Special issue on microgrids and energy management
Microgrids comprise low and medium voltage distribution systems with distributed energy sources, storage devices and flexible loads, operated connected to the main power network or islanded, in a controlled, coordinated way.
From the customer point of view, Microgrids provide both thermal and electricity needs, and in addition enhance local reliability, reduce emissions, improve power quality by supporting voltage and reducing voltage dips, and potentially lower costs of energy supply. From the Utility point of view, application of distributed energy sources can potentially reduce the demand for distribution and transmission facilities. Clearly, distributed generation located close to loads will reduce flows in transmission and distribution circuits with two important effects: loss reduction and ability to potentially substitute for network assets. Furthermore, the presence of generation close to demand could increase service quality seen by end customers. Microgrids can provide network support in times of stress by relieving congestions and aiding restoration after faults. Clearly these benefits need to be quantified and incorporated into an appropriate commercial and regulatory framework so that a level playing filed can be established.
Technical challenges associated with the operation and control of Microgrids are immense. Effective energy management within micro grids is a key to achieving vital efficiency benefits by optimizing production and consumption of heat, gas and electricity. The coordinated control of a large number of distributed sources with probably conflicting requirements and limited communication is a very challenging problem imposing the adoption of distributed intelligence techniques.
This special issue features 11 excellent papers providing state-of-the-art developments in Microgrids with emphasis on operation management and control issues (4 papers). economic, environmental, and operational effects (7 papers).
The first paper entitled ''Architecture of a microgrid energy management system'' by J. Jimeno, J. Anduaga, J. Oyarzabal and A. Gil de Muro describes the general architecture of a microgrid energy management system (EMS) based on multi-agent system (MAS) technologies providing control of distributed generation and load management. It also describes the implementation of a secondary control system based on the microgrid EMS architecture and its tests on an actual Microgrid in order to assess its performance and demonstrate its applicability.
The second paper entitled ''Advanced control and management functionalities for multimicrogrids'' by A. G.