Power Flow Control Capability Research Articles

Comparison of Sen Transformer and UPFC for congestion management in hybrid electricity markets

Congestion management (CM) is one of the most important and challenging tasks of the Independent System Operator (ISO) in the deregulated environment. Recently, Sen Transformer (ST) has emerged as an important power flow control device which has the capability of power flow control over a wide range like UPFC. This device with a conventional transformer and tap changers has the capability of bidirectional control of active and reactive power and can play a very important role in future markets for mitigating the congestion problems. In this paper, the capability of ST has been utilized to manage transmission line congestion for hybrid based electricity market model. The main contribution of the paper is: (i) to develop an optimal rescheduling of generators strategy for real time congestion management and impact of ST for congestion management, (ii) the comparison of ST with unified power flow controller (UPFC) for congestion management, (iii) the secure bilateral transactions determination in a hybrid market model and congestion management with both power flow controllers in combined pool and bilateral market model. The optimal location of ST and UPFC has been obtained solving mixed integer non-linear programming model of congestion management. The proposed model has been applied for results on IEEE 24-bus RTS test system.

Control of a hybrid wind turbine/battery energy storage power generation system considering statistical wind characteristics

This paper presents controller design and simulation studies of a hybrid wind turbine/battery energy storage power generation interface to control active and reactive power in distribution systems. First, the modeling of grid-connected hybrid power system was illustrated. A known Weibull distribution presented the wind speed. Further analysis has been considered based on the law of large number and the wind power generated from a closed-form. Power electronic converters used to connect hybrid power system to the AC system. Fuzzy sliding mode controller for the voltage source converter has been presented to control reactive and active powers in the utility grid. In order to verify the proper operation of the proposed controller, a known load profile has been considered. Finally, simulation results have been illustrated to show power flow control capability of the developed control strategy in distribution systems.

Use of IPFC Detailed Dynamic Model for Analysis of Power Flow Control and Small‐Signal Stability Enhancement

AbstractThis paper presents a study of the power flow control capability of the interline power flow controller (IPFC) and its effect on small‐signal stability enhancement. A detailed dynamic model of IPFC suitable for power system electromechanical stability analysis is developed in this paper. The power flow control capability of the proportional‐integral (PI) controllers and their effect on power oscillation damping are evaluated first, and modal analysis of the power system is carried out to demonstrate their effectiveness in small‐signal stability enhancement. Then the eigenvalue sensitivity based parameter optimization technique is adopted to optimize the control parameters of PI controllers in order to stabilize the oscillatory modes having insufficient damping ratios. Numerical simulation results demonstrate that the IPFC with the proposed control is an effective tool for power flow control and small‐signal stability enhancement, and the optimized PI controllers also have a positive effect on improving the performance of IPFC in power flow control. Copyright © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.

A Lyapunov theory based UPFC controller for power flow control

Unified power flow controller (UPFC) is the most comprehensive multivariable device among the FACTS controllers. Capability of power flow control is the most important responsibility of UPFC. According to high importance of power flow control in transmission lines, the proper controller should be robust against uncertainty and disturbance and also have suitable settling time. For this purpose, a new controller is designed based on the Lyapunov theory and its stability is also evaluated. The Main goal of this paper is to design a controller which enables a power system to track reference signals precisely and to be robust in the presence of uncertainty of system parameters and disturbances. The performance of the proposed controller is simulated on a two bus test system and compared with a conventional PI controller. The simulation results show the power and accuracy of the proposed controller.

Active Power Flow Control for Generating a Quiet Zone in a Thin Plate (Feedback Control System Based on Cluster Control Method)

This paper addresses active power flow control of a distributed-parameter planar structure. From the viewpoint of wave propagation, this paper presents a novel power flow control employing vibration intensity as a criterion of vibration energy flow. It enables to generate a quiet zone where structural vibration is completely suppressed in the vibrating structure. Applying cluster feedback control approach, a control method generating a quiet zone on a designated area of the target panel is proposed. Finally, a numerical simulation and an experiment are conducted with a simply supported plate, demonstrating the capability of the active power flow control for generating a quiet zone.

Power flow control with controllable reactive series elements

The basic features of controllable reactive series elements (CRSE) (i.e. controllable series compensation (CSC) and a static synchronous series compensator (SSSC)) for system power flow control are presented. Mathematical models of CRSE, including a simplified transmission system model, have been developed. Based on this, the CRSE impact on a longitudinal transmission system was studied. The physical background of the basic differences between a CSC and an SSSC in terms of power flow control has been presented. According to theoretical considerations, from the point of view of power flow control capability, SSSC is superior to CSC, especially at low transmission angles. Therefore SSSC seems to be suitable in situations where power flow needs to be controlled in short lines or in light-load conditions.