Dynamic Threshold Energy Storage for Grid Frequency Deviation
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Solution Overview
Problem
The existing power grid systems face challenges in managing frequency deviations due to imbalances between supply and load, particularly at hour crossings, leading to excessive use of primary and secondary controls, which can result in their failure during true emergencies and compromise grid stability.
Innovation Solution
A method and system utilizing energy storage, such as flywheels, that dynamically adjusts a threshold based on system parameters and time-of-day to proactively counteract frequency deviations, reducing the need for primary and secondary control deployment and enhancing grid stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If energy storage is constantly deployed to equalize turbine output, then frequency deviations are reduced, but the storage capacity is depleted and requires frequent recharging
Solution Approach 1:
The patent implements periodic action by operating the energy storage system in cyclic charge-discharge cycles. The control algorithm monitors frequency deviations and triggers energy release only when deviations exceed a threshold, then recharges the storage during normal conditions. This periodic operation pattern allows the energy storage system to sustain frequency suppression capabilities over extended periods without complete depletion, optimizing both frequency stability and operational duration.
2Ease of operation
If a fixed threshold is used for frequency deviation response, then the control logic is simple, but it cannot adapt to varying system conditions and time-of-day variations
Solution Approach 1:
The patent applies dynamics by transitioning from a fixed threshold to a dynamic, adaptive threshold that varies based on system conditions and time-of-day. The control algorithm continuously adjusts the frequency deviation threshold according to grid conditions, renewable energy generation patterns, and historical data. This dynamic adaptation enables the system to respond appropriately to varying conditions while maintaining operational simplicity through automated adjustment rules.
3Reliability
If primary and secondary controls are used for normal operations, then frequency deviations are addressed, but the deployment cost increases and operational lifespan decreases
Solution Approach 1:
The patent implements preliminary action by deploying energy storage capacity in advance to prevent frequency deviations from requiring primary and secondary control intervention. The energy storage system is pre-charged and positioned to respond to anticipated frequency deviations, particularly during high-renewable-generation periods. This preliminary positioning of energy storage reduces the need for costly and wear-inducing primary and secondary control deployments, thereby extending their operational lifespan while maintaining frequency stability.
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
The approach effectively reduces frequency deviations by 20.7% and decreases the deployment of primary control power by 29%, while maintaining the ability to reserve primary and secondary controls for true emergencies, thus improving grid stability and extending their operational lifespan.
Implementation Method 1
utilizing energy storage, such as flywheels, that dynamically adjusts a threshold based on system parameters and time-of-day to proactively counteract frequency deviations
Data Source
AI summary
A method of suppressing frequency deviations in a power grid relative to a desired frequency behaviour, in particular at hour crossings, wherein an energy storage is connected to the grid, includes: monitoring frequency in the grid relative to the desired frequency behaviour, to determine detected frequency deviations; comparing detected frequency deviations with a threshold; if detected frequency deviations exceed the threshold, deploying the storage to charge therein energy from the grid or to discharge energy therefrom into the grid; and setting a variable threshold. A corresponding system includes: a connection to a power grid; an energy storage selectively connectable to the connection; a frequency monitor connected to the connection; and a control to configured to selectively deploy the energy storage in accordance with the method.