In power systems, it is not possible to exploit the full capacity of transmission lines because of voltage drops, stability constrains, etc.As a result of that, the power limit allowable to flow through these lines is less than the maximum power that can be flow meeting the heating limit.With the advent of deregulated power system and open access power system, a competitive market has emerged.And as a result of that using the full capacities of transmission lines are avoidable.The competition between producers and the contracts issues between the producers and consumers of electrical energy in restructured power systems might cause on unwanted increase in power interchange beyond transmission lines capacity . if the power interchange is not well-mangaed ,it would often cause overloads in specific path .this phenonon is termed as lines congestion.Congestion in a transmission system whether multiple organized or single, cannot be permitted except for very short duration , because with continuance congestion ,non convergence power flow equation , Waste system stability and system security and system reaches in the collapse situation .For solves congestion lines must