Effective method of using electromagnetic coupling of air-core reactor

To reduce joule loss due to ripple current in multiphase current reversible chopper, we manufactured reactors, which achieve an optimal electromagnetic-coupling coefficient and we tested the new reactors. As a result, the new reactors whose electromagnetic-coupling coefficient is 0.60 reduces ripple current both on each phase and on the total combined when those operate with differential coupling and shift-phase switching. The loss from ripple current is reduced to 31% when the chopper operates with abovementioned condition. When the chopper operates with equal-phase switching and cumulative coupling and employs new reactors whose electromagnetic-coupling coefficient is 0.97, the joule loss due to ripple current is reduced to 11%.