External Network Parameter Estimation Using Internal Measurements
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional systems for estimating equivalent parameters of external networks in power systems rely on external measurements, which are not feasible for real-time operational applications, especially when partial or no measurements are available, leading to inaccurate responses to internal network events.
Innovation Solution
A method to estimate equivalent parameters for external networks by establishing a simplified network based on internal network state variables and boundary bus measurements, using optimization techniques to tune network parameters and minimize residuals, thereby eliminating the need for external network measurements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional systems use external network measurements to predict equivalent parameters, then measurement precision may be improved, but device complexity and operational feasibility deteriorate due to requirements for multiple time period measurements and external data collection infrastructure
Solution Approach 1:
The invention extracts and eliminates the dependency on external network measurements by formulating an optimization problem that determines equivalent parameters using only internal network measurements. The external network is represented by equivalent parameters (admittances) that are optimized to match boundary bus measurements, removing the need for external measurement infrastructure.
Solution Approach 2:
The invention creates a simplified copy of the external network in the form of equivalent parameters (admittances connected to boundary buses). This equivalent model replicates the external network's effect on the internal network without requiring actual external measurements, enabling accurate parameter estimation using only internal system data.
2Measurement precision
If conventional systems require measurements at multiple time periods for external equivalent parameter estimation, then measurement precision may be improved, but productivity deteriorates due to extended estimation time not feasible for real-time operations
Solution Approach 1:
The invention segments the power system into internal network and external network components, representing the external network by equivalent parameters at boundary buses. This segmentation allows the estimation problem to be solved using only internal network measurements at a single time period, eliminating the need for multi-period data collection while maintaining accuracy.
Solution Approach 2:
The invention performs preliminary formulation of the optimization problem that directly computes equivalent parameters from current internal network measurements. By pre-defining the objective function and constraints based on power flow equations, the system enables immediate real-time estimation without requiring historical data collection or iterative multi-period analysis.
3Device complexity
If conventional systems assume simplified external network models, then device complexity is reduced, but measurement precision deteriorates due to inaccurate equivalent parameters when no external measurements are available
Solution Approach 1:
The invention changes the approach from assuming fixed external network models to dynamically optimizing equivalent parameters (admittances) based on internal network measurements. The objective function minimizes the difference between measured and calculated boundary bus quantities, automatically adapting the equivalent parameters to accurately reflect the actual external network state without requiring simplifying assumptions.
Data Source
Figure 1
Figure 2
Figure 3a~3b
AI summary
Embodiments of present disclosure relates to stable and reliable, method and system to estimate equivalent parameters 213 for external network 105. Simplified network 303 is established for power system 102 comprising internal network 104. 301, 401 and external network 105. Simplified network 303 may be established based on state variables of internal network 104. 301, 401. External network 105 is represented as bus with predefined state variables 502.1, 502.2 for external network 105. Simplified network 303 is established by estimating network parameters 209 for external network 105 using state variables and measurements of internal network 104. 301, 401, and boundary buses of power system 102. Further, tuning of network parameters 209 is performed. Tuning comprises performing state estimation of power system 102 using network parameters 209, determining residual associated with state estimation, and optimizing network parameters 209 for performing further state estimation of power system 102 when residual is determined to be greater than threshold value 212. Tuning is performed until residual is determined to be lesser than threshold value 212. Upon optimizing, network parameters 209 are provided as equivalent parameters 213 for external network 105.