Ballston Spa, NY
MTECH Laboratories, LLC
Advanced Engineering, Research, and Development
What is Superconductivity?
Superconductivity is an unusual phenomenon exhibited by a number of materials when they are cooled to very low temperatures. The transition between normal behavior and the superconducting state occurs at the “critical temperature,” which varies with each material. Properties of superconducting materials include:
1) Zero electrical resistance to the flow of direct current (DC) and relatively small losses associated with alternating currents (AC). These properties allow for very high-field magnets with little or no losses, and enable highly power dense motors and generators, transmission lines, and other power devices.
2) The Josephson effect, in which magnetic flux is quantized in a loop. This is useful in magnetic field sensing and computing.
3) Expulsion of magnetic flux, which can be used for shielding and levitation.
Superconducting Transmission Lines
Superconductivity offers the most efficient means for transferring electric signals and power. The technology has existed for decades, but costs of materials and refrigeration are cited as the "barrier" for commercialization. Moving beyond prototype projects, MTECH is working with the Advanced Superconductor Manufacturing Institute (ASMI) to promote investment in scaling up these technologies in the US.
Cryogenic Power Converter / Inverter
Cryogenic power converters operate at cryogenic temperatures and are very efficient. CryoPower converters are usually designed to interface to superconducting devices, and can incorporate superconducting filter components and power busses.
Superconducting Fault Current Limiter
This device takes advantage of the limitations of superconductivity. When the current in the device exceeds a critical current, the conductor ceases to be a superconductor and becomes a normal metal with high resistance. This sudden change in resistance can be used to limit the current in a power network.
Utilizing superconducting windings in a transformer can reduce losses, leading to more efficient power transfer. The size of the wire can also be reduced, leading to high power densities and reduced size and weight. While the windings need to be cryogenically cooled for superconducting operation, the transformer cores can be installed at room temperature.
Superconducting Motors and Generators
Superconducting motors and generators contain superconducting windings. There are many types of both motors and generators in AC and DC configurations.
Superconducting DC motors (such as homopolar motors) are extremely efficient. However, they usually require brush technology, which in itself, is very challenging.
In theory, AC motors can be designed to operate with only air cores, without iron. Air core AC superconducting motors are possible if AC worthy superconductors can be manufactured with sufficiently high current densities and low losses.
The same is true for superconducting generators.
Superconducting magnets are electromagnets with superconducting windings. These magnets can achieve very high fields (above 20 Tesla), not reachable using normal conductors such as copper.
Magnets can be made with superconducting joints, allowing them to operate in the so-called persistent mode (in which no excitation is required to sustain the flow of current). Persistence magnets have enabled NMR and MRI, two of the most significant applications of superconductivity in history.
In addition to electromagnets, there are trapped superconducting magnets in the form of closed rings having no excitation terminals. In this case, the rings are cooled to the superconducting state in the presence of an external magnetic field. When the external field is subsequently removed, the superconducting rings are induced with current which persists indefinitely.
Superconducting Power Filter
A superconducting power filter contains superconductors instead of copper. This reduces the resistance of the filter, leading to extraordinarily high Qs.
SMES (Superconducting Magnetic Energy Storage)
Energy can be stored by chemical means (batteries), electrical means (capacitors), or magnetic means (inductors). Superconducting magnets (large inductors) are capable of charging and discharging rapidly through multiple cycles without degradation. This makes them particularly good for installations requiring a high degree of power quality.
SC Wind Turbine Generator
High-power wind turbines and windmills require powerful generators to be mounted on high towers. The overall scale of wind turbines is limited by how large and heavy the turbine is, and how much weight the tower can support. Superconductivity can reduce the size and weight of these generators, leading to larger, higher-power, and safer installations. Superconducting wind turbines are mostly envisioned for off-shore use, as the wind currents are highest in these regions.
SC Hydroelectric Generator
Hydroelectric generators can be made more efficient and powerful through the use of superconductors. Hydroelectric plants can also take advantage of superconducting fault current limiters and transformers.
