Using the criterion of technical efficiency for set-up of line distance relay protection

For several years at the Tomsk Polytechnic University the probabilistic methods and algorithms for technical efficiency of the electric network relay protection has been developed. The most representative and reliable results of making losses: refusals of operation, false and excessive actions take place at definition of their expressions as products of probabilities of corresponding conditions (faults on a protected line and in an external network, normal working operational conditions, asynchronous and open-phase modes, etc.) on conditional probabilities of losses in these conditions. The conditional probabilities are formed on the method SBID (selection the borders of intervals of the in and out data) allowing to define the full probability distribution law (PDL) of all determined or random functional dependences of any dimension on one-dimensional PDL of arguments of these dependences. In the case of distance protection line reasonable to approximate PDL response parameter (the measured resistance by distance) to uniform law PDL that has allowed simplifying to calculate conditional probability of the losses and as a whole technical effect. Determining the criteria for technical efficiency is an objective indicator quality of functioning relay protection. Therefore, by its extremum or the nearest approximation to its extremum, determine the meaning and content of each stage distance protection, to determine the optical practical setting of distance protection.