Pub Date : 2022-08-23DOI: 10.24143/2073-1574-2022-3-77-81
A. Bordyug
In relay protection devices with information digital processing the input controlled values are the currents and voltages of the protected object received from traditional measuring transformers, which are converted into voltage signals using appropriate converters. To limit the frequency spectrum these signals are subjected to preliminary analog filtering, after which they are discretized in time with a desired step Δt and are quantized by level. The difference between adjacent discrete values of the controlled value is proved to depend on its amplitude, and the minimum value of this difference can be observed in the minimum signal mode. When choosing the minimum step Δt the mode with the minimum amplitude of the controlled value is decisive. It has been proved that the difference between adjacent discrete values of the controlled value depends on the frequency and decreases with a decrease in the latter, i.e. when choosing the minimum sampling step Δt it is necessary to take into account the minimum possible value of the frequency. There is shown an example of the dependence of the minimum sampling step of a sinusoidal signal with a frequency of 50 Hz on the ADC bit depth. The analysis of the presented dependences shows that the minimum value of the sampling step Δt is largely determined by the multiplicity of the controlled value and the ADC bit depth. There has been inferred the possibility of using the proposed methods for a rough estimation of the minimum value of a sampling step of input quantities in relay protection devices with information digital processing.
{"title":"Calculating discretization step of controlled values in relay protection communication channels","authors":"A. Bordyug","doi":"10.24143/2073-1574-2022-3-77-81","DOIUrl":"https://doi.org/10.24143/2073-1574-2022-3-77-81","url":null,"abstract":"In relay protection devices with information digital processing the input controlled values are the currents and voltages of the protected object received from traditional measuring transformers, which are converted into voltage signals using appropriate converters. To limit the frequency spectrum these signals are subjected to preliminary analog filtering, after which they are discretized in time with a desired step Δt and are quantized by level. The difference between adjacent discrete values of the controlled value is proved to depend on its amplitude, and the minimum value of this difference can be observed in the minimum signal mode. When choosing the minimum step Δt the mode with the minimum amplitude of the controlled value is decisive. It has been proved that the difference between adjacent discrete values of the controlled value depends on the frequency and decreases with a decrease in the latter, i.e. when choosing the minimum sampling step Δt it is necessary to take into account the minimum possible value of the frequency. There is shown an example of the dependence of the minimum sampling step of a sinusoidal signal with a frequency of 50 Hz on the ADC bit depth. The analysis of the presented dependences shows that the minimum value of the sampling step Δt is largely determined by the multiplicity of the controlled value and the ADC bit depth. There has been inferred the possibility of using the proposed methods for a rough estimation of the minimum value of a sampling step of input quantities in relay protection devices with information digital processing.","PeriodicalId":129911,"journal":{"name":"Vestnik of Astrakhan State Technical University. Series: Marine engineering and technologies","volume":"382 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122925746","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-05-31DOI: 10.24143/2073-1574-2022-2-80-84
A. Bordyug
Voltage transformers with capacitive loading during transients can cause significant distortion of the secondary voltage of the ship's network. For the analysis, a well-known nonlinear model of a single-phase two-winding transformer is used, in which the magnetic flux is divided into “working” and leakage fluxes coupled to individual windings that close outside the core. For practical purposes, when using such transformers, it is important to know both the conditions for the occurrence of autoparametric oscillations and the dynamics of the transient process. It is convenient to carry out a comparative evaluation of capacitive power take-off schemes on a computer, which makes it possible to reproduce non-linear characteristics and vary parameters over a wide range, which is difficult in physical modeling. The results of the study of a short circuit downstream of the reactor in the capacitor selection circuit proved that the short circuit at the terminals of the intermediate transformer does not affect the elements of the upper arm of the voltage divider, but significantly affects the lower arm of the divider and the compensating reactor, as a result, subharmonics appear. It is shown that the developed model is convenient for studying the influence of transient processes (short circuits) on the elements of a voltage divider. The applied model is universal for ship power networks and can be used for both capacitive and inductive dividers. A divider circuit with specific parameters has been modeled and relevant studies have been carried out. Mathematical results are verified on a physical model, which confirmed the correctness of the mathematical model. It has been inferred that a decrease in the phase voltage leads to a decrease in the overvoltage on the divider elements during a short circuit behind the compensating reactor of the power take-off circuit.
