INVESTIGATIONS ON MICRO-PROCESSOR CURRENT DIRECTED PROTECTION OF DISTRIBUTION NETWORK LINES

Abstract

The paper considers a microprocessor current directed protection of lines with adaptive elements and also presents investigations results of its technical modernization. An investigation of the technical modernization pertaining to the proposed protection has been executed while using computer program which is based on mathematical model of 10–35 kV distribution network with two power sources. The protection behaviour has been investigated not only at metallic short circuits but also at short circuits through transition resistance.The investigations have revealed that solutions laid in the basis of the microprocessor current directed protection ensure higher indices of its technical modernization in comparison with the existing analog protection and also a selective action and correct operation in all operating modes of the protected line.