Interval State Estimation of Electricity-Gas Systems Considering Uncertainties of Network Parameters and Measurements

The large-scale coverage of electricity–gas systems makes the demand for system status monitoring increase continuously. Nevertheless, the imprecise system parameters and measurements deviations increase the difficulty of state estimation and the uncertainty of results for electricity–gas systems. To this end, it is imperative to establish state estimation models of electricity–gas systems considering the existing uncertainty. This article presents an interval state estimation method for the electricity–gas systems considering uncertainties of network parameters and measurements. First, the network parameters and measurements uncertainties in the electricity–gas systems are integrated into a unified framework, and the uncertainties are represented in intervals. Then, the interval linear equations with input and output ports are developed for the state estimation of electricity–gas systems with network parameters and measurements uncertainties, so as to model the state estimation of electricity–gas systems under various uncertainties. Furthermore, an effective method is proposed to solve the interval boundary of state estimation, which can provide the ideal interval boundary under the influence of various uncertainties without need for interval iterative calculation. The proposed method is tested on an integrated electricity–gas system (IEGS) composing of the ten-node natural gas network and IEEE 14-bus system. Comparison with Krawczyk operator method illustrates that the proposed method has greater superiorities in accuracy and calculation efficiency.