FIELD: electrical engineering. SUBSTANCE: use: in electric power engineering. Method includes following steps: obtaining computer model of power system (110), receiving from external source in obtained model of measurement values from measurement systems (120), checking the number of measurement points of power or energy flows (130), checking measurement values for presence of coarse errors and excluding such errors (140), establishing relationships (150) between measurement values and values of estimated operating parameters in nodes and branches of the network through a balance model, obtaining data on accuracy classes of measurement systems (160), recording accuracy of iterative calculation (170), minimizing measurement errors (180), returning the value of calculated vector (190) to the user and/or writing to the memory device. EFFECT: technical result is high accuracy of determining mode parameters in conditions of incompleteness of information on power system, as well as enabling use of measurements of currents, active and reactive powers and energies, modules of node voltages.