A Novel Contactless Current Sensor for HVDC Overhead Transmission Lines

Measuring the current in high-voltage direct current (HVDC) systems is always regarded as a challenging task. For transmission systems, dc current transformers or sensors are only available in substations and converter stations. In order to provide more flexibility and convenience, this paper proposes a contactless dc current sensor, which can be easily placed on-site in the environment of HVDC overhead transmission lines. The proposed method significantly improves the convenience and safety of the HVDC current measurement. Using a magnetic-field sensor array, the proposed current algorithm can optimally calculate the overhead-line currents with partially known overhead-line geometry. The simulation results in this paper demonstrate that the proposed method can accurately calculate the HVDC current. Moreover, the proposed method is validated by a reduced-scale HVDC overhead transmission line.

I. Introduction

In recent years, continuous development in fields such as materials science [1], power electronics [2], and manufacturing technology [3] have significantly improved high-voltage direct current (HVDC) transmission technology. HVDC transmission systems have many advantages, including good stability, low energy loss, small interference to the power grid, and low transmission-line investment and maintenance cost. For these reasons they continue to play an increasingly important role in the transmission systems around the world.