The NASA Electric Aircraft Testbed (NEAT) is a

NASA The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the federal government of the United States, US federal government responsible for the United States ...

reconfigurable

testbed A testbed (also spelled test bed) is a platform for conducting rigorous, transparent, and replicable testing of scientific theories, computing tools, and new technologies. The term is used across many disciplines to describe experimental research ...

Plum Brook Station NASA John H. Glenn Research Center at Lewis Field is a NASA center within the cities of Brook Park and Cleveland between Cleveland Hopkins International Airport and the Rocky River Reservation of Cleveland Metroparks, with a subsidiary facil ...

, Ohio, used to design, develop, assemble and test

electric aircraft An electric aircraft is an aircraft powered by electricity. Electric aircraft are seen as a way to reduce the environmental effects of aviation, providing zero emissions and quieter flights. Electricity may be supplied by a variety of methods, ...

power systems, from a small, one or two person aircraft up to

airliner An airliner is a type of airplane for transporting passengers and air cargo. Such aircraft are most often operated by airlines. The modern and most common variant of the airliner is a long, tube shaped, and jet powered aircraft. The largest ...

research agreements (NRA) are granted to develop electric-propulsion components. They will be completed in 2019 and the internal NASA work by 2020, then they will be assembled in a megawatt-scale drive system to be tested in the

narrowbody A narrow-body aircraft or single-aisle aircraft is an airliner arranged along a single aisle, permitting up to 6-abreast seating in a cabin less than in width. In contrast, a wide-body aircraft is a larger airliner usually configured with m ...

-sized NEAT.

Machines

The

University of Illinois The University of Illinois Urbana-Champaign (UIUC, U of I, Illinois, or University of Illinois) is a public university, public land-grant university, land-grant research university in the Champaign–Urbana metropolitan area, Illinois, United ...

is developing a 1-megawatt

permanent magnet synchronous motor A synchronous electric motor is an AC electric motor in which, at steady state, the rotation of the shaft is synchronized with the frequency of the supply current; the rotation period is exactly equal to an integer number of AC cycles. Synch ...

spinning at 18,000 rpm to drive a Rolls-Royce LibertyWorks' Electrically Variable Engine turbofan from a battery for taxiing, takeoff and idle descent in a

parallel hybrid Hybrid vehicle drivetrains transmit power to the driving wheels for hybrid vehicles. A hybrid vehicle has multiple forms of motive power, and can come in many configurations. For example, a hybrid may receive its energy by burning gasoline, but swi ...

Ohio State University The Ohio State University (Ohio State or OSU) is a public university, public Land-grant university, land-grant research university in Columbus, Ohio, United States. A member of the University System of Ohio, it was founded in 1870. It is one ...

is building 300-kW and 1-megawatt prototype motors, a 2,700 rpm, 1-m (3.3-ft) diameter, 2.7-megawatt

liquid cooled Liquid cooling refers to cooling by means of the convection or circulation of a liquid. Examples of liquid cooling technologies include: * Cooling by convection or circulation of coolant, including water cooling * Liquid cooling and ventilatio ...

ring

induction motor An induction motor or asynchronous motor is an AC motor, AC electric motor in which the electric current in the rotor (electric), rotor that produces torque is obtained by electromagnetic induction from the magnetic field of the stator winding ...

and designed a 5,000 rpm, 10-megawatt turbofan integrated ring motor. These

electric machine Electricity is the set of physical phenomena associated with the presence and motion of matter possessing an electric charge. Electricity is related to magnetism, both being part of the phenomenon of electromagnetism, as described by ...

s target 13 kW/kg and over 93% efficiency, while NASA

Glenn Research Center NASA John H. Glenn Research Center at Lewis Field is a NASA center within the cities of Brook Park, Ohio, Brook Park and Cleveland between Cleveland Hopkins International Airport and the Rocky River Reservation of Cleveland Metroparks, with a s ...

is developing a superconducting electric machine with a 16 kW/kg goal and above 98% efficiency: a 0.4-m-dia, 6,800 rpm, 1.4-megawatt wound-field

synchronous motor A synchronous electric motor is an AC electric motor in which, at steady state, the rotation of the shaft is synchronized with the frequency of the supply current; the rotation period is exactly equal to an integer number of AC cycles. Sync ...

using a self-cooled,

high-temperature superconducting High-temperature superconductivity (high-c or HTS) is superconductivity in materials with a critical temperature (the temperature below which the material behaves as a superconductor) above , the boiling point of liquid nitrogen. They are "high- ...

rotor winding.

