Adaptive Protection of Distribution Grids with Distributed Generation

Due to development of modern distribution systems, distributed generation (DG) has become more important. Since circuit breakers are not used in distribution systems, protection of these systems has raised some problems which are mostly due to malfunction of circuit breakers and lack of coordination between them. That is, if a fault occurs, some parts of the grid may be separated from the main grid which may not be faulted. In this paper, the division of power grid by disconnection of circuit breakers in the vicinity of fault is discussed. An algorithm for removing one-phase and three-phase faults is obtained and tested using PSCAD software. An adaptive method is also proposed which considers the effects of distributed generation and is independent of its rating, type and place.