scholarly journals Ship power plant with reversible shaft generator unit operating by dual-power machine scheme and variable speed diesel generator

2021 ◽  
Vol 2021 (3) ◽  
pp. 93-100
Author(s):  
Oleg Stanislavovich Khvatov ◽  
Ilya Aleksandrovich Tarpanov ◽  
Pavel Vadimovich Kuznecov
Keyword(s):  
Frequency Converter ◽  
Sharp Decrease ◽  
Simulation Models ◽  
Electric Power System ◽  
Small Displacement ◽  
Variable Speed ◽  
Diesel Generator ◽  
Low Speed ◽  
Operating Modes ◽  
Generator Unit

The article presents the analysis of the operating modes of small displacement vessels, which states that most of the working time the vessels are in standby mode, or move at low speed. The main ship diesel engines operate at a load of 10-15% (maximum 20%), which impacts the operational performance: the oil and water jacket of the engine do not have time to warm up, fuel and oil consumption increases. There takes place coking of piston rings, intercoolers and other components, which leads to a sharp decrease in the service life of the engine. In order to eliminate the disadvantages happening in the main engines operation in shared load modes, it is considered to use the shaft generator unit as a propeller shaft unit in the prolonged operation of the vessel at passing with a low speed and maneuvering. Such a variant of the shaft generator can be called a reversible shaft generator unit (RSGU) capable of operating in both generator and motor modes. At the same time, it is advisable to power the reversible shaft generator and general ship consumers from a diesel generator, which, in order to save fuel, can be applied as a variable speed diesel generator unit. There is presented a RSGU variant based on an asynchronous machine with a phase rotor and a frequency converter in the rotor (a double power supply machine). The functional and structural schemes of the ship’s electric power system using the variable speed diesel generator and the propulsive system based on the reversible shaft generator are presented. In the Matlab software there are developed the simulation models and presented the results of simulation modeling of the operating modes of the above systems.

scholarly journals Development of a mathematical model of diesel-generator units with a valve-inductor generator

2021 ◽  
Vol 2057 (1) ◽  
pp. 012076
Author(s):  
V A Zhigarev ◽  
A V Minakov ◽  
D V Guzei ◽  
M I Pryazhnikov ◽  
V I Panteleev
Keyword(s):  
Mathematical Model ◽  
Calculated Data ◽  
Power Losses ◽  
Diesel Generator ◽  
Fuel Injectors ◽  
Operating Modes ◽  
Effective Operation ◽  
Generator Unit ◽  
Operation Parameters

Abstract The paper presents a comprehensive mathematical model of a diesel-generator units with a valve-inductor generator. The calculated data obtained using this model allows optimizing the operation of fuel injectors and adjust the injection characteristics. The electromagnetic part of the model allows taking into account the power losses and efficiency of the generator, calculating the phase windings and their connection schemes, methods for setting the voltage or current of any shape that feeds the windings of the valve-inductor generator, as well as the characteristics of the rotor, stator, and winding materials to obtain the most effective operation parameters of the engine in various operating modes as part of the generator unit.

scholarly journals Determination of reliability of power supply of ship's responsible power receivers

2020 ◽  
pp. 22-26
Author(s):  
С.Е. Кузнецов ◽  
Н.А. Алексеев ◽  
А.А. Виноградов
Keyword(s):  
Power Systems ◽  
Power System ◽  
Power Supply ◽  
Electric Power System ◽  
Time To Failure ◽  
Parallel Operation ◽  
Diesel Generator ◽  
Operating Modes ◽  
Reliability Indicators ◽  
Supply Reliability

Изложена методика расчета показателей безотказности электроснабжения (вероятности безотказного электроснабжения и средней наработки до отказа) ответственных приемников морского судна, подключаемых к аварийному электрораспределительному щиту. Методика реализована применительно к судовой электроэнергетической системе с тремя источниками электроэнергии – двумя основными дизель-генераторными агрегатами, подключенными к главному электрораспределительному щиту, и одним аварийным дизель-генераторным агрегатом, подключенным к аварийному электрораспределительному щиту. Рассмотрены различные режимы работы судовой электроэнергетической системы: при работе до первого отказа одного основного дизель-генератора, при параллельной работе двух основных дизель-генераторов, при работе одного аварийного дизель-генератора; а также после обесточивания с учетом возможности последующего включения резервного или (и) аварийного дизель генератора. Методика, с соответствующими корректировками, может быть использована для расчета показателей безотказного электроснабжения в судовых электроэнергетических системах другой комплектации. Расчет показателей безотказности электроснабжения необходим при проектировании для обеспечения требуемого уровня надежности электроснабжения судовых приемников электроэнергии, а при эксплуатации – для предупреждения отказов и планирования технического обслуживания и ремонта элементов судовых электроэнергетических систем. The methodology for calculating the indicators of the reliability of power supply (the probability of failure-free power supply and the mean time to failure) of critical receivers of a sea vessel connected to the emergency electrical switchboard is presented. The technique is implemented in relation to a ship power system with three sources of electricity - two main diesel generator sets connected to the main electrical switchboard, and one emergency diesel generator set connected to an emergency electrical switchboard. Various operating modes of the ship's electric power system are considered: during operation until the first failure of one main diesel generator, during parallel operation of two main diesel generators, during operation of one emergency diesel generator; as well as after de-energizing, taking into account the possibility of subsequent switching on of the backup and / or emergency diesel generator. The technique, with appropriate adjustments, can be used to calculate indicators of reliable power supply in ship power systems of a different configuration. Calculation of power supply reliability indicators is necessary during design to ensure the required level of power supply reliability for ship power receivers, and during operation - to prevent failures and plan maintenance and repair of elements of ship power systems.

