| The coordinated operation of the integrated electricity-hydrogen energy system(IEHS)is of great importance to improve the operational efficiency of the whole system and promote renewable energy accommodation such as wind and photovoltaic power in local areas.To this end,this paper takes the regional IEHS with multiple hydrogen energy subsystems as the research object and focuses on the optimal scheduling strategy of this system.The main work of this paper is as follows:(1)Considering the flexible load resources on the demand side,an IEHS optimization model considering the integrated demand response(IDR)is developed.First of all,the structure of regional IEHS with multiple hydrogen energy subsystems is constructed.The model of the power to hydrogen and storage station(PHSS)which is composed of a proton exchange membrane electrolyzer,compressor,hydrogen storage tank and hydrogen gas turbine is established.Then,considering the upward adjustment ability of flexible load,the electricity-hydrogen IDR model including transferable load,curtailable/increasable load and convertible load is proposed.Finally,an optimal scheduling model of IEHS is formulated and the effectiveness of this model is verified through a case study.(2)In order to further promote the optimal distribution of wind and photovoltaic power in space and thereby reduce their curtailment,the interaction of hydrogen energy subsystems by hydrogen tube trailer(HT)is considered and an operation mode namely "onsite hydrogen production-hydrogen transportation by HT" is proposed.An IEHS optimization model incorporating hydrogen transportation cost is formulated based on the transportation model of HT and the objective function is linearized using the piecewise linearization method.A case study of IEHS consisting of a 30-node power system and 3 hydrogen energy subsystems is used to illustrate the validity of the proposed model.Besides,the sensitivity analysis of the number of HTs in each hydrogen subsystem and the hydrogen storage tank capacity of the PHSS is performed.The simulation results manifest that the proposed operation mode effectively promotes the wind and photovoltaic power accommodation and enhances the economic operation of IEHS.(3)Considering that the source-load uncertainty increases the demand for flexibility of IEHS and reserve capacity of power system,a two-stage scheduling strategy that coordinates multiple flexible resources including flexible load,HT and PHSS is proposed.Stochastic scenarios are used to describe the source-load uncertainty.Monte Carlo simulation and K-means clustering method are used for scenario generation and reduction.A reserve model of PHSS considering the upper and lower bound constraints on hydrogen storage amount is established,then a two-stage stochastic optimization model is formulated based on the proposed scheduling strategy and big-M approach is adopted to linearize the nonlinear terms.Ultimately,the model is solved by calling the CPLEX solver through GAMS software.The optimization results show that the scheduling strategy proposed in this paper can ensure the economic,secure and reliable operation of IEHS while promoting the accommodation of wind and photovoltaic power under the source-load uncertainty.In addition,the allocation of the power system reserve capacity is further optimized thanks to the reserve capacity of PHSS.In summary,the optimal scheduling strategy of IEHS is investigated in this paper from the perspectives of the IDR scheme,interaction of hydrogen energy subsystems and coordinated optimization of multiple flexible resources under the source-load uncertainty.The simulation results verify that the scheduling strategy proposed in this paper can effectively promote renewable energy accommodation and enhance the economic operation of IEHS simultaneously. |