{"title":"Developing model of transient processes in transformer under capacitive load","authors":"A. Bordyug","doi":"10.24143/2073-1574-2022-2-80-84","DOIUrl":"https://doi.org/10.24143/2073-1574-2022-2-80-84","url":null,"abstract":"Voltage transformers with capacitive loading during transients can cause significant distortion of the secondary voltage of the ship's network. For the analysis, a well-known nonlinear model of a single-phase two-winding transformer is used, in which the magnetic flux is divided into “working” and leakage fluxes coupled to individual windings that close outside the core. For practical purposes, when using such transformers, it is important to know both the conditions for the occurrence of autoparametric oscillations and the dynamics of the transient process. It is convenient to carry out a comparative evaluation of capacitive power take-off schemes on a computer, which makes it possible to reproduce non-linear characteristics and vary parameters over a wide range, which is difficult in physical modeling. The results of the study of a short circuit downstream of the reactor in the capacitor selection circuit proved that the short circuit at the terminals of the intermediate transformer does not affect the elements of the upper arm of the voltage divider, but significantly affects the lower arm of the divider and the compensating reactor, as a result, subharmonics appear. It is shown that the developed model is convenient for studying the influence of transient processes (short circuits) on the elements of a voltage divider. The applied model is universal for ship power networks and can be used for both capacitive and inductive dividers. A divider circuit with specific parameters has been modeled and relevant studies have been carried out. Mathematical results are verified on a physical model, which confirmed the correctness of the mathematical model. It has been inferred that a decrease in the phase voltage leads to a decrease in the overvoltage on the divider elements during a short circuit behind the compensating reactor of the power take-off circuit.","PeriodicalId":129911,"journal":{"name":"Vestnik of Astrakhan State Technical University. Series: Marine engineering and technologies","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130167266","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-05-31DOI: 10.24143/2073-1574-2022-2-92-101
A. Kuznetsov, A. Sampiev, A. Semenov, A. Kirichenko
The article highlights the design process aimed to develop a non-existing object, which should correspond to all the requirements. As far as the physical creation of an object is started only after finishing the design process, the whole procedure includes discussing different models and information. The result of sea terminals design is the documentation which consists of not only the necessary for construction and exploitation information, but also almost all physical, operational, exploitation and financial parameters of the object. The elements of behavior research, i.e. exploration of the output parameters reaction to the change of input ones and the data that were calculated on the previous steps of the design process, is a necessary part of each next step. The variation of requirements to the precision, sustainability and specification of data on different steps of design require to use different in complexity and precision models to analyze them. The capitalization of infrastructural objects of sea transport, the acceptance of liquidity and the scale of social-economic impact on the society define the special requirements to this branch of activity, which are applied in strict regulation and formulation of rules of all design processes. It has been stated that the active rules define the methods of sea terminals design, but this definition has been unchanged for a long time. The great evolution of nature, structure and volumes of data bring a conflict with the documental requirements to the calculations. There are developed the general rules of mathematical modelling used as an instrument of design on different steps of sea terminals design. There is carried out a brief content analysis of the typical steps of a design process, which allows to correspond the consequence of technological design stages with using the statistical modelling and queueing theory design methods. It also includes the description of a new concept of simulation modelling, which allows to connect gnoseological advantages of this approach with universality of traditional methods. Saving the universality and objective process of consequent adequacy provement of all the described models allow to put a question of utilization of this instrument into the general rules and recommendations of sea terminal design.
