Adaptive Overcurrent Protection Applied to Power Systems with Distributed Generation and Active Network Management

In this paper, an adaptive protection system applied to distribution electric power systems (EPS) which include distributed generation and active network management (ANM) is proposed. Obtained results provide also coordination and selectivity for all analyzed scenarios, as the possibility to use proposed adaptive protection methodology to indicate the deactivated directional function. Traditional adjustments do not provide an accurate coordination system. Modern techniques of control and operation in EPS have been extremely important to the development of solutions to old EPS problems, like loss of coordination and selectivity in protection systems after topological or operational modifications. Methodologies able to keep all protection devices coordinated after network modifications, provoked by ANM system, are actual and relevant. The benefits of the coupled actuation of these techniques made more evident when small generators have been connected to the power grid, a fact that improves a high level difficult to determine power protection parameters based on overcurrent relays. The obtained results indicate for reductions of up to 45% of the improper operations of protection system when compared to the traditional protection systems.