Voltage Stability Monitoring Under Renewable Output Fluctuations
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Solution Overview
Problem
Existing voltage stability monitoring devices face challenges in accurately calculating and monitoring voltage stability in power systems with fluctuating renewable energy sources and weather-dependent power outputs, leading to increased calculation complexity, potential unconvergence, and reduced accuracy, which can result in voltage instability and economic inefficiencies.
Innovation Solution
A voltage stability monitoring device and method that account for various fluctuation conditions, including weather and system failures, by using a computer system configured with databases for measurement and calculation data, employing state estimation, voltage stability limit prediction, and geometrical parameterization techniques to reduce calculation complexity and ensure convergence, thereby maintaining economic efficiency and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional voltage stability monitoring methods are used in power systems with fluctuating renewable energy sources, then the monitoring can be performed with existing devices, but the calculation complexity increases and convergence becomes difficult
Solution Approach 1:
The patent segments the voltage stability monitoring process into distinct functional modules: a fluctuation condition determination unit that identifies specific fluctuation scenarios, a selection unit that chooses appropriate calculation methods based on the determined conditions, and a voltage stability calculation unit that executes the selected calculation. This segmentation allows the system to handle complex renewable energy fluctuations without overwhelming computational requirements, as each module performs a specialized function rather than a monolithic complex calculation.
Solution Approach 2:
The patent applies preliminary action by determining the fluctuation condition before performing the actual voltage stability calculation. The fluctuation condition determination unit analyzes system states and identifies specific fluctuation patterns (such as renewable energy output variations, load changes, or topological changes) in advance. Based on this preliminary determination, the system selects the most appropriate calculation method, avoiding unnecessary complex calculations and ensuring convergence by matching the calculation approach to the specific system conditions.
2Measurement precision
If comprehensive fluctuation conditions are considered in voltage stability calculation, then the monitoring accuracy improves, but the calculation time increases
Solution Approach 1:
The patent implements dynamics by making the calculation method selection adaptive to real-time system conditions. The selection unit dynamically chooses from multiple calculation methods based on the fluctuation condition determined by the fluctuation condition determination unit. This dynamic adaptation allows the system to use simpler, faster calculation methods when system conditions permit, while resorting to more accurate but computationally intensive methods only when necessary, thereby balancing accuracy requirements with calculation time constraints.
Solution Approach 2:
The patent changes calculation parameters based on detected fluctuation conditions. Different fluctuation scenarios (such as renewable energy fluctuations, load variations, or topological changes) trigger different calculation approaches with appropriate parameter settings. This parameter adaptation allows the system to maintain high monitoring accuracy by adjusting calculation parameters to match the specific system state, while avoiding the constant use of the most computationally intensive methods, thus reducing overall calculation time.
3Reliability
If multiple calculation methods are used to handle different fluctuation conditions, then the convergence reliability improves, but the device complexity increases
Solution Approach 1:
The patent introduces an intermediary component - the selection unit - that mediates between the fluctuation condition determination unit and the voltage stability calculation unit. This selection unit receives information about system fluctuation conditions, determines the appropriate calculation method from multiple available options, and directs the calculation process accordingly. This intermediary structure allows the system to leverage multiple calculation methods for improved convergence reliability while maintaining a clear, organized system architecture that manages complexity through structured decision-making logic.
4Reliability
If voltage stability is monitored under severe fluctuation conditions, then the system reliability improves, but economic efficiency decreases due to increased calculation resources
Solution Approach 1:
The patent applies partial action by selectively applying comprehensive voltage stability calculations only when severe fluctuation conditions are detected. The fluctuation condition determination unit identifies specific scenarios (such as extreme renewable energy variations, critical load changes, or topological disruptions) that warrant detailed analysis. For normal operating conditions, the system uses simplified assessment methods, thereby reducing overall calculation resource consumption while maintaining high reliability when it matters most - during severe fluctuation conditions that could threaten system stability.
Data Source
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AI summary
A voltage stability monitoring device and a method capable of obtaining information of voltage stability that can be served to practical use within a range of assumed conditions during a predetermined monitoring period are provided. The present invention provides a voltage stability monitoring device for estimating a voltage stability by using a voltage stability curve representing the voltage stability in an electric power system, including a voltage stability limit prediction unit for predicting a voltage stability limit, a voltage stability calculation condition determination unit for determining voltage stability calculation conditions by using a prediction result of voltage stability limit, a voltage stability curve calculation unit for calculating the voltage stability curve using a result of the voltage stability calculation condition determination, and a voltage stability margin calculation unit for calculating a voltage stability margin using a calculation result of the voltage stability curve.