Research On Energy Management Of Renewable Energy Microgrids Considering Shared Consumption And Coordinated Operation

China’s energy demand has been rising to meet social and economic development requirements in recent years.The “dual carbon” strategy aims to address the enormous challenges posed by the rapid depletion of fossil fuels and the massive emissions of greenhouse gases.The new-type power system based on new energy sources requires the simultaneous development of centralized and distributed energy sources.Microgrid(MG)is one of the essential branches of the smart grid,which effectively utilizes distributed energy sources.The development of China’s MG has entered the green empowerment stage,and the large-scale deployment of random,fluctuating and intermittent renewable energy reduces MG output controllability.The penetration of distributed renewables brings challenges to the MG regarding scheduling and operation,such as low utilization ratio of energy sources,insufficient flexibility of renewables consumption,susceptibility to source-load uncertainty,and lack of friendly interaction with the distribution network.To this end,this paper takes renewable energy MG as the research object and focuses on two aspects: the shared consumption of multiple energy bodies within the MG and the coordinated operation of the MG on multiple time scales.The main research contents are as follows.Firstly,to address the problems of low utilization ratio of distributed energy sources and insufficient flexibility of renewables consumption,this paper establishes an MG energy sharing cloud mechanism and proposes a cluster operation method for the cloud platform of MG.The proposed MG energy sharing cloud includes three participating subjects: the energy service provider,cloud users,and the main grid.According to the responsibilities of the three participating entities,a coordinated operation decision process of the energy sharing cloud is given.To realize the cluster operation of cloud platform,the basic operating model of the cloud user and the cluster optimization operation model of the cloud platform are built,respectively.An MG containing multiple end-users is used as a test system to verify the correctness and effectiveness of the proposed method.Secondly,a double-layer energy management system for cloud users under the MG energy sharing cloud mechanism is proposed to participate in utilizing distributed energy sources in the renewable energy MG.This paper determines the operation process of the cloud user’s virtual prosumer by constructing household load models,renewables generation service models,an energy storage service model,and an energy conservation model.The proposed double-layer energy management system includes upper energy management for monthly capacity planning and lower energy management for daily dispatch optimization.A multi-objective energy scheduling decision considering electrical comfort and operational economy is proposed to improve the applicability of cloud users’ optimization decisions.Simulation analysis is performed with an end-user connecting the cloud platform and the main grid.Three numerical simulation scenarios verify the correctness and effectiveness of the proposed method.Again,to address the vulnerability of renewable energy MGs to source-load dual-side uncertainty,an online rolling optimization strategy considering hybrid energy storage and temperature-controlled loads is proposed for renewable energy MGs.The proposed strategy introduces supercapacitors to undertake frequent charging and discharging operations on a real-time time scale.Moreover,an energy trigger mechanism is designed for supercapacitors to cope with the energy overrun caused by the accumulation of short-term asymmetric power fluctuations.By analyzing the characteristics of temperature-controlled loads with controllable power and micro perception regulation,their remaining power capacity is used as virtual energy storage to participate in MG power regulation jointly.Simulation analysis is performed with a typical grid-connected MG executing different operation strategies to verify the correctness and effectiveness of the proposed method.Finally,a multi-time-scale energy management approach based on the dynamic operating reserve is proposed because the energy interaction between renewable energy MGs and the distribution grid is not friendly enough.The proposed approach first designs a dynamic reserve scheme for energy storage based on quantile prediction to avoid excessive or shortage of battery reserve capacity.Considering the limitations of the current time-varying tariffbased demand response,a tie-line power distribution response model is further proposed to evaluate and regulate the power distribution.In addition,two time-scale optimal operations,including a day-ahead dispatch plan and an intra-day rolling correction,are proposed to ensure the applicability of the day-ahead tie-line power,and their coordinated operation algorithm is determined.A park-level grid-connected renewable energy MG is used as a test system to verify the correctness and effectiveness of the proposed method.