The impedance element shall be set less than the calculated impedance derived from 115% of: Phase distance relay (1) Real Power output 100% of the aggregate generation gross – 0.85 per unit of the line nominal (21) directional – 14a MW reported to the Transmission Planner, and voltage toward the (2) Reactive Power output 120% of the aggregate generation – Transmission MW value, derived from the generator nameplate MVA rating at system installed on rated power factor the high-side of the Elements that GSU transformer OR connect the GSU transformer(s) to the The impedance element shall be set less than the calculated Transmission system If the relay is impedance derived from 115% of: Simulated line voltage coincident that are used installed on the with the highest Reactive Power (1) Real Power output 100% of the aggregate generation gross – exclusively to export generator-side of the 14b output achieved during field-forcing MW reported to the Transmission Planner, and energy directly from GSU transformer in response to a 0.85 per unit nominal (2) Reactive Power output of the aggregate generation a BES generating unit use Option 7 –100% voltage prior to field-forcing maximum gross Mvar output during field-forcing as determined or generating plant. by simulation Elements may also supply generating plant loads. to synchronous generators The same application continues on the next page with a different relay type
Elements that connect the GSU transformer(s) to the Transmission system that are used exclusively to export energy directly from a BES generating unit or generating plant. Elements may also supply generating plant loads. to synchronous generators Phase distance relay (21) – directional toward the Transmission system installed on the high-side of the GSU transformer If the relay is installed on the generator-side of the GSU transformer use Option 7 14a 0.85 per unit of the line nominal voltage The impedance element shall be set less than the calculated impedance derived from 115% of: (1) Real Power output – 100% of the aggregate generation gross MW reported to the Transmission Planner, and (2) Reactive Power output – 120% of the aggregate generation MW value, derived from the generator nameplate MVA rating at rated power factor OR 14b Simulated line voltage coincident with the highest Reactive Power output achieved during field-forcing in response to a 0.85 per unit nominal voltage prior to field-forcing The impedance element shall be set less than the calculated impedance derived from 115% of: (1) Real Power output – 100% of the aggregate generation gross MW reported to the Transmission Planner, and (2) Reactive Power output –100% of the aggregate generation maximum gross Mvar output during field-forcing as determined by simulation The same application continues on the next page with a different relay type
PRC_025_2_Generator_Relay_Loadability_Draft_2017_05_23.docx