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The article deals with the issue of ensuring the sustainable operation of ship electrical power systems. Experimental oscillograms of power exchange and in-phase oscillations during parallel operation of diesel generator units are presented. The results of mathematical modeling allow us to conclude that it is necessary to limit the change in the values and ratios of the transmission coefficients of the governor. It is proposed to limit the change in the transmission coefficients of the governor when eliminating power exchange oscillations.

Unmanned seagoing vessels are increasingly being used. In the paper the dump scow Rabochaya is considered as an example of an unmanned vessel. An extended marine control system, a video surveillance subsystem, a surveillance and search engine are additionally installed on the scow to carry out industrial tasks in unmanned mode. The correct operation of these systems and the whole vessel depends on the high-quality operation of the ship's electrical power system. The aim of the study is to identify abnormal modes of parallel operation of marine diesel generator sets and to develop methods and means for their elimination. The results of the experimental research and mathematical modeling have revealed the existence of power exchange oscillations when the ship generators operating in parallel. Power exchange oscillations can be detected with the help of generator current oscillations. It has been proposed to introduce a unit for eliminating power exchange oscillations (EPEO) into the automatic control system of ship electrical power systems for eliminating such oscillations. An algorithm for the operation of the EPEO unit has been developed, it controls the settings of the rotational speed regulators of diesel-generator sets. The proposed methods and tools reduce the amplitude of power exchange oscillations to an acceptable value, and therefore contribute to the high-quality operation of the ship's electrical power system and control systems in unmanned mode. The results obtained make it possible to ensure reliable and trouble-free operation of any autonomous electrical power system during the operation mode without maintenance personnel.

THE PURPOSE. Consider the issue of the presence of distortions in the form of sinusoidal voltage and current in autonomous electrical power systems with electrical propulsion systems, built on the principle of the unified electric power system. Compare the results of the study of voltage distortion for electrical power systems with electrical propulsion systems of various structures and give recommendations for their application.METHODS. For research, unified electric power systems with DC electrical propulsion systems on the Yeysk ferry and alternating current on the asymmetric icebreaker Baltika are considered. The possibilities of programming with frequency control of modern drives of rudder propellers with AC motors are analyzed.RESULTS. Oscillograms of voltages and currents of generators were obtained using thyristor converters and inverters to control electrical propulsion systems in various modes. Significant ripples and distortions of the sinusoidal voltage and generator currents were noted when thyristor converters are used to power DC propulsion electric motors. Also, small deviations from the sinusoidal form of the ship's network voltage were recorded when inverters were used to control AC propulsion motors as part of rudder propellers.CONCLUSION. The issue of ensuring the quality of electricity produced in autonomous electrical power systems of sea vessels is of great relevance and importance. To ensure the best results, it is advisable to use azimuthing podded drive with AC electric motors, the rotation speed of which is implemented by inverter frequency converters with a DC link.

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.

THE PURPOSE. Consider the use of propeller electric installations as part of ship electrical complexes with a single electric power system. Highlight the rudder drives as a special type of electric propulsion of ships in northern latitudes. Investigate unified electric power systems with a propeller electric installation for the existence of power exchange oscillations in them. Propose methods and means for eliminating power oscillations in such systems.METHODS. To carry out the research, a single electric power system with electric rudder propellers of the world's only asymmetric icebreaker Baltika was considered. All the main elements of such system have been analyzed in detail. Experimental studies were carried out aimed at studying the operating modes of a unified electric power system.RESULTS. Experimental oscillograms of currents of parallel operating diesel-generator sets in different modes have been obtained. The existence of exchange and in-phase power oscillations during the operation of the unified electric power system of the icebreaker "Baltika" is noted. The data on the negative influence of power oscillations on the operation of the electrical complex of the icebreaker are presented.CONCLUSION. The use of ice-class sea vessels is an extremely important task for the Russian Federation. The installation of blocks that eliminate exchange and in-phase power oscillations will improve the reliability and efficiency of the use of marine vessels with electric rudder propellers when servicing hydrocarbon production on the Arctic shelf.

THE PURPOSE. Consider the most pressing and important problems of parallel operation of generator sets as part of autonomous electrical complexes of modern sea vessels, such as the transition of diesel generator sets to reverse power mode and the existence of power exchange oscillations during parallel operation. Consider the possibility of improving the method for eliminating power exchange oscillations using maps of dependences of the amplitude of oscillations on the parameters of diesel generator sets. METHODS. When solving the problem, a mathematical model of an autonomous electrical complex was used, which allows to take into account the backlash clearances in the control loops of the rotation frequency of parallel diesel generator sets. RESULTS. A map of the dependence of the load angle on the backlash clearances was constructed. The complete identity of the maps of the dependence of the load angle on the backlash clearances and the maps of the dependence of the amplitude of the power exchange oscillations on the backlash gaps has been proved. In the criterion for determining the value of the amplitude of the power exchange oscillations, it is proposed to use the load angle of the generators instead of the envelope currents of the generators. CONCLUSION. The use of the load angle of parallel operating generators allows to increase the speed and accuracy of the unit for eliminating power exchange oscillations. The developed approach makes it possible to control the transition of generating sets to the reverse power mode and the appearance of power exchange oscillations based on measuring the load angles of the generators.

