1. Contactless HVDC Overhead-Line Current Measurement With a Self-Contained Calibration Function
- Author
-
Yukai Xiang and Kun-Long Chen
- Subjects
Earth's magnetic field ,Sensor array ,Computer science ,business.industry ,Electrical engineering ,Overhead (computing) ,High-voltage direct current ,Power engineering ,business ,Overhead line ,DC bias ,Voltage - Abstract
In order to provide an on-site easy-to-use solution for power engineers to carry out field measurements in high voltage direct current (HVDC) systems, this study proposes a new contactless DC current measurement method for HVDC overhead lines. The proposed method adopts a vertical sensor array of three three-axis TMR magnetic sensors to measure the spatial magnetic fields, and then the overhead line currents can be calculated based on the measured magnetic fields with the overhead-line geometry specification which can be obtained from power companies. In addition, a magnetic shield mechanism is designed to correct an inevitable DC offset outputted from the magnetic sensor. This DC offset includes the quiescent voltage of magnetic sensor self-circuit and the sensor output voltage caused by earth’s magnetic field. Thus, the problem that the DC offset is misjudged as a magnetic field produced by the measured DC current can be effectively solved. Regarding the core algorithm of the proposed method, the geomagnetic invariance is utilized to not only calibrate the three-axis sensing directions of the three TMR sensors but also strengthen the algorithm convergence. Finally, the proposed method has been validated by numerical simulations and experimental tests on a reduced scale model of an 800-kV HVDC overhead line. more...
- Published
- 2021
- Full Text
- View/download PDF