507 research outputs found

    Integration of a mean-torque diesel engine model into a hardware-in-the-loop shipboard network simulation using lambda tuning

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    This study describes the creation of a hardware-in-the-loop (HIL) environment for use in evaluating network architecture, control concepts and equipment for use within marine electrical systems. The environment allows a scaled hardware network to be connected to a simulation of a multi-megawatt marine diesel prime mover, coupled via a synchronous generator. This allows All-Electric marine scenarios to be investigated without large-scale hardware trials. The method of closing the loop between simulation and hardware is described, with particular reference to the control of the laboratory synchronous machine, which represents the simulated generator(s). The fidelity of the HIL simulation is progressively improved in this study. First, a faster and more powerful field drive is implemented to improve voltage tracking. Second, the phase tracking is improved by using two nested proportional–integral–derivative–acceleration controllers for torque control, tuned using lambda tuning. The HIL environment is tested using a scenario involving a large constant-power load step. This provides a very severe test of the HIL environment, and also reveals the potentially adverse effects of constant-power loads within marine power systems

    Concept study of 20 MW high-speed permanent magnet synchronous motor for marine propulsion

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    High-speed permanent magnet synchronous machines are of great interest in the applications where high utilization factor and efficiency are required. Depending on application, power requirements change from kilowatts to megawatts. To investigate power limits of high-speed machines, the present feasibility study focuses on a 20 megawatt (MW) electric drive for marine propulsion. However, in addition alternative propulsion systems, ranging 100 kW to 20 MW, have been considered in an attempt to highlight some of the scaling rules that are apparent to high-speed machine considering their specific power level. In marine propulsion, the electric drive has to provide high torque at low speed to the propeller, however at different levels due to pole towing or open water operation. For electric drives, this tends to require high frequencies (large number of poles) as well as high currents. In general, ocean-going ships exist to provide affordable transport for cargo or passengers. In this respect, there exists a range of speeds within which virtually all ocean-going ships have operated and still operate. Within this range of speeds, roughly 10-30 knots, ship propulsion speed, in revolutions-per-minute (rpm), lie within a certain range, up to a couple of hundred rpm. The horsepower range coupled with propulsion rpm makes ship propulsion motor applications a high-torque, slow-speed electric drive. To deliver 20 MW propulsion power at a rotational speed of 150 rpm requires almost 1,300,000 newton meter (Nm) of torque. Emerging ship designs that employ different propulsion, e.g. water jets, may change this. However, in the following decades, ship propulsion motors will remain to be dominated by high torque, slow-speed motors, which are likely to remain for quite some time yet. In this respect, state-of-the-art ship propulsion motors are almost entirely alternating current (AC) synchronous wound field water cooled motors, or AC asynchronous induction motors. This report aims to give a general introduction to the concept of electrically-propelled vessels and presents specifically a feasibility study to a 20 MW high-speed permanent magnet synchronous motor (PMSM) to be used for ship propulsion. Although that also an initial attempt is documented to provide scaling laws for high-speed PM motor ranging from 100 kW to 20 MW. The purpose of this report constitutes a concept study and not an in-depth system analysis that would be required when implementing this technology for an electrical drive in future propulsion systems, such as ships or large vehicles. However, special attention is given to the apparent design challenges for these large high speed electric drives and their possible solutions

    Analysis of engine propeller matching using separately excited DC motor As a main propulsion based on laboratory scale

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    Perkembangan industri pelayaran selalu mengarah kepada penekanan biaya operasi dengan tidak menambah polusi. Propulsi diesel atau disebut juga propulsi konvensional adalah yang paling efisien sekaligus penyumbang polusi maritime terbesar sampai saat ini. Propulsi elektrik memanfaatkan motor listrik sebagai penggerak utama. Terdapat dua jenis motor listrik yang memungkinkan digunakan dalam sistem propulsi elektrik, yakni; motor DC dan motor induksi tiga fasa. Mengacu pada kemungkinan tersebut, studi ini akan membahas mengenai karakteristik antara voltase terminal dan torsi, juga arus medan dan torsi. Dihasilkan bahwa torsi yang diproduksi oleh motor DC berbanding lurus dengan kecepatan motor (RPM). Peningkatan kecepatan motor akan mempengaruhi besar torsi. Voltase masuk dan terminal sebagai pengatur variabel-variabel hasil dalam pengoperasian motor. Dalam kasus ini, voltase medan yang divariasikan memberikan hasil berupa grafik operasi motor. Dengan voltase medan 50 volts, jangkauan grafik operasi motor maksimum terletak pada 150% kecepatan dan 160% daya. Sementara, dengan voltase medan 60 volts dihasilkan jangkauan grafik operasi yang lebih luas dibandingkan dengan voltase medan 50 volts. ========================================================= The development of shipping industry always searches through the most benefits system for reducing costs of propulsion system without create more pollution. Diesel propulsion system or also known as conventional propulsion system is efficient but requires high operating costs and create high level of marine pollution. Electrical propulsion system is using electric motors as the prime mover of the propeller. There are 2 types of electric motors that will be used for research of electric propulsion system, there are; DC motors and three-phase induction motor. As the use of DC motor as a prime mover for this electrical propulsion system, this study determines the characteristic between voltage terminal with torque and also field current with torque. It results that torque produced by the DC motor is in the same magnitude with the speed (RPM). The higher the speed have shaped the value of the torque. The input and terminal voltages adjusts all variables and results. In this study, different field voltage creates different pattern of motor envelope. Its manner to propeller curve occurs total different results. With field voltage of 50 volts, the ranges of motor envelope immoveable in the point of 150% of present speed and 160% power. While field voltage of 60 volts serves larger ranges of motor envelope which possible to reach further than 50 volts curv

