Research on High Bandwidth Rogowski Coil for Measuring Lightning Traveling Wave Current on Double Circuit Transmission Line

Double circuit transmission line is an important part of the power grid, which is vulnerable to lightning and may endanger the security and stability of the power grid. In order to design a sensor which can monitor the lightning traveling wave current on double circuit transmission line, simulations of lightning on the double circuit transmission line were conducted. The simulation result shows that besides high frequency components, the traveling wave contains a lot of low frequency components. Based on the equivalent model and the frequency response of the self-integrated Rogowski coil, it turns out that the widely used self-integrated Rogowski coil is not suitable for this application as the problem of low frequency distortion. In this paper, through theoretical analysis and simulations in Matlab, an improved Rogowski coil with analog integrator is proposed which can correct the low frequency distortion of the self-integrated Rogowski coil. All the simulations, experiments and operating data installed to a double circuit transmission line in China verify the validity of the high bandwidth Rogowski coil.