Alternative ways for voltage control in smart grids with distributed electricity generation

In this paper, we have studied different strategies for managing voltage fluctuations in distribution networks originating from decentralized electricity generation systems (DEGS) or increased loads, which are highly important issues in the smart grid context. A starting point for system design when increasing load or local power production could be to limit the voltage fluctuations to +/- 5% from nominal voltage. Strategies to regulate voltage include cable improvement, transformer management, Demand side management, storage, and line interconnection. We present a mathematical model applicable for both a static and dynamic analysis to quantify effects from these measures, though the best solution will depend on local conditions and needs to be determined case by case. Combining several voltage control options simultaneously may lead to further positive effects. Strategies when doubling the load and increasing DEGS production to twice the electricity demand were analyzed here in detail. It also needs to be pointed out that other factors related to power quality besides voltage may need consideration when large amounts of DEGS are integrated to distribution networks. Copyright (c) 2011 John Wiley & Sons, Ltd.