A Hybrid Approach to Find Maximum Loadability Limits of a Power System

In this paper, a hybrid approach to find maximum loadability limits of a power system is proposed. The proposed approach consists of firefly algorithm (FA) and load incremental algorithm (LIA) in combination. Firefly algorithm is a population based approach which is inspired from the behavior of fireflies and is successfully implemented in various maximization problems. Therefore, in this paper, it is implemented to maximize the loading on PQ buses while voltage constraint is not violated. In this work, initially firefly algorithm is implemented to find maximum line loadability limits of power system. To get best results using firefly algorithm, population size and number of iterations for firefly are varied for lesser computation burden while solution quality is not compromised. The optimal solution obtained using FA is updated using LIA with a small load increment (δ) on load buses. To obtain optimal results with less computation efforts, step size of load increment is chosen in LIA for 30-bus system. To check effectiveness and applicability of suggested approach it is tested on 30-bus. To compare the results, the statistical analysis is done for proposed method and other existing evolutionary algorithms i.e. Differential Evolution (DE) and DEPSO (DE and particle swarm optimization). On comparison it is found that the results obtained with proposed approach are more promising.