THE PURPOSE. To investigate the problem of evaluating the energy-efficient operation of low-voltage switching devices installed in electrical complexes, to analyze the current state of the Russian market of electrical devices and to develop an algorithm and models of the main technical characteristics of circuit breakers of electromagnetic starters and contactors of various manufacturers.

METHODS. In solving this problem, the ratio of the nominal current of the device and the resistance of contacts and contact connections of devices of some manufacturing plants is investigated. The analysis of experimental data showed what kind of functional dependences of contact resistances on the rated current have.

RESULTS. Approximating functions have been developed based on the results of experimental studies of the value of contact resistances from the main nominal parameters of automatic machines, electromagnetic starters and contactors of some manufacturers.

CONCLUSION. The article develops an algorithm and models for evaluating the energy efficiency of operation of low-voltage electrical devices, allowing to specify the amount of power (electricity) losses in equipment and recommended to increase the reliability of calculating electricity losses in low-voltage networks of electrical complexes.

THE PURPOSE. The main purpose of the study is to develop the calculation algorithm of energy efficiency indicators. To develop an algorithm, it is necessary to consider the features of the power supply system of the oil and gas production enterprise. Then, the power and electricity balance calculation algorithm should be designed to evaluate the share of the technological processes’ consumption, analyze losses, and determine the source of imbalance. The assessment of energy efficiency indicators will require adaptation of the parameter’s identification method for rotating electrical machines in operating modes. To calculate the specific equipment energy, it is necessary to use power tracing in the algorithm. The final stage is to develop a visualization of a software prototype for monitoring and control energy efficiency indicators of an oil and gas production enterprise.

METHODS. The equipment parameters identification method based on actual measurements is used for designing a mathematical model. To calculate the steady-state, the nodal-voltage method is used in couple with an addressing matrix for tracing power flows.

RESULTS. The paper proposes an algorithm for calculating energy efficiency indicators of equipment for an oil and gas production enterprise. The algorithm is based on the processing and analysis of actual data from the electricity metering devices installed at the enterprise. Analysis of the power consumption information together with the oil production indicators will reveal the most efficient operating mode of the equipment. The calculating algorithm for the specific electricity consumption is considered in the example of a typical hierarchy of metering devices at a field. Further, the paper discusses the possibility of applying the targeting flow distribution principle for reducing power losses. A parameters identification technique is presented for multi equipment nodes to assess energy efficiency and monitor operating parameters.

CONCLUSION. The algorithm considered in the paper was introduced into the information system of the production control center at the field as an additional module for assessing energy efficiency. The large deviation of the indicator's values from the specified ones is messaging about the equipment's normal mode violations. It allows creating an optimal schedule of organizational and technical measures to regulate energy consumption and improve the energy efficiency of the enterprise.

THE PURPOSE. Investigation of the time structure forthedistortion source identification of the electric power quality and a method for its reduction using of a mobile software and hardware instrumentation system.

METHODS. The analysis of the number of complaints regarding low-quality electric power, the structure and values of the time spent on the identification of the distortion sources of the electric power quality indicators (PQI) for the standard values, taking into account all its components, was carried out.

RESULTS. It is determined that the number of complaints received by the power grid company regarding lowquality electric powerremains high. At the same time, it takes a long time to identify the distortionsource before putting in place the necessary remedial measures. According to the analyzed data, it can take up to 21 days. The number of cases when the distortion source of the PQI couldn’t be detected within two days was 117 cases of 419 analyzed. The solutions to reduce this time are proposed.

CONCLUSIONS. The solutions presented in the article make it possible to reduce the time spent on the source distortion identificationofthe PQI due to the use of a mobile hardware and software instrumentation system (HSIS). A variant of the HSIS structure is proposed, which includes sensors and the HSIS central unit. The proposed HSIS can be used in the absence of external communication channels through the use of data transmitted from the sensors of the system to the central unit using Long Range (LORA) or Wireless Fidelity (Wi-Fi) technologies. In addition, the HSIS provides time synchronization of all the sensors.

THE PURPOSE. Broadband passive filters (BBF) are an effective measure to mitigate harmonic resonance in power systems with nonlinear harmonic producing loads. The disadvantage of simple second-order broadband filters are pure selectivity and excessive fundamental frequency losses. This is especially evident in devices designed for low-order harmonics mitigation. This paper presents new broadband filter configurations with superior performances and low fundamental frequency losses.

