Superconductivity in the electric power industry: present and future

The general pattern of our time is the narrowing of the gap between a particular discovery and its implementation. Once this interval reached hundreds of years, now it has decreased to a minimum. For example, the introduction of photography is 112 years behind its opening. Mineral fertilizers began to be used 70 years after their creation, telephone communications - after 50 years, radio broadcasting - after 35, radar - after 15, television - after 12, an atomic bomb - after 6 years, a transistor - after 3, and a laser - after only 2 of the year.

The beginning of the technical use of superconductors dates back to 1955, when the first electromagnet was created using them. 56 years have passed since the discovery of superconductivity to its introduction. What is the matter?

According to some British physicists, this delay is due to two reasons: the insufficient development of cryogenic technology and the discovery of only soft, pure superconductors. Hard materials with technically acceptable parameters became known only in 1930, and only a quarter of a century after that, conductors from such materials were actually created. And immediately a solenoid with a superconducting winding was built and successfully tested. Technical superconductivity was born.

Thus, the invention and the beginning of the use of technically suitable superconducting materials coincided in time (1955). But the actual invention of superconductors occurred, perhaps, later. After all, it was only in 1963 that it was possible to create really workable wires, which had to be slowed down for thermal stabilization. Paradoxically, it is a fact: the introduction of superconductors began eight years earlier than their actual discovery.

Today, superconductors are practically used in physics, where large research facilities and new devices have been used for many years. From the press it is known single applications of superconducting electric motors, gyroscopes, solenoids on ships, aircraft. In medicine, superconducting meters of magnetic fields created by living organisms have appeared.

The use of superconductors in the energy sector and in transport is highly relevant. Here, preparatory work has been ongoing for many years, but new machines and cables are not yet in operation. Why?

There are many reasons that postpone the date of the massive use of superconductors in the national economy. For example, it was not easy to develop a theory of superconductivity, but it is no less difficult for engineers to master this theory. An unexpectedly difficult task was the construction of superconducting wires, there is no other word for the process of creating a multi-element composition from different metals. The production of superconducting tapes, tires and wires required the development of special technology, the creation of special machines and even new industries.

Great difficulties are associated with the cryogenic supply of superconducting objects, because superconductivity arises only at very low temperatures. High power refrigerated trucks were required.

The development of cryogenic technology is unthinkable without the use of a deep vacuum, so you need to learn how to receive and maintain it. And of course, measurements: we need special sensors and devices, control wires that pass through cavities with different temperatures.

But when it is possible to overcome all these difficulties, it will not be easy to solve the electrical problem. Until now, in high-power electrical engineering, currents of tens to hundreds of amperes are usually used, and it is technically and economically feasible to transfer currents thousands of times higher through superconductors. But are such multi-amp installations necessary?

Such installations exist, but they are few. It is not easy to create them, because the current carrying capacity of traditional conductors, copper and aluminum, is limited. Now that with the help of superconductors it is possible to repeatedly increase the current densities and the currents themselves, it would be realistic to talk about the modernization of all electric power facilities from power plants to consumers. But is such a adjustment necessary? If not, why create superconducting electrical components?

Such units should be multi-ampere, this is undeniable. After all, superconductors are a wonderful conductor material. But the electrical circuits are designed for small currents and very high voltages. Well, embed multi-ampere objects into low-ampere circuits? Unreal. And the complete restructuring of all electrical energy equipment is a huge task. Will superconductors really find their place only in unique physical installations?

However, the difficulties of the problem associated with the introduction of superconductors are gradually being resolved. When applied work with superconductors began, the lack of trained personnel, new materials, equipment and devices was especially acute. But still, one after another, small models arose. There has been a steady demand for new wires, fluidizers, instruments and sensors. Physicists and mathematicians are involved in solving purely practical problems: determining critical fields and currents, evaluating AC losses, calculating the thermostable behavior of superconductors in liquid helium.

Today, hundreds of research teams are engaged in the problems of technical superconductivity. Long-term research plans have been identified, chains of work have been formulated, lists of facilities to be implemented are ready.

In general, it can be considered that the search work necessary to create the leading samples of the superconductors of the equipment was performed by about 30-50%. Among the created models are electromagnets for physical research and for turbogenerators, engines, superconducting transformers and cable sections, bearings and devices.

“The next few years will be crucial for the transition of superconductors from laboratories to industry for large-scale applications,” says J. Bardin, Nobel Prize winner, twice.

Read about the future of superconductivity in the next article.

Mikhail Chernov https://env.electricianexp.com

Continuation:

The future is superconductors