{"title":"Directions of seaport technological rules development","authors":"A. Kuznetsov, A. Sampiev, A. Semenov, A. Kirichenko","doi":"10.24143/2073-1574-2022-2-92-101","DOIUrl":"https://doi.org/10.24143/2073-1574-2022-2-92-101","url":null,"abstract":"The article highlights the design process aimed to develop a non-existing object, which should correspond to all the requirements. As far as the physical creation of an object is started only after finishing the design process, the whole procedure includes discussing different models and information. The result of sea terminals design is the documentation which consists of not only the necessary for construction and exploitation information, but also almost all physical, operational, exploitation and financial parameters of the object. The elements of behavior research, i.e. exploration of the output parameters reaction to the change of input ones and the data that were calculated on the previous steps of the design process, is a necessary part of each next step. The variation of requirements to the precision, sustainability and specification of data on different steps of design require to use different in complexity and precision models to analyze them. The capitalization of infrastructural objects of sea transport, the acceptance of liquidity and the scale of social-economic impact on the society define the special requirements to this branch of activity, which are applied in strict regulation and formulation of rules of all design processes. It has been stated that the active rules define the methods of sea terminals design, but this definition has been unchanged for a long time. The great evolution of nature, structure and volumes of data bring a conflict with the documental requirements to the calculations. There are developed the general rules of mathematical modelling used as an instrument of design on different steps of sea terminals design. There is carried out a brief content analysis of the typical steps of a design process, which allows to correspond the consequence of technological design stages with using the statistical modelling and queueing theory design methods. It also includes the description of a new concept of simulation modelling, which allows to connect gnoseological advantages of this approach with universality of traditional methods. Saving the universality and objective process of consequent adequacy provement of all the described models allow to put a question of utilization of this instrument into the general rules and recommendations of sea terminal design.","PeriodicalId":129911,"journal":{"name":"Vestnik of Astrakhan State Technical University. Series: Marine engineering and technologies","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130514431","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-05-31DOI: 10.24143/2073-1574-2022-2-65-72
V. Dorovskoy, V. A. Kucherenko, E. G. Zinchenko, K. Chernobai
For introspective identification of the automatic control system (ACS) of a DC motor there has been developed a specific simplified technique of studying the optimization of a linear automatic control system. The technique is based on using the MATLAB computer simulation program, which helps to easily obtain the transition function of the ACS model, on the understanding a few ACS properties and using the directed search method. The work can be done in three stages, in accordance with the tasks. Draft models are considered, in which the researcher must set up the parameters of the elements, activate the simulation process and keeping under control the type of the transient function select the values of the optimal gains of the controllers. The time constant of the PI controller is chosen equal to the largest time constant of the ACS loop elements. It is often the time constant of the control object. In this case it is the time constant of a DC motor. The optimal choice of the system will also determine the tasks of identification, due to which it will be possible to correctly select a technological object by a specific ACS, its control variable and disturbance to provide the solution of the problem facing ACS. The static characteristics of an object determine the dependence of the controlled variable on the controlling variable and disturbances. In simple cases they can be obtained analytically by using the physical laws that link the controlled variable to the input parameters. Parametric optimization of indicators has been identified and tested on simulation examples in a simulation package and makes it possible to judge the correctness of simulation with a minimum error value.
{"title":"Identification of ship equipment processes by methods of introspective analysis","authors":"V. Dorovskoy, V. A. Kucherenko, E. G. Zinchenko, K. Chernobai","doi":"10.24143/2073-1574-2022-2-65-72","DOIUrl":"https://doi.org/10.24143/2073-1574-2022-2-65-72","url":null,"abstract":"For introspective identification of the automatic control system (ACS) of a DC motor there has been developed a specific simplified technique of studying the optimization of a linear automatic control system. The technique is based on using the MATLAB computer simulation program, which helps to easily obtain the transition function of the ACS model, on the understanding a few ACS properties and using the directed search method. The work can be done in three stages, in accordance with the tasks. Draft models are considered, in which the researcher must set up the parameters of the elements, activate the simulation process and keeping under control the type of the transient function select the values of the optimal gains of the controllers. The time constant of the PI controller is chosen equal to the largest time constant of the ACS loop elements. It is often the time constant of the control object. In this case it is the time constant of a DC motor. The optimal choice of the system will also determine the tasks of identification, due to which it will be possible to correctly select a technological object by a specific ACS, its control variable and disturbance to provide the solution of the problem facing ACS. The static characteristics of an object determine the dependence of the controlled variable on the controlling variable and disturbances. In simple cases they can be obtained analytically by using the physical laws that link the controlled variable to the input parameters. Parametric optimization of indicators has been identified and tested on simulation examples in a simulation package and makes it possible to judge the correctness of simulation with a minimum error value.","PeriodicalId":129911,"journal":{"name":"Vestnik of Astrakhan State Technical University. Series: Marine engineering and technologies","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125307151","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-05-31DOI: 10.24143/2073-1574-2022-2-33-43
