Solution of Profit Based Unit Commitment Including Wind Energy Using Improved Shuffled Frog Leaping Algorithm

Abstract

—This paper presents the use of Improved Shuffled frog leaping Algorithm for the solution of unit commitment of the profit based GENCO environment with thermal and wind units. Wind energy is a promising resource of renewable energy and also free from emission. The wind energy is intermittent in nature and it depends on various factors like humidity, temperature. The available energy from wind units is calculated based on the wind speed. But the thermal units should be scheduled such that there is enough reserve is maintained to overcome the intermittent nature of wind energy. The thermal units are scheduled so that the GENCOs get the maximum profit. The thermal units are scheduled while satisfying the lowest up/ down time and the constraints related to ramp rate. The system power balance is taken as a softer constraint but the schedule should be such that enough spinning reserve is maintained to ramp up and down whenever there is a sudden drop or rise in wind generation. The proposed Improved Shuffled Frog Leaping algorithm is a memetic algorithm is based on the food searching behavior of frogs. Leaping of the frog is improved by the using a cognitive component. It will  ensure the faster convergence and global optimal solution. Implementation of the integer coded UC is done which avoids any extra penalty function for satisfying the lowest up/down constraint. Two cases have been considered such as Profit Based Unit Commitment (PBUC) case with no wind units included, and PBUC with wind units included. The results are discussed related to  these cases to explain the effect of wind in GENCOs profit. Also the inclusion of emission constraints has been compared for the above two cases. Standard 10 bus system is taken along with two wind farms each having 10 units to validate the results.