| Integrated Energy Systems(IES)are highly flexible and can be optimally dispatched to minimise fluctuations in new energy sources.However,the optimal scheduling of IES is closely related to the configuration of the power supply equipment and the planning and design of the network structure in the early stages.The existing planning methods are usually independent planning of sources or networks,and the lack of coordination between the network structure and energy equipment leads to a lack of reasonable system planning,thus making the optimal scheduling of the system after completion affected by the planning stage and unable to reach the optimum.To address the above problems,this paper will systematically study the coordinated planning methods for the network structure of IES and the siting and capacity of energy devices.The details of the study are as follows:Firstly,the network structure and source equipment configuration of IES are addressed to the network-source co-ordinated planning problem,and equipment such as micro gas turbines,electricity to gas equipment,photovoltaic power generation systems,fuel cells,battery energy storage systems and gas storage tanks are systematically modelled.Constraints such as energy balance constraints and operational limit constraints are considered in the modelling process,laying a theoretical and experimental foundation for subsequent research on IES network-source coordinated planning methods.Then,to address the problem that the existing independent planning does not have global optimality,resulting in the subsequent operation phase also failing to achieve optimality,an IES network-source coordination planning method that considers both energy production equipment planning and network expansion planning is proposed.The method covers the following:(1)the planning model takes the minimisation of network source investment and operating costs as the objective and the system operating constraints as the constraints;(2)for the added electric load and gas load the planning set of candidate transmission lines and gas pipelines should be created,and the added load nodes are compared with the load nodes of the original system for the DC current calculation of the lines to determine whether the planned lines satisfy the DC current equation of the lines;For the increased gas node load with the original system node to meet the gas node balance constraints;(3)In addition to the use of binary variables to indicate the transmission line and gas pipeline planning state,the model also introduces integer variables to indicate the detailed location and number of power supply planning,the planning results include the best transmission line,gas pipeline,power supply equipment location and number.The simulation analysis shows that the coordinated network-source planning method is coordinated,flexible and more economical than existing independent planning methods.Finally,a planning method based on IES network-source coordinated robust optimisation is proposed to address the problem of high operating costs in the subsequent operation of deterministic methods due to the random and fluctuating nature of PV power output.The method adopts the fundamental uncertainty set to describe the fluctuation range of PV output,adjusts the uncertainty of PV output by introducing robust parameters,and linearises the constraints and objective function by means of pairwise theory,thus transforming the problem into a mixed-integer linear programming problem,and then establishes an IES network-source coordinated robust planning model.The conservative degree of uncertainty in power supply investment cost,system operating cost and total cost arising from the regulation of the robust parameters under four scenarios is analysed by simulation,and the results show that the proposed robust planning method has better economy compared with the deterministic planning method. |
