| With the further development of human society,the depletion of fossil fuels has been difficult to meet the growing energy needs of mankind.The energy pattern based on fossil fuels is changing.How to use cleaner and more environmentally friendly energy instead of traditional fossil fuels and how to increase the utilization rate of energy through the complementarity between different energy sources have become the focus of current research.Taking the electricity as the core,an integrated energy system that includes various energy forms such as electricity,wind,solar,gas,and geothermal energy came into being under this energy background.The richness of energy forms has caused a huge change in the energy structure.Taking the electric-gas integrated energy system as an example,the development of gas turbines and P2 G equipment has made the coupling of natural gas and power systems increasingly close with the energy flowing in both directions.The addition of natural gas systems and the use of multienergy equipment have also brought new challenges to the safe and reliable operation of power systems.Based on the impact of the natural gas system on the power system,this paper focuses on the evaluation and research of the operation reliability of the distribution network under the electric-gas integrated energy environment.The main research contents are as follows:1)Analyze the influencing factors of short-term operation reliability of distribution network,establish short-term outage model of distribution network components,and put forward the evaluation index system of distribution network operation reliability.The steadystate energy flow model of natural gas is established,and the second-order cone relaxation method is used to solve the optimal natural gas load shedding model.The output model of the electric-gas coupling element-gas turbine is established.Non-sequential Monte Carlo sampling is used to evaluate the reliability of the distribution network,and the impact of the external environment,natural gas failures and different day-ahead scheduling strategies on the distribution network’s operation reliability are analyzed.2)Consider the influence of the natural gas dynamic characteristics on the reliability of distribution network operation.The natural gas pipeline flow equation which is a complex partial differential equation is linearized by the Lax-Wendroff difference method,and is added to the natural gas optimal load shedding model constraints in order to quantify the impact of the dynamic performance on load shedding after system failure.The evaluation indexes before and after taking the natural gas dynamic characteristics into account are calculated,and the effects of gas turbine permeability,the degree of failure of natural gas components and the initial line pack on the distribution network operation reliability are analyzed.3)Add P2 G and gas storage tank equipment to the electric-gas integrated energy network,establish P2 G and gas storage tank models,and establish wind power output and load uncertainty models at the same time.The influence coefficient of P2 G on wind power absorption rate and the influence coefficient index of gas storage tank on load shedding index are proposed to quantitatively analyze the influence of P2 G and gas storage tank on the operation of distribution network.An operational reliability assessment process that considers P2 G and gas storage tank control strategies is constructed.Through case simulation analysis,the effects of P2 G capacity,initial gas volume of the gas storage tank and other factors on the system operational reliability are studied. |
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