EE 702 · Chapter 6
Utilization of Electrical Energy past question
6.4 Causes and Disadvantages of Low Power Factor and Different Techniques to Improve Power Factor
An industry consumes 50000 units of electricity in a year at average power factor of 0.7 lag. The recorded max. demand is 400 kVA. The tariff is Rs. 120/kVA plus Rs. 5.50 per kWhr. Calculate the annual cost of supply and find out annual saving in cost by installing power factor improving device costing Rs. 1000 per kVAR which raises the power factor from 0.7 to 0.9 lagging. Allow 10% per year on the cost of the improving device to cover all additional cost.