Abb Research Ltd.

Abb Technology Ag

Piotr Pierz

Eugeniusz Rosolowski

Murari Mohan Saha

Jan Izykowski

Przemyslaw Balcerek

Marek Fulczyk

Murari Saha

The present invention is concerned with a method of distance protection of parallel transmission lines applicable both to series compensated and uncompensated electric power lines, using a distance relay. The method is characterized in that a pair of flags (ff, ff) are calculated for indication faulted and healthy circuits in parallel lines and in the same time a flag (Internal_Fault) for indication internal or external fault in parallel lines is calculated independently. Next gathering all calculated flags (ff, ff, Internal_Fault) an analyze of the value of these flags are performed and depending on the values of flags (ff, ff, Internal_Fault) and on their reciprocal relationship, a trip permission signal from the protection relay () is released and sent to the alarms devices or to the line breakers, or a block signal from the protection relay () is generated and sent to protect parallel lines before damage.

Method of distance protection of parallel transmission line

The present invention is concerned with a method for faulted phase selection and fault type determination in electric power lines applicable both to series compensated and uncompensated power lines. The method comprising a fault inception detection and an estimation of fault phase current signals, pre-fault current signals and zero-sequence current in order to receive the absolute value of incremental current signals and their maximum value from which real value indicators for phase to phase faults, real value indicators for 3-phase fault and a real value indicator for ground fault are determined. The method further comprises

Method of fault phase selection and fault type determination

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Wroclaw, Poland

Piotr Pierz