approach 1:
The control device segments the grid disturbance response into distinct phases by using different sampling periods: a first (shorter) sampling period for the initial phase of disturbance and a second (longer) sampling period for the later phase. This segmentation allows the control system to adapt its measurement and response strategy to the specific phase of disturbance, improving response adaptability while maintaining reasonable control system structure
Solution Approach 2:
The control device changes the sampling period parameter based on the phase of disturbance detected. By switching between different sampling period values depending on whether the system is in the initial or later phase of frequency variation, the control system achieves adaptive response without requiring complex structural modifications
Data Source
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AI summary
A control device of a wind turbine generator capable of controlling an active power based on an instruction value, includes a measurement means configured to measure a frequency of a utility grid. The instruction value for controlling the active power is generated to a direction suppressing a variation of the frequency of the utility grid based on conversion information which indicates a predetermined relation between the variation of the frequency and the instruction value when the variation of the frequency of the utility grid measured by the measurement means exceeds a predetermined standard. A wind turbine generator which controls suppression of a disturbance of a grid in its initial stage is realized.