Fault recovery of integrated energy system considering electric-gas coupling characteristic and robust chance-constrained power balance.

• A chance-constrained power balance model is introduced for the IES fault recovery. • The IES fault recovery strategy is proposed considering natural gas delay. • The developed model is converted into a solvable second-order cone problem. After the integrated energy system (IES) encounters extreme disasters, the uncertainty of renewable energy may lead to the imbalance of power supply and demand. This makes the IES fault recovery strategy very complicated. Considering the influence of the electric-gas coupling characteristic of natural gas delay, this paper proposes a fault recovery strategy, including the load recovery and economic efficiency of the operation of the IES. In the recovery stage, a chance-constrained power balance model is employed to solve the power supply and demand imbalance caused by uncertainty. Next, the chance-constrained power balance model is processed via distributionally robust optimization, and it is reformulated into a second-order cone programming (SCOP) problem by dual transformation and conditional value-at-risk approximation. To deal with nonlinear terms, the piecewise linearization method is used to model the load recovery result, renewable energy output, and total operation cost of each period during the fault. Finally, the effectiveness of the proposed strategy is verified by an IES composed of an IEEE 39-node electricity subsystem, a 20-node natural gas subsystem, and a 6-node thermal subsystem. [ABSTRACT FROM AUTHOR]