Research on Transmission Characteristic of Electronic Current Transformer Shunt for Flexible HVDC

This paper studies the transmission characteristics of electronic current transformer (ECT) shunt for flexible HVDC. Firstly, the influences of temperatures and skin which effect on measurement errors are analyzed on the basis of introducing the working principles of ECT. Then, according to the ECT used in engineering application for flexible HVDC, the simulation model is established in PSCAD/EMTDC. Finally, study transmission characteristics by measuring current of the Nan'ao flexible HVDC system as well as changing critical parameters of the model. Simulation results indicate that the main reasons of causing measurement errors are temperatures and skin effect. It is obviously that the measurement errors can be reduce by reducing shunt conductor radius. Besides, the design of ECT shunt should be checked against by the installation location.