A novel DC transmission system using a new type of converter transformer is proposed and its topology is analyzed. Focus of discussion in the paper is the influence of the level of reactive power compensation on the operation of DC transmission system， when the corner delta windings of the new type of converter transformer are connected with the filtering and reactive-load compensation equipment on the valve side. Through statistical analysis on the variations of the commutating resistance of the new type of converter transformer at different levels of reactive power compensation， the characteristic curves of commutating angle， DC voltage， and the converter’s reactive power characteristic are obtained， so that the operating characteristics of the novel DC transmission system influenced by the level of reactive power compensation are analyzed. The analytical results show the superiority of the new system with the new type of converter transformer.