Reliability Evaluation Of Microgrid Based On Time Sequential Simulation

Microgrid has been widely concerned by domestic and overseas scholars because of its flexible and reliable operation.However,the flexible operation mode and complex operation characteristics also bring challenges to the reliability evaluation of microgrid.In this paper,a microgrid system is established,which has a micro turbine model with the timing life characteristics of "operation-fault",a photovoltaic model with intermittent and fluctuating output,a wind turbine output power model based on wind speed,a load model with time-series fluctuation and randomness,and a charge and discharge model of energy storage system considering operational constraints.The whole time sequence Monte Carlo simulation is used to study the random operation characteristics of microgrid system.The equipment capacity configuration scheme is proposed from the perspective of energy abundance,operation reliability and economy.Therefore,the microgrid system can keep flexible,economic and reliable operation.From the view of energy abundance,the influence of micro turbine,photovoltaic,energy storage capacity and power change on reliability is studied,and the change rule of equipment capacity on reliability index is analyzed.The results show that the reliability indices present ladder effect and saturation effect in the coordinate of energy storage power and capacity.And the calculation methods of boundary parameters in these two effect areas are given.From the view of operation reliability and economy,the change rules of photovoltaic capacity on system reliability are analyzed,and the coupling relationship between optical storage capacity and power is proposed.The results show that the integrated configuration of optical storage capacity and power can achieve better reliability benefits.And the installation of optical storage system at the location with lower load demand can achieve better reliability benefits and minimum total cost.From the perspectives of reliability,economy and environmental protection,the wind-PV-ESS complementary system is established,and the influence of equipment capacity and energy storage capacity allocation under different wind power penetration on the reliability of wind-PV-ESS complementary system is evaluated.The results show that a large amount of energy storage investment will bring considerable reliability benefits and higher energy storage costs.Then,the proportion of wind power penetration can be added to reduce the input capacity of energy storage under certain reliability.And a reasonable proportion of wind power penetration can achieve the best compromise of reliability and economy of power generation system.Based on the reliability evaluation of microgrid with time series simulation,the sensitivity analysis of reliability indices is carried out by taking into account the shape parameters of Beta distribution,wind speed,wind and PV penetration change.The results show that the change of shape parameters in Beta distribution can affect the output of PV and then affect the reliability of the system.Then,the increase of wind speed can improve the output of wind turbine,and then improve the reliability of the system.And the reliability of the system is under different wind and PV configurations not the same,and the reasonable planning of the configurations can obtain better reliability benefits.