Abstract:
Optimization of fossil-fuel power plants plays an important role in increasing efficiency of the plants. Economic dispatching of well combined power plants in unit commitment may place those plants in maximum efficiency. Lagrange multiplier, a method in economic dispatch, was utilized for rescheduling the demand of peak load in power system of PT. PLN branch Manokwari. The power system of the electrical company includes nine units and the other rental units of diesel power plant. Based on the investigation in the time of peak load for a week operation, diesel power plant units in the company system had not worked in optimal operation while handling the peak load. This condition has increased the operation cost of the generating system. By rescheduling the power plants using Langrange method, the company can save operation cost about USD 9548 per week of operation in peak load time. On the other hand, by recommitting efficient power plants for handling the peak load using simple unit commitment, the company can save cost about USD 11869 per week. This condition can also save fuel and reduce emission of carbondioxide.
