scholarly journals A Review on the Faults of Electric Machines Used in Electric Ships

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Dionysios V. Spyropoulos ◽  
Epaminondas D. Mitronikas

Electric propulsion systems are today widely applied in modern ships, including transport ships and warships. The ship of the future will be fully electric, and not only its propulsion system but also all the other services will depend on electric power. The robust and reliable operation of the ship’s power system is essential. In this work, a review on the mechanical and electrical faults of electric machines that are used in electric ships is presented.

2020 ◽  
Vol 2020 ◽  
pp. 1-21
Author(s):  
Peng Zheng ◽  
Jianjun Wu ◽  
Yu Zhang ◽  
Biqi Wu

To develop the satellites for a low-Earth-orbit environment, atmosphere-breathing electric propulsion (ABEP) systems have become more attractive to researchers in the past decade. The system can use atmospheric molecules as the propellant to provide thrust compensation, which can extend the lifetime of spacecraft (S/C). This comprehensive review reviews the efforts of previous researchers to develop concepts for ABEP systems. Different kinds of space propulsion system are analysed to determine the suitable propulsion for atmosphere-breathing S/C. Further discussion about ABEP systems shows the characteristic of different thrusters. The main performance of the ABEP system of previous studies is summarized, which provides further research avenues in the future. Results show great potential for thrust compensation from atmospheric molecules. However, the current studies show various limitations and are difficult to apply to space. The development of ABEP needs to solve some problems, such as the intake efficiency, ionization power, and electrode corrosion.


Author(s):  
A.S. Kornev ◽  
V.I. Kuznetsov ◽  
H. Pan ◽  
A.P. Senkov

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.


2016 ◽  
Vol 5 ◽  
pp. 113-119 ◽  
Author(s):  
Editha Kötter ◽  
Ludwig Schneider ◽  
Frank Sehnke ◽  
Kay Ohnmeiss ◽  
Ramona Schröer

2019 ◽  
Vol 7 (6) ◽  
pp. 168
Author(s):  
Hyeonmin Jeon ◽  
Jongsu Kim ◽  
Kyoungkuk Yoon

In the case of the electric propulsion system on the vessel, Diode Front End (DFE) rectifiers have been applied for large-sized ships and Active Front End (AFE) rectifiers have been utilized for small and medium-sized ships as a part of the system. In this paper, we design a large electric propulsion ship system using AFE rectifier with the proposed phase angle detector and verify the feasibility of the system by simulation. The phase angle derived from the proposed phase angle detection method is applied to the control of the AFE rectifier instead of the zero-crossing method used to detect the phase angle in the control of the conventional AFE rectifier. We compare and analyze the speed control, Direct Current (DC)-link voltage, harmonic content and measurement data of heat loss by inverter switch obtained from the simulation of the electric propulsion system with the 24-pulse DFE rectifier, the conventional AFE rectifier, and the proposed AFE rectifier. As a result of the simulation, it was confirmed that the proposed AFE rectifier derives a satisfactory result similar to that of a 24-pulse DFE rectifier with a phase shifting transformer installed according to the speed load of the ship, and it can be designed and applied as a rectifier of a large-sized vessel.


Author(s):  
Ioannis Roumeliotis ◽  
Lorenzo Castro ◽  
Soheil Jafari ◽  
Vassilios Pachidis ◽  
Louis De Riberolles ◽  
...  

Abstract Future aircraft and rotorcraft propulsion systems should be able to meet ambitious targets and severe limitations set by governments and organizations. These targets cannot be achieved through marginal improvements in turbine technology or vehicle design. Hybrid-electric propulsion is being widely considered as a revolutionary concept to further improve the environmental impact of air travel. One of the most important challenges and barriers in the development phase of hybrid-electric propulsion systems is the Thermal Management System (TMS) design, sizing and optimization for addressing the increased thermal loads due to the electric power train. The aim of this paper is to establish an integrated simulation framework including the vehicle, the propulsion system and the fuel-oil system (FOS) for assessing the cooling capability of the FOS for the more electric era of rotorcrafts. The framework consists of a helicopter model, propulsion system models, both conventional and hybrid-electric, and a FOS model. The test case is a twin-engine medium (TEM) helicopter flying a representative Passenger Air Transport (PAT) mission. The conventional power plant heat loads are calculated and the cooling capacity of the FOS is quantified for different operating conditions. Having established the baseline, three different Power Management Strategies (PMS) are considered and the integrated simulation framework is utilized for evaluating FOS temperatures. The results highlight the limitations of existing rotorcraft FOS to cope with the high values of thermal loads associated with hybridization for the cases examined. Hence, new ideas and embodiments should be identified and assessed. The case of exploiting the fuel tank as a heat sink is investigated and the results indicate that recirculating fuel to the fuel tank can enhance the cooling capacity of conventional FOS.


2021 ◽  
Vol 1 (395) ◽  
pp. 132-140
Author(s):  
I. Kalinin ◽  

Object and purpose of research. This paper discusses electric propulsion system of leader icebreaker. Its purpose was to develop mathematical and computer-based model of electric propulsion drive powered by asynchronous motor with three stator windings for further investigation of steady, transitional, asymmetric and emergency operation scenarios of electric power and propulsion system for the leader icebreaker. Materials and methods. Hardware and methods for computer-based simulation of complex engineering structures. Main results. Development of the mathematical model representing asynchronous motor with three windings in phase coordinates. Computational studies on direct startup of 15 MW propulsion motor, as well as on steady and transitional operational conditions of ship electric power system consisting of 36 MW synchronous genset, two-winding transformers and electric propulsion drive with 15 MW asynchronous motor in phase coordinates with three stator windings and three-level frequency converter. Calculation of voltage non-sinusoidality ratio for MSB buses with operation of 15 MW propulsion motor driven by 36 MW synchronous genset. Conclusion. Mathematical model of asynchronous motor suggested in this paper could be used to calculate steady and transitional operation scenarios of marine power systems with frequency-controlled three-winding asynchronous motor, as well as to calculate electromechanical and electromagnetic processes and refine frequency control algorithms. This is especially relevant because each of the asynchronous electric machines used in the electromechanical assemblies of leader icebreaker propulsion motors has three stator windings, and this icebreaker is the first experience of applying a 15 MW marine electric drive.


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