Optimal re-distribution of demand responsive loads in Microgrids

Abstract

The sudden surge in the fuel cost and increase in environmental impact causes a reduction in electricity generation through conventional energy sources. The power system is moving towards the incorporation of distributed energy resources (DERs) into the existing microgrid (MG). Distributed generation (DG), storage system and geographically scattered loads forms a MG. The stochasticity and unpredictable output associated with DGs may create imbalance in supply and demand. Further, the unexpected peak loads on the system mayjeopardize the system reliability. Hence, proper energy management system is obligatory for peak reduction so as to maintain the power balance. One of the emerging and efficient energy management techniques is demand response. While incorporating demand response, a part of curtailed loads i.e., shiftable loads at peak loads should be re-distributed to other off-peak hours where the load demand and electricity offer price is less. The re-distribution of loads at non-peak hours eventually increases the market clearing price (MCP). Increment in MCP mostly effects the inelastic loads as they cannot shift their schedule from one horizon to another since they are must run loads and of on/off in nature. In this context, the present work focuses on optimal rescheduling of the redistributed loads that doesn’t impact much MCP and operational cost (OC) of the MG much and should able to maintain the dynamic balance between supply and demand. A cost-based method was employed in which grey wolf optimization (GWO) algorithm is used to optimize the OC of the MG.