Interaction Between Two Ring Shaped YBaCuO Superconductors with currents ia and ib

Abstract

Two rings with currents ia and ib become magnets that can either attract or repel each other. If mechanical work is extracted from this ring system, either by bringing closer the rings during an attraction or by separating them as the result of a repulsion, the energy of the rings, the only existing source of energy in the system, decreases: $\frac{1}{2}LI_{a}^{2}+\frac{1}{2}LI_{b}^{2}$ If an energy either of attraction or repulsion is communicated to the system, (working against the forces) its energy increases, i.e. the currents in the rings increase. This happens because the currents existing in the rings are free, i.e. not linked to any device which imposes a current (power supply, constant current). Similarly, the effect of electromagnetic induction can increase or decrease the currents with the corresponding mechanical work linked to these developments. Not only does the current in the rings decrease as they get closer during the attraction, but it also can be cancelled and, if the effect continues, it may even change its direction. An application that already exists is the levitation train. It is attracted by the rail and held on it, but if it is very close to this due to the weight of the goods a strong repulsion (levitation) occurs. Another application would be the accumulation of energy in these rings, where they can spend large amounts of current, not only because of its high critical currents but also by the fact that the magnetic flux remains constant, cannot increase. Another advantage in this storage system is its reversibility in the exchange of electromagnetic energy and mechanical work. In the energy storage system, the greater the current flowing through the ring, the greater its energy is. In order to attain this, there has been made a study of the ideal conditions to store as much energy as possible.