Improved genetic and Harmony Search Algorithms for single and multi stage expansion planning of power system

Meta-heuristic algorithms are widely used to address optimization problems. However these methods give only suboptimal solutions in case of complex problems with constraints. This calls for modification in the algorithm in accordance with the problem to result in optimal solution with reasonable consistency. In this paper, Genetic Algorithm (GA) and Harmony Search Algorithm (HS) are discussed and compared. Improvements for HS and GA are suggested for Single and Multi stage expansion of Multi state Power System, which is an optimization problem with availability constraints. The modified HS employed for Single Stage expansion drastically improved the consistency and the time taken. Modification of GENITOR (a variant of GA) for Multi-Stage expansion resulted in achieving the solution in less number of iterations. This feature gives scope to the algorithm for application in real time complex problems with constraints. Also, the key feature of GENITOR is incorporated into HS for Multi-Stage expansion, in order to achieve the solution in lesser number of iterations. MatLab R2010a is used for the purpose of programming.