Probabilistic analysis of small signal stability of microgrid using point estimate method

This paper presents a two-point estimate (TPE) based method for probabilistic analysis of small signal stability of a microgrid (MG) considering uncertainties. The uncertainties may arise from different sources as load demand or generation unit outages. This method combines the TPE method and probabilistic small signal stability analysis. Stability indices and the judgment of unstable types for microgrid´s probabilistic small signal stability are also addressed. Instead of using a large number of simulations, which is required in Monte Carlo approach, for a system with N uncertain parameters, the TPE method uses 2N calculations of stability to quantify the uncertainty while keeping enough precision. The small signal model of a microgrid, which consists of a conventional synchronous machine and two electronically interfaced distributed generations, is used to evaluate the performance of the proposed method. Simulation results of the MG verify the effectiveness of the proposed method.