    Marine Engines Performance and Emissions

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    This book contains a collection of peer-review scientific papers about marine engines’ performance and emissions. These papers were carefully selected for the “Marine Engines Performance and Emissions” Special Issue of the Journal of Marine Science and Engineering. Recent advancements in engine technology have allowed designers to reduce emissions and improve performance. Nevertheless, further efforts are needed to comply with the ever increased emission legislations. This book was conceived for people interested in marine engines. This information concerning recent developments may be helpful to academics, researchers, and professionals engaged in the field of marine engineering

    Systems modeling for electric ship design

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    Thesis (Nav. E. and S.M.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 2004.Leaf 185 blank.Includes bibliographical references (leaves 172-174).Diesel and gas turbine electric ship propulsion are of current interest for several types of vessels that are important for commercial shipping and for the next generation of war ships. During the design process of a platform, a choice has to be made between two different fundamental concepts regarding propulsion; a conventional arrangement, and a diesel or gas turbine electric propulsion. For both concepts, the electrical installation is present and the demand for additional electric energy becomes a dominant parameter. In both cases, the selection of the prime mover significantly influences the effectiveness of the design. In this thesis, the simulation modeling of a complete propulsion system will be attempted, with overall emphasis on the prime movers. In the first part a diesel engine is considered. The time delay between changing a set point for the revolutions of the engine and the change of the real revolutions is often modeled as a first order system. However, this modeling is too simple to describe the real behavior of the diesel engine. More complex models exist, but in general they are too complex, describing the full thermodynamic behavior of diesels.(cont.) So there is a need for a model that is more advanced than a first order system and less complex than complete thermodynamic models. Such a model has been derived, based on the Seiliger (thermodynamic) process. The results of the model show that the diesel engine behaves like a second order system when operating in the governor area and more like a first order system in the constant torque (overload) area. The simulation model of a diesel engine can be regarded as an explanation of the real engine operation, which combines the mathematical relationship between the relative components and can be used to simulate dynamic loading of the diesel engine. In the second part, a development of a nonlinear gas turbine model for loop- shaping control purposes is presented. The nonlinear dynamic equations of the gas turbine are based on first engineering principles. In order to complete the model, constitutive algebraic equations are also needed. These equations describe the static behavior of the gas turbine at various operating points.(cont.) The complete, substituted nonlinear model is presented along with its model verification results based on a simulator and measured data. A mathematical description for the electric part of the propulsion and energy generation system with respect to numbers of components such as generators and thruster drives is attempted. Other electrical loads may be represented with an aggregate load. Based on the control functions focus on power production, advanced dynamic models shall be used for the generators and simplified static models shall be used for thruster drives and other loads. The final model shall be in a state-space vector form, suitable for control design. As a conclusion, a reliability analysis on the decision for the electric propulsion system is utilized based on market data, speed and electric energy requirements studies. The purpose of this study is to justify the employment of innovative and efficient electric propulsion systems for the future needs of the commercial and naval ship industries.y Charalambos Soultatis.Nav.E.and S.M

    All electric battery service vessel - Dynamic modeling of a battery fed IPMSM propulsion plant as a tool for energy estimates and functional description for an energy management system

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    "Designing an all-electric battery vessel, knowledge of the dynamic performance of the electrical propulsion plant becomes crucial to produce adequate estimates of needed battery capacity. An energy management system is to control the on-board power flow and ensure energy efficient operation of the vessel. This thesis presents a solution for dynamic simulation of an all-electric battery vessel based on an internal permanent magnet synchronous machine propulsion plant. Insight in system dynamics forms the basis of a proposed functional description for further design of an energy management system. Through description of the different modes and transitions between them, critical aspects and functionality of the control system are enlightened. The thesis presents a tuning guide showing how to tune the model to convergence using measured data from the vessel sea trial. When tuned, the presented model can be used for dimensioning future battery vessels. The model is designed in MATLAB Simulink. Key words: Energy management system, dynamic modeling, battery vessel, IPMSM, electric propulsion.

    Supervisory Control Implementation on Diesel-Driven Generator Sets

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    Climate Change Control Systems and Technology Series

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    Man lives in two worlds, the biosphere and the techno sphere world over the years, time needs, growth, speed, and knowledge and competition have created demand that necessitated man to build a complex institution. Ship design is not left out in this process. Inland water, are under treat from untreated waste that can feed bacteria and algae, which in turn exhaust the oxygen. The ocean covers 70 percent of the globe, many think that everything that runs into it is infinite, the ocean is providing the source of freshening winds and current that are far more vulnerable to polluting activities that have run off into them too many poisons, that the ocean may cease to serve more purpose if care is not taking to prevent pollution. This issue of the environment becomes so sensitive in recently and most are linked to infrastructure development work. Most especially in maritime industry polluting activities from oil bilge to ballast pumping that has turned into poison has advert effect on water resources. Some have choked too much estuarine water where fish spawn. In a nutshell, the two worlds we live in are currently are out of balance and in potential conflict. Man is in the middle, and since the treat are mostly water related, ship is in the middle too. Historical records of a number of calamities that has resulted in heavy lost and pollution call for the environmentally sound ship. This has to lead to a number of regulations today that will subsequently affect policies change and procedures interaction with the system. The current situation has affected the design of new ships and modification of existing ships. This paper review and discuss green technology emanating from regulations and highlight new system design being driven by marine pollution prevention and, protection and control regulation

    Modeling, Control, and Optimization for Diesel-Driven Generator Sets

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