The More-Electric Aircraft and Beyond

Aviation is a significant contributor to greenhouse gas (GHG) emissions in the transportation sector. As the adoption of electric cars increases and GHG emissions due to other modes of transport decrease, the impact of air travel on environmental pollution has become even more significant. To reduce pollution and maintenance, and ensure cheaper and more convenient flights, industry and academia have directed their efforts toward aircraft electrification. Considering various types of aircraft, several frameworks have been proposed: more-electric aircraft (MEA), hybrid electric aircraft (HEA), and all-electric aircraft (AEA). In the MEA framework, propulsion is generated by a conventional jet engine; however, all secondary systems (hydraulic, pneumatic, and actuation) are electrified. By further increasing electrification, electric motors can provide propulsion with the electric power supplied by the conventional engine (i.e., HEA) or from electrical energy storage (i.e., AEA). Power electronics and electrical machines play a key role in this scenario in which electric power must be efficiently generated, distributed, and consumed to satisfy extremely high requirements of aviation safety. This article provides an overview of recent advancements in aircraft electrification, and trends and future developments referenced to the global aviation roadmap

Optimal control of three-phase embedded power grids

This paper presents an automated and scalable approach for the tuning of power converters control systems in embedded power grids. These are composed by different power converter interconnected to each other and are increasingly adopted in a range of applications among which micro-grids and more electric aircrafts. The interaction between the grid components may lead to instability, especially in presence of small passive filters. A structured state feedback optimal control approach is proposed to jointly design all power converters controllers in a coordinated way to maximize the performance of the grid and avoid instability due to converters interactio

10-kV SiC MOSFET Power Module With Reduced Common-Mode Noise and Electric Field

The advancement of silicon carbide (SiC) power devices with voltage ratings exceeding 10 kV is expected to revolutionize medium- and high-voltage systems. However, present power module packages are limiting the performance of these unique switches. The objective of this research is to push the boundaries of high-density, high-speed, 10-kV power module packaging. The proposed package addresses the well-known electromagnetic and thermal challenges, as well as the prominent electrostatic and electromagnetic interference (EMI) issues associated with high-speed, 10-kV devices. The high-speed switching and high voltage rating of these devices causes significant EMI and high electric fields. Existing power module packages are unable to address these challenges, resulting in detrimental EMI and partial discharge that limit the converter operation. This article presents the design and testing of a 10-kV SiC mosfet power module that switches at a record 250 V/ns without compromising the signal and ground integrity due to an integrated screen reduces the common-mode current by ten times. This screen connection simultaneously increases the partial discharge inception voltage by more than 50%. With the integrated cooling system, the power module prototype achieves a power density of 4 W/mm 3

Toward robust stability of aircraft electrical power systems: using a ?-based structural singular value to analyze and ensure network stability

Transport accounts for nearly two-thirds of the global crude oil consumption and about a quarter of carbon dioxide (CO2) emissions (International Energy Agency 2009, Intergovernmental Panel on Climate Change 2014). The energy use and CO2 emissions in this sector are predicted to increase 80% by 2050 (International Energy Agency 2009). The major contributors of greenhouse effects are expected to be light-duty vehicles (43%), trucks (21%), aviation (20%), and shipping (8%) by 2050 (International Energy Agency 2009). Buses and railways are already sustainable modes of transport. To mitigate the impact of the emissions on climate change, the Intergovernmental Panel on Climate Change, which is the leading international body assessing climate change, recommends a reduction of at least 50% in global CO2 emissions by 2050 (International Energy Agency 2009). This target cannot be met unless there is a deep cut in CO2 emissions from the transportation sector. On the other hand, independent of climate policy actions, the projections are that fossil fuel reserves will become exhausted within the next 50 years. If a more sustainable future is to be achieved, the issues of greenhouse emissions and energy security must be addressed. One long-term solution may well lie in both the adoption of current best technologies and in the development of more advanced technologies, in all sectors of transportation (International Energy Agency 2009). A shift toward more efficient modes of transport, including the more electric aircraft (MEA), are not merely needed, but are required

Design and development of a high-density, high-speed 10 kV SiC MOSFET module

High-density packaging of fast-switching power semiconductors typically requires low parasitic inductance, high heat extraction, and high thermo-mechanical reliability. High-density packaging of high-voltage power semiconductors, such as 10 kV SiC MOSFETs, also requires low electric field concentration in order to prevent premature dielectric breakdown. Consequently, in addition to the usual electromagnetic, thermal, and mechanical analyses, the electric fields must also be evaluated. This is the first detailed report on the optimization of a high-voltage SiC MOSFET power module

Dual Active Bridge based Battery Charger for Plug-in Hybrid Electric Vehicle with Charging Current Containing Low Frequency Ripple

High power density is strongly preferable for the on-board battery charger of Plug-in Hybrid Electric Vehicle (PHEV). Wide band gap devices, such as Gallium Nitride HEMTs are being explored to push to higher switching frequency and reduce passive component size. In this case, the bulk DC link capacitor of AC-DC Power Factor Correction (PFC) stage, which is usually necessary to store ripple power of two times the line frequency in a DC current charging system, becomes a major barrier on power density. If low frequency ripple is allowed in the battery, the DC link capacitance can be significantly reduced. This paper focuses on the operation of a battery charging system, which is comprised of one Full Bridge (FB) AC-DC stage and one Dual Active Bridge (DAB) DC-DC stage, with charging current containing low frequency ripple at two times line frequency, designated as sinusoidal charging. DAB operation under sinusoidal charging is investigated. Two types of control schemes are proposed and implemented in an experimental prototype. It is proved that closed loop current control is the better. Full system test including both FB AC-DC stage and DAB DC-DC stage verified the concept of sinusoidal charging, which may lead to potentially very high power density battery charger for PHEV