ABSTRACT
Microgrids now a days stand out to complement traditional wide-area power grids with the advantages of distributed generation and integration of renewable energy sources. But renewable energy sources such as solar, wind and so on generate power intermittently due to continuously changing climatic parameters. The major issues in integrating renewable energy sources with microgrids are faithful operation, efficient control and reduction of harmonics and protection techniques. In order to address these problems, several control techniques have been proposed in the literature. State-of-the-art control techniques include droop control, model predictive control and multi-agent systems. Microgrids usually operate in two modes, grid-connected mode and islanded mode. Once the microgrid infrastructure is setup, a control mechanism needs to be deployed to address the demand and load balancing functions, maintain the quality of power delivered to loads, regulate voltage and frequency for grid-connected systems and so on. Control can be implemented in either centralized or decentralized mode. For effective control of both source and load, the objective functions must be described correctly. Different optimization techniques such as linear programming, non-linear programming, dynamic programming, stochastic programming and so on have been proposed in the past to address economic dispatch conditions. With the development of microgrids, the electrical demand of the world is inevitably prompted towards the acceptance of multi-energy microgrids as an alternative to conventional power grids. It can be foreseen that future power systems will comprehensively be a smart combination of renewable energy sources, adaptive power electronic control and distributed power generation systems. This chapter discusses the development trends in microgrids and their operation and control topologies.