Voltage

The highest voltage used now is 540 (±270) volts, but distributing megawatt-scale power will require higher

voltage Voltage, also known as (electrical) potential difference, electric pressure, or electric tension, is the difference in electric potential between two points. In a Electrostatics, static electric field, it corresponds to the Work (electrical), ...

to reduce

current Currents, Current or The Current may refer to: Science and technology * Current (fluid), the flow of a liquid or a gas ** Air current, a flow of air ** Ocean current, a current in the ocean *** Rip current, a kind of water current ** Current (hydr ...

for smaller, lighter electric cables. One megawatt over need 900 kg at 540 V but would be reduced to 200 kg at 2,000 V DC. A near-term hybrid would need 1,000–3,000-volt and a fully turboelectric large aircraft 5,000–10,000-volt, like ship power systems but

arcing An electric arc (or arc discharge) is an electrical breakdown of a gas that produces a prolonged electrical discharge. The current through a normally nonconductive medium such as air produces a plasma, which may produce visible light. An ar ...

occurs at much lower voltages at low pressures than at sea level.

Inverters

While a

battery Battery or batterie most often refers to: * Electric battery, a device that provides electrical power * Battery (crime), a crime involving unlawful physical contact Battery may also refer to: Energy source * Battery indicator, a device whic ...

power source would use a

direct current Direct current (DC) is one-directional electric current, flow of electric charge. An electrochemical cell is a prime example of DC power. Direct current may flow through a conductor (material), conductor such as a wire, but can also flow throug ...

distribution, a

gas turbine A gas turbine or gas turbine engine is a type of Internal combustion engine#Continuous combustion, continuous flow internal combustion engine. The main parts common to all gas turbine engines form the power-producing part (known as the gas gene ...

power source would also allow

alternating current Alternating current (AC) is an electric current that periodically reverses direction and changes its magnitude continuously with time, in contrast to direct current (DC), which flows only in one direction. Alternating current is the form in w ...

which would need

power converter Power may refer to: Common meanings * Power (physics), meaning "rate of doing work" ** Engine power, the power put out by an engine ** Electric power, a type of energy * Power (social and political), the ability to influence people or events Math ...

s, mainly

inverter A power inverter, inverter, or invertor is a power electronic device or circuitry that changes direct current (DC) to alternating current (AC). The resulting AC frequency obtained depends on the particular device employed. Inverters do the op ...

s to convert DC to controlled, variable-frequency AC to regulate a motor speed and torque.

Silicon carbide Silicon carbide (SiC), also known as carborundum (), is a hard chemical compound containing silicon and carbon. A wide bandgap semiconductor, it occurs in nature as the extremely rare mineral moissanite, but has been mass-produced as a powder a ...

iCand

gallium nitride Gallium nitride () is a binary III/ V direct bandgap semiconductor commonly used in blue light-emitting diodes since the 1990s. The compound is a very hard material that has a Wurtzite crystal structure. Its wide band gap of 3.4 eV af ...

aNswitches can operate at higher frequencies with lower losses, increasing efficiency. GE is building a 2,400-volt DC, 1-megawatt inverter with SiC switches and its 1.7-kW

MOSFET upright=1.3, Two power MOSFETs in amperes">A in the ''on'' state, dissipating up to about 100 watt">W and controlling a load of over 2000 W. A matchstick is pictured for scale. In electronics, the metal–oxide–semiconductor field- ...

s power modules. The University of Illinois is building a 1,000 volts DC, 200-kW "flying capacitor" scalable to a 1-megawatt with GaN-based

field-effect transistor The field-effect transistor (FET) is a type of transistor that uses an electric field to control the current through a semiconductor. It comes in two types: junction FET (JFET) and metal-oxide-semiconductor FET (MOSFET). FETs have three termi ...

switches. Both are liquid cooled and target 19 kW/kg at 99% efficiency, but

Boeing The Boeing Company, or simply Boeing (), is an American multinational corporation that designs, manufactures, and sells airplanes, rotorcraft, rockets, satellites, and missiles worldwide. The company also provides leasing and product support s ...

is developing a cryogenically cooled 1-megawatt inverter for 26 kW/kg and 99.3% efficiency with off-the-shelf silicon semiconductors, and is currently fabricating a liquid-nitrogen-cooled 200-kW inverter before a 1-megawatt one.

References

{{reflist Glenn Research Center Science and technology in Ohio