In this paper,for solving the 5thand 7thharmonics generated by the TCT( thyristor controled transformer) type adjustable reactor of Dyn connection and achieving good application of the equipment,the double secondary winding control mode is used to offset the 5thand 7thharmonics generated by the equipment by way of phase shift. And test circuit is set up for validation. It is shown by the result that the elimination ratio of the 5thand 7thharmonics in the double secondary winding is above 90%,which assures e...