Distributed Power System State Estimation via Subsystem Segmentation
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Solution Overview
Problem
Centralized power system state estimation faces challenges such as communication congestion, information processing bottlenecks, maintenance difficulties, and privacy issues due to the increasing scale and complexity of power systems, particularly in managing and coordinating data across interconnected sub-systems.
Innovation Solution
The method involves dividing the power system into sub-systems, establishing linear models with target functions and constraint conditions to minimize residual squares and penalty terms, using the alternating direction multiplier method to solve for state variables, and performing nonlinear transformations to obtain final state variables, ensuring bad data sparsity and consistency across sub-systems without requiring centralized management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of information
If centralized management system is used for power system state estimation, then comprehensive state information can be obtained, but communication congestion and information processing bottlenecks occur due to huge grid scale
Solution Approach 1:
The patent divides the power system into multiple sub-systems, each independently performing state estimation on local data. This segmentation eliminates the need to transmit all raw measurement data to a central processor, thereby reducing communication congestion and processing bottlenecks while still achieving comprehensive system-wide state information through coordination of sub-system results
2Reliability
If centralized management system is used for power system state estimation, then global model maintenance is possible, but maintenance difficulty increases due to large number of interconnected sub-systems and frequent alien changes
Solution Approach 1:
The patent segments the global power system model into multiple independent sub-system models. Each sub-system maintains its own model locally, which significantly reduces the complexity of model maintenance. When changes occur in one sub-system, only that local model needs updating rather than the entire global model, thereby improving ease of repair while maintaining global model accuracy through coordination
3Loss of information
If centralized management system is used for power system state estimation, then complete system information can be collected, but privacy protection becomes difficult due to trade secrets of different operators
Solution Approach 1:
The patent enables each sub-system to perform state estimation independently on local data, so sensitive information remains localized and is not transmitted to central or other sub-systems. This segmentation approach protects the trade secrets and privacy of different operators while still achieving comprehensive system-wide state estimation through coordination of boundary conditions and state variables
Solution Approach 2:
The patent introduces boundary state variables and coordination mechanisms as intermediaries between sub-systems. Instead of directly sharing sensitive operational data, sub-systems exchange only necessary boundary information and state variables through a coordination layer, which mediates the information exchange to protect privacy while maintaining system-wide estimation accuracy
Data Source
AI summary
A method and a device for estimating a state of a power system are provided. The method includes: dividing the power system into a plurality of sub-systems; establishing a first linear model of the power system for a first stage; solving the first linear model by an alternating direction multiplier method to obtain the intermediate state variables of each sub-system; performing a nonlinear transformation at a second stage on the intermediate state variables to obtain intermediate measured values; establishing a second linear model of the power system for a third stage according to the intermediate measured values; and solving the third linear model by the alternating direction multiplier method to obtain the final state variables of each sub-system.