METHODS. A general method of broadband passive filter design is considered. The filter has the form of single-loaded ladder LC-two-port. Conditions of minimal fundamental frequency loss of the filer are determined.

RESULTS. This paper presents new broadband filter configurations with superior damping performances and low fundamental frequency losses. Different broadband filter configurations are compared. The results show that 3-5 order broadband ladder filters have better filtering performance and lower power loss than traditional C-type filters.

CONCLUSION. The proposed broadband filters can be used for industrial power systems with powerful nonlinear loads. This will normalize the power quality and at the same time improve the energy efficiency of compensating devices.

THE PURPOSE. Development of a methodology for modeling the modes of power supply systems for railways equipped with devices to improve the quality of electricity in the networks supplying stationary objects of railway transport. Two design solutions were considered that ensure the reduction of unbalance and voltage deviations on the 0,4 kV buses of substations supplying these objects. The first of them was based on the use of suction transformers, and the second - on the use of lines with a grounded phase.

METHODS. The studies were carried out using the Fazonord software package, which provides complex modeling in phase coordinates of the modes of power supply systems.

RESULTS. The results obtained made it possible to draw the following conclusions: when using suction transformers, which were included in the rail cut, the average value of the unbalance coefficient in negative sequence on the 0.4 kV buses of the object's substation decreased by 2,5% compared to the absence of such devices; in the presence of transformers, which were included in the return wire, this indicator decreased by 19%. The use of lines with a grounded phase instead of a two-wire-rail line made it possible to improve the quality of electricity on 0.4 kV buses, while the maximum of the unbalance coefficient in the negative sequence was reduced by 40%.

CONCLUSION. On the basis of computer modeling, it is shown that the use of suction transformers with a return wire and 25 kV lines with a grounded phase makes it possible to improve the quality of the electric power industry in the power supply systems of stationary objects of railway transport.

THE PURPOSE. Consider the structure of the centralized and autonomous power supply system for gas field (GF) №1 of «Gazprom dobycha Yamburg» LLC. Perform the calculation of the main energy indicators (consumed active, reactive and apparent power, power factors, reactive power factors) for each section of busbars (SB) of complete transformer substations (CTS) according to wattmetrograms taken by electromechanical meters on the linear cells of closed switchgear (CS) during a calendar year. Calculate the peak current of a group of electric receivers (ER) for each CS CTS. To analyze the features of the functioning and the load factor of the autonomous power supply system from diesel power plants (DPP) according to the schemes: “one generator - a separate group of electrical consumers” (EС-1) and a single generation center with a cascade (ring) switching circuit (EС-2). Compare the annual fuel consumption of diesel power plants with EС-1 and EС-2 by monthly load factors.

METHODS. When solving the problem, an approximate method was used to determine the energy indicators of electrical loads at each CS CTS and the load factors of DPP according to the readings of active power (wattmetrograms) for the period under consideration.

RESULTS. The article describes the relevance of the topic, considers the features of the construction and functioning of the EC for a centralized and autonomous power supply system. An approximate calculation of the energy parameters at the each CTS SB of the integrated gas treatment plant (IGTP) and the booster compressor station (BCS) was made based on the readings of the active power consumed during the period under consideration. This article discusses the fuel and energy characteristics and features of the functioning of DPP. The monthly and annual weighted average load factors were calculated and the peak currents of the ER group were determined for each DPP. The calculation of the annual fuel consumption of DPP with EС-1 and EС-2 has been made according to monthly load factors.

CONCLUSION. As a result of the analysis of the structure and energy characteristics, the features of the functioning of the centralized and autonomous power supply system were revealed, which determine the range of problems and shortcomings that require further research and study, with the subsequent development of a set of measures to improve the energy efficiency of the EC.

THE PURPOSE. Investigation of the control system of the cargo movement mechanism when using different variants of sensorless control. The search for the optimal option, in which the formation of the speed is identical to the data obtained from the speed sensor. Analysis of the results obtained during the study, including the results obtained taking into account the heating of the motor windings.

METHODS. The tasks set during the research are implemented by simulation modeling using the Matlab Simulink computer simulation environment.

