| With the continuous development of microgrid technology,multiple adjacent microgrids are connected to the same power distribution area to form multi-microgrids system,which is conducive to improving the stability and economy of the overall operation of the system.At the same time,in order to improve the efficiency of energy utilization and promote the cascade utilization of energy,the energy supply form of the microgrid has gradually developed from the traditional single electric energy to the multi-energy form such as cold,heat and electricity.Therefore,energy optimal scheduling strategy of multi-microgrids system has become the focus of current research.Compared with a single microgrid,multi-microgrids has the characteristics of diversification of stakeholders.As different stakeholders of the multi-microgrids system,the multi-microgrids system operation stakeholder and the sub-microgrids stakeholders enjoy certain autonomous scheduling right,and there is a game relationship in the optimization of scheduling,and the microgrid no longer focus on autonomous optimization operation,while the traditional centralized optimization dispatching needs to collect the operating parameters and forecast data of all equipment in the system layer by layer,and optimize the overall scheduling of the multi-microgrids system with multiple stakeholders,which cannot reflect the game relationship between different stakeholders,so this method is no longer applicable.Therefore,the research on energy optimal scheduling strategy of multi-microgrids system that takes into account the interests of multiple stakeholders has important reference value and practical significance.This paper focuses on the research on energy optimal scheduling strategy of multimicrogrid systems.The main research contents are as follows:(1)The energy dispatch architecture of the multi-microgrids system is studied,and the energy supply structure of a typical combined cooling,heating and power microgrid is given.On this basis,a multi-microgrids system energy scheduling mathematical model is established,including the mathematical model of distributed power equipment,auxiliary energy supply and energy storage equipment.(2)A two-layer optimal scheduling strategy for energy of multi-microgrids system is proposed.This strategy is based on the bi-level programming theory and establishes a multimicrogrids system energy optimal scheduling problem based on bi-level programming.The upper layer is the energy optimal scheduling problem of the multi-microgrids system operation stakeholder,and the lower layer is the energy optimal scheduling problem of the sub-microgrids stakeholders.The bi-level optimization problem is transformed into a single-level optimization problem through the Karush-Kuhn-Tucker condition for solution.Finally,a calculation example is used to analyze the rationality of the energy optimal scheduling result of the multi-microgrids system based on the Karush-Kuhn-Tucker condition.The optimization results of the energy optimal scheduling strategy of the multi-microgrids system are compared and analyzed with the traditional centralized optimization strategy to verify the feasibility and effectiveness of the proposed strategy.(3)Based on the optimal scheduling problem in Chapter 3,a multi-microgrids system energy optimal scheduling problem considering the shiftable load is established,and in order to protect the stakeholders’ private information and reduce the requirements on the communication system and control system,an energy optimal scheduling strategy of multimicrogrids system based on the analytical target cascade method is proposed.This strategy is based on the basic analysis framework of the analytical target cascade method,and uses the tie line power as coupling variables to decouple the problem into an independent optimization problem for the multi-microgrids system operation stakeholder and the sub-microgrid user stakeholders,and adopts a two-layer loop solution method to carry out optimization solution for the problem.Finally,a calculation example is used to analyze the rationality of the energy optimal scheduling results of the multi-microgrids system and the convergence of the algorithm based on the target cascading method,and to compare the calculation accuracy and calculation efficiency with the traditional centralized optimization strategy to verify the feasibility and the effectiveness of the proposed strategy. |
