In this paper application of Particle Swarm Optimization (PSO) based algorithm for Optimal Power Flow (OPF) in Economic Dispatch (ED) was studied. Firstly. this method is dynamic in nature and it beats the arrears of other evolutionary computation techniques such as premature convergence and provides high quality solutions. Secondly. https://www.allfixelectricales.shop/product-category/defrost-cutout-thermostat/