Three-phase power flow analysis in sequence component frame using Hybrid Particle Swarm Optimization

Power flow is an important tool in power system studies. Usually, a power system is assumed to be balanced and the power flow analysis is carried out for the same. Practical power system networks are highly unbalanced and it is required to obtain load flow (power flow) solution for such unbalanced networks. The unbalancing in power system is unavoidable due to the untransposed transmission lines and imbalance in loading. Hence, a power flow analysis dealing with three-phase configuration of power systems is necessary for proper planning and stability studies. The paper presents an algorithm for solving the three-phase load flow problem in symmetrical component frame using Hybrid Particle Swarm Optimization (HPSO) technique. A sequence coupled transformer model and a sequence line model are used. The objective function is formulated using the sequence models of three-phase power system and is solved using Hybrid PSO. The proposed method eliminates the formation of Jacobian matrix and its inversion and thus reduces the complexity of the problem. Ill-conditioned power system problems can also be solved by this method. Without any modification, this algorithm can also be applied to obtain load flow solution of the balanced networks. The validity of the proposed method is verified by a numerical example.