Series capacitors are used in the bulk power system to re-direct power flow and improve system stability. Series capacitors present very high impedance to the flow of GIC. NERC has recommended two modeling methods in their GIC application guide: model the series capacitor with a very large resistance such as 1 megohm (MΩ); or remove the line segment representing the series capacitor from the model completely. In the ERCOT GIC system model, the PGDTF has decided to use the 1 MΩ method for all series capacitors. Substation Data The format for the Substation Data record is shown in Appendix B. This Substation Data record will be provided by the facility owner. Field Description Source Substation Station Number – A unique station numbering system separate but similar to the bus numbering system. TSPs will model station/bus relationship for their facilities in accordance with Appendix A. ERCOT will model station/bus relationship for Resource Entity (RE) facilities in accordance with Appendix A. List of Buses Comma separated list of Bus Numbers that belong in this station. TSPs will model station/bus relationship for their facilities in accordance with Appendix A. ERCOT will model station/bus relationship for RE facilities in accordance with Appendix A. NAME Station Name ERCOT will provide long or short name for RE stations. TSPs will provide long or short name for their stations. LATITUDE Station Latitude in degrees ERCOT will provide for RE stations. TSPs will provide this data for their stations. LONGITUDE Station Longitude in degrees ERCOT will provide for RE stations. TSPs will provide this data for their stations. RG Substation dc grounding resistance (ohms) for stations with high side wye grounded transformers and shunt reactors. ERCOT will provide for RE stations. TSPs will provide this data for their stations. EARTH MODEL Name of the Earth Model EARTH MODEL is USGS standard earth ROS Approved: June 9, 2016
the last layer is infinity. This is specified as any value less than 0.0 (=-999.0 for example). The thickness value less than 0.0 is also used as end of earth model data. The format for Earth Model Data (v34) is shown in Appendix B. Field Description Source NAME NAME may be up to 12 characters. This name should be different than the Standard US and Canada Earth Models. No default allowed. REs will provide this value through EPPRE, and TSPs will provide this value through the workbook. BETA FACTER Earth Model scaling factor used when calculating branch induced electric field for Benchmark GMD event. BETAFTR=1 by default REs will provide this value through EPPRE, and TSPs will provide this value through the workbook. DESCRIPTION Description of the earth model. NAME maybe up to 72 characters. This is for information purpose only. DESC = “ by default REs will provide this value through EPPRE, and TSPs will provide this value through the workbook. RESISTIVITY LAYER 1 Layer 1 Resistivity in ohm-m. No default allowed. REs will provide this value through EPPRE, and TSPs will provide this value through the workbook. THICKNESS LAYER 1 Layer 1 Thickness in km. No default allowed. REs will provide this value through EPPRE, and TSPs will provide this value through the workbook. ROS Approved: June 9, 2016