Adaptability Analysis of Traditional Differential Protection Applied to Lines Connected to PV

Due to the significant difference in short-circuit characteristics between photovoltaic inverter and traditional synchronous machine, the large-scale grid connection of photovoltaic may bring new challenges to the differential protection principle of existing grid-connected photovoltaic (PV) lines. The existing research did not quantify the impact, and did not really consider the actual situation. In this paper, a simulation model of grid-connected PV system using the real inverter controller is built on the RTDS simulation platform to simulate the operation characteristics of the current differential protection, and a detailed theoretical analysis is made. The simulation results and theoretical analysis show that the operation reliability of traditional differential protection is reduced to a certain extent due to the large-scale PV connection.