Aiming at the flexible HVDC DC current transformer

we researched the test technology of the protection characteristics of step response

according to the current status of DC transformer protection characteristic test equipment lack. Moreover

we proposed a modular-combined test technology

and developed a step test system of the DC current transformer with a rapid rise and long-pulse large-current test source. The simulation and experiment results show that the proposed flexible HVDC DC current transformer protection test method can greatly reduce the test power supply capacity

and meet the requirements of step square wave current output of rapid rise of long pulse order standard. The performance meets the requirements of tests when the DC current transformer protection characteristic and step response is used in the flexible HVDC project. The research can help solve the difficult problem of protecting the transient characteristics of DC transformer

which is difficult to accurately evaluate the safety.