Converter Meets Distance Protection: A Good Match?

Abstract

State of the art distance protection can misoperate in electricity grids fed by power electronic converters. This paper investigates how these converters should inject fault currents to mitigate such misoperations. Three fault current injection strategies are investigated in a transient simulation. Findings are validated in a laboratory setup with a commercial distance protection relay. The main result is that injecting positive and negative fault current to balance the converters’ voltages in conjunction with an adapted quadrilateral characteristics can render distance protection effective.