This article considers and develops a method for identifying the parameters of mathematical models of electromechanical consumers of regionally isolated electrotechnical complexes. The validity of the proposed method application to identify parameters to determine influence of consumer characteristics on the quality of electrical energy at the point of common coupling is shown. The description of the mathematical model of the electrical energy distribution point consisting of several consumes is shown. The mathematical model is developed in the Cauchy normal form. A modification of the Marquardt method is proposed as an identification tool.

There is considered probabilistic forecasting of the most important characteristics of sudden power supply interruptions — damage and downtime of electromechanical and heat-and-power equipment — for process plants typical for installations of a regionally isolated electrotechnical complex. These specifications are considered as random functions of the power supply interruptions duration. A feature of the specifications considered is the presence of finite jumps when the power supply exceeds the critical values. Generalized theoretical equations are obtained for continuous functions of mathematical expectation and variance of process downtime and damage when there is any number of finite jumps of certain implementations and there is consideration of the discontinuity points as random variables with different distribution laws. The obtained specifications are used to optimize the cost of creating power supply systems considering their reliability.