Question

Q1: You are working in a load-substation and have collected the following data; from your 11kV, 50HZ substation. Actually, you are assigned to use systematic and professional approach to find out the monthly electricity bill with an appropriate tariff system, applied in Oman. With proper justification for the tariff system applied; suggest the monthly electricity bill. [10 Marks] Time in hr. 0-6 6-10 10-14 14 - 16 16.22 22 - 24 2485A at 5800A at 5250A at 4630A at 1750A at Current & 1750A at pf 0.9 pf lagging 0.9 pf lagging 0.9 pflagging 0.95 pf lagging 0.95 pf lagging 0.85 pf lagging

what the information need

Answer 1

Current and Power factor	Power P=1.732*VI*powerfactor (in Megawatts ) (V= 11kV given in question)	Energy = Power * Time (in MWh)	Cost @24rial/MWh tarriff
1750A @0.9 lag	1750*0.9*1.732*11000=30MW	30*6 = 180MWh	4320 rial
[email protected] lag	2485*0.95*1.732*11000=44.97MW	44.97*4=179.88MWh	4372 rial
[email protected] lag	5800*1.732*0.95*11000 = 104.97 MW	104.97 *4 = 419.88MWh	10077 rial
[email protected] lag	5250* 1.732* 0.9*11000=95.02 MW	95.02 *2 = 190.04MWh	4561 rial
4630A@ 0.85 lag	4630*1.732*0.85*11000=83.80MW	83.80* 6= 502.8MWh	12067 rial
1750 A @0.9 lag	1750*0.9*1.732*11000=30MW	30 *2 = 60 MWh	1440 rial
NET COST (per day or for 24 hours )			36837 rial

So,

Cost for 30 days or month

= 36837 * 30

= 1105110 Rial