Application Status and Research Progress of DC Current Measuring Device for HVDC Transmission System

DC current measuring devices provide input signals for control and protection system of HVDC transmission lines. With the continuous increase of HVDC voltage class,DC current measurement in high- pressure environment has become a new subject. First,the structure and working principle of high voltage DC current measuring devices which has been put into operation at home and abroad are reviewed in this paper,and their problems are pointed out.Then,the research progress of high- voltage DC current measurement techniques in China is introduced,which mainly covers zero flux DC current transformer,active DC current transformer,all- fiber DC optical current transformer,DC current transformers based on giant magneto- resistance effect( GMR) and DC current transformer based on fiber Bragg grating( FBG). The paper is expected to be a useful reference for the design,implementation,operation and maintenance of future high- voltage DC current measuring device.