Micro-grid-Based Active Distribution Grids

Driven by economic, technical and environmental reasons, the energy sector is moving towards a new era of "Smart Active Distribution Systems" where clusters of converter-based distributed generation (DG) units, local loads and other filtering devices form micro-grids (MG), which can be regarded as the building blocks of future active distribution grids. However, several undesirable interaction dynamics could occur between the DG converters, which are usually equipped with high-order LC or LCL filters and system components such as power-factor correction capacitors, static and dynamic loads. Moreover, the lack of coordination between DG entities in single and multiple micro-grid systems results in inaccurate power sharing, frequency deviation and system instabilities.To solve these problems, this dissertation provides detailed modeling, analysis and control of micro-grid systems with compromised voltage or power stability issues due to system uncertainties in presence of different types of loads, electronic devices or line parameter variation. Several robust converter- and system-level control interfaces are also proposed to mitigate such stability challenges.