Insulation coordination of MV power cables

In medium voltage power cables, the concept of costlreliability has been current since the end of the 1980s when the Brazilian Standards introduced ethylene-propylene-rubber (EPR) insulated cables, with different thicknesses of insulation for conventional cables and for those with blocked conductors or with water tightness consbuctions. However, despite the benefits obtainable by use of such cables, they have had limited use by electrical power utilities, perhaps because the concept has not become widely recognized. This paper intends to clanfy and submit a new approach for design the dielectric system of medium voltage cables, for use in underground and insulated overhead distribution feeders. Theoretical aspects of s i z i i the dielectric system, by means of coordinating the insulation, and also using reliability parameters, will be dealt with herein. Results of practical applications are also presented and discussed.