PRODUCTION COSTING. W.D. Prasad Lecturer Dept. of Electrical Engineering University of Moratuwa. Introduction. Electricity generation system planning requires minimization of the total cost of supplying the demand during a specified period of time. Short term, Medium term or Long term.
Dept. of Electrical Engineering
University of Moratuwa
Ci ; Ci = Capacity
Load and Generator Models Cont…
Where T is the total duration
where ICi is the incremental cost of generator i
Where ng is the number of generator units
where n is the no. of availability levels
The total energy left to be served after loading all the generating units is called the Expected System Unserved Energy.
Table 1: Load Variation
Table 2: Generator Data
b] Comment on possible changes to the answers in (a) if generator 2 and 3 are replaced with generator 4 given in Table 3 having an incremental cost of 1100 Rs/MWh
Table 3: Generator 4 Data
When generators 2 and 3 are combined the resultant generator will have an availability distribution with four levels of operation as given below.
This distribution is exactly the same as the generator 4 distribution given. Thus even though the generators 2 and 3 are replaced with the generator 4, the final probability distribution will not change. This means that the LOLP and the expected system unserved energy also will not be modified. However, the production cot will change due to the modified incremental cost.
Total energy served by generator 2 & 3 = 3470.7 MWh
Total production cost of generator 2 & 3 = Rs 3593415
Energy served by generator 4 = 3470.7 MWh
Production cost of generator 4 = Rs 3817770