Dmitrii Alekseevich Pichugin, Anastasiya Surikova, Vladimir Alekseevich Surikov
Today, methods of determining the tensile strength of concrete are of considerable interest. These methods using the anisotropy of brittle materials and, in particular, concrete, with respect to compressive and tensile stresses, make it possible, based on the findings of the theory of elasticity, to determine the tensile strength when tested with a compressive load, which can be transferred to the sample much more easily than tensile forces. The results of tests of concrete by the method of compression of cylindrical samples and crushing of cube samples with hewn ribs between two round metal rods lying in the same plane closely match the tensile strength values obtained with direct tension. For all studied compositions, the value of the strength ratio increases as the water-cement ratio increases, both for concrete without additives and with additives of surfactants. Using additives of surface-active organic substances without changing the dependence of the strength ratio on the hardening time makes it smoother. It has been found that the fast decreasing value of the strength ratio, hardening period that corresponds to its minimum value, and further increase or stabilization of Rp / Rc depend on a number of factors of the cement used, storage conditions of surfactant additives, composition, etc. Under the influence of the different factors the position of the characteristic points on the curve of the strength ratio dependence on the hardening time can change and obey the general pattern. For concretes and mortars, the decrease in the strength ratios in the transition from 28 days to the age of 90 days makes up to 10–25% (and in some cases much more), which must be taken into account in appropriate cases when designing structures.
{"title":"Analysis of hydraulic concrete strength test methods","authors":"Dmitrii Alekseevich Pichugin, Anastasiya Surikova, Vladimir Alekseevich Surikov","doi":"10.24143/2073-1574-2022-2-33-43","DOIUrl":"https://doi.org/10.24143/2073-1574-2022-2-33-43","url":null,"abstract":"Today, methods of determining the tensile strength of concrete are of considerable interest. These methods using the anisotropy of brittle materials and, in particular, concrete, with respect to compressive and tensile stresses, make it possible, based on the findings of the theory of elasticity, to determine the tensile strength when tested with a compressive load, which can be transferred to the sample much more easily than tensile forces. The results of tests of concrete by the method of compression of cylindrical samples and crushing of cube samples with hewn ribs between two round metal rods lying in the same plane closely match the tensile strength values obtained with direct tension. For all studied compositions, the value of the strength ratio increases as the water-cement ratio increases, both for concrete without additives and with additives of surfactants. Using additives of surface-active organic substances without changing the dependence of the strength ratio on the hardening time makes it smoother. It has been found that the fast decreasing value of the strength ratio, hardening period that corresponds to its minimum value, and further increase or stabilization of Rp / Rc depend on a number of factors of the cement used, storage conditions of surfactant additives, composition, etc. Under the influence of the different factors the position of the characteristic points on the curve of the strength ratio dependence on the hardening time can change and obey the general pattern. For concretes and mortars, the decrease in the strength ratios in the transition from 28 days to the age of 90 days makes up to 10–25% (and in some cases much more), which must be taken into account in appropriate cases when designing structures.","PeriodicalId":129911,"journal":{"name":"Vestnik of Astrakhan State Technical University. Series: Marine engineering and technologies","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131300897","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-05-31DOI: 10.24143/2073-1574-2022-2-102-114
O. Mazurenko, I. Rusinov
The article is focused on computer modeling of the sea cargo front of export coal terminal seaside in Anylogic environment. The main stages of development and formalization of the model have been analyzed. Using the statistical data on Rosterminalugol, JSC and Daltransugol, JSC, the dependences of the deadweight of bulk carriers on their length, width and draft were determined. A general classification of bulk carriers has been formed according to transport and technological characteristics. On the basis of statistical data, the number of bills of lading and/or grades of coal loaded onto bulk carriers at sea coal terminals have been assessed. Requirements for the selection of ship-loading equipment are formulated. The main types of berthing ship-loading machines used today are determined. Most export coal terminals use ship-loaders of the coordinate type with a lifting fixed boom. The choice of layout and technological scheme of the simulated sea front was carried out. The sea export coal terminal of Rosterminalugol, JSC in the seaport of Ust-Luga was taken as a basis. There is given a description of constructing a discrete-event simulation model of the sea cargo front in Anylogic software. It has been stated that the developed simulation model allows calculating the performance of the sea cargo front with several different layout options: with 1 or 2 berths, as well as with different capacity of cargo-loading machines. The results of the model operation make it possible to select a front layout option with the required annual throughput of berths and without exceeding the specified average time of vessel stay under loading. There are shown the basic principles of the model operation, explained the functionality of all logic blocks of the simulation model algorithm. The configuration control elements of the cargo front model have been presented, as well as the results of the work and conclusions.