RESULTS. The article considers systems with different types of velocity observers. A system is implemented that takes into account the heating of the stator and rotor windings of an asynchronous motor, in which a non-adaptive observer and different types of neural network controller were introduced. A combined method of using neural network regulators is proposed.

CONCLUSION. Sensorless control systems are relevant for use in industries with the presence, according to the conditions of the technological process, of high temperatures. The conducted research has shown that the use of neural network technologies allows you to work with settings of different levels and types. The proposed method, implying the use of joint work of neural network observers with various neurostructures, allows for speed testing in the entire range. The connection with cloud storage present in the proposed structure leads to the unloading of the management system, allowing to increase the process of analyzing data coming from the object.

THE PURPOSE. Consider the use of special purpose vessels with a dynamic positioning system. To conduct observations and research of the operation of electrical power systems of such vessels for the existence of problems in them that affect the performance of technological operations. To propose methods and means aimed at eliminating situations and processes that adversely affect the operation of shipboard electrical power systems when laying pipelines.

METHODS. For observation and research, the unified electrical power systems with electric rudder propellers and a system for laying an underwater pipeline of the "Seven Vega" cable layer was considered. Collected information on all the main electrical systems of the vessel "Seven Vega". Experimental studies were carried out aimed at studying the operating modes of the electrical power system during the laying of pipelines.

RESULTS. Experimental oscillograms of currents of parallel operating diesel-generator sets in different modes have been obtained. The existence of power exchange oscillations during the operation of the unified electric power system of the cable-laying ship “Seven Vega” is noted. The data on the negative influence of power oscillations on the operation of tensioners during the laying of underwater pipelines were obtained.

CONCLUSION. The use of sea-going vessels with dynamic positioning for laying pipelines and performing oil and gas production operations requires ensuring the operation of their electrical power systems. To ensure the high-quality operation of tensioners in pipeline laying systems, it is necessary to ensure the adjustment of their regulators and to exclude the occurrence of power exchange oscillations during parallel operation of generator sets.

PURPOSE. Asynchronous motors are the main consumers of the electrical energy. Increasing their energy performance can contribute to a significant reduction in energy consumption in general. Using a combined 12-zone winding instead of the standard 6-zone one theoretically can lead to a decrease in electrical losses in the stator winding of the asynchronous motor and to reduce additional losses caused by the higher spatial harmonics. The main purpose of the work is to assess the effect of using a combined winding stator on the energy characteristics of the induction motor.

METHODS. The study was performed on two AIR71V4 electric motors, one of which had a standard winding and the other had a combined winding. In the experiment, the engines were rated voltage, and the load was carried out using an electromagnetic loading device. The engines were tested in the range of loads from idle to the nominal. The experiment was performed five times.

RESULTS. The work under analysis shows the dependences of the current strength, consumed active and reactive power, efficiency, and power factor from engine load.

CONCLUSION. The results of the study showed that an asynchronous motor with the combined winding over the entire investigated range of loads has a lower consumption of both active and reactive power, compared to a motor with a standard winding, while the power factors of these motors are practically the same. The greatest difference in efficiency was observed at loads lower than the nominal in favor of an improved engine model, but also at rated load, the motor with a combined winding has the higher efficiency of 3,1%.

THE PURPOSE. In modern control systems of various industrial units, the basis for the automation of technological processes is an electric drive. High requirements for the quality of the control process determine the formulation and solution of scientific and practical tasks for the development and creation of new promising control systems for electric drives (EDCS), allowing to maintain the required quality of functioning under the influence of destabilizing factors. These factors can affect the control system in the form of external disturbances and be summed up with the corresponding signals of the closed EDCS, and also be expressed in the form of parametric disturbances. The need arises to create such a control system that will allow for the identification of the parameters of the EDCS by introducing the appropriate identification algorithms into its structure.

METHODS. When solving the problem, a search-free gradient method of adaptive identification was used, implemented by means of the MatLab software environment.

RESULTS. The paper considers the problem of parametric identification of an electric drive with a DC motor based on the definition of sensitivity functions. Wherein to construct an algorithm for parametric identification, an inverse model of the studied EDCS is used, the quality indicator is the squared discrepancy, and the identifiable parameter is the overall transmission coefficient of the electric drive.

