Microgrids

5

Operation of Multi-Microgrids

João Abel Peças Lopes, André Madureira, Nuno Gil and Fernanda Resende

5.1 Introduction

This chapter aims to study the management of distribution networks with an increased microgrid penetration, that is, corresponding to a situation where most of the low voltage (LV) networks turn into active microgrids. It is therefore assumed that the microgrid concept is extended, leading to the development of a new concept – the multi-microgrid [1]. A full exploitation of this concept involves the design of a new control architecture as well as the development of new management tools or the adaptation of existing distribution management systems (DMS) tools.

The novel concept of multi-microgrids corresponds to a high-level structure, formed at the medium voltage (MV) level, consisting of several LV microgrids and distributed generation (DG) units connected to adjacent MV feeders. For the purpose of grid control and management, microgrids, DG units and MV loads under active demand-side management control can be considered as active cells in this type of power system. In this new scenario, the possibility of having some MV responsive loads able to receive control requests under a load curtailment strategy is regarded as a way to ensure additional ancillary services.

A large number of LV networks with microsources and loads, that are no longer passive elements of the distribution grid, then need to be operated together in a coordinated way. Therefore, the system ...