{"title":"Discrete-event simulation of sea cargo front of export coal terminal in Anylogic environment","authors":"O. Mazurenko, I. Rusinov","doi":"10.24143/2073-1574-2022-2-102-114","DOIUrl":"https://doi.org/10.24143/2073-1574-2022-2-102-114","url":null,"abstract":"The article is focused on computer modeling of the sea cargo front of export coal terminal seaside in Anylogic environment. The main stages of development and formalization of the model have been analyzed. Using the statistical data on Rosterminalugol, JSC and Daltransugol, JSC, the dependences of the deadweight of bulk carriers on their length, width and draft were determined. A general classification of bulk carriers has been formed according to transport and technological characteristics. On the basis of statistical data, the number of bills of lading and/or grades of coal loaded onto bulk carriers at sea coal terminals have been assessed. Requirements for the selection of ship-loading equipment are formulated. The main types of berthing ship-loading machines used today are determined. Most export coal terminals use ship-loaders of the coordinate type with a lifting fixed boom. The choice of layout and technological scheme of the simulated sea front was carried out. The sea export coal terminal of Rosterminalugol, JSC in the seaport of Ust-Luga was taken as a basis. There is given a description of constructing a discrete-event simulation model of the sea cargo front in Anylogic software. It has been stated that the developed simulation model allows calculating the performance of the sea cargo front with several different layout options: with 1 or 2 berths, as well as with different capacity of cargo-loading machines. The results of the model operation make it possible to select a front layout option with the required annual throughput of berths and without exceeding the specified average time of vessel stay under loading. There are shown the basic principles of the model operation, explained the functionality of all logic blocks of the simulation model algorithm. The configuration control elements of the cargo front model have been presented, as well as the results of the work and conclusions.","PeriodicalId":129911,"journal":{"name":"Vestnik of Astrakhan State Technical University. Series: Marine engineering and technologies","volume":"140 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132772119","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-05-31DOI: 10.24143/2073-1574-2022-2-58-64
Konstanin Viktorovich Dolgiy, A. N. Dyadik, Nikolay Pavlovich Malyh
The article considers the problems of regulating the seawater level in the absorber for removing carbon dioxide from a hydrogen mixture. Decreasing or increasing the water level in the absorber lead to its low operation efficiency, the pressure in the absorber being constant in various modes of operation. The feed valve’s main function is to maintain the necessary water level. There has been given a functional diagram of the channel controlling the feed valve from the pressure regulator with a task signal adjusted by the water level in the absorber. Analysis of changing twelve parameters of the absorber under typical operating modes with the external water pressure of 0.5 and 1.6 MPa was conducted by using the LabVIEW software. The results obtained confirmed the possibility of using the control method to maintain the water level in the absorber within the specified limits. Regulating the water level in the absorber with the correction of the pressure setting signal to the pressure regulator by signals from the limiting regulators of the upper and lower water levels in the absorber is also examined. It is recommended to adjust the signal of the set pressure value, according to the level changes beyond the limits by increasing or decreasing it depending on the level going beyond the upper or lower permissible limits for increasing the duration and accuracy of maintaining the assigned pressure in the absorber. The duration of maintaining the assigned pressure in the absorber has been referred as to be increased by changing the design characteristics of the absorber: increasing the water volume in the absorber tank, increasing the range of permissible changes of the water level.
