A novel large current rectifier based on six windings isolated transformer

摘要

In order to enlarge the output current of the rectifier, a large current rectifier based on six windings isolated transformer is proposed. The proposed rectifier uses the six windings isolated transformer as the phase-shift transformer, and the primary windings of the transformer are connected in delta, the secondary windings are independent and provide three groups of single-phase voltage with 120°phase shifting in turn to feed three single-phase rectifiers. The three windings of the inter-phase reactor (IPR) are connected with the output positive electrodes of the three single-phase rectifiers, respectively. According to the structure of the isolated transformer, the input line current and load voltage of the large current rectifier are analyzed in theory, and the configuration parameters of the IPR are also calculated, related experiments are carried out. Theoretical analysis, simulating and experimental results demonstrate that the power quality on the input side and load side of the large current rectifier is similar to the traditional dual inverse-star rectifier, and the output current is 1.5 times of the dual inverse-star rectifier. In addition, the kVA rating of the isolated transformer is smaller than that of the transformer in the dual inverse-star rectifier, which can improve the power density of the proposed rectifier to some degree.