Problems of Constructing the Distribution Network Relay Protection System under Market Economy Conditions

Abstract

The influence of the Russian Federation electric power industry market mechanisms on the operation of the distribution network relay protection system is analyzed. The normative and legal documentation regulating the interaction between various electric power industry entities is studied, and the cause of a problem affecting the construction of the distribution network relay protection system is pointed out. To confirm this hypothesis, an example with connection of a 10/0.4 kV transformer substation is considered. The actuation parameters (current and time) are calculated both for the 10 kV relay protection and 0.4 kV circuit breakers with electronic releasing devices installed in them. The calculation results were used to compile a protective devices selectivity map, based on which areas with non-selective actuation of the transformer substation protection system have been identified. Recommendations on eliminating the current situation associated with limiting the maximum time delay from the transformer substation power supply side are given.