Renewable Energy Control System for Grid Frequency Stability
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Solution Overview
Problem
Renewable energy power generation equipment, such as wind and solar power, struggles to maintain frequency stability in power grids due to limited inertia energy, which is insufficient to support output adjustments over several minutes to tens of minutes, a critical period for Load Frequency Control (LFC).
Innovation Solution
A control system for renewable energy power generation equipment that adjusts output based on frequency deviations and meteorological data, using a control device to calculate and transmit commands for wind and solar power generation systems to restrict or release output adjustments dynamically, thereby influencing frequency stability without auxiliary equipment like batteries.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If renewable energy power generation equipment is increased in the power grid, then the capacity ratio of middle-load and peak-load power supply is decreased, but frequency stability is reduced due to lack of supply and demand adjustability
Solution Approach 1:
The control device calculates a correlation coefficient between frequency deviation and expected power output in advance, and determines output restriction/release based on this pre-calculated correlation. This preliminary analysis enables the system to proactively adjust output before significant frequency deviations occur, maintaining frequency stability even with reduced middle-load and peak-load power supply capacity
Solution Approach 2:
The system continuously monitors frequency deviation and expected power output, calculates their correlation coefficient, and uses this feedback to dynamically determine whether to restrict or release output. This closed-loop feedback mechanism ensures frequency stability is maintained through real-time adjustments based on actual grid conditions
2Adaptability or versatility
If renewable energy power generation equipment using wind power generation and solar power generation is connected to the power grid through a power converter, then the ratio of power supply of rotary machine type having inertia is decreased, but frequency variation is increased
Solution Approach 1:
The patent replaces the mechanical inertia provided by rotary machines with a control-based system that uses correlation coefficient calculation and dynamic output restriction/release. The control device substitutes the physical inertia function with an intelligent control mechanism that achieves frequency stabilization through calculated output adjustments rather than mechanical mass
Solution Approach 2:
The control device acts as an intermediary between the renewable energy power generation equipment and the power grid. It calculates the correlation coefficient between frequency deviation and expected power output, and uses this intermediate calculation to determine appropriate output adjustments, thereby mediating the connection and reducing frequency variations without requiring rotary machine inertia
3Speed
If output of wind power generation is adjusted in response to a change in the frequency of the power grid and a change in wind velocity, then frequency variation of approximately several seconds is suppressed, but frequency variation with a period of several minutes to several tens of minutes cannot be effectively addressed
Solution Approach 1:
The control device performs preliminary calculation of the correlation coefficient between frequency deviation and expected power output before significant frequency variations occur. This advance calculation enables the system to prepare appropriate output restrictions or releases that address slower frequency variations with periods of several minutes to tens of minutes, rather than merely reacting to rapid changes
Solution Approach 2:
The system dynamically adjusts its control strategy based on the calculated correlation coefficient. When the correlation indicates a strong relationship between frequency deviation and expected power output, the system implements output restriction or release to address slower frequency variations. This dynamic adaptation allows the system to effectively handle both rapid and gradual frequency changes
Data Source
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AI summary
The invention provides a control system of renewable energy power generation equipment which can contribute to a suppression of frequency variation with a period of several minutes to several tens minutes that is a control region of LFC without using auxiliary equipment such as a battery. A control system of renewable energy power generation equipment of the invention includes a measuring unit that measures a frequency of a power grid; a measuring unit that measures meteorological characteristics of the renewable energy power generation equipment; a calculating unit that calculates frequency deviation of the power grid; a calculating unit that calculates an expected power output of the renewable energy power generation equipment and an increase and decrease state value thereof based on the meteorological characteristics measured by the measuring unit that measures meteorological characteristics of the renewable energy power generation equipment; a calculating unit that calculates a correlation coefficient between the frequency deviation of the power grid and the expected power output of the renewable energy power generation equipment; and a determining unit that determines whether or not output adjustment of the renewable energy power generation equipment is necessary by using the correlation coefficient between the frequency deviation and the expected power output, and the increase and decrease state value of the expected power output.