| The multi-energy system is composed of interconnected subsystems with complex structure and various components.The interconnected subsystems of electricity,gas and heat are closely linked,which makes the reliability assessment of multi-energy systems face challenges.At present,the reliability evaluation method for single subsystem is becoming more and more mature,but the research on the reliability evaluation of multi-energy system with coupling interconnection is still in its infancy.In order to ensure the safe and reliable operation of multi-energy coupling interconnection system,it is necessary to study the model and method of multi-energy system reliability evaluation.Based on the working state selection,working state analysis and evaluation index calculation of multi-energy system,this dissertation studies the reliability evaluation of multi-energy system.The main research contents are summarized as follows:(1)A decoupling calculation model for multi-energy system coupled power flow and an optimization model for load reduction based on energy hub are established.Firstly,models of power network,natural gas network,heat network and coupling component models are established.Then,the decoupling solution method of power flow of multi-energy system is introduced based on the unified iterative solution method of coupling power flow.Furthermore,in order to calculate the optimal load reduction amount of multi-energy system,the optimal load reduction calculation method based on energy hub is established.Finally,the effectiveness of the decoupling solution method of multi-energy flow and the optimal load reduction calculation method is verified through a simulation example.(2)A probabilistic calculation model of multi-energy system state based on the general generating function method is established.Firstly,according to the basic theory of universal generating function,the reliability of components in multi-energy system is analyzed.Secondly,the reliability model of components in multi-energy system is established.Then the calculation method of multi-energy system state probability is proposed.Finally,an example is given to verify the feasibility of the model for calculating the system state probability.(3)A reliability evaluation method for multi-energy systems based on sequential Monte Carlo sampling is proposed.Firstly,the evaluation indexes of load loss probability and energy shortage expectation are established for load energy supply,and the indexes of multi-energy system weakness and component importance are established for the identification of system weak links.Then,this dissertation puts forward the multi-energy system evaluation method based on sequential Monte Carlo simulation method,design the reliability of the multiple energy system evaluation process.Finally,a 14-node multi-energy system is used to calculate the system reliability index under different conditions to verify the effectiveness of the proposed method. |