The application of autonomous electrical complexes with parallel diesel generator sets based on synchronous generators is considered. The problem of the existence of exchange power fluctuations in such technical systems is described. A mathematical model has been developed that allows conducting research of an autonomous electrical complex. It is proposed to implement graphical visualization of the dependence of the amplitude of power exchange fluctuations on time constants in the speed control circuits of diesel generators in the form of configuration maps. An example of using the proposed method for a specific electrical complex is given. The possibility of reducing the amplitude of exchange power fluctuations by reducing the values of time constants of frequency control circuits is justified, which is the basis of a new method for eliminating exchange power fluctuations and makes it possible to improve the method, which is based on changing the transmission coefficients of frequency regulators.

The problem of the existence of common-mode and exchange power fluctuations when parallel operation of synchronous generators in autonomous electrical systems is considered. The methods of mathematical modeling obtained the amplitude and period of common-mode oscillations in the whole possible range of settings of the object under study. A method has been developed for constructing maps of the dependence of the amplitude and period of common-mode power oscillations on the values of the transfer coefficients and setpoints in terms of the rotation frequency of the speed governors of diesel generators. The use of such cards allows you to apply the method of eliminating exchange power fluctuations, taking into account the possible occurrence of common-mode oscillations. Mapping the settings of the amplitude and the period of the common-mode power oscillations makes it possible to understand the tendency of the amplitude and the period of the common-mode power oscillations to change and to carry out an in-depth analysis of the operation of the autonomous electrotechnical complex.

The application of autonomous electric power equipment having in their composition parallel operating diesel-generator sets on the basis of synchronous generators is considered. The problem of existence of exchange power fluctuations in such technical systems is described. A mathematical model has been developed that makes it possible to carry out investigations of an autonomous electric power equipment. The technique for constructing maps of the amplitude of the exchange power fluctuations, from the backlash gaps in the speed control circuits of diesel generators is obtained. The use of such cards makes it possible to introduce recommendations on limiting the amplitude of exchange power fluctuations to normative documents, both of a general nature, and specifically for certain types of equipment. In the same way, the cards make it possible to determine the gap gaps existing in the frequency control loop from the measured amplitudes of the exchange power fluctuations.

We introduce the notion of language uniform theory and study topological properties related to families of language uniform theory and their E-combinations. It is shown that the class of language uniform theories is broad enough. Sufficient conditions for the language similarity of language uniform theories are found. Properties of language domination and of infinite language domination are studied. A characterization for E-closure of a family of language uniform theories in terms of index sets is found. We consider the class of linearly ordered families of language uniform theories and apply that characterization for this special case. The properties of discrete and dense index sets are investigated: it is shown that a discrete index set produces a least generating set whereas a dense index set implies at least continuum many accumulation points and the closure without the least generating set. In particular, having a dense index set the theory of the E-combination does not have $e$-least models and it is not small. Using the dichotomy for discrete and dense index sets we solve the problem of the existence of least generating set with respect to $E$-combinations and characterize that existence in terms of orders. Values for $e$-spectra of families of language uniform theories are obtained. It is shown that any $e$-spectrum can be realized by $E$-combination of language uniform theories. Low estimations for $e$-spectra relative to cardinalities of language are found. It is shown that families of language uniform theories produce an arbitrary given Cantor-Bendixson rank and given degree with respect to this rank.

We investigate closure operators and describe their properties for $E$-combinations and $P$-combinations of structures and their theories including the negation of finite character and the exchange property. It is shown that closure operators for E-combinations correspond to the closures with respect to the ultraproduct operator forming Hausdorff topological spaces. It is also shown that closure operators for disjoint $P$-combinations form topological $T_0$-spaces, which can be not Hausdorff. Thus topologies for $E$-combinations and $P$-combinations are rather different. We prove, for E-combinations, that the existence of a minimal generating set of theories is equivalent to the existence of the least generating set, and characterize syntactically and semantically the property of the existence of the least generating set: it is shown that elements of the least generating set are isolated and dense in its $E$-closure. Related properties for P-combinations are considered: it is proved that again the existence of a minimal generating set of theories is equivalent to the existence of the least generating set but it is not equivalent to the isolation of elements in the generating set. It is shown that $P$-closures with the least generating sets are connected with families which are not $\omega$-reconstructible, as well as with families having finite $e$-spectra. Two questions on the least generating sets for E-combinations and P-combinations are formulated and partial answers are suggested.

The problem of preprocessing training samples to improve the efficiency of trainable recognition systems is considered in the paper. A new method for solving the problem of outliers removal based on constructing weighted reduced samples of w-objects is proposed. The wGridDC method for constructing the weighted sample of w-objects by superimposing the grid features on the space and constructing weighted objects of new sample by analyzing the contents of cells is used as a basis for the proposed method. Within the proposed method, two outliers removal algorithms are developed. The algorithm for constructing the weighted training sample of w-objects with simultaneous outliers removal at a given filtering threshold is focused on the use in the tasks that require not only filtering the original data, but also controlling the size of the sample. Herewith, filtering threshold is user-defined. The algorithm for constructing the weighted training sample of w-objects with simultaneous outliers removal at automatic filtering threshold detection is focused on the tasks that require constructing samples, providing the highest efficiency of the system. Analysis of the effectiveness of the proposed method has shown that the main advantage of the threshold filtering algorithm is the ability to control the size of the sample. The main advantage of the non-threshold filtering algorithm is the ability to automatically select the value of the filtering threshold that provides the greatest efficiency of the recognition system as a whole. Thus, the proposed method in general and both its constituent algorithms allow to obtain the samples, providing high efficiency of trainable recognition systems. [ABSTRACT FROM AUTHOR]