Coordinated wind power dispatch model for an integrated heat and power system by a novel scenario-dependent algorithm

Abstract

Combined heat and power (CHP) units required to meet high heat demands over heating periods in North China have high power injections into electrical grids, greatly aggravating the wind generation curtailment. To deal with this issue, this paper develops a coordinated wind power dispatch model for the CHP units which are integrated with a thermal energy storage (TES) and an electric boiler (EB) placed at the CHP thermal output side and power demand side respectively. The dispatch model optimises the operation of all the components integrated within the system by minimising the total dispatch cost associated with electricity and heat generation and wind curtailment. The CHP thermoelectric coupling constraint is decoupled based on a scenario decomposing strategy where the feasible operation region of CHP units is converted into inequality constratins, permitting to solve the economic dispatch problem by the use of a scenario-dependent elitist genetic algorithm combind with an interior point method. The coordinated dispatch model is tested on a modified IEEE 30-bus system with different combinations of TES and EB. The dispatch results show that the proposed model can optimise the schedules of TES and EB to maximise the use of wind generation and lower the overall dispatch cost across the plan time horizon. In addition, the relationship between the EB heat-supply propotion and the dispatch cost is discussed.