Adaptability evaluation of relay protection in a GFM inverter system

This paper introduces typical Grid-Forming (GFM) technologies in power grids, including steady-state and fault current limiting strategies, studies the equivalent structures of steady-state and fault traversal under GFM technology, analyses electrical characteristics under different fault types from the voltage plane, and illustrates the differences from traditional synchronous systems. This paper analyses the phase current differential protection, zero sequence current differential protection, and positive sequence voltage polarisation distance protection applied in traditional power grids, and clarifies their action behaviour under the GFM system. The analysis shows that the GFM technology creates a relatively good operating environment for relay protection by simulating the basic characteristics of synchronous generators, which is conducive to improving the operational performance of relay protection.