Transient stability and power flow model of the unified power flow controller for various control strategies (original) (raw)

APPLICATION OF UNIFIED POWER FLOW CONTROLLER TO ENHANCE THE POWER SYSTEM TRANSIENT STABILITY

Flexible AC transmission systems (FACTS) controllers are emerging as viable and economic solutions to the problems of large interconnected AC networks, which can endanger the system power system security. The unified power flow controller is a versatile controller, which can be used to control the active and reactive power in the line independently and also to control the voltage, magnitude and phase of the transmission line.

Steady-state and dynamic models of unified power flow controller (UPFC) for power system studies

Power Systems, IEEE …, 1996

This paper provides comprehensive development procedures and final forms of mathematical models of unified power flow controller (UPFC) for steadystate, transient stability a$ eigenvalue studies. Based on the developed models, the impacts of control strategy, parameters and location of UPFC on power system operating conditions are discussed. The accuracy of the developed models is verified through comparing the study results with those obtained from detailed time-domain simulation using the Electromagnetic Transients Program (EMTP).

Performance evaluation of unified power flow controller using transient simulation

Proceedings of Second International Conference on Power Electronics and Drive Systems, 1997

The Unified Power Flow Controller (UPFC) is a power electronic controller which can be used to control active and reactive power flows in a transmission line by injection of (variable) voltage in series and reactive current in shunt. In this paper we evaluate the performance of a control strategy for UPFC in which we control real power flow through the line, while regulating magnitudes of the voltages at its two ports using transient simulation. The real power reference is modulated in order to improve the damping of power swings in the line. The effectiveness of the UPFC with this control strategy is clearly brought out by the simulation study T0pic:Applications: FACTS; Computer Simulation.

Transient Stability Enhancement of a Power System Using Unified Power Flow Controller

International Review on Modelling and Simulations, 2013

In this paper an attempt has been made to investigate the transient stability enhancement of SMIB system using UPFC controller. UPFC modeling has been done by measuring the parameters locally at the bus. The proposed controller is found to be suitable for operating in both voltage regulation and PQ mode. To mitigate the power oscillations in the system, the required amount of series voltage injected by UPFC controller has also been computed. It is also found that the proposed controller works effectively under low as well as high range of power rating of generator.

Transient Stability Enhancement of Power System Using UPFC (Unified Power Flow Controller)

International Journal of Engineering, 2017

In the power grid system, the prime subjects are to transmit power with supreme power factor and high power quality, supreme transient stability, economical and minimum risk of system failure. The constantly growth of electrical power demands and loads, particularly non-linear loads making the power system network become more obscure to operate and the system becomes unstable with large power flows without proper control and operation. The development in power system with time have brings new challenges and sometimes it is tough to operate system in stable condition due to complex system network. Though, on the other side there is vast development been made in power electronics, which helps the power system to continue in stable condition during most horrible condition occurred due to fault. One of the creation of power electronics is FACTS technology. FACTS (Flexible Alternating Current Transmission Systems) devices are created on power electronics and other dynamic controllers that provide control of one or more AC transmission system parameters to enhance controllability and growth power transfer capability. One way to enhance the power system control is by applying FACTS controller such UPFC (Unified Power Flow Controller). UPFC can control voltage, impedance and phase at alike time. The UPFC control scheme for the grid connected power system is simulated by MATLAB/PSAT in power system block set. By means of IEEE 9 bus power system network, the effectiveness of UPFC are tested by applying the 3-phase fault at dissimilar buses and evaluated the performance of FACTS devices in IEEE nine bus power system during fault condition.

Power System Stability Enhancement Using Unified Power Flow Controller

2010

Problem statement: The enhancement of transient stability of the powe r system is one of the most challenging research areas in power engine er. Approach: This study presents the method to enhance transient stability of power system by Unif ied Power Flow Controller (UPFC). The mathematical model of power system equipped with a UPFC is systematically derived. The parameters of UPFC are modeled into power flow equation and thus it is used to determine control strategy. The swing curves of the three phase faulted power syste m without and with a UPFC are tested and compared in various cases. Results: The swing curve of system without a UPFC gets increases monotonically and thus the system can be considered as unstable whereas the swing curves of system with a UPFC can return to stable equilibrium point. Conclusion: From the simulation results, the UPFC can enhance transient stability of power syste m.

Unified Power Flow Controller (UPFC) Modeling and Analysis Technique by using Matlab and EMTP

Renewable Energy and Power Quality Journal

The UPFC is a state-of-the-art control device that has the ability to enhance electrical power system network operation more precisely and effectively. This device encompasses of shunt and series parts to readjust capacitive and inductive compensation of the network based on their ratings to dynamically control the operating parameters of the transmission-network. These dynamic parameters comprise of phase angles, line impedance and line voltage. During the detailed investigation, a set of equations are introduced to compute UPFC operations/control behaviour on shared two bus system networks. In fact, the EMTP and Matlab models are introduced and customized to determine and validate UPFC effectiveness with precision. In this investigation, a pragmatic approach demonstrated and provided roadmap for the planning and control electrical engineer to evaluate UPFC operational behaviour and its significant impact on Electrical power transmission network operations. This device has the ability to address all types of time based contingencies in order for a seamless operation.

A new control strategy for the unified power flow controller

Power Engineering Society …, 2002

Abstract: The Unified Power Flow Controller (UPFC) is the most versatile among a variety of Flexible AC Transmission System (FACTS) devices, which can be used for power flow control, enhancement of transient stability, damping system oscillations and voltage regulation. In this paper, we ...

Stability Analysis of a Unified Power Flow Controller

The paper concerns with stability analysis of a Unified Power Flow Controller (UPFC). A nonlinear model is described in the abc-reference frame and then transformed into the dq0-reference frame. The model includes shunt and series compensators of the UPFC. Stability analysis is presented first in a three-dimensional space of system parameters. A linearized model is obtained in state-space form to be used in small-signal stability studies. Effects of system parameters on stability are investigated using eigenvalue analysis. These include resistance, reactance, and modulation indices of the shunt and series components of the UPFC. Simulation results show that the stability of the UPFC can be affected by these parameters. The results are useful for UPFC designers and engineers who set technical specifications of these control devices.

UNIFIED POWER FLOW CONTROLLER CONTROL STRATEGIES for POWER FLOW

Yanbu Journal of Engineering and Science

In order to address power flow control issues, this study introduces the use of Unified Power Flow Controller (UPFC) models. These models are based on regulating the variables influencing the transmission line’s power flow, and they are capable of controlling the bus voltage, the line’s actual and reactive power, all at once and independently. The idea behind the UPFC technique proposed in this paper is to provide the unique functional capability of independently controlling both the real and reactive power flow in the line. The in-phase component of the series injected voltage dominates the reactive power while the quadrature component affects the real power. A conventional controlling steady-state analysis and dynamic stability analysis of the power system is developed based on the UPFC model. UPFC provides real-time controlling of all or any combination of the power system parameters which determine the transmittable power. UPFC can force and maintain strategically chosen values ...