An overview of the present grid codes for integration of distributed generation

Power systems are passing through profound changes, mainly due to the liberalization of electricity markets, the depletion of primary energy resources and the concern about climate change. The aforementioned premises have created a favorable frame for development of distributed energy resources. As a result, the level of integration of distributed generation (DG) technologies, especially in distribution networks has increased. In order to counteract the impact of DG on the stability and reliability of power systems, the transmission and distribution systems operators have started to reconsider and update their national grid codes. This paper provides an overview of the most recent and comprehensive grid codes regarding the DG integration at distribution level.