{"title":"Algorithms of controlling water discharge for maintaining water level in absorber by using pressure regulator","authors":"Konstanin Viktorovich Dolgiy, A. N. Dyadik, Nikolay Pavlovich Malyh","doi":"10.24143/2073-1574-2022-2-58-64","DOIUrl":"https://doi.org/10.24143/2073-1574-2022-2-58-64","url":null,"abstract":"The article considers the problems of regulating the seawater level in the absorber for removing carbon dioxide from a hydrogen mixture. Decreasing or increasing the water level in the absorber lead to its low operation efficiency, the pressure in the absorber being constant in various modes of operation. The feed valve’s main function is to maintain the necessary water level. There has been given a functional diagram of the channel controlling the feed valve from the pressure regulator with a task signal adjusted by the water level in the absorber. Analysis of changing twelve parameters of the absorber under typical operating modes with the external water pressure of 0.5 and 1.6 MPa was conducted by using the LabVIEW software. The results obtained confirmed the possibility of using the control method to maintain the water level in the absorber within the specified limits. Regulating the water level in the absorber with the correction of the pressure setting signal to the pressure regulator by signals from the limiting regulators of the upper and lower water levels in the absorber is also examined. It is recommended to adjust the signal of the set pressure value, according to the level changes beyond the limits by increasing or decreasing it depending on the level going beyond the upper or lower permissible limits for increasing the duration and accuracy of maintaining the assigned pressure in the absorber. The duration of maintaining the assigned pressure in the absorber has been referred as to be increased by changing the design characteristics of the absorber: increasing the water volume in the absorber tank, increasing the range of permissible changes of the water level.","PeriodicalId":129911,"journal":{"name":"Vestnik of Astrakhan State Technical University. Series: Marine engineering and technologies","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124764905","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-05-31DOI: 10.24143/2073-1574-2022-2-73-79
A. Vyngra
The use of electrical receivers with a non-linear load on ships significantly affects the electric power characteristics. The main devices that reduce the distortion of the sinusoid of current and voltage in electrical networks are active, passive and combined filters. There are considered the main types and principles of active filters operation, shown the current methods for detecting a distortion and forming a compensating effect by active filters. Using the active filters for electric drives of reciprocating mechanisms with an uneven, but periodic predictable load on the shaft is demonstrated. The operation of such devices in the ship electrical power system worsens the electric power characteristics (e.g. high iTHD, harmonic components). The effectiveness of using an active filter operating on a perturbation from a reference signal for electric drives of reciprocating compressors has been theoretically grounded. There has been presented an algorithm for operation on a perturbation determining the spectrum of the selected interharmonic distortion and presenting it in the form of a Fourier series to create a compensating effect. Application of the algorithm helps increase the speed of the control system, eliminates temporary errors and simplifies the operation of the system. The range of active filters operation according to this algorithm is found limited due to a necessary periodic load or fixed interference. The control software for a three-phase active filter was designed by using the algorithms. The software project is presented in the MATLAB/Simulink mathematical modeling environment. A specific feature of the software using a memory block to organize the calculation of the compensation pattern for harmonic distortion and using the algorithms for generating a compensating signal in the frequency domain. The hardware modeling is considered and the firmware of the board is made. The interface, code and results of the software work are given. It has been inferred that the software effectively controls the power elements of the active filter with current feedback.
