In the oil industry, autonomous electric power sources containing renewable energy sources are used to power remote consumers with an occasional load, mainly valve assemblies on pipelines. The need for electric energy sources of this type is determined by the need to install valve assemblies at pipeline intersections with water barriers, at intersections with transport arteries, and in a number of other cases. Very often in such places there are no available power lines or substations. In this case, the only alternative is the use of autonomous sources, or the expensive construction of an extended overhead line. In some cases, the developer decides to abandon the overhead line due to its high cost and the need for additional land acquisition. From the point of view of ecology, such a decision in favor of autonomous sources of electric energy also has an additional positive effect. Since the installation of valve assemblies is dictated mainly by environmental considerations, high requirements are placed on the reliability of power supply. Violation of these conditions can lead to hydraulic shocks in the system and possible destruction and breakage of system elements. A wind turbine or solar panels are undoubtedly an independent source of power supply and, when paired with batteries or a diesel generator set, can formally provide high reliability of power supply. On the other hand, there are periods of time when the power of a wind turbine or solar battery is insufficient to supply a given load. As a consequence, the decision on the reliability of power supply should be made on the basis of additional studies of the static and dynamic stability of the entire electrical power generation complex.
Keywords: renewable energy sources, valve assembly on pipelines, ecology, static stability, dynamic stability
The main process of stratum fluid extraction in Russia is mechanized lifting. It is observed that the stock of wells equipped with electric centrifugal pumps units has grown by 50% over the past 10 years, to almost 100,000 units. Growth detected in the average time between overhauls of the oil-well stock during this period increased by 50%, to almost 800 days. Mathematical modeling becomes a tool for further improving energy efficiency and reliability. The purposes of this work is to analyze existing models of submersible electric motors and their area of operations, identify existing shortcomings and limitations, and formulate requirements for the refined model and its application potential. The results of a thermоvisional inspecting of the rotor of a submersible electric motor after long-term operation in idle mode are presented. The temperature dispersion of the rotor packages is recorded from 36.68 °C to 46.67 °C. Different packages temperatures lead to uneven changes in the active resistances of the windings, which affect the contribution of each package to the integral operating and Electromechanical characteristics of the submersible motor. For taking into account the detected effect, it is proposed to model a submersible asynchronous electric motor as an electrotechnical complex consisting of an interacting and mutually influencing set of elementary electric machines. Spatial and mathematical models are presented that take into account temperature fluctuations in individual parts of the electric motor. The results of verification of the mathematical model are presented. Its validity in the field of applicability is shown.
Keywords: electric submersible motor, ESP, rotor pack, mathematical model, thermal processes
The decentralized electric power supply zone occupies about 60-70% of the territory of the Russian Federation. Electric power supply here is carried out using electric generator sets with diesel drive engines. In combination with the difficult logistics of fuel and lubricants materials delivery, this leads to a high prime cost of electricity energy generated. In the capacity of a measures to the costs of electricity reduction, renewable energy sources are used, while maintaining diesel generation as a guaranteed supplier of electricity. Renewable energy is characterized by significant stochastic fluctuations. Based on experimental data, the article shows that the daily load curves of small settlements contain a significant stochastic component, which greatly exceeds the seasonal, daily, and technological components in amplitude. The purpose of this work is to substantiate the structure and parameters of a hybrid energy storage device (HESD) for the synthesis of electrical power generation complexes using renewable energy sources. Spectral analysis using the window Fourier transform is used as a tool. It is established that the energy approach to the choosing of HESD components requires N types of electric energy storage devices, which differ in the ratio: the permissible frequency of the charge-discharge cycle to the cost of the component. As a criterion for choosing the structure and parameter values of a hybrid energy storage device, an estimate is proposed for the levelized cost of electricity (LCOE).
Keywords: hybrid energy storage, electrotechnical complex, renewable energy, daily load curve, spectral analysis, Fourier series