Micro-grid Reliability Calculation Method Study Considering The Time Relevance And The Component Operation Hours

The extension and utilization of renewable energy resource(RER)generation are effective solutions for global energy crisis.Micro grid(MG)is considered as a significant way of promoting the coordination between RER generation and existing power grid,while the reliability calculation for MG considering RER generation is a major part of evaluating the feasibility of RER integration.The reliability calculation of MG differs from that of the utility grid in several aspects including grid structure,operation mode,component failures and time sequence property,hence an overall consideration of time-correlation character and component operation time will excessively improve the validity of MG reliability calculation.This paper focused on the methodology of reliability calculation of MG consisting of RER generation.Firstly,character analysis on wind speed and radiation intensity is done to obtain corresponding curves,thus time-correlation character between RER generation and load can be established using time label.Then the accurate sampling of wind speed is realized via a modified Latin hypercube sampling method.The operation time is considered to obtain accurate component failure rate via the bathtub curve of each component.Finally,methodology of MG reliability calculation considering time-correlation character and component operation time is proposed based on state duration sampling method.The proposed method is applied and verified on a case study of a MG,and contrastive analysis is done between calculation results of the proposed method and multi-state reliability calculation.The proposed method is able to reveal the asymmetry between RER generation and load,and the changing of failure rate can be traced during the operation time of each component.Hopefully this method shall provide a practical solution for MG reliability calculation considering RER integration.