CONCLUSION. Modeling in the MatLab software environment showed a high robustness of the developed identification algorithm to parametric disturbances that do not affect the steadystate value of the identified parameter. The proposed method for compensating the moment of resistance electric drive also made it possible to provide a low sensitivity algorithm to external disturbances. The identification of the overall transmission coefficient of a DC electric drive is carried out with an error not exceeding 0.5% in real time under the conditions of the influence of disturbances of various physical nature.

THE PURPOSE. With the help of data from smart electricity meters, an analysis of the profiles of electrical loads of commercial organizations that are part of apartment buildings was carried out. The results obtained are compared with their current standard values. New values of specific electrical loads for public premises are considered: pharmacies, grocery and manufactured goods stores, catering establishments, office premises.

METHODS. Half-hour load profiles were obtained from intelligent electricity metering devices installed directly at the objects under study, data transmission was carried out by an automated electricity metering system. The observation intervals were several tens of days. To process the experimentally obtained data, statistical methods for the analysis of electrical loads were used.

RESULTS. The article describes the relevance of the topic, presents the profiles of electrical loads of public premises with the highlighting of characteristic features separately for each group of electricity consumers. New specific design electrical loads are considered, including an analysis in comparison with existing standards.

CONCLUSION. The calculated values of electrical power in order to ensure technological connection for public premises, including social and cultural facilities, must be updated, since today there is a significant difference between the actual and calculated according to regulatory documents electrical loads. Updating the specific design electrical loads of public premises will reduce the locked capacity of these facilities, at the same time reduce the cost of technological connection, thereby increasing the rating of the investment climate in the region.

The article proposes a solution to the problem of optimizing the magnetic system design of a low-speed synchronous motor with permanent magnets (PMSM) as a part of a linear drive of a single-stage piston compressor that is promising for use in compressor construction for a given law of motion of the moving part. The maximum efficiency of the electromechanical converter is used as an optimality criterion. By solving the optimization problem, the relationship between the design parameters and the energy performance of the PMSM was established in an analytical form. The substantiation of the maximum possible efficiency of the PMSM for the sinusoidal and non-sinusoidal laws of motion of the inductor is given.

PURPOSE: Obtaining a solution to the problem of optimizing the magnetic system design of a low-speed PMSM as a part of a linear drive of a single-stage reciprocating compressor for a given law of motion of the moving part that meets the criterion of maximum efficiency of an electromechanical converter.

METHODS: The methods of the theory of electromechanical energy converters, theoretical electrical engineering, mathematical modeling, optimization methods, variational, differential and integral calculus, as well as experimental methods are used.

RESULTS: The results of an experimental study of the developed prototype of a low-speed SDPM as a part of a linear drive of a long-stroke single-stage reciprocating compressor are presented.

CONCLUSION: The highest efficiency of the PMSM is achieved when the current in the armature winding changes with time in direct proportion to the speed of the inductor. To ensure this mode, it is proposed to use an open-source frequency converter, which makes it possible to implement the time dependence of the current in the armature winding in accordance with the given law of motion of the moving part. The PMSM is controlled by a frequency converter based on structural models created in the MexBios environment.

THE PURPOSE. Modern requirements for electric drives impose increasingly stringent conditions for energy efficiency, dimensions and weight. The weight and size parameters are especially noticeable in relation to the rapidly developing electric transport. The achieved technological limits practically do not give tangible results in improving the characteristics of known structures, so there is a struggle for units of percent and fractions of a percent in terms of increasing the efficiency of equipment.

MATERIALS. Debugging and fine-tuning of electric drive elements requires numerous tests on research benches using measuring channels and analog-to-digital conversion (ADC), digital-to-analog conversion (DAC), digital-to-digital conversion (DDC).

RESULTS. The creation of research stands implies the development of a hardware-software complex (HSC) based on high-speed computing devices. The structure of the HSC included the developed frequency converter with the possibility of adjusting the algorithms for controlling the electric motor and the mathematical model of the electric motor itself. The object of experimental research was prototypes of electric drives based on asynchronous electric motors with a squirrel-cage rotor and a combined stator winding.

CONCLUSION. The article discusses ways to organize the measuring and control channels of the measuring and information system of the research stand, which makes it possible to study samples of asynchronous electric motors in idling and under load modes.