Yaremak I. Multiobjective optimization of steady operation modes of electric drive pumping stations of the main oil pipelines

The thesis is devoted to increase of efficiency and reliability of work of pumping units of oil pumping stations by developing the structure of hierarchical automated system for determining the optimal mode of operation of the main oil pipeline section with the use of multiobjective optimization methods. The analysis of modern automated systems of regulation of operating modes of pumping units of oil pumping stations has been carried out, the main criteria of optimization of their operation have been determined. The complex mathematical model of the electric pumping unit on the basis of the method of electrohydraulic analogy has been developed, which made it possible to combine the models of energy converters of different physical nature and efficiently recalculate the characteristics of the efficiency and reliability of the centrifugal pump and the electric conducting engine, taking into account their technical condition. The parametric identification was carried out by means of the method of the least squares of the polynomial coefficients of the models of efficiency and reliability of pumping units depending on their flow rate duty as the main operating mode parameter of oil pipeline. The functions of one-objective optimization and the global target function of the multicriterial task for the determination of optimal operating modes of the unregulated and regulated pumping unit of the oil pumping station according to the criteria of efficiency and reliability were formalized. The method of visualization of scalarization procedure was developed by considering the angles of "inconsistency" of spatial vector of target functions with respect to the utility axis, which made it possible to simplify the process of making a compromise solution. The structure of the hierarchical automated system for determining the optimal mode of operation of the main oil pipeline section for controlling the flow rate duty of pumping stations with the possibility of its integration into the existing automated control system of the pumping process has been developed, which made it possible to reconcile the control program of the dispatching station and ensure their uninterrupted operation.