Adaptive Protection for a Microgrid with PV Generation

Distributed generation has proved to be a successful inclusion to the conventional electrical power network and it has led to the development of microgrids. Microgrids are smaller power grids that may operate connected to a utility network or they can operate as a stand-alone network, because of this ability, it is known to have two modes of operation. Protection systems for a microgrid are different to those in conventional grid. For the different operation modes the protection relays will see different fault characteristics and it is important that relays can operate efficiently in both modes. In order for the protection to be effective it must be adaptive and allow for variable fault conditions. The aim of this paper is to present and investigate innovative ways to protect a microgrid containing a Solar PV generation plant. This paper is developed in such a way that abnormalities caused by faults and system operations are explored. In order to cover the aspect of adaptive relaying, only digital relay configurations are considered for modelling and simulating the scheme. The proposed protection scheme is a representation of the use of different types of relays working together in a system to protect a Microgrid and its components.