Reduction of Reactor Weight by Using Electromagnetic Coupling

This paper investigates the use of electromagnetic coupling for an air-core reactor in order to reduce joule loss due to ripple current in multiphase current reversible chopper. They system is for an energy storage system on a train. The relationships among the amplitude of ripple current, duty factor and electromagnetic-coupling coefficient was investigated. A specific optimal coefficient of electromagnetic coupling was found to reduce current ripple both on each phase and on total combined. Experiments were conducted with newly manufactured reactors in order to verify the hypothesis. The reactors in the experiments achieved the optimal electromagnetic coefficient. The new reactor has the additional advantage of being considerably lighter than a conventional three-phase reactor.