This study presents a static method for measuring torque ripple of the high power starter generator (SG), which has an advantage over the traditional dynamic method. The method proposed accurately ...measures the torque ripple of the SG during the start mode. The results can be applied to analyse the harmonics of the torque ripple. The accuracy of the method is verified by the experiments.
More electric aircraft (MEA) becomes a trend for next generation aircraft to respond to the global wide energy shortage. The technological advancement in power electronics makes MEA possible. Airbus ...and Boeing have advanced their research and application 30 years or earlier than China does. As a major civil aircraft manufacturer in China, COMAC can play an important role in applying and promoting new technologies for next generation aircraft. Based on authors' practice in recent years MEA development project, in this study, the challenge for MEA design is identified and the key technologies for MEA are elaborated from the aircraft, system and component level, and an attempt is made to address the challenge encountered. The method for MEA system integration is given in lieu of ARP 4754A. Finally, an innovative collaboration between original equipment manufacturer (OEM) and suppliers is suggested to achieve win–win situation in developing next generation aircraft.
High‐voltage direct current (HVDC) electric power system (EPS) is a promising architecture for more electric aircraft (MEA). With more electric power used, a higher voltage is necessary to make ...aircrafts more efficient and less weighted. However, there are no standards can be followed to evaluate the power quality of HVDC EPS, especially for 540 VDC system. In this study, a potential HVDC EPS is proposed and power quality is studied by simulation. Behavioural models of the system are established in detail from source to load. Three kinds of typical loads of MEA are defined and their impacts on power quality are analysed including resistances, power electronic converters, and motors. Some suggestions are provided for design and integration of the EPS for MEA.
The transient behaviour of electric heating and de‐icing of the wing is studied by numerical method. The thermal convection coupling method based on the equivalent heat transfer coefficient and the ...boundary condition iteration is developed for the two designed schemes of the electric heating system. According to the surface temperature, the internal temperature, and the icing condition, the system transient performance is investigated. The purpose of this study is to establish the de‐icing transient model of the wing ice protection system, simulate the transient de‐icing process and form the method of performance estimation. The results under different working conditions show that the temperature distribution of the skin surface is not uniform, rather presents certain regularity. The rising rate of temperature decreases with the increase of the temperature. The trend is more obvious at lower ambient temperature, when the ambient temperature rises, the surface temperature rises rapidly in a short period. Scheme 2 has certain advantages in heating capability, while the hot knives structure of scheme 1 can narrow and split the icing area.
Abstract
Liquid cooling system mainly provides cooling to high-power power electronic equipment on civil aircraft. It is an important support that it can ensure the high-power power electronic ...equipment working normally. In this paper, the modeling and simulation of cooling system are carried out. And it mainly focuses on the liquid cooling plate of high-power power electronic equipment. First, three kinds of simulated conditions are confirmed, which are variable temperature of cooling liquid, variable heat load of power electronic equipment and variable flow of cooling liquid. Then according to three kinds of simulated conditions, the performance of cooling system is validated, which is benefit to the design of liquid cooling system and liquid cooling plate.
Abstract
For the evaluation of civil aircraft hydraulic system, Fuel Consumption is a very important index. However, there is no effective method to perform analysis for different architecture. This ...paper proposes that taking fuel weight penalty as a major mathmatical modeling method to analysis traditional architecture and more electric architecture. The result shows that the fuel consumption of more electric architecture is less than traditional architecture.
Abstract
The thesis has carried out design and simulated analysis of low flux cold plate for high-power power electronics equipment. First, according to heat distribution and design requirements, two ...kinds of flow passage for low flux cold plate is designed. Then performance characteristics simulation of different flow passage for cold plate is performed. And the heat dissipation characteristics of two kinds of flow passage can both meet the design requirements. Finally, from the perspective of high temperature, temperature difference, pressure drop and so on, the simulated results are comparative analysis. And it is helpful to the design and optimizing of cold plate for high-power power electronics equipment.
It is an important trend to develop the more electric aircraft (MEA) ±270 V high‐voltage direct current (HVDC) power system because of its better reliability, power quality and power density. ...However, there also exists the low‐voltage 28 V DC system in HVDC power system, for the aviation battery and some equipment still rely on it. In traditional MEA power systems, battery is only used as a backup power supply, hardly participating in the adjustment of the power system. On the other hand, the function of turbine engine is unidirectional. Hence, it's necessary to add an energy storage port. In this research, the authors put forward the problems of power coupling and strong non‐linearity in traditional three‐port triple active bridge (TAB) converters, and propose a decoupled TAB topology, which has the feature of decoupled power flow. The topology is compatible with ±270 V DC, 28 V DC and energy storage system with high‐power density and efficiency. In addition, the authors unify the efficiency optimisation problem of dual active bridge topology mathematically and provide an optimal parameter design approach for inductance and turns ratio. Simulation results show the power flow control strategy is appropriate for the topology.
The most important characteristics of aircraft power system are power density, reliability, availability and power quality. The traditional more electric aircraft (MEA) 28 VDC network is used to ...power the core electronic system. However, the 28 VDC network in modern MEAs such as B787 or A380 is a centralised power network obtained by transformer rectifier unit (TRU), battery charge and rectifier unit (BCRU) or two‐stage power conversion (AC/DC + DC/DC) from 230 VAC, 400–800 Hz variable frequency input. The traditional centralised architecture is of low‐power density and low fault tolerance. Furthermore, compared to distributed power network, the centralised architecture is of less availability inherently, therefore a single‐stage, isolated, low‐power and high‐power density power supply is required to achieve the distributed 28 VDC network. In this study, a three‐phase single‐switch discontinuous mode AC–DC flyback converter is proposed. The converter directly rectifies a three‐phase, 400–800 Hz, 230 VAC network into a 28 VDC network. The operation modes of the converter are analysed. A prototype is carefully designed and implemented using high‐frequency planner transformer and SiC MOSFET techniques, aiming at higher performance. Experimental results demonstrate the practicability and high performance of the proposed power supply system.
A high‐voltage direct current (HVDC) electric power system (EPS) has become an attractive power distribution architecture for the more electric aircraft. The structure of a typical HVDC parallel EPS ...based on the permanent magnet synchronous machine (PMSM) starter/generators (S/Gs) is proposed in this study. On the basis of this structure, the control strategy for a single PMSM S/G system is presented, which is suitable for wide‐speed operation and high‐power application. It can not only achieve both starter and generator functions but also achieve the stability of DC bus voltage. A master–slave current sharing method is derived and can be applied in the HVDC parallel system, compared with the droop‐control strategy. The validity of the proposed strategies is verified by simulation studies in a Matlab/Simulation environment.
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