Pratap technical experience

  Question = The annual working Cost of a power station is represented by the formula RS ( a+b kW+c kwh ) where the various terms have their usual meaning . Determine the value of a , b and c for a 60 MW station operating at annual load factor of 50% from the following data :  • F = fixed charges , R = running charges ,  (1) capital cost of building and equipment is RS 5 × 10⁶ ( 50 lakh ) ,  (2) the annual cost of fuel , oil , taxation and wages of operating staff is RS 9,00,000 ( 9 lakhs ) . (R) (3) the interest and depreciation on building and equipment are 10% per annum , (F) (4) annual cost of organisation and interest on cost of site etc is RS 5,00,000 ( 5 lakhs ) . (F)  Solution = is given ,  » annual operating cost = RS ( a + b kw + c kwh ) ,   » a = annual fixed cost , • b = b × kW = annual semi fixed cost , • c =  c × kWh =  annual running cost ,  (1) a = annual fixed cost = the annual fixed cost is due to the annual cost of organisation and interest on the cost of site .

  Question = At the end of a power distribution system , a certain feeder supplies three distribution transformers ,each one supplying a group of customer whose connected load are as under :  • transformer no. 1 load 10 kw , demand factor 0.65 , diversity of groups 1.5 , • transformer no. 2 load 12 kw , demand factor 0.6 , diversity of groups 3.5 , • transformer no. 3 load 15 kw , demand factor 0.7 , diversity of groups 1.5 , If the diversity factor among the transformer is 1.3 , find the maximum load on the feeder ?  Solution = Show a feeder supplying three distribution transformers .  » formula = maximum demand or , load  on feeder = sum of maximum demand transformer 1 + transf 2 +trans 3  ÷ diversity factor ,  » So , maximum demand trans.. no. 1 = ( connected load of trans. 1 × demand factor ) ÷ diversity factor  ,  = ( 10 kW × 0.65 ) ÷ 1.5 , = 4.33 kw ,  » maximum demand of trans . 2 =  ( 12 kw × 0.7 ) ÷ 3.5 , = 2.057 kw ,  » maximum demand of trans.  3 = ( 15 kw