Pilot wire line differential CT accuracy selection per IEEE

[lakshmanan1974]

Can any one suggest me which IEEE/ANSI Standards give brief description / worked examples to calculate knee point voltage and to select the required CT 'C' Voltage for pilot wire line differential protection for Medium Voltage (15kV) underground cables..?

Will the CT 'C' voltage selection be similar to transformer differential protection CTs in line with IEEE C37.110 ?

Thanks in advance.