Techno-Economic Performance Evaluation of Photovoltaic based Micro-Grid with Energy Management Strategies

Abstract

The operational performance of grid connected micro-grid system can be affected by many factors e.g. techno-economic sizing, appropriate energy management strategy, geographical locations, grid constrains and electricity energy pricing dynamics. To make renewable energy based micro-grid system more reliable as well as efficient and economically viable, it is imperative to consider a holistic approach and investigate all these factors for design and operation of the micro-grid system. In this work, techno-economic sizing of distributed generator(s) with energy storage are analyzed for operating grid connected PV based system as a micro-grid, even during the possible grid outage period. Energy management strategies have been proposed and evaluated for improving techno-economic performance of the PV based micro-grid system. Performance of the micro-grid system can be significantly improved using appropriate energy management strategies for maximizing the use of local energy resources and battery energy throughput. Impact of electricity energy pricing dynamics has been analyzed for techno-economic operation of the grid connected PV based micro-grids at the selected geographical locations (i.e. Tropical and Nordic climates). The local grid limits on the operation of the micro-grid system has been evaluated for maximizing the local energy resources utilization with consideration of peak demand and energy pricing. The regional energy pricing dynamics and local grid limits have considerable impact on performance of the PV based micro-grid. The maximum penetration of PV based micro-grid (i.e. hosting capacity study) within the distribution power network has been assessed considering the network constraints (e.g. voltage or/and loading of the power lines, etc.) and they have significant impact on PV capacity installations at different buses. The increasing penetration of PV based micro-grid system affects the voltage quality within the distribution network. The reactive power versus voltage (Q-V) droop control technique has been evaluated for managing the voltage profile within the prescribed limits. The Q-V droop function has been implemented in the PV inverter and tested its operation using the real time digital simulator and power hardware- in- loop method for improving the voltage profile within the distributed network. The presented results in this work are going to be useful for promoting the PV based micro-grid within the distribution network.