Combined Economic Emission Dispatch With Consideration of Nonlinear Restrictions of Power Plants Based on a new Hybrid Method

Pollutant gases emission due to the consumption of fossil fuel in power plants leads to especial attention to minimization of the pollution problem in addition to operation costs. In this paper، the problem of economical and environmental distribution of loads among thermal power plants with the purpose of minimization of the operation cost and environmental pollutions is solved using a hybrid algorithm of honey bees and gravitational search. Simultaneously، power plants nonlinear limitations i. e.، steam valves effect، the production prohibited areas and the rate of change in productivity of power plants are considered in solving the problem. In the proposed method، the information exchange among the bees is based on Newton''s laws and Gravity since this factor leads to the usage of all the capacity of the honey bees algorithm. In order to show the efficiency of this method، it is tested on IEEE 30-bus and 118-bus systems at different load levels and the results are compared with other methods. Based on the comparison، it is proved that the proposed method has high accuracy and speed rate in solving complex problems related to power system and its placement in local optimum points is far less than other methods. Finally، in order to determine the final operation point of the system، a sensitivity analysis with respect to the fuel cost factor is done and the results are presented