Study On Optimal Dispatching Of CCHP(Combined Cooling, Heating And Power) Microgrid With Multi-time Scale

The micro-grid of CCHP can realize the cascade utilization of energy,improve the energy utilization rate and the absorption capacity of renewable energy such as photovoltaic and wind power,and reduce environmental pollution.In the micro-grid of CCHP,renewable energy penetrates a lot,the load of CCHP fluctuates greatly,and the micro-grid of CCHP has great randomness.In the micro-grid of CCHP,there are three kinds of energy flows: cold,heat and electricity,and the energy can be converted,so the system has good flexibility.Therefore,this paper establishes a multi-time scale optimal dispatching model for the micro-grid of CCHP,which can adapt to the randomness of the system and realize flexible dispatching of the system.Firstly,a flexible micro-grid of combined cooling,heating and power supply is constructed,which includes photovoltaic,wind power,micro-gas turbine,gas boiler,electric boiler,electric refrigeratory,absorption refrigeratory and so on.It can convert electric energy into heat energy,electric energy into cold energy,and thermal energy into cold energy.The mathematical models of each unit and environmental penalty cost in the system are established,which will be the basis for the establishment of multi-time scale scheduling model in the following chapters.Secondly,aiming at the randomness of photovoltaic,wind power and load Combined cooling and heating and power,considering the time-sharing price,environmental benefits and other factors,a non-linear interval optimization model aiming at the lowest comprehensive operation cost of the system is established.According to the interval probability model,the uncertain model is transformed into a deterministic model,which is solved by the adaptive weighted particle swarm optimization(AWPSO).The rationality and flexibility of the model are verified by an example,and the influence of interval probabilit y and load fluctuation on integrated operation cost is analyzed with simulation results.Finally,a four-hour rolling model in a day and a 15-minute real-time dispatching model in a 15-minute time are established to minimize the integrated operation cost of the combined cooling,heating and power supply micro-grid.It is proved that day-ahead scheduling provides the basis for rolling-real-time scheduling.Day-ahead rolling-real-time scheduling adjusts the power and load deviation of each unit and makes more accurate scheduling plan.