A Non-Pilot Protection Scheme for Transmission Lines Connected to Inverter-Interfaced Power Source

The fault characteristics of transmission lines connected to inverter-interfaced power sources such as photovoltaic stations and permanent magnetic synchronous generator are fundamentally different from traditional power grids, and traditional protection methods have adaptability issues. The protection on the system side and the inverter side of the transmission line has inconsistent characteristics of sensitivity, reliability, and speed. When the system side protection operates and controls breaker tripping, the distance protection on the station side then can operate reliably in a longer time. In this regard, this article proposes a non-pilot protection scheme that utilizes low sampling rate single ended electrical quantities. For different types of faults, zero sequence current, negative sequence current, and voltage harmonic components are used as acceleration criteria for distance protection, which can reliably accelerate the local distance protection action after the opposite breaker trips. A photovoltaic station transmission system model is built in PSCAD, and the simulation results verify the effectiveness of the proposed scheme.