Research On The Day-ahead Optimal Scheduling Strategy For Integrated Power And Heat Energy Systems

In recent years,due to the constraints of the grid structure and the construction of external transmission channels,there have been problems such as the difficulty in limiting wind power,limiting power consumption,and excess production capacity,which are not conducive to the development of wind power.Studying the power and heat coordination of integrated power and heat energy system will help to achieve energy-saving regional energy dispatch and improve wind power acceptance.The assembly lag of the heating monitoring equipment at this stage cannot be realized in the dispatching center.The "power determined by heat" scheduling mechanism was optimized to study the optimal scheduling strategy of the "transition period" from the traditional "power determined by heat" to power and heat coordination scheduling.First of all,it is clear that the coupling electricity and heat relationship is the key to achieving the unified and coordinated operation of the power system and the heating system.From the point of view of space coupling,the coupling electricity and heat characteristics of the combined heat and power unit and the mechanism of operation of heat storage devices such as regenerators and electric boilers together with cogeneration units were analyzed.From the point of view of time coupling,the influence of the time lag of the heating system on the electrical scheduling of the system is explored,and the time scale of the thermal inertia of the building is matched with the time scale of the electricity dispatch.The power and heat space-time coupling characteristics lay the foundation for the establishment of a unified scheduling model for integrated power and heat energy system.Then,through the analysis of the thermal storage characteristics of buildings,a day-ahead optimization scheduling model that accounts for the thermal storage characteristics of heating buildings was established.Integrated power and heat energy system scenes is set such as unused heat storage characteristics of heating buildings,configuration of heat storage devices,and utilization of heating and building heat storage characteristics.The results of different scenarios are used to verify the comprehensive energy utilization capabilities of the optimized dispatch to the limited resources in the region.Finally,the reasons for the current bottleneck of the scheduling plan are analyzed in light of the incompleteness of the current "power determined by heat" mechanism.By constructing the minimum heating load model and the optimization model of heat load to optimize the scheduling mechanism during the peak-loading bottleneck period,a two-stage strategy for day-ahead optimal scheduling of the "transition period" is proposed.In order to explore the willingness of each unit to respond to system dispatch,the factors affecting the integration of integrated power and heat energy system are analyzed.The factors involved include marginal cost factors,peak load compensation factors and coal consumption cost factors.The research results show that the integrated power and heat energy system dispatching using the heat storage capacity of the heating building can achieve the same effect as the configuration of the heat storage device to receive more wind power.The optimal scheduling strategy of the integrated power and heat energy system can accurately calculate the optimal indoor temperature of the building that can be used to improve the flexibility of the system.The two-phase strategy of optimizing the dispatch in the "transition period" can optimize the traditional "power determined by heat" dispatching mechanism and improve the ability of the system to accept wind power.From the aspect of each unit responding to system scheduling,the marginal cost factor mainly has a great influence on the response system scheduling of the conventional thermal power unit,and the peaking compensation factors mainly have a greater impact on the system scheduling of the combined heat and power unit.