{"title":"Developing algorithms and software for power active filters of ship electric power systems","authors":"A. Vyngra","doi":"10.24143/2073-1574-2022-2-73-79","DOIUrl":"https://doi.org/10.24143/2073-1574-2022-2-73-79","url":null,"abstract":"The use of electrical receivers with a non-linear load on ships significantly affects the electric power characteristics. The main devices that reduce the distortion of the sinusoid of current and voltage in electrical networks are active, passive and combined filters. There are considered the main types and principles of active filters operation, shown the current methods for detecting a distortion and forming a compensating effect by active filters. Using the active filters for electric drives of reciprocating mechanisms with an uneven, but periodic predictable load on the shaft is demonstrated. The operation of such devices in the ship electrical power system worsens the electric power characteristics (e.g. high iTHD, harmonic components). The effectiveness of using an active filter operating on a perturbation from a reference signal for electric drives of reciprocating compressors has been theoretically grounded. There has been presented an algorithm for operation on a perturbation determining the spectrum of the selected interharmonic distortion and presenting it in the form of a Fourier series to create a compensating effect. Application of the algorithm helps increase the speed of the control system, eliminates temporary errors and simplifies the operation of the system. The range of active filters operation according to this algorithm is found limited due to a necessary periodic load or fixed interference. The control software for a three-phase active filter was designed by using the algorithms. The software project is presented in the MATLAB/Simulink mathematical modeling environment. A specific feature of the software using a memory block to organize the calculation of the compensation pattern for harmonic distortion and using the algorithms for generating a compensating signal in the frequency domain. The hardware modeling is considered and the firmware of the board is made. The interface, code and results of the software work are given. It has been inferred that the software effectively controls the power elements of the active filter with current feedback.","PeriodicalId":129911,"journal":{"name":"Vestnik of Astrakhan State Technical University. Series: Marine engineering and technologies","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131391971","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-05-31DOI: 10.24143/2073-1574-2022-2-85-91
S. Valkova, Viktoriya Evgen'evna Stepanec, Elena Vital'evna Kiseleva
The article focuses on the problems of interaction between seaports and railway transport and their impact on the port operation efficiency. Railway transport in Russia plays a significant role in ensuring goods transportation. Despite the crisis phenomena taking place in Russia and in the world, the volume of transported cargoes entering and leaving the ports by railway is steadily growing. This trend is projected to continue, according to the Strategy for Development of the Russian Sea Port Infrastructure until 2030. It has been analyzed that the performance of seaports will be largely due to the effective operation of the rail transport and to their coordinated interaction. The increasing cargo traffic to the ports of Vladivostok and Vostochny led to a collapse in 2021. It affected the transportation of container cargoes to a greater extent. There are listed any possible reasons for such a situation: refusal of cargo owners to transport the cargo by sea; imbalance of rolling stock; limited capabilities of the railway; unavailability of the port infrastructure for a significant increase in cargo turnover; problems of coordinated interaction between ports and railway transport. It has been stated that particular attention should be paid to the lack of a clear and well-coordinated interaction between the seaport and rail transport, which entails both demurrage of ships and rail cars, increased time spent by the railway and sea transport in the port under processing, which ultimately affects the time of delivery of goods to the recipients. It has been inferred to develop a solution to the problem of control and coordination of the interaction between the port and the port railway station. There has been illustrated the scheme of information exchange in the port, suggested the complex system of information exchange, using which will contribute to solving the above-mentioned problems and optimize the activities of both seaports and railway transport.
{"title":"Improving interaction between sea ports and railway transport","authors":"S. Valkova, Viktoriya Evgen'evna Stepanec, Elena Vital'evna Kiseleva","doi":"10.24143/2073-1574-2022-2-85-91","DOIUrl":"https://doi.org/10.24143/2073-1574-2022-2-85-91","url":null,"abstract":"The article focuses on the problems of interaction between seaports and railway transport and their impact on the port operation efficiency. Railway transport in Russia plays a significant role in ensuring goods transportation. Despite the crisis phenomena taking place in Russia and in the world, the volume of transported cargoes entering and leaving the ports by railway is steadily growing. This trend is projected to continue, according to the Strategy for Development of the Russian Sea Port Infrastructure until 2030. It has been analyzed that the performance of seaports will be largely due to the effective operation of the rail transport and to their coordinated interaction. The increasing cargo traffic to the ports of Vladivostok and Vostochny led to a collapse in 2021. It affected the transportation of container cargoes to a greater extent. There are listed any possible reasons for such a situation: refusal of cargo owners to