A polarised-mho phase comparator connected for red-phase-to-earth faults on a single-end line is supplied with inputs:...

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A polarised-mho phase comparator connected for red-phase-to-earth faults on a single-end line is supplied with inputs: S₁ = IZR-V S₂ = V-k/60° VB where voltage V = VR-N and current I=IR + KI resid. (ie current includes earth-fault compensation) so that in terms of system impedance the comparator inputs can be shown to be: S₁ = ZR-Z S₂ = √3k ( /-30° + p /30°)Zs 2+9 Zso where p =- and q =. Zs Zo Y/N + (1+k) Z Zs and Z are positive-sequence source and line impedances. Zso and Zo are zero-sequence source and line impedances. Construct the polar diagram for this relay assuming k = 0.2, IZSI/IZRI = 5, p =3/0°, q = 2.5/0° and that the argument of Zg is 90° and of ZR = 70° A polarised-mho phase comparator connected for red-phase-to-earth faults on a single-end line is supplied with inputs: S₁ = IZR-V S₂ = V-k/60° VB where voltage V = VR-N and current I=IR + KI resid. (ie current includes earth-fault compensation) so that in terms of system impedance the comparator inputs can be shown to be: S₁ = ZR-Z S₂ = √3k ( /-30° + p /30°)Zs 2+9 Zso where p =- and q =. Zs Zo Y/N + (1+k) Z Zs and Z are positive-sequence source and line impedances. Zso and Zo are zero-sequence source and line impedances. Construct the polar diagram for this relay assuming k = 0.2, IZSI/IZRI = 5, p =3/0°, q = 2.5/0° and that the argument of Zg is 90° and of ZR = 70°

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9 bolanzed mho phose Red Phate to earth fault on ground fault ... View the full answer