Maglev Mass Transit
Maglev (magnetic levitation) is a means of levitating objects using forces generated by magnetic fields. Superconductivity is ideal for this application because of the strong magnetic fields that can be generated by superconducting electromagnets.
In addition, superconductors can trap magnetic flux and exclude magnetic flux (the Meissner effect), which be utilized for levitation. The most practical mass transit applications use superconducting electromagnets that can also be configured as linear motors to propel a vehicle.
The low conduction losses and high currents associated with superconductors make this a very promising technology of the future.
All Electric Ship
For several years now, the Navy has recognized the advantages of all-electric ships, which employ electrical rather than mechanical systems for both propulsion and advanced electric weapons. Superconductors can efficiently transmit power at high currents, and can be used in motors and generators for efficient high-power systems.
All Electric Plane
NASA is developing a turboelectric propulsion system for all-electric aircraft. In this concept, propulsion is achieved using large fans driven by superconducting motors. The electrical power for these fans, in turn, is generated by an efficient superconducting hydrogen or natural gas turbine.
Superconductors are ideal for transmitting power at high currents, and can be used in propulsion motors and generators. In this case, the superconducting propulsion motors (connected to fans) can be controlled individually using MTECH’s cryogenic power inverters. Full electric control of the propulsion motor is key to the appeal of this concept. The gas turbine can be run at optimum speed for fuel efficiency.
High-Efficiency Datacenter Power
Datacenters require a significant amount of power. The power demand will continue to grow as the demand for the internet continues to expand. Power is required for processors, power supplies, cooling systems, and the power distribution system. CryoPower and superconductivity can play a major role in reducing these power loads.
Superconducting transmission lines offer zero-loss power transmission. Conventional CMOS processors are more efficient and run faster at cryogenic temperatures. Power supplies can be more efficient at low temperatures.
These savings, which are enabled by cryogenic computers, cryogenic power electronics, and superconductivity, coupled with efficient refrigeration, can lead to high-efficiency datacenters in the future.
Superconducting Digital Computers
Superconducting digital computers are similar to room-temperature classical computers, which utilize binary numbers. However, superconducting digital computers are based on superconducting quantum interference devices (SQUIDS) rather than silicon integrated circuits (CMOS). These computers operate best at lower temperatures (4.2K or below), where they offer up to 5 times the performance with only 1/40th of the power utilized by conventional computers.
A very aggressive superconducting digital computer project called the Cryogenic Computer Complexity (C3) program is currently being funded by US intelligence agencies, which hope to deploy these technologies in their future datacenters.
Superconducting Quantum Computers
Quantum computers will revolutionize the computer world as we know it. Quantum computers are based on quantum mechanical phenomena, and promise up to 100,000,000 times increase in performance in computing specific types of problems.
Superconductivity-based quantum computers are extremely efficient and operate at very low cryogenic temperatures (milli-kelvins). Quantum computer R&D is currently being funded by the government and several private firms, such as IBM, Google, and D-Wave.
MRI (Magnetic Resonance Imaging)
MRI is an extremely powerful medical imaging device that has revolutionized medicine. Superconducting MRI systems are known to produce the most stable and highest resolution images.
Cryogenic pre-amplifiers and superconducting receiver coils are sometimes used in MRI to reduce the image noise, leading to ultra-high-resolution images and spectroscopy, which can be used for imaging biochemistry in the body. MRI is also used for inspecting foods, oil exploration, and industrial applications.
Superconducting quantum interference devices (SQUIDs) are capable of detecting extremely small magnetic fields, and are used for mapping fields generated by the earth or by biological systems. Medical applications include brain and cardiac imaging.
MRFM (Magnetic Resonance Force Microscopy)
Low temperature electronics and superconductivity can enhance magnetic force microscopy instrumentation. MRFM is capable of sensing the magnetic force generated by single atoms or spins - a major breakthrough for basic research.