scholarly journals Способы компенсации высших гармоник напряжения в судовых электроэнергетических системах

2020 ◽  
Author(s):  
A.S. Kornev ◽  
V.I. Kuznetsov ◽  
H. Pan ◽  
A.P. Senkov
Keyword(s):  
Electric Power ◽  
Electric Propulsion ◽  
Frequency Converter ◽  
Electric Power System ◽  
Propulsion Systems ◽  
Higher Harmonics ◽  
Frequency Converters ◽  
Three Phase ◽  
Harmonic Components ◽  
Waveform Distortions

В статье выполнен анализ способов компенсации высших гармоник в судовой сети единой электроэнергетической системы (ЕЭЭС), в составе которой, основным потребителей электроэнергии является система электродвижения (СЭД). Рассмотрены три схемы компенсации высших гармоник, создаваемых неуправляемыми выпрямителями, входящими в состав преобразователей частоты (ПЧ). Проведено компьютерное моделирование фрагмента структуры ЕЭЭС, запатентованной фирмой Siemens , схемы 18-пульсного выпрямителя, а также схемы с двумя 12-пульсными выпрямителями. Результаты моделирования показали, что в структуре ЕЭЭС фирмы Siemens , пропульсивный трансформатор обеспечивает компенсацию только части высших гармоник, из-за чего, искажения формы напряжения в судовой сети могут быть значительными. Схема, содержащая два 12-пульсных выпрямителя, а также трехфазный трансформатор с четырьмя трехфазными обмотками, имеющими сдвиг фаз на 15 электрических градусов, показала наилучшие показатели по качеству тока, обеспечивая эффективную компенсацию 5, 7, 11, 13 гармонических составляющих тока. Предложенная схема с двумя 12-пульсными выпрямителями позволяет в составе ПЧ применить трехуровневые автономные инверторы напряжения, характеризующиеся высоким качеством тока в обмотках гребного электродвигателя.The article analyzes the methods for compensating for higher harmonics in the ship network of the unified electric power system (UEPS), in which the main electric power consumers are electric propulsion systems (EPS). Three compensation schemes for higher harmonics created by uncontrolled rectifiers that are part of frequency converters are considered. Computer simulation of a fragment of the UEPS structure patented by Siemens, an 18-pulse rectifier circuit, and also circuits with two 12-pulse rectifiers were carried out. The simulation results showed that in the Siemens UEPS structure, a propulsive transformer provides compensation for only a part of the higher harmonics, due to which, voltage waveform distortions in the ship network can be significant. The circuit, containing two 12-pulse rectifiers, as well as a three-phase transformer with four three-phase windings having a phase shift of 15 electrical degrees, showed the best current quality indicators, providing effective compensation for 5, 7, 11, 13 harmonic components of the current. The proposed circuit with two 12-pulse rectifiers allows the use of three-level autonomous voltage inverters, which are characterized by high quality current in the windings of the propeller motor, as part of the frequency converter.

scholarly journals Variable-Speed Engines on Wind Farm Support Vessels

2020 ◽  
Vol 8 (3) ◽  
pp. 229 ◽  
Author(s):  
Kristian Eikeland Holmefjord ◽  
Lars Husdal ◽  
Martijn de Jongh ◽  
Sverre Torben
Keyword(s):  
Direct Current ◽  
Diesel Engines ◽  
Wind Farm ◽  
East Coast ◽  
Frequency Converter ◽  
Real Life ◽  
Alternating Current ◽  
Variable Speed ◽  
Fixed Frequency ◽  
Fuel Savings

We examine the fuel savings of Edda Passat, a newly constructed wind farm support vessel that utilizes a common direct current (DC) grid. This enables its diesel engines to operate at variable speeds by using frequency converter technology. A detailed investigation of these benefits has been performed based on real-life measurements from three months of operations in the Race Bank wind farm off the east coast of England. The calculated fuel savings of Edda Passat achieved via its variable-speed engines are 21% lower compared to using a conventional alternating current (AC) grid with a fixed frequency. This paper will explain the technology, measurements, and results in detail.

Sign in / Sign up

Export Citation Format

Share Document