Methodology of investments for medium voltage networks and improvement of reliability indices

This paper presents an evaluation methodology of investments for medium voltage networks and improvement of reliability indices, as proposed by ANEEL (Brazilian Government Regulation Agency), in Resolution 024/2000. This methodology considers operation and maintenance actions as alternatives to expanding the electrical system. This objective is accomplished by using an aggregate investment planning methodology that proposes appropriate modeling concerning: the network and the load representation, the evaluation of the operational performance and the network expansion model. In this model the following operation and maintenance actions were included: tree trimming, compact network installation, recloser installation, network rebuilding, lightning-arrester (maintenance actions); and increasing of maintenance teams. These actions allow the improvement of reliability indices. The competition between expansion reinforcements, operation and maintenance actions is carried out by a benefit/cost evaluation, which was expressed by the Initial Profitability Rate of Investment (IPRI), limited to the annual budget.