Design of Risk Prediction Assessment for Ship-Integrated Electric Propulsion System

2021 ◽  
pp. 1-9
Author(s):  
Pengfei Zhi ◽  
Zhiyu Zhu ◽  
Wanlu Zhu ◽  
Haiyang Qiu
Keyword(s):  
Risk Assessment ◽  
Risk Prediction ◽  
Electric Propulsion ◽  
Internal Combustion Engines ◽  
Viterbi Algorithm ◽  
Propulsion System ◽  
Operating Conditions ◽  
Assessment System ◽  
Electric Propulsion System ◽  
The Future

A design of risk prediction assessment is proposed to improve the safety and economy of ship-integrated electric propulsion system(SIEPS). Firstly, the article puts forward a multihidden Markov model (MHMM)–Viterbi algorithm to predict fault state probabilities of each component in the continuous time points in the future. Secondly, according to the influence of dynamic ocean condition, the fault states of the components of SIEPS are predicted by using the MHMM–Viterbi algorithm. Thirdly, the risk assessment system of network topology of SIEPS is designed, and power flow analysis under the abnormal condition is repeatedly calculated by using the MonteCarlo simulation. Finally, the article takes a SIEPS as an example and the risk prediction assessment results is given. Introduction With the establishment of increasingly stringent standards by the International Maritime Organization in terms of ship emissions and the increasing scarcity of petroleum resources, electric propulsion systems are gradually replacing internal combustion engines, which will become the future direction of ship power development. Electric propulsion ships do have many advantages such as high efficiency, high automation, environmental protection, energy saving, and emission reduction. However, ship-integrated electric propulsion system(SIEPS) is also the soft underbelly of electric propulsion ships. First of all, the complexity of the external environment factors such as high humidity and high salinity of ships (especially marine vessels) under long-term operating conditions, and the coupling of electromagnetic, thermal, and vibration signals of SIEPS will increase the failure rate of electrical equipment, thereby increasing the risk of SIEPS. Secondly, for electric propulsion ships, the SIEPS risk is likely to lead to chain failure of important systems such as power, control, navigation, resulting in the ship. Equipment and even personnel cause irreparable damage, causing fatal damage to electric propulsion ships. Therefore, in order to improve the safety, reliability, and economy of electric propulsion ships, it is necessary to carry out research on relevant technologies for SIEPS risk assessment (Wen et al. 2012; Guangfu et al. 2013).

scholarly journals Development of fully superconducting 5 MW aviation generator with liquid hydrogen cooling

2022 ◽  
pp. 62-73
Author(s):  
Dmitry Dezhin ◽  
Roman Ilyasov
Keyword(s):  
Electric Propulsion ◽  
Fem Simulation ◽  
Synchronous Generator ◽  
Liquid Hydrogen ◽  
Propulsion System ◽  
Moscow Aviation Institute ◽  
Cross Sectional ◽  
Electric Propulsion System ◽  
The Future ◽  
Hydrogen Cooling

The use of liquid hydrogen as a fuel will be inevitable in the aviation of the future. This statement means that manufacturers will also implement liquid hydrogen for cooling all superconducting aviation equipment of an electric propulsion system. The development of fully electric aircraft is the most promising solution in this case. Scientists from the Department of electrical machines and power electronics of Moscow aviation institute have conducted calculations and theoretical researches of critical specific mass-dimensional parameters (MW/ton and MW/m3 at 21 K) of fully superconducting aviation synchronous generator of the electric propulsion system. The results are in this article. The article discusses the results 3D finite element modeling (FEM) simulation of a 5 MW fully superconducting synchronous generator with combined excitation. Superconducting armature and axial excitation windings based on second generation high temperature superconductors (HTS-2G) are located on the stator, which makes it possible to contactlessness and the absence of sliding seals. A dry gap will reduce gas-dynamic losses and increase the nominal peripheral speed of the rotor. The use of liquid hydrogen as a coolant makes it possible to significantly increase the linear load of the generator, and high current densities to reduce the cross-sectional area of the coils, which will make it possible to place them in individual cryostats in the future. Individual cryostats will allow to remove the heat release of magnetic losses from the cryogenic zone and reduce the consumption of refrigerant. For the purpose of internal redundancy of the HTS coils, the machine has a complete set of reserve winding made of ultrapure aluminum, also cooled by liquid hydrogen. If the superconducting coils get out of the stand, the generator will provide 15 % power on standby

scholarly journals Modelling and Experimental Validation of a Hybrid Electric Propulsion System for Light Aircraft and Unmanned Aerial Vehicles

