calculate 3 reach points on offset mho circle? 1

[meeko]

hey there,

was doing a reach test on a SEL relay today with a RCA of 79.6deg., Z1 = 1.43, after some calculations i came up with these values below. this worked fine for finding 1 single point of the offset mho circle. I couldnt figure out how to calculate another point on the circle to test at a different angle or reach point.(3 is required)

I was wondering if anyone had any formula i could use to find more points on a mho circle- also so i plot the complete circle on excel.

Angle
Va 33.22 301.97
Vb 33.22 298.03
Vc 66.40 120.00 == 1.14 ohm relay picks up zone 1 and trips breaker
Ia 1.00 310.40
Ib 1.00 130.40
Ic 0.00 120.00

z1 mag --> 1.43 ohm
z1 RCA --> 79.6

80% Z1 (circle 1) = 1.14 ohm

any help is appreciated.

 

[desertfox]

This might help, scroll down till reach page 8

https://www.eiseverywhere.com/file_uploads/121fe1ee46274aad56a3b993da3bc7f4_per_pap.pdf