Distance protection relays installation prioritization in distribution networks using analytic hierarchy process and cost-benefit analysis

摘要

Due to the increasing low capacity distributed generators (DGs) installations and penalization of supply disruptions in electrical distribution grid, it is necessary to invest in the distribution protection system. This paper discusses profitability of installation of relays with distance protection function that could protect lines of different voltage levels, lengths and other relevant attributes. The aim is to determine which lines are worth protecting with distance protection and according to that, order of investment by multi-criteria decisionmaking method - analytic hierarchic process (AHP). The first part is an introduction where the circumstances, potential benefits and problems that may arise in distribution grids are presented. This is followed by theory of distance protection and analytic hierarchy process. The final part describes the criteria that should be considered and the way of applying the AHP method with a real example from Croatian distribution grid.