A review of protection systems for distribution networks embedded with renewable generation

The rapid growth of grid-connected embedded generation is changing the operational characteristics of power distribution networks. Amongst a range of issues being reported in the research, the effect of these changes on so-called 'traditional protection systems' has not gone without attention. Looking to the future, the possibility of microgrid systems and deliberate islanding of sections of the network will require highly flexible distribution management systems and a re-design of protection strategies. This paper explores the envisaged protection issues concerned with large penetrations of embedded generation in distribution networks extending into auto-reclosure and protection device coordination. A critical review of recently reported protection strategies for grid-connected only and microgrid operation is also undertaken. The outcome is a list of recommendations to achieve microgrid protection adequacy in future networks.