Stochastic Operation Framework of Microgrid under Uncertainties of Load, Generation, and Contingency

Abstract

This paper proposes the idea of independent models of a microgrid (MG) based on operation modes. In grid-connected operation, optimal power flow is proposed to minimize the power generation cost. A new decision variable was introduced to represent a MG as an equivalent unit from the viewpoint of the upstream network. In island operation, contingency condition was considered and reliability improvement of the MG through load restoration is proposed. A new performance index is proposed to model MGs as small self-adequate islands in contingency. The main distinction between this research and the literature is the consideration of the uncertainty of the components of the MG. Monte Carlo simulation (MCS) was used as a framework to consider the uncertainty of components, including load consumption, renewable power generation, and fault duration. The proposed probabilistic models can be used to assess the generation adequacy and to indicate vulnerable loads in grid-connected and island operation modes, respectively. The proposed method was applied to the IEEE 69-bus test system and the results were discussed.