Test and analysis of protection behavior on parallel lines with mutual coupling

Most of the overhead lines within our transport networks are operated as double lines today. During operation of such parallel lines the electromagnetic coupling (mutual coupling) between the different systems has a considerable impact on the fault impedances measured for single-phase faults. Using new test software it is possible to investigate this impact for the different fault scenarios with a transient network simulation and to analyze the behavior of protection devices. Additionally different possibilities and setting values to cope with mutual coupling within protection devices are presented and compared. Finally real line configurations with mutual coupling are investigated and concepts for protection designs with good selectivity are discussed.