Station-Network Coordinated Scheduling For Integrated Electricity And Natural Gas System With Operation Characteristics Of Compressor Stations Incorporated

In recent years,with the growing of gas-fired units installed proportion and the development of power to gas technology,the coupling and synergy between the power system and natural gas system have attracted extensive attention from academice and industrial fields worldwide.Coordinated operation of integrated electricity and natural gas system(IEGS)have gradually developed into an important research field of the integrated energy system,and a large number of research results have emerged.However,in the existing research on IEGS,most models of the compressor station are relatively rough and ignore the speed regulation control,surge limit and other operational characteristics of the compressor.In addition,most research is based on the scheduling center of natural gas network or IEGS to decide the start-up,shutdown and load distribution of each compressor,which is inapplicable to the hierarchical scheduling mode of station-network coordination adopted in the actual natural gas network scheduling operation.According to the above problems,this paper first studies the optimal power-gas flow(OPGF)model and its solution method considering the operational characteristics of the compressor station.On this basis,the scheduling method of IEGS considering the stationnetwork coordination mechanism is further studied.The main work and research results are as follows:1)Propose an OPGF model and its solution method considering the characteristics of compressor stations.The speed of the centrifugal compressor is introduced as the control variable in the optimal power-gas flow model,and compressor operation constraints including characteristic curve,efficiency characteristics,and surge limit are considered in modeling of the compressor stations.Furthermore,an OPGF model considering the operation characteristics of compressor station is proposed.To solve the nonlinear problem,a twostage method based on different special ordered sets and convex relaxation is proposed to formulate the original model into a mixed-integer second-order cone programming(MISOCP)problem.A compressor station sample and two IEGS samples are applied to verify the effectiveness and adaptability of the proposed model and method.2)Propose a two-stage station-network coordinated scheduling model of IEGS.Based on the refined model of compressor stations and considering the hierarchical scheduling mode of compressor station and gas network,a two-stage station-network coordinated scheduling model of IEGS is proposed.The superior scheduling considers three operating modes(compression,closing,and bypass)of compressor stations.It aims at minimizing the operation cost of the whole network and takes the IEGS scheduling center as the decision-maker to decide the operating mode,total flow and compression ratio of each compressor station in IEGS.The subordinate scheduling takes the total flow and compression ratio issued by the superior scheduling center as the boundary condition.It aims at minimizing the operation cost of the compressor station and takes the compressor station control center as the decision-maker to decide the start/stop status and flow of each compressor.In terms of the solution method,the superior model is transformed into a MISOCP problem by using second-order cone relaxation and the Mc Cormick envelope.To solve the problem efficiently,the subordinate problem is further transformed into a two-stage problem of first deciding the compressor start/stop status and then distributing the compressor flow.Two samples are applied to verify the effectiveness of the proposed station-network coordinated scheduling method,and the results of station-network coordinated scheduling and the existing integrated scheduling are compared and analyzed3)Propose a distributed scheduling method of IEGS considering information privacy.Based on the IEGS station-network coordinated scheduling method,further considering the information privacy of power and natural gas subsystems,a distributed coordinated scheduling model of IEGS is proposed based on the alternating direction method of multipliers(ADMM).In terms of the model solving,to solve the problem that the convergence of mixed-integer ADMM model can not be guaranteed and the update of multipliers is slow,an iterative algorithm combining integer variable heuristic strategy and ADMM parameter improved strategy is proposed.An IEGS sample is applied to verify the effectiveness of the proposed distributed coordinated scheduling method,iterative algorithm and parameter improvement method of ADMM.