Line Pilot Protection of Flexible DC Grid Based on Traveling-Wave JS Divergence

Abstract

The proportion of renewable energy mainly including hydropower, photovoltaic and wind power is growing rapidly. DC transmission technology has become the main tool of new energy transmission. The protection scheme of the voltage source converter-based high voltage DC (VSC-HVDC) power grid is the prerequisite for the DC system. But, problems such as high resistance faults, distributed capacitance, and noise interference reduce the reliability of existing protection schemes. To solve the problem of resistance and noise interference in existing protection schemes, a double-ended protection scheme based on traveling wave JS divergence is proposed. First, the flexible HVDC transmission system is analyzed, according to which the expression of traveling wave power is derived, and its fault characteristics are summarized. Subsequently, a combined algorithm of the JS divergence based on the energy of the S-transform was proposed, and the modified algorithm was used to express the fault characteristics of traveling wave power. Finally, a flexible DC transmission system model is built. The performance of the scheme is verified by setting different interference factors (resistance, noise, distributed capacitance, synchronization error).