Toshiba developing lightweight, compact, high-power superconducting motor for mobility applications
24 June 2022
Toshiba Energy Systems & Solutions Corporation (Toshiba ESS) has developed a prototype superconducting motor to meet the needs of the mobility sector. This superconducting motor, with a maximum output of 2 MW, can realize lightweight, high-output density and high-speed rotation, and can be made available for large mobility applications.
Toshiba ESS says that this superconducting motor with these features is the first of its kind. Toshiba ESS is aiming to commercialize this technology by the late 2020s.
The 2MW is approximately 500 mm in diameter and 700 mm in length (excluding the shaft).
Movements to reduce greenhouse gas emissions are accelerating rapidly in the mobility industry. The aviation industry, for example, is aiming to reduce emissions of CO2 to zero (carbon-free) by 2050. In doing so, conventional fossil fuel gas will gradually be replaced by sustainable aviation fuel (SAF). However, to achieve total carbon neutrality, it is necessary to explore not only carbon-free SAF, but also aviation systems as a whole; thus, the industry needs to develop lightweight and high-powered motors for propulsion systems.
The superconducting motor was developed by a team of engineers and experts at Toshiba ESS’s Keihin Operations, which has a track record in developing and manufacturing generators and superconductive products for nuclear power generation and thermal power generation.
The newly developed superconducting motor is less than 1/10th the weight and size of a conventional motor with the same level of power output, and Toshiba ESS expects it will make a significant contribution to the electrification of aircrafts and the mobility sector. The company will further improve this technology and accelerate efforts toward its implementation.
Two of these would work well in an ATR72 sized aircraft of ~23 tons.
Now you just need an energy storage plan.
Say it can cruise at 1/2 power, that is 2 MW for 2 of these engines.
Then, you need 2 MWh for a 1 hour flight.
Say 166 wh / kg, so 12 tons of batteries - maybe not.
Maybe better add the RR turbogenerator and say 1-2 tons of batteries.
Now we are talking.
Posted by: mahonj | 24 June 2022 at 08:23 AM
@mahonj Good start. Batteries should be sized to power takeoff to cruise altitude and they can be recharged during decent to landing. This could be much more efficient than the existing design.
Posted by: GdB | 24 June 2022 at 01:40 PM
RR turbogenerator fuel could be NH3 to achieve zero emissions and long range.
Posted by: GdB | 24 June 2022 at 01:41 PM
Why not supply the aircraft from the ground with beamed power? That obviates the need for batteries for climb, and eliminates the weight also.
Seriously, these things are not so difficult.
Posted by: Engineer-Poet | 25 June 2022 at 05:28 AM
@GdB there is a bit of work to be done on ammonia.
https://onlinelibrary.wiley.com/doi/10.1002/er.6232#:~:text=When%20ammonia%20is%20used%20in,from%20the%20exhaust%20without%20burning.
@EP, you mean using microwaves (or lasers) to beam power up - have you any references?
Even it if worked, it would be a bit nerve wracking - if the transmitter malfunctioned, you'd be in trouble, so you would want some batteries to tide you over.
One thing struck me is that you should be able to transmit power to the plane right up until the moment of takeoff, like an electric train - at least only use the batteries when you are off the ground. (Might be tricky in crosswinds).
Posted by: mahonj | 25 June 2022 at 06:18 AM
mahonj,
energy is mostly spent climbing to cruising altitude and reaching cruising speed, so electrifying the runway is not that useful. Not much energy is spent until take off.
For electric airplanes, I think one can assume battery energy densities much higher than 166 wh/kg. Probably higher than 200 wh/kg.
Car batteries are heavier, but cost matters more in cars...
Posted by: peskanov | 25 June 2022 at 08:37 AM
Who says you have to have only one transmitter? You could have dozens of redundant ones, with battery backup... on the ground. That would also allow a bunch to be taken out of service for maintenance while the system was running.
This is the philosophy behind the PPPP laser-launch scheme: the only things which leave the ground are Payload, Propellant and Photons, Period.
Posted by: Engineer-Poet | 25 June 2022 at 03:16 PM
@EP
Your idea may not be far off. Except use batteries for takeoff and refuel in the air. DARPA thinks that may work. Read: “Tankers Charging Drones With Lasers The Focus Of New DARPA Program”. https://www.thedrive.com/the-war-zone/tankers-charging-drones-with-lasers-the-focus-of-new-darpa-program
Posted by: Gryf | 27 June 2022 at 08:45 AM
Great !!! This superconduction motor has Liquid Hydrogen (LH2) spelled all over it. The LH2 will be routed around the SC magnets in order to maintain superconducting temperatures.
In combination, the LH2 and the greatly-downsized motors (to 1/10th) will greatly reduce propulsion weight for the long-range vehicle, especially planes, allowing much higher payload capacity than ever possible with petroleum /ICE combination, while realizing Zero-Emission and Zero-CO2 transportation.
The advantage of using e-motor for ducted fan aircraft is that the fans can be embedded inside the rear portion of the wings or fuselage, in order to greatly reduce nacelle drag, since fire and explosion hazard will be much reduced with the use of e-motors instead of gas turbines. The use of blended-wing-body aircraft for storage of LH2 will also lend the very thick central wing section to cover the fans, thus resulting in a very clean configuration in order to even further enhance aerodynamic efficiency.
Thus we will be getting 3 sources of efficiency gain: from major gross-take-off weight reduction, from higher motor efficiency, and from aerodynamic drag reduction. This will greatly give economic incentive for the use of LH2 for SC motors in blended-wing body aircraft to replace the grossly inefficient existing petroleum/ICE/cigar-shaped fuselage/huge engine-fan nacelle configuration.
Posted by: Roger Pham | 27 June 2022 at 10:57 AM
@mahonj
In my opinion fuel cells are the way to go with airplanes. SOFCs, none of that hydrogen nonsense.
The fuel could have better energy density than typical jet fuel, and the fuel cell could be highly efficient.
Posted by: M_zsolt | 27 June 2022 at 02:49 PM
@Roger Pham
How do you come up with liquid hydrogen. It's not mentioned anywhere.
Besides, it's very troublesome and highly unlikely in the age of high temperature superconductors that only require liquid nitrogen cooling.
Posted by: M_zsolt | 28 June 2022 at 01:40 AM
@M_zsolt,
Airbus and several other aircraft makers are working on LH2 for air transport. The most important benefit of LH2 is massive fuel weight reduction, only 1/3 the weight of Jet fuel per BTU of energy. Blended-wing-body aircraft design is the prime candidate because of increase in volume to surface ratio that will permit lower drag even with the larger volume of fuel due to the low-density LH2.
Blended-wing-body configuration with very thick wing root section is also beneficial to embed the ducted-fan nacelle within the wing root, thus another major drag reduction of this configuration when using electric motor ducted fan propulsion. There are several incredible synergies that will result in unprecedented level of efficiency gain from the use of LH2 powering Fuel Cells and Super-Conducting motor in blended-wing-body aircraft with embedded electric ducted fan nacelles.
Posted by: Roger Pham | 28 June 2022 at 07:02 PM