Answer Happy

2. a) What are the different types of tariffs? Explain each of them in detail. b) State Kelvin's economy law related to the selection of most economic conductor size. Prove that this size is obtained whenever the variable part of annual charge equals the cost of energy losses in the year. c) A consumer has an average demand of 400 kW at a p.f of 0.8 lagging and annual load factor of 50%. The tariff is Tk. 50 per kVA of maximum demand per annum plus 5 paisa per kWh. If the power factor is improved to 0.95 lagging by installing phase advancing equipment then calculate (i) the capacity of phase advancing equipment and (ii) the annual saving effected. The phase advancing equipment costs Tk 100 per kVAR and the annual interest and depreciation together amount to 10%.