EPRI Grounding Policy Data Requirements Available to each

EPRI Grounding Policy Data Requirements Available to each utility • • • DER rating User defined positive sequence current reference limit Minimum concurrent load in islanded grid Supplemental ground source zero-sequence impedance Maximum phase - ground voltage target Requires assumptions by from some utilities • Connected load power factor • Percentage of load connected line-ground • Supplemental ground source zero-sequence X/R ratio Requires assumptions by all utilities • Inverter negative sequence impedance angle THE JOINT UTILITIES OF NEW YORK 1

Follow-up Questions for EPRI 1. Can EPRI provide additional information on how to define the “Minimum concurrent load in islanded grid”? 2. Should “connected load power factor” consider the impact connected generation has on overall circuit power factor? I. e. can this input be retrieved from power flow models if generation is masking load? 3. Can EPRI provide additional background on the worst-case scenario assumptions for the inverter negative sequence impedance assumptions? THE JOINT UTILITIES OF NEW YORK 2

Conclusions to Date • Not all data inputs are readily available. • Some variables will require assumptions, estimates, or a modified approach where data is not available. • The JU are currently in the process of evaluating each assumption to determine if the proposed policy is a feasible solution. THE JOINT UTILITIES OF NEW YORK 3