| The construction of the new power system is a key way to achieve the goal of peaking carbon emissions by 2030 and carbon neutrality by 2060 for China.For the power generation side,developing renewable energy vigorously,such as wind power and photovoltaic power,can accelerate the process of replacing fossil fuels with clean energy.For the electricity consumption side,the process of electrification for different sectors is implemented,especially for the transportation system,especially in which fuel vehicles will be replaced by deploying electric vehicles.Meanwhile,developing seasonal energy storage vigorously can not only improve the power system’s ability to manage the seasonal uneven distribution of renewable energy but also improve the ability of renewable energy accommodation.In the process of constructing the new power system,the main challenges are to optimize the allocation of source-load-storage and maintain the power balance on multiple time scales during the operation simulation.Therefore,it is imperative to investigate the optimization planning of new power systems to meet the needs of clean,safe,flexible,and efficient power systems.Under the low carbon emission goal,the research on the optimization planning of the new power system is facing new challenges,including 1)The problem-solving efficiency of the operation simulation model is low.The operation simulation of the power system with seasonal energy storage is a large-scale mixed-integer programming(MIP)problem with coupling constraints between consecutive intervals(the coupling constraints include ramp rate constraints and minimum on/off time constraints of thermal units,and state of charge constraints of seasonal energy storage),which is often computationally intractable.2)The feasibility of the planning solutions is unpromising.The planning solution obtained from power system planning based on representative scenarios is difficult to meet the feasibility of the rate of lost loads and carbon emission constraints in the sequential full-time operation simulation.3)The issue of co-planning of power generation side and electric vehicles of the demand side.The current power system planning method does not fully consider the planning of the number of new energy vehicles,leading to insufficient consideration of the coupling relationship between renewable energy,electric vehicles under the electricity consumption side,and hydrogen energy storage.Therefore,this thesis takes the new power system planning problem as the object,problem-solving efficiency breakthrough,and feasibility improvement as the core,and studies how to realize the low-carbon target and improve the overall economy of the new power system.Firstly,an operation simulation method for the power system with seasonal energy storage is proposed to improve the problem-solving efficiency of the unit commitment problem.Then,a new power system planning method considering operation simulation is proposed to ensure the feasibility of the proposed planning solutions to meet the carbon emission and rate of lost load in the full-sequence operation simulation.Finally,a dispatchable region formation approach for electric vehicles considering the flexibility of charging piles is proposed to capture its availability flexibility in dispatching.On this basis,a new power system planning method containing hydrogen energy storage and electric vehicles is proposed to realize the coordinated planning of the power system,electric vehicles,and hydrogen energy storage,and to reduce emission reduction costs in the whole of society.The contributions can be summarized as:(1)An operation simulation method for the power system with seasonal energy storage is proposed to improve the solution efficiency of operation simulation problems with coupling constraints between consecutive intervals.Based on the constraint splitting and parallel solving,the operation simulation problems with coupling constraints are split into several subproblems that can be solved independently to improve their solution efficiency.First,an operation simulation model of the power system with seasonal energy storage is constructed.Then,for the coupling constraints of adjacent time periods of conventional units,a constraint decomposition method is proposed.The operation simulation problem with coupling constraints between consecutive intervals is split into several subproblems that can be solved independently,so as to realize the decoupling of the coupling constraints.Then,for the multi-day time series coupling constraints of seasonal energy storage,a decoupling method for long-term time series coupling constraints is proposed,which realizes the global optimization of the state of charge of seasonal energy storage.The arbitrage operation mode based on the peak-valley electricity price is proposed to determine the boundary conditions of seasonal energy storage in each sub-problem.Finally,the proposed method is verified on the modified IEEE 24-bus system.The results show that the computation time of the unit combination problem can be reduced by 97.8%,and the error is 3.62%.The proposed algorithm accelerates the solution efficiency of MIP problems by decomposing and coordinating the original problem,and can quickly obtain high-quality feasible solutions.(2)A new power system planning method considering the operation simulation is proposed,which ensures that its planning solution meets the requirements of the rate of lost load and carbon emission constraints in the sequential full-time operation simulation.First,a power system planning model with carbon emission constraints is constructed.Then,an efficient iterative solution method for the power system planning model considering the operation simulation is proposed,which softly links the operation simulation model of the power system with the power system planning model.The identification method of extreme scenarios based on the information from the operation simulation model itself is proposed,to ensure that the planning solutions meet security constraints during preventive extreme scenarios.The proposed iterative solution method can make sure that the planning solution meets the requirements of the rate of lost load and carbon emission constraints in the sequential full-time operation simulation.Meanwhile,an efficient solution algorithm is proposed to improve the solution efficiency of operation simulation models with carbon emission constraints.Finally,the proposed method is tested on the modified IEEE 24-bus system.The results show that the computation time of the proposed planning model is reduced by 70%,and the error remains within 2%.(3)An operation simulation model of the power system considering the dispatchable flexibility of electric vehicles is proposed to realize the optimal interaction between the power system and electric vehicles,so as to improve the economy of the power system.First,an electric vehicle charging load model based on trip chain theory is constructed to capture the spatiotemporal distribution of electric vehicle charging loads.Secondly,a dispatchable power and energy boundary approach to electric vehicles considering the availability of charging piles is established to capture precisely the dispatchable flexibility of electric vehicles.Then,a power system operation simulation model considering the dispatchable flexibility of electric vehicles is established to reduce the power system operating cost and improve the system load distribution by orderly charging electric vehicles.Finally,the proposed method is tested on the modified IEEE 24-bus system.The results show that the proposed method reduces the total operating cost of the system by 4.0% and the peak load by 6.2%.(4)A new power system planning model with hydrogen energy storage and electric vehicles is proposed to realize the coordinated low-carbon transformation of the power system and the transportation system and to minimize the emission reduction cost for the whole of society.First,a coordinated planning model of the new power system with hydrogen energy storage and electric vehicles is constructed,in which the optimal decision variables for the ownership of electric vehicles are first developed.The objective function of the proposed model is to minimize the total cost of investment and operation of the power and transportation systems while satisfying the carbon emission constraints.Among the proposed model,energy supply and demand models for different fuel types and vehicle types are established considering the dispatchable flexibility of electric vehicles.Then,the hydrogen energy storage model and the hydrogen refueling station model are constructed to capture the coupling characteristics of the integrated electricity-transportation-natural gas system.Finally,the proposed coordinated planning model is tested on the Texas power system.The results show that the annual cost of the system can be reduced by up to about 2% through the coordinated planning of the power and transportation system.Deploying the hydrogen energy storage could reduce the curtailment of renewable energy by 97%. |
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