Chapter 6 - Experimental Evaluation of Urban Direct Current Microgrid

Abstract

The development of microgrids reveals the importance of the smart grid for the next years by smart grid implementation, which is designed to meet these requirements as reducing public grid peak consumption or avoiding undesired injections and optimizing energy cost for the end user and the public grid operator. This chapter presents the experimental results for the proposed direct current microgrid controlled by the multilayer supervisory structure described in chapter “Direct Current Microgrid Supervisory System Design”. As the photovoltaic array (PVA) power predictions, the solar irradiance hourly forecast provided by the national weather forecasting service is used. The energy management layer takes into account the PVA predicted power and predicted load power (always arbitrary profile) while satisfying constraints such as storage capability, grid power limitations, grid time-of-use pricing, and grid peak hour. Experimental results show that the proposed multilayer supervisory structure is able to control the power flow at near optimum cost and ensures self-correcting action capability. However, the optimization effect relies largely on the precision of previsions. Even with uncertainties the experimentally obtained real-time power flow has shown the features of optimization in reduced grid peak or fuel consumption, avoiding undesired grid injection, and making full use of the produced energy with respect to all constraints. The feasibility of implementing optimization in real-time operation while respecting rigid constraints by proposed control is validated.