Unified state estimation in integrated natural gas and electricity networks

The increasingly tighter interdependency between natural gas and power systems because of the increasing number of natural gas-fired units for electricity production has motivated research on the operational effects associated with this coupling. To evaluate the effects of this interaction, however, the operating status of the integrated gas and electricity networks must first be estimated. Hence, this paper proposes and implements a static state estimator that assesses the operating state of integrated electricity and natural gas networks. The proposed approach is based on the equality-constrained weighted least squares algorithm, which simultaneously upgrades the estimated values of the state variables associated with both energy infrastructures for a unified solution in a single frame of reference. The effectiveness of the proposed approach is demonstrated in a multi-energy system composed of the 20-bus Belgium gas system and a 3-bus electric power system.