Research On Reliability Evaluation Of Microgrid Including Wind Power,Photovoltaic System,Diesel Generator,and Battery Storage

With the emergence of energy crisis and environmental problems,as well as the increasing reliability requirement of load point,microgrid has become a research hotspot both home and abroad.The microgrid can effectively integrate various types of distributed generations and switch flexibly between island operation and grid-connected operation,so as to improve the power quality and power supply reliability of the microgrid.The reliability evaluation of microgrid has very important theoretical meaning and great value in engineering application because the evaluation results can provide some decision support for the planning,design and operation of microgrid.However,the randomness output of distributed generation and the operation characteristics of microgrid have brought new problems to reliability evaluation of microgrid.So,this paper does some in-depth study focusing on reliability evaluation of microgrid.Firstly,the wind power model,the photovoltaic power model,the charge and discharge model of energy storage devices and the time series load model are established.The state space method is used to calculate the reliability parameters of wind units,photovoltaic units and energy storage devices.Secondly,taking a specific microgrid as an example,the quantitative evaluation indices of power system reliability is got based on the Well-being theory.The result shows that: The combination of traditional reliability indices and Well-being reliability evaluation theory can evaluate the reliability of microgrid power system more comprehensively.In order to improve the reliability of power supply,the proportion of wind power capacity should be higher than the proportion of photovoltaic capacity when the power capacity of microgrid is configured.Then,this paper establishes component failure rate model and fault repairing time model considering several factors.The control mode of island microgrid is studied.The effect of component fault on microgrid operation is analyzed.Taking into account of two aspects of factors including location and load importance,load shedding strategy in islanded mode is researched.Considering the stochastic output characteristic of power,control methods,the component failure,the load shedding method and the grid structure,a power supply reliability evaluation algorithm of an island microgrid based on the sequential Monte-Carlo simulation method is proposed.Taking an island microgrid as an example,the quantitative evaluation indices of reliability is got.Correctness of the proposed algorithm is proved and effect of different control methods on the reliability is analyzed.Finally,failure influence of component on operation mode is analyzed.The control mode of grid-connected microgrid is studied.The loads outage factors of grid-connected microgrid are summarized.A power supply reliability evaluation algorithm of grid-connected microgrid based on the sequential Monte-Carlo simulation method is proposed.Taking a grid-connected microgrid as an example,the quantitative evaluation indices of reliability is got.Correctness of the proposed algorithm is proved.The result shows that: no matter under any kind of control mode,the reliability of grid-connected microgrid is higher than that of the island microgrid,and the system reliability indices of grid-connected microgrid under two control modes are similar.When the microgrid is in grid-connected mode,the reliability in peer-to-peer control mode is better than that of the master-slave control mode which takes diesel generator as its main power.