| With the rapid reform of the terminal energy system,the Interdependency between the natural gas and the electricity networks is increasing.Gas-fired generating units can respond quickly to the uncertainty of the output of renewable energy,and cause great fluctuations in the natural gas networks at the same time.Therefore,this paper proposes an effective model and method to analyze the interaction of electricity-gas coupling network dynamically.At the same time,this paper proposes an economical stable operation model containing P2G of electricity-gas coupling network.Detailed research contents are described as follows:(1)Taking "energy flow" as the core,it pays attention to the overall energy transfer law of power network and natural gas network,and lists the network equations in the form of matrix.The network equations of matrix form are easier to express and suitable for computer calculation.It is more convenient to simulate and analyze the model after embedding the algorithm.On the basis of this model,the safe operation constraints,operational state classification,expected accident set and flow of the static safety analysis of the electricity-gas coupling network are given.(2)This thesis improves the partial differential equation model,which becomes a state equation model that can effectively reflect the characteristics of natural gas pipeline ports.Compared with the traditional model,this model can significantly reduce the complexity and calculation.Also,it’s more suitable for online analysis of electricity-gas coupling networks.Based on this,taking into account the dynamic characteristics of the compressor,a stabilization control method based on variable compression ratio for the electricity-gas coupling network is proposed,which ensures safe and stable operation of the electricity-gas coupling network.Finally,through the simulation example,the accuracy of the proposed model and the effectiveness of the control method are verified.(3)Combined with the constraints of the electricity-gas coupling network,considering the gas turbine climbing rate constraint is closely related to the limit and change rate of pressure fluctuation of natural gas network,the interaction mechanism of the electricity-gas coupling network is proposed.In the simulation,the paper adopts the singular perturbation theory to describe the dynamic processes of electricity-gas coupling network with two time scales.The interaction of electricity-gas coupling network is effectively reflected by the 6-node natural gas network and the 7-node power network simulation.(4)Due to the increasing installed capacity of renewable energy power generation and the unsynchronized power grid construction,there have been phenomena such as abandoning wind and abandoning light,resulting in waste of energy.When the wind power is surplus,the P2G technology is used to convert the excess wind power into natural gas for storage,to promote wind power consumption and improve the utilization rate of the wind turbine.Firstly,this thesis models the electricity-gas coupling network containing P2G in modularization.On this basis,an economic stable operation model of dual-target electricity-gas coupling network with simultaneous consideration of grid transient stability and lowest cost of electricity-gas coupling network is established. |
