Dynamic scheduling of MicroGrid connected system with storage devices

Abstract

Technological development and restructuring of power system have encouraged the Independent Power Producers (IPPs) to connect their Distributed Energy Resources (DERs) to the existing power system. DERs can be used to its maximum efficiency through MicroGrid (MG). This also led to a path for Smart MicroGrid (SMG) where DERs are scheduled and dispatched economically as well as eco-friendly. Due to intermittent nature of Renewable Energy Sources (RESs) in MG and dynamic nature of demand static dispatch of modern power system is not of any use. Thus, it is very important to research economical scheduling and associated dispatch of power system connected with MG. This considers random variations of DERs referred as dynamic dispatch. This paper presents the economic as well as environmental dispatch scheduling of a power system connected to MG composed of different distributed energy resources and storage devices. The overall generation cost of static and dynamic dispatch of proposed system has also been compared. A mathematical model of given system has been formulated considering all the system constraints and ramp rate constraint of generators to minimize the operational and pollutant treatment cost. The optimization study has been carried out in two different modes: (i) Grid connected with MG; and (ii) Isolated grid operation. Mixed Integer Non Linear Programming technique has been used to solve the Unit Commitment (UC) and dispatch problem. The influence of scheduling strategies on operational cost and pollutant treatment cost has been obtained and compared and the impact of MG interconnection with the power system has been shown in terms of operational cost, pollutant treatment cost, total cost and on the unit commitment of power system to reduce the burden on grid generators.