A Megawatt-Scale Medium-Voltage High Efficiency High Power Density “SiC+Si” Hybrid Three-Level ANPC Inverter for Aircraft Hybrid-Electric Propulsion Systems

Unmanned Aerial Vehicle (UAV) propulsion technology is significantly related to the flight performance of UAVs, which has become one of the most important development directions of aviation. It should be noted that UAVs have three types of propulsion systems, namely the fuel, hybrid fuel-electric, and pure electric, respectively. This paper presents and discusses the classification, working principles, characteristics, and critical technologies of these three types of propulsion systems. It is helpful to establish the development framework of the UAV propulsion system and provide the essential information on electric propulsion UAVs. Additionally, future technologies and development, including the high-power density motors, converters, power supplies, are discussed for the electric propulsion UAVs. In the near future, the electric propulsion system would be widely used in UAVs. The high-power density system would become the development trend of electric UAVs. Thus, this review article provides comprehensive views and multiple comparisons of propulsion systems for UAVs.

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Design of high-power density and high-efficiency IM for hybrid electric aircraft

2011 International Conference on Electrical Machines and Systems ◽

10.1109/icems.2011.6073940 ◽

2011 ◽

Author(s):

Lv Zhongshu ◽

Ren Yanlong ◽

Wang Sen ◽

Cao Baixing

Keyword(s):

Power Density ◽

High Power ◽

High Efficiency ◽

High Power Density ◽

Electric Aircraft ◽

Hybrid Electric

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Near-field thermophotovoltaics for efficient heat to electricity conversion at high power density

Nature Communications ◽

10.1038/s41467-021-24587-7 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Rohith Mittapally ◽

Byungjun Lee ◽

Linxiao Zhu ◽

Amin Reihani ◽

Ju Won Lim ◽

...

Keyword(s):

Power Density ◽

High Power ◽

High Efficiency ◽

Near Field ◽

Electrical Power ◽

Photovoltaic Cells ◽

High Power Density ◽

Pv Cell ◽

Electrical Power Output ◽

Power Densities

AbstractThermophotovoltaic approaches that take advantage of near-field evanescent modes are being actively explored due to their potential for high-power density and high-efficiency energy conversion. However, progress towards functional near-field thermophotovoltaic devices has been limited by challenges in creating thermally robust planar emitters and photovoltaic cells designed for near-field thermal radiation. Here, we demonstrate record power densities of ~5 kW/m2 at an efficiency of 6.8%, where the efficiency of the system is defined as the ratio of the electrical power output of the PV cell to the radiative heat transfer from the emitter to the PV cell. This was accomplished by developing novel emitter devices that can sustain temperatures as high as 1270 K and positioning them into the near-field (<100 nm) of custom-fabricated InGaAs-based thin film photovoltaic cells. In addition to demonstrating efficient heat-to-electricity conversion at high power density, we report the performance of thermophotovoltaic devices across a range of emitter temperatures (~800 K–1270 K) and gap sizes (70 nm–7 µm). The methods and insights achieved in this work represent a critical step towards understanding the fundamental principles of harvesting thermal energy in the near-field.

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