International Journal of Electrical and Computer Engineering (IJECE) Vol. 10, No. 4, August 2020, pp. 3343~3349 ISSN: 2088-8708, DOI: 10.11591/ijece.v10i4.pp3343-3349  3343 Journal homepage: http://ijece.iaescore.com/index.php/IJECE Comparative study of the price penalty factors approaches for Bi-objective dispatch problem via PSO Mohammed Amine Meziane 1 , Youssef Mouloudi 2 , Abdelghani Draoui 3 1,2,3 Departement of Electrical Engineering, University of Tahri Mohammed, Bechar, Algeria 1,2,3 Smart Grids and Renewable Energies Laboratory (SGRE), Algeria Article Info ABSTRACT Article history: Received Jul 28, 2018 Revised Jan 24, 2020 Accepted Feb 2, 2020 One of the main objectives of electricity dispatch centers is to schedule the operation of available generating units to meet the required load demand at minimum operating cost with minimum emission level caused by fossil-based power plants. Finding the right balance between the fuel cost the green gasemissionsis reffered as Combined Economic and Emission Dispatch (CEED) problem which is one of the important optimization problems related the operationmodern power systems. The Particle Swarm Optimization algorithm (PSO) is a stochastic optimization technique which is inspired from the social learning of birds or fishes. It is exploited to solve CEED problem. This paper examines the impact of six penalty factors like "Min-Max", "Max-Max", "Min-Min", "Max-Min", "Average" and "Common" price penalty factors for solving CEED problem. The Price Penalty Factor for the CEED is the ratio of fuel cost to emission value. This bi-objective dispatch problem is investigated in the Real West Algeria power network consisting of 22 buses with 7 generators. Results prove capability of PSO in solving CEED problem with various penalty factors and it proves that Min-Max price penalty factor provides the best compromise solution in comparison to the other penalty factors. Keywords: Bi-objective dispatch problem Combined economic emission dispatch Particle swarm optimization Price penalty factor Real West Algeria electrical network Copyright © 2020 Institute of Advanced Engineering and Science. All rights reserved. Corresponding Author: Mohammed Amine Meziane, Faculty of Science and Technology, Departement of Electrical Engineering, Smart Grids and Renewable Energies Laboratory (SGRE), University of Tahri Mohammed, BP 417, 08000 Bechar, Algeria. Email: aminemohmeziane@gmail.com 1. INTRODUCTION Electric utility systems are interconnected to achieve high operating efficiency and to produce cheap electricity with minimum production cost, maximum reliability, and better operating conditions [1]. The optimal power flow problem (OPF) is an important tool in operation and control of large modern power systems, it was first discussed by Carpentier in 1962 [2], the main purpose of OPF is to find the optimal output power of generators to minimize the total generation cost and satisfy the equality and inequality constraints. Operating at absolute minimum cost can no longer be the only criterion for dispatching electric power due to increasing concern over the environmental issues. The generation of electricity from fossil fuel resources releases several contaminants, such as SOx, NOx and CO2 into the atmosphere [3]. In this paper the used term Economic Dispatch Problem (ED) is the short-term which refers to the determination of the optimal output of a number of electricity generation facilities. The aim of every generating station is to produce electricity at the lowest possiblefuel consumption and emission rates, but these two constraints cannot be metsimultaneously. Nowadays,the demand for energy is increasing at a high pace, which makes it highly crucial to run generators at very minimal cost. This is the main goal of an Economic Dispatch Problem. With the exceptional production of carbon emissions by