Transient optimization control strategy of hybrid capacity regulating transformer

Abstract

In order to overcome the problems of the traditional capacity regulating transformer, this paper presents a hybrid capacity regulating transformer(HCRT) that uses anti-parallel thyristors instead of mechanical switches. Advantages of presented HCRT are there is no arc in such transformer, faster response speed and longer service life. Taking into account of the characteristics of the semi-controllable thyristor, this paper proposes a transient optimization control strategy to avoid internal short circuit and load voltage loss in HCRT. After receiving the capacity regulating command which is the delay time calculated by the parameters of transformer, the closing time of the switch group is controlled, therefore, the continuity of the magnetic flux and load voltage in each phase in the process of capacity regulating is ensured. Finally, the simulation results of comparative experiments are provided to illustrate the advantages and effectiveness of the proposed method. Meanwhile, the experimental results obtained on the prototype of HCRT are provided to verify the effectiveness of transient optimization control strategy for HCRT.