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3969
Author(s):  
Massimo Cardone ◽  
Bonaventura Gargiulo ◽  
Enrico Fornaro
Keyword(s):  
Unmanned Aerial Vehicles ◽  
Model Validation ◽  
Electric Propulsion ◽  
Combustion Engine ◽  
Propulsion System ◽  
Operating Conditions ◽  
Total Power ◽  
Electric Propulsion System ◽  
Aerial Vehicles ◽  
Hybrid Electric

This article presents a numerical model of an aeronautical hybrid electric propulsion system (HEPS) based on an energy method. This model is designed for HEPS with a total power of 100 kW in a parallel configuration intended for ultralight aircraft and unmanned aerial vehicles (UAV). The model involves the interaction between the internal combustion engine (ICE), the electric motor (EM), the lithium battery and the aircraft propeller. This paper also describes an experimental setup that can reproduce some flight phases, or entire missions, for the reference aircraft class. The experimental data, obtained by reproducing two different take-offs, were used for model validation. The model can also simulate anomalous operating conditions. Therefore, the tests chosen for the model validation are characterized by the EM flux weakening (“de-fluxing”). This model is particularly suitable for preliminary stages of design when it is necessary to characterize the hybrid system architecture. Moreover, this model helps with the choice of the main components (e.g., ICE, EM, and transmission gear ratio). The results of the investigation conducted for different battery voltages and EM transmission ratios are shown for the same mission. Despite the highly simplified model, the average margin of error between the experimental and simulated results was generally under 5%.

scholarly journals Design of Hybrid-Electric Megayachts: The Impact of Operative Profile and Smart Berthing Infrastructures

2021 ◽  
Vol 9 (2) ◽  
pp. 186
Author(s):  
Francesco Mauro ◽  
Elia Ghigliossi ◽  
Vittorio Bucci ◽  
Alberto Marinó
Keyword(s):  
Electric Propulsion ◽  
Propulsion System ◽  
Storage Devices ◽  
Electric Propulsion System ◽  
Hybrid Electric ◽  
The Impact

Nowadays, sustainable navigation is becoming a trending topic not only for merchant ships but also for pleasure vessels such as motoryachts. Therefore, the adoption of a hybrid-electric propulsion system and the installation of on-board storage devices could increase the greenness of a megayacht. This paper analyses the performance of three commercial propulsive solutions, using a dynamic operative profile and considering the influences of the smart berthing infrastructures. Results compare the yearly fuel consumptions of the analysed configurations for a reference megayacht.

scholarly journals Design and In-orbit Demonstration of REGULUS, an Iodine electric propulsion system

2021 ◽  
Author(s):  
Nicolas Bellomo ◽  
Mirko Magarotto ◽  
Marco Manente ◽  
Fabio Trezzolani ◽  
Riccardo Mantellato ◽  
...  
Keyword(s):  
Electric Propulsion ◽  
Specific Impulse ◽  
Input Power ◽  
Propulsion System ◽  
Electric Propulsion System ◽  
Propulsive Performance ◽  
Plasma Thruster ◽  
Total Impulse ◽  
Acceptance Tests

AbstractREGULUS is an Iodine-based electric propulsion system. It has been designed and manufactured at the Italian company Technology for Propulsion and Innovation SpA (T4i). REGULUS integrates the Magnetically Enhanced Plasma Thruster (MEPT) and its subsystems, namely electronics, fluidic, and thermo-structural in a volume of 1.5 U. The mass envelope is 2.5 kg, including propellant. REGULUS targets CubeSat platforms larger than 6 U and CubeSat carriers. A thrust T = 0.60 mN and a specific impulse Isp = 600 s are achieved with an input power of P = 50 W; the nominal total impulse is Itot = 3000 Ns. REGULUS has been integrated on-board of the UniSat-7 satellite and its In-orbit Demonstration (IoD) is currently ongoing. The principal topics addressed in this work are: (i) design of REGULUS, (ii) comparison of the propulsive performance obtained operating the MEPT with different propellants, namely Xenon and Iodine, (iii) qualification and acceptance tests, (iv) plume analysis, (v) the IoD.

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