Application of ESGA hybrid approach for voltage profile improvement by capacitor placement

This paper presents elite-based simplex-GA hybrid approach combined-with multipop-GA (ESGA) to determining the location, size, and number of capacitors to improve voltage profile and minimize power losses in unbalanced distribution systems. One of the main obstacles in applying GA to complex problems has been the high computational cost due to their slow convergence rate. To alleviate this difficulty, ESGA hybrid approach was developed that combines elite-based simplex-GA hybrid approach with multipop-GA. The objective, function formulated consists of two terms: cost for energy losses and cost related to capacitor purchase and capacitor installation. The cost function associated with capacitor placement is considered as a step function due to banks of standard discrete capacities. Its efficiency was proved through the application in IEEE 13-bus and 3.4-bus test systems and was compared with several methods using GA.