Synchrophasor Initiative in India - erldc

SYNCHROPHASORS - INITIATIVE IN INDIA JUNE 20125.4 Validation of protection system with synchrophasor dataAnalysis of the operation of the protection system has been illustrated in the earlier sections.The section ahead illustrates few case studies of audit of the df/dt relays, Disturbance Recorderand System Protection Schemes.5.4.1 Case Study-20: Validation of Auto-reclose of EHV lineSingle phase auto reclosure has been provided in 400 kV lines for transient faults. The loperation of single phase autoreclosure gets recorded in the Disturbance Recoder and Eventlog in the transmission substations. At the Regional/State Load Despatch Centre the Autoreclosure operation is recorded in the Sequence of Events available through the SCADAsystem. The synchrophasors data available at every 40 ms has enabled visualization andvalidation of the auto reclosure operation in the Load Despatch Centre. In Northern RegionPMU has been installed at 400 kV Bassi substation also. The voltage input to this PMU is from400 kV bus CVT and the current input is from 400 kV Agra-Bassi I and 400 kV Agra-Bassi IIlines. The event of auto-reclosure of 400 kV Bassi-Heerapura I on 2 nd January 2012 could beinferred with the help of data received from Bassi PMU and confirmed with the help of SCADASequence of Events (SOE) records at NRLDC.Sequence of events in SCADA shows the opening and closing time of 400kV Heerapura-Bassickt-1 breaker is shown. It is observed that the breaker closes after 1 second which indicates itsclosure after dead time. The event as visulaized with the help of the voltage phasor dataavailable from the PMU installed at 400kV Bassi substation is displayed as figure 69.POSOCO Page 80 of 143