Transient characteristics verification method for DC transformer used in flexible HVDC system

Abstract

Previous studies have proposed higher requirements for the transient characteristics of a DC transformer used in a flexible high-voltage direct current (HVDC) system to achieve faster sampling speed and meet wider bandwidth requirements of the control and protection signal, and to eventually suppress the large transient fault current. In this study, a transient characteristics verification method is proposed for transient characteristics verification of a DC transformer used in a flexible HVDC system based on resampling technology and LabVIEW measurement technology after analyzing the key technology for transient characteristics verification of a DC transformer. A laboratory experiment for the transient characteristics of a full-fiber electronic DC transformer is conducted, and experimental results show that such verification method can be employed for frequency response and step response verification of a DC transformer at 10% of the rated voltage and current, and can eventually improve the screening of a DC transformer. Keywords: DC transformer, Step response, Transient characteristic, Resampling technology, Verification method