Modelling of Microgrid-Renewable Generators Accounting for Power-Output Correlation

The possibility to operate in islanding mode some portions of a distribution network, after fault occurrence, helps to improve system reliability. In this perspective, it is crucial to estimate the ability of distributed generators (DGs) to meet the local load. A major issue in the adequacy assessment is to take into account the correlation existing among the power outputs of DGs based on the same renewable intermittent primary energy source (sun, wind). This paper presents a new modelling approach to provide the hourly generation models for each type of renewable DGs, by taking into account both power correlation and hardware availability. An interesting aspect of the proposed approach is that it encompasses such correlation, avoiding the analytical calculation of its value. An innovative method to obtain hourly load models is also presented. Finally, a method to evaluate analytically loss of load probability by using the proposed generation and load models is also described. Both the presented method and Monte Carlo simulations (MCS) are applied to the IEEE RBTS-BUS6. Applying the proposed models and analytical method actually enables obtaining benchmark results to test approximated models and/or MCS results.