Higher harmonics in load-adapting mains frequency resonant converter

A slow and soft switching AC-DC power converter is described. In each phase a capacitor, main and additional inductor is switched between the rectifier bridge and transformer. During the commutation of the rectifier bridge the capacitor and the inductor are switched from parallel to series and vice versa in each half period. The natural frequency on the oscillating circuits formed is approximately equal to supply frequency. The commutation angles are very high, from 30/spl deg/ up to 60/spl deg/ in nominal mode. Compared to traditional rectifier the harmonics are 3 times less. The power factor is very high (approximately 0, 99 in nominal mode). The converter fits well to supply powerful electric arc. It solves almost all the problems with electromagnetic compatibility better and less costly than all-known solutions, that use dynamic compensation of reactive power and passive filters for higher harmonics.