transport the cargo by sea; imbalance of rolling stock; limited capabilities of the railway; unavailability of the port infrastructure for a significant increase in cargo turnover; problems of coordinated interaction between ports and railway transport. It has been stated that particular attention should be paid to the lack of a clear and well-coordinated interaction between the seaport and rail transport, which entails both demurrage of ships and rail cars, increased time spent by the railway and sea transport in the port under processing, which ultimately affects the time of delivery of goods to the recipients. It has been inferred to develop a solution to the problem of control and coordination of the interaction between the port and the port railway station. There has been illustrated the scheme of information exchange in the port, suggested the complex system of information exchange, using which will contribute to solving the above-mentioned problems and optimize the activities of both seaports and railway transport.","PeriodicalId":129911,"journal":{"name":"Vestnik of Astrakhan State Technical University. Series: Marine engineering and technologies","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115857334","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-05-31DOI: 10.24143/2073-1574-2022-2-51-57
M. Pokusaev, A. V. Trifonov, Vasiliy Aleksandrovich Kostyrenko
Using a cooling system in water transport is considered the most effective way to increase the energy efficiency of a vessel. Currently, closed-loop cooling systems and frequency-controlled drives of seawater electric pumps are actively used. An option of improving the energy efficiency of cooling systems with mounted seawater pumps is being studied. The hydraulic scheme of the unit with an energy-efficient ship engine cooling system is presented. To study ways to reduce mechanical losses in the drive of auxiliary mechanisms of a marine engine, the laboratory “Marine Diesels” of Astrakhan State Technical University developed a test bench for the Iveco 8041I06 engine. The engine cooling system does not have a thermostat to control the thermal state; instead of a thermostat on the engine, an electronically controlled variator is installed between the engine power take-off shaft and the VKS 1/16 pump. At a constant engine speed, the variator allows changing the pump speed, supply of sea water through the heat exchanger and regulating the thermal state of the engine. It has been found that during engine tests it is necessary to maintain the temperature of the outboard water constant. A description is given of the use of tanks with thermal insulation at the stand to reduce heat exchange with the environment. Variants of types of containers and materials for insulation are considered. To prepare water of the required temperature a chiller is connected to the cooling system at the experimental stand. The calculation of thermal insulation and comparison of the result with a real test is given. On the stands for testing diesel engines the change in the thermal state of the engine is carried out only by changing the load on the engine. On the developed stand, the thermal state can also be changed, including by controlling the seawater temperature, which expands its capabilities for modeling real processes.
{"title":"Developing cooling system for small-sized marine diesel engines operating at different seawate temperatures in laboratory conditions","authors":"M. Pokusaev, A. V. Trifonov, Vasiliy Aleksandrovich Kostyrenko","doi":"10.24143/2073-1574-2022-2-51-57","DOIUrl":"https://doi.org/10.24143/2073-1574-2022-2-51-57","url":null,"abstract":"Using a cooling system in water transport is considered the most effective way to increase the energy efficiency of a vessel. Currently, closed-loop cooling systems and frequency-controlled drives of seawater electric pumps are actively used. An option of improving the energy efficiency of cooling systems with mounted seawater pumps is being studied. The hydraulic scheme of the unit with an energy-efficient ship engine cooling system is presented. To study ways to reduce mechanical losses in the drive of auxiliary mechanisms of a marine engine, the laboratory “Marine Diesels” of Astrakhan State Technical University developed a test bench for the Iveco 8041I06 engine. The engine cooling system does not have a thermostat to control the thermal state; instead of a thermostat on the engine, an electronically controlled variator is installed between the engine power take-off shaft and the VKS 1/16 pump. At a constant engine speed, the variator allows changing the pump speed, supply of sea water through the heat exchanger and regulating the thermal state of the engine. It has been found that during engine tests it is necessary to maintain the temperature of the outboard water constant. A description is given of the use of tanks with thermal insulation at the stand to reduce heat exchange with the environment. Variants of types of containers and materials for insulation are considered. To prepare water of the required temperature a chiller is connected to the cooling system at the experimental stand. The calculation of thermal insulation and comparison of the result with a real test is given. On the stands for testing diesel engines the change in the thermal state of the engine is carried out only by changing the load on the engine. On the developed stand, the thermal state can also be changed, including by controlling the seawater temperature, which expands its capabilities for modeling real processes.","PeriodicalId":129911,"journal":{"name":"Vestnik of Astrakhan State Technical University. Series: Marine engineering and technologies","volume":"63 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125460437","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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