Optimal energy management in microgrid including stationary and mobile storages based on minimum power loss and voltage deviation

Abstract

The grid-connected microgrid (MG) may depend on the utility grid (UG) during peak load hours to meet its unequaled load demand. Also, the rapid increase in penetration of plug-in hybrid electric vehicles (PHEV) affects the system's stability and the load demand. Therefore, it is an indisputable fact that MG demands, an effective energy management strategy to manage the peak load that occurred due to PHEV charging. To address this challenge, an optimal energy management strategy (OEMS) is proposed that aims at maximum utilization of DERs, promotes energy trading, and diminishes the dependency of MG on UG. It is achieved by optimizing the energy exchanged between MG and UG with simultaneously minimizing the active power losses (APL) and voltage deviation (VD) of a MG. Further, a state flow-based coordinated charging/discharging scheduling algorithm is also proposed to improve the performance, lifetime, and utilization of an energy storage system. The performance of OEMS is evaluated for different PHEV penetration levels (EVPL) and simulation results are compared with the recently reported strategy. The obtained results reveal that the proposed OEMS is superior to other strategy as it fulfills the MG's load with the minimum APL and VD and by optimally feeding energy to the UG it increases the MG operator's (MGO) profit in the range of 8.4%–13%. Lastly, the peak load management of MG is achieved and the efficacy of OEMS is further improved by introducing Governed charging/discharging mode of PHEVs in the system. The economic analysis discloses that OEMS with GCDM has increased the MGO's profit by 10.8%–29.5% depending on EVPL.