Directional earthfault protection operation and setup aspects in medium voltage compensated network

Most of 20 kV networks in Latvia are compensated. Network are built of both cables and overhead lines, as a result an earthfaults have significant proportion of total amount of fault cases. Compensated network is challenging for earthfault protection due to relatively small value of fault current. An objective of developed methodology is to improve operation of earthfault protection function as well as to describe an approach of relay protection unit and Peterson coil controller setup.