Distance Protection of Transmission Lines Connected to Inverter-Based Resources

The increasing integration of inverter-based resources, such as wind and photovoltaic systems, poses significant challenges for protection devices. Reduction in fault current is expected to compromise power system protection performance. Traditional overhead line protection schemes have primarily been designed focusing on the dynamic behaviour of rotating machines as the primary generation sources, neglecting the unique dynamic response of inverter-based resources governed by inverters. Consequently, the effectiveness of distance or impedance relays in safeguarding lines with inverter-based resources requires special attention. This study developed a comprehensive model of a 110 kV network comprising traditional and inverter-based resources using DigSilent PowerFactory. Electromagnetic transients (EMT) analysis is conducted on distance protection devices within the network. The findings presented in this paper highlight the complex challenges encountered when employing distance relay protection in the presence of inverter-based resources.