Viktor M. Rulevskiy

Currently, spacecrafts are firmly embedded in everyday life, providing communications, navigation, weather forecasting, and safety around the world. The key role in any spacecraft is assigned to the power supply system, which directly affects functioning of all other on-board systems. However, traditional methods of designing a power supply system often use overly simplified mathematical models that ignore the interaction of subsystems, dynamic processes and possible emergencies. This necessitates designing for excessive mass and dimensions, reduces actual reliability and leads to inefficient use of the spacecraft’s resources. This problem is most acute in small spacecraft. Despite their relatively short operational lifespan, they are subject to the same stringent reliability requirements as heavy-duty satellite platforms. Therefore, creation of new structural and functional solutions for power supply systems for small spacecraft, which make it possible to more accurately predict the behavior of the system, optimize it in terms of a set of indicators (mass, reliability, energy quality) and shorten the duration of ground testing, is an urgent scientific and technical task. The purpose of the research is to develop the architecture of the energy–converting complex of the power supply system for a small digitally controlled spacecraft, which ensures a reduction in weight and size reserves, increased reliability and reduced bench testing time. Materials and methods. The object of the study is the energy–converting complex of a small spacecraft, the subject is a structurally functional circuit with digital control, including power modules based on a three-port power converter with soft switching and a zone power distribution algorithm. Theoretical (analysis of existing circuits, synthesis of zone control, calculation of electromagnetic processes) and experimental methods are used. Prototypes of power modules based on the GW1N-LV9QN48C6/I5 programmable logic integrated circuit were produced. The simulation was performed in the MATLAB/ Simulink program, whilst the programmable logic integrated circuits were programmed using the GOWIN FPGA Designer CAD system in Verilog. The tests were carried out on a test bench with equipped with an IBS-210/8-4 solar panel simulator, the IAB-35/130 battery and the IPCHN-100 electronic load. Results. A modular block diagram of a power conversion system is proposed, featuring separate conversion of energy from solar panels and battery banks, and operating on a zonal principle. A three-port power converter with soft switching was developed, which allows to increase the efficiency to 0.97. A digital control system for each power module based on a programmable logic integrated circuit was created, which implements extreme power control modes by a solar battery and adapts operation to different voltage levels. Prototypes of the power modules were manufactured and tested. The specific performance figures for the power conversion system, ranging from 370 W/kg (with three power modules) to 514 W/kg (with seven power modules), are in line with global standards. Conclusions. The newly developed digitally controlled power conversion system provides controlled battery charging, dynamic power redistribution between the load and the battery, scalability through changing the number of power modules, as well as high energy efficiency and competitive dimensions and weight. The results of practical experiments confirmed the theoretical calculations and stated provisions.

The article considers the scheme of the converter with accessory voltage and the link of intermediate conversion of elec-tric energy parameters on alternating current, made on the basis of two bridge voltage inverters with serial connection of output windings. The first unregulated inverter is made with 180° control, and the second - with a full range of output voltage regulation. The total output voltage of the inverters contains an unregulated constant component and an ad-justable pulse component. The amplitude of the output voltage of the regulated inverter is selected based on the re-quired range of regulation of the converter output voltage. The article presents the results of studying the influence of the amplitude and duration of the pulse component on the ripple current of the inductors and the voltage on the filter capacitors, on the value of the current of the regulated inverter keys, as well as on the conditions of the intermittent cur-rents in the inductor of the converter output filter. It has been proved that the converter with accessory voltage provides reduction of ripple current of inductors and voltage on the capacitors of input and output filters, as well as the current of the regulated inverter keys, in comparison with the converter scheme with a full range of output voltage regulation. The results are obtained on a model assembled using MATLAB Simulink software.

In this paper, we study the combinatorial set of pieces formed when slicing a disk with a given number of straight cuts. The cardinality function of this combinatorial set is described by the central polygonal numbers. Using the obtained cardinality function, we construct the corresponding AND/OR tree structure and determine a bijection between the set of variants of the AND/OR tree and the considered combinatorial set. In addition, we develop ranking and unranking algorithms for the combinatorial set.

Одной из основных характеристик имитатора солнечной батареи (ИБС), определяющей его соответствие реальной солнечной батарее, является внутренний импеданс, который должен соотноситься с участками его вольт-амперной характеристики следующим образом. Когда ИБС работает на участке тока, он должен представлять собой источник тока, внутренний импеданс которого должен быть много больше импеданса нагрузки; на участке напряжения ИБС должен представлять собой источник напряжения, чей внутренний импеданс должен быть много меньше импеданса нагрузки. Измерение модуля импеданса имитатора позволяет оценить его фактическое соответствие этим требованиям. Измеренные значения модуля гораздо точнее определяют его характеристики по сравнению с расчетными, а также позволяют оценить степень их достоверности и выявить резонансные частоты, на которых зависимости модулей ИБС от частоты изменения нагрузки, соответствующие участкам тока и напряжения, существенно отличаются от расчетных, что обусловлено наличием распределенных параметров активной и реактивной составляющих внутреннего импеданса ИБС. Стандартные методики расчета, основанные на использовании параметров элементов схемы, этого не учитывают. Реальная зависимость модуля импеданса имитатора от частоты изменения нагрузки позволит спрогнозировать поведение каждого элемента системы, располагая его аналогичными...

The considered problem is constructing an optimal voltage regulator for power supply system of remote-controlled underwater unmanned vehicle, providing specified power system quality indi-cators when changing the operation mode of the submerged part payload. Proposed approxi-mation technique of a nonlinear multidimensional power supply system model with the trans-mission of alternating current energy through a cable by means of smaller order linearized mathematical model in the space of state variables. Based on the reduced model, a variable structure controller for voltage regulation is constructed using the methods of linear control theo-ry. It compensates for the effect of parametric load changes on the quality indicators of a closed system.