a. Assuming that zero sequence current = 0, calculate the positive and negative sequence current for each of the above record.

b. Based on the result in (a), what kind of protection can be used to detect such high contact resistance fault.

c. Critically evaluation the assumption that zero sequence current = 0 in calculating positive and negative sequence current

2. Three phase unbalance current was detected in a short 110kV cable as shown in the table below:- Date of Measurement Ib Ic 20/10/2018 00:33 15.94883 15.90672 15.90755 21/03/2019 23:47 22.18787 19.5238 21.06879 22/03/2019 10:45 30.03768 26.73209 29.06373 22/03/2019 10:57 47.20966 44.2589 46.90733 01/04/2019 10:35 53.33588 40.45242 44.20396 It was later found that a high contact resistance (shown in attached picture) existed inside the GIS cable sealing end due to installer error in b-phase. Large gap 2. Three phase unbalance current was detected in a short 110kV cable as shown in the table below:- Date of Measurement Ib Ic 20/10/2018 00:33 15.94883 15.90672 15.90755 21/03/2019 23:47 22.18787 19.5238 21.06879 22/03/2019 10:45 30.03768 26.73209 29.06373 22/03/2019 10:57 47.20966 44.2589 46.90733 01/04/2019 10:35 53.33588 40.45242 44.20396 It was later found that a high contact resistance (shown in attached picture) existed inside the GIS cable sealing end due to installer error in b-phase. Large gap