Impacts of stochastic forecast errors of renewable energy generation and load demands on microgrid operation

Evaluating the impacts related to stochastic forecast errors (SFE) of renewable energy generation and load demands on the operation of micro grid is an important issue. In previous researches, the negative effects of SFE on micro grid are mainly focusing on power quality, system control, and operation, etc. The objective of this study is to investigate how SFE affects the operation stability of energy storage system (ESS) from the perspective of the state of charge (SOC). To this end, novel SFE propagation and accumulation models are introduced. Efficient quantification models of impacts of SFE on the variance of SOC are presented. These models elucidate in detail the mechanism of ESS working from stable to unstable state due to SOC deviation. Then, some metrics are introduced to evaluate the impacts of SFE on service lifetime of units, the cycle life of ESS and operation economy of micro grid. Finally, illustrative numerical results are provided and compared using a self-developed new simulation program named MG-ROS, which can simulate the actual operation of micro grid under SFE.