GE D30

viii D30 LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL
TABLE OF CONTENTS
8 APPLICATION OF
SETTINGS
8.1 Application guidelines ...........................................................................................8-1
8.1.1 Overview ...................................................................................................................................8-1
8.1.2 Impact of memory polarization .....................................................................................8-1
8.1.3 High set overcurrent elements.......................................................................................8-1
8.2 Distance elements (stepped distance scheme).................................................8-2
8.2.1 Phase distance.......................................................................................................................8-2
8.2.2 Ground distance....................................................................................................................8-3
8.3 Series compensated lines .....................................................................................8-5
8.3.1 Overview ...................................................................................................................................8-5
8.3.2 Distance.....................................................................................................................................8-6
8.3.3 Ground directional overcurrent .....................................................................................8-7
8.3.4 High-set phase overcurrent.............................................................................................8-7
8.4 Phase distance through power transformers...................................................8-8
8.4.1 Phase distance protection................................................................................................8-8
8.4.2 Example.....................................................................................................................................8-9
9 THEORY OF
OPERATION
9.1 Distance elements..................................................................................................9-1
9.1.1 Overview ...................................................................................................................................9-1
9.1.2 Phasor estimation.................................................................................................................9-2
9.1.3 Distance characteristics....................................................................................................9-2
9.1.4 Fast distance algorithm.....................................................................................................9-7
9.1.5 Memory polarization ...........................................................................................................9-7
9.1.6 Distance elements analysis .............................................................................................9-9
9.2 Phase distance applied to power transformers .............................................9-11
9.2.1 Description............................................................................................................................9-11
9.2.2 Example..................................................................................................................................9-15
9.3 Ground directional overcurrent.........................................................................9-17
9.3.1 Description............................................................................................................................9-17
9.3.2 Example..................................................................................................................................9-18
9.4 Series compensated lines ...................................................................................9-18
9.4.1 Description............................................................................................................................9-18
9.5 Fault locator ..........................................................................................................9-22
9.5.1 Fault type determination................................................................................................9-22
10 MAINTENANCE 10.1 Monitoring .............................................................................................................10-1
10.1.1 Devices with Site Targets ...............................................................................................10-1
10.1.2 Data with Modbus Analyzer..........................................................................................10-1
10.2 General maintenance ..........................................................................................10-3
10.2.1 In-service maintenance..................................................................................................10-3
10.2.2 Out-of-service maintenance ........................................................................................10-3
10.2.3 Unscheduled maintenance (system interruption) ..............................................10-3
10.3 Retrieve files..........................................................................................................10-3
10.3.1 CyberSentry security event files..................................................................................10-4
10.4 Convert device settings.......................................................................................10-5
10.5 Copy settings to other device ............................................................................10-7
10.6 Compare settings .................................................................................................10-7
10.6.1 Compare against defaults .............................................................................................10-7
10.6.2 Compare two devices ...................................................................................................... 10-8
10.7 Back up and restore settings .............................................................................10-8
10.7.1 Back up settings .................................................................................................................10-8
10.7.2 Restore settings............................................................................................................... 10-11
10.8 Upgrade software.............................................................................................. 10-13
10.9 Upgrade firmware ............................................................................................. 10-14