Lightning Current Monitoring Based on Accurately Tracking State of Polarization by Measuring Stokes Parameters of Optical Signal in OPGW Fiber

Abstract

This paper proposes a scheme of lightning current monitoring based on measuring Stokes parameters in OPGW (Optical Power Ground Wire). Compared with traditional lightning current monitoring schemes, this design has many advantages including simple structure and high anti-interference ability. Polarization state of the signal in the OPGW fiber rotates in the direction of propagation due to the magnetic field generated by lightning strong current according to Faraday effect. Accurate tracking of state of polarization can be achieved by analyzing the change of Stokes parameters on Poincare sphere. In the experiment, lightning strikes with a current of 600 kA is successfully monitored by this scheme. Meanwhile, the error of current monitored via the scheme is approximately 1.5% when the interference RSOP is added.