For the systems engineer, there are no typical microgrid projects. Every client has unique needs and a very personal vision of what the finished product will look like and can do.
However, there are principles common to all microgrid projects that systems engineers need to understand. One of those principles is energy management system (EMS).
In microgrids, an energy management system is essential for optimal use of these distributed energy resources in intelligent, secure, reliable and coordinated ways. And EMS guarantees a secure operation of an islanded microgrid under possible imbalances between generation capacity and loads demand. The EMS performs an optimal calculation of low priority loads to be shed, as well as charging and discharging cycles of batteries within the microgrid.
A nonlinear model‐predictive control (NMPC) algorithm is selected for implementing the EMS, which processes a data set composed of loads measurements, generation capacity, batteries state of charge (SOC), and a set of operation constraints. The EMS is designed under the assumption of having an advanced metering infrastructure (AMI) installed in the microgrid.
The EMS is tested in a simulation platform that integrates models of the microgrid components, as well as their distributed controllers (DCs). Simulation results show the effectiveness of the proposed approach, since critical variables as the microgrid’s frequency and voltage magnitude operate within a secured interval even under the presence of faults in one of the DCs.
In order to achieve optimal operation conditions in a microgrid with Energy Management System (EMS), a communication system is needed. It is important to consider in-depth different characteristics of communication systems regarding issues like determinism, time constrains, cost effectiveness etc.
Also, the uncertain nature of renewable energy sources such as wind and photovoltaic generations, market prices and loads has led to difficulties in ensuring power quality and in balancing generation and consumption. To tackle these problems, many experts in the field believe that microgrids should be managed by an EMS that facilitates the minimization of operational costs, emissions and peak loads while satisfying the microgrid technical constraints. Over the past years, microgrids’ EMS have been studied from different perspectives and have recently attracted considerable attention of researchers.
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