Transmission pricing is an important issue in view of increased deregulation. Purpose of pricing is to recover cost of transmission encourage efficient use and investment. Wheeling charges for power transmission can be reduced by FACTS devices as they are effective means of controlling the power flow in the network. The unified power flow controller (UPFC) integrates properties of both shunt an...

In this article is proposed a Centralized Sliding Mode Control (CSMC) applied to a UPFC device for controlling power flow and enhancing power system stability. First, we establish a state-space dynamic model of UPFC based on Kirchhoff’s equations and (d-q) transformation. This model includes the two voltage source inverters and the DC bus voltage link. Furthermore, in order to cancel the effect...

This paper presents a particle swarmoptimization (PSO) based algorithm to perform congestionmanagement by properplacement and sizing of one unified power flow controller (UPFC). The proposed approach makes use of the PSOalgorithm to allocate the near-optimal GenCos as well as the optimal location and size of UPFC whereas the Newton–Raphson solution minimizes the mismatch of the power flow equat...

The growth in the demand of electrical energy is leading to load on the Power system which increases the occurrence of frequent oscillations in the system. The reason for the oscillations is due to the lack of damping torque which is required to dominate the disturbances of Power system. By using FACT devices, such as Unified Power Flow Controller (UPFC) can control power flow, reduce sub-synch...

Long distance AC transmission is often subject to stability problems , which limits the transmission capability.Large interconnected power systems often suffer from weakly damped swings between synchronous generators and subsystems.This paper presents two methods , based on the use of nonlinear system model , to improve transient stability and damping of power swings using UPFC. A statevariable...

This paper proposes a sensitivity based technique for optimal placement of Unified Power Flow Controller (UPFC) to enhance voltage stability margin under contingencies. The sensitivity of system loading factor with respect to the reactive power flowing through lines computed for the system intact case and critical contingency cases have been used to decide optimal location for the placement of ...

Weakly damped power swings are one of the main problems endangering secure operation of power systems. This paper presents two methods , based on the use of nonlinear system model , to improve damping of power swings using UPFC. A statevariable control strategy has been derived using local available signals of real and reactive power. The results of simulation tests of two control methods, unde...