DOC11.1

EXECUTIVE SUMMARY

The aim of the DER-IREC 22 @ Microgrid project is to implement a micro grid at IREC facilities in Barcelona, which is connected to ENDESA’s distribution network and incorporates the electric vehicle as specific load.

The present deliverable DOC11.1 entitled “Preliminary study of the micro grid” has been produced as part of work package PT110, which studies the design of the micro grid. PT110 package is part of overall work package PT100, coordinated by CIRCUTOR, which main objective is to study the measurement and control of the assets of the micro grid.

Firstly, this document describes the elements that are already installed in the current micro grid. This current micro grid consists of 3 AC/DC converters, connected to the main grid in the AC side and connected to emulators in the DC side.

These emulators consist of another 3 AC/DC converters that simulate any situation, emulating the performance of the real system they are replacing. Therefore, each converter can connect to the grid elements of different nature. Three types of functions have been considered: generation emulator with different types of generation such as wind or solar systems, energy storage emulator as required for either conventional battery or for an electric vehicle, and finally load emulator. These three systems are the minimum elements needed to represent all possible scenarios present in a real micro grid. Moreover, these converters can be adjusted within considered power limits, allowing adjustment of active or reactive power.

The great advantage of using emulators instead of real systems is that you can create all needed scenarios without having to wait, for example, for appropriate weather conditions. Another advantage of the configuration used is that the consumption of the emulated loads is returned to the main grid, consuming from the grid only the losses associated with the testing system.

Within the DER-IREC 22 @ Microgrid project it is planned to expand the current micro grid with real generation or consumption instead of using emulated elements. New items that will be added to the micro grid are: photovoltaic generation, micro wind turbine generators, battery storage system, supercapacitors, and recharging points for electric vehicles. This extension will allow the micro grid to work in island mode, but only in case that an element that can act as a voltage source will be installed.

In this document it has been also proposed a topology for the wiring of the micro grid. The proposed topology allows working independently with two subparts of the same micro grid, one with the three emulators and the other with the real generations and consumptions. In addition, when batteries can act as voltage source, the proposed configuration allow working with any of the two subparts in islanding mode separately from the rest of the micro grid.

Finally, models that describe the operation of elements present in the micro grid are also explained. These models will make possible future simulations that will be used to validate control strategies developed during the project.