natural gas system (IEGS), operating reserve and gas storage are both useful support to cope with contingencies in IEGS. This paper proposes a day-ahead SCUC model for the IEGS to schedule the operating reserve and gas storage simultaneously. The multi-state models for generating units and gas wells are firstly established. Based on the multi-state models, the expected unserved energy cost (EUEC) criterion is proposed based on probabilistic methods considering random failures of generating units and gas wells. Then, the EUEC criterion is incorporated into the day-ahead SCUC model, which is nonconvex and mathematically transformed into a solvable mixed integer linear programming (MILP) problem. The proposed model is studied using a 6-bus-6-node IEGS with natural gas storage.
Keywords integrated electricity and natural gas system, operating reserve, natural gas storage, expected unserved energy cost.