Real-time congestion management for networked microgrids using optimal resources rescheduling and reconfiguration considering multi-level thermal rate

The high penetration of distributed energy resources raises new challenges in microgrid operation due to their stochastic and intermittent characteristics. This exacerbates the difficulty of congestion management of microgrids in comparison with conventional power systems. In addition to intermittent generation of renewable resources, some other factors such as load forecasting errors and forced outage of generating units can lead to real-time congestion (RTC) in a microgrid. To implement real-time congestion management (RTCM), some approaches can be employed by the microgrid central controller (MGCC) including network reconfiguration using remote control switches, generation and up-grid power rescheduling and load shedding. In this paper, a two-stage programming model is proposed to find the optimal solution of RCTM under different temperature conditions. Therefore, following an unexpected condition and the occurrence of congestion, at the first stage, MGCC implements reconfiguration as the lowest-cost approach to mitigate RTC. Soccer league algorithm is employed in first stage to find the optimal network topology. Subsequently, based on the obtained results from the first stage, a programming model is applied at the second stage to completely eliminate the RTC. The proposed model minimizes a weighted objective function which includes the generation and up-grid rescheduling cost, load shedding cost and congestion clearing time. To improve the operational planning in unexpected conditions, the allowable congestion clearing time is determined based on multi-level thermal rate due to temperature conditions. The numerical results demonstrate the efficacy of the proposed model.