5-314 L90 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUALGROUPED ELEMENTS CHAPTER 5: SETTINGS5The following settings are available.COMPENSATED OV Zc MAG — This setting specifies the magnitude of the impedance ZC in secondary ohms. Set it to half thepositive-sequence series impedance of the line. Alternately, if the positive-sequence charging currents and local andremote voltages are known, then this value can be calculated from equation above.COMPENSATED OV Zc ANG — This setting specifies the angle of the impedance ZC in degrees.COMPENSATED OV I_1max — This setting specifies the maximum expected positive-sequence line current for which aremote overvoltage is anticipated.COMPENSATED OV STG1 PKP, COMPENSATED OV STG2 PKP, COMPENSATED OV STG3 PKP — These settings specify the pickup levelfor each of the three stages. If any stage is set with no intentional time delay, then set the pickup setting 15% above theanticipated steady state overvoltage to prevent an operation during line energization. A stage that is not used can be setto its maximum setting value (3.000 pu) to effectively disable it.COMPENSATED OV STG1 DELAY, COMPENSATED OV STG2 DELAY, COMPENSATED OV STG3 DELAY — These settings specify the timedelay for each of the three stages in seconds.Figure 5-179: Compensated overvoltage logic5.7.15 Supervising elements5.7.15.1 MenuSETTINGS GROUPED ELEMENTS SETTING GROUP 1(6) SUPERVISING ELEMENTS SUPERVISING ELEMENTS DISTURBANCE DETECTORSee below 87L TRIPSee page 5-318
