scholarly journals Applications of FACTS devices for improving power system transient stability

2015 ◽  
Vol 18 (3) ◽  
pp. 47-54
Author(s):  
Khanh Tuan Dang ◽  
Liem Van Nguyen

As the power demand has been increasing rapidly, today’s modern power system becomes to be more complex and faces many challenges. It is envisaged that transient stability will play the important role in ensuring the steady state operation of power systems in the event of three phases fault or switching of lines. This paper investigates models of Flexible AC Transmission Systems (FACTS) and applications of FACTS devices for improving the rotor angle stability. FACTS devices are applicable in shunt connection Static Var Compensator (SVC), in series connection Thyristor-Controlled Series Capacitor (TCSC), or in the combination of both. Mathematical models of power systems having FACTS devices are set of Differential - Algebraic Equations (DAEs). Trapezoidal rule and Newton - Raphson method are applied to solve DAEs. The simulation results of rotor angles demonstrate the effectiveness and robustness of proposed the SVC and TCSC on transient stability enhancement of power systems.

2020 ◽  
Author(s):  
Gilles Mpembele ◽  
Jonathan Kimball

<div>The analysis of power system dynamics is usually conducted using traditional models based on the standard nonlinear differential algebraic equations (DAEs). In general, solutions to these equations can be obtained using numerical methods such as the Monte Carlo simulations. The use of methods based on the Stochastic Hybrid System (SHS) framework for power systems subject to stochastic behavior is relatively new. These methods have been successfully applied to power systems subjected to</div><div>stochastic inputs. This study discusses a class of SHSs referred to as Markov Jump Linear Systems (MJLSs), in which the entire dynamic system is jumping between distinct operating points, with different local small-signal dynamics. The numerical application is based on the analysis of the IEEE 37-bus power system switching between grid-tied and standalone operating modes. The Ordinary Differential Equations (ODEs) representing the evolution of the conditional moments are derived and a matrix representation of the system is developed. Results are compared to the averaged Monte Carlo simulation. The MJLS approach was found to have a key advantage of being far less computational expensive.</div>


Author(s):  
Naraina Avudayappan ◽  
S.N. Deepa

Purpose The loading and power variations in the power system, especially for the peak hours have abundant concussion on the loading patterns of the open access transmission system. During such unconditional state of loading the transmission line parameters and the line voltages show a substandard profile, which depicts exaction of congestion management of the power line in such events. The purpose of this paper is to present an uncomplicated and economical model for congestion management using flexible AC transmission system (FACTS) devices. Design/methodology/approach The approach desires a two-step procedure, first by optimal placement of thyristor controlled series capacitor (TCSC) and static VAR compensator (SVC) as FACTS devices in the network; second tuning the control parameters to their optimized values. The optimal location and tuning of TCSC and SVC represents a hectic optimization problem, due to its multi-objective and constrained nature. Hence, a reassuring heuristic optimization algorithm inspired by behavior of cat and firefly is employed to find the optimal placement and tuning of TCSC and SVC. Findings The effectiveness of the proposed model is tested through simulation on standard IEEE 14-bus system. The proposed approach proves to be better than the earlier existing approaches in the literature. Research limitations/implications With the completed simulation and results, it is proved that the proposed scheme has reduced the congestion in line, thereby increasing the voltage stability along with improved loading capability for the congested lines. Practical implications The usefulness of the proposed scheme is justified with the computed results, giving convenience for implementation to any practical transmission network. Originality/value This paper fulfills an identified need to study exaction of congestion management of the power line.


Author(s):  
V. VIJAY VENU ◽  
A. K. VERMA

In this paper, beginning with a concise overview of the Available Transfer Capability (ATC) evaluation methods, we make a proposition for reliability management in the planning horizon of deregulated power systems through the concept of Adequacy Resiliency. The derived indices are meant as indicators of adaptability of power systems to ensure the required reliability levels. Improvements to this conceptualization upon the deployment of Flexible AC Transmission System (FACTS) devices are then put forward. We also explore the option of employing the created indices to the operational horizon of power systems, explaining the means of market enhancement. Core reliability issues arising out of the usage of FACTS are then discussed.


2020 ◽  
Author(s):  
Gilles Mpembele ◽  
Jonathan Kimball

The analysis of power system dynamics is usually conducted using traditional models based on the standard nonlinear differential algebraic equations (DAEs). In general, solutions to these equations can be obtained using numerical methods such as the Monte Carlo simulations. The use of methods based on the Stochastic Hybrid System (SHS) framework for power systems subject to stochastic behavior is relatively new. These methods have been successfully applied to power systems subjected to stochastic inputs. This study discusses a class of SHSs referred to as Markov Jump Linear Systems (MJLSs), in which the entire dynamic system is jumping between distinct operating points, with different local small-signal dynamics. The numerical application is based on the analysis of the IEEE 37-bus power system switching between grid-tied and standalone operating modes. The Ordinary Differential Equations (ODEs) representing the evolution of the conditional moments are derived and a matrix representation of the system is developed. Results are compared to the averaged Monte Carlo simulation. The MJLS approach was found to have a key advantage of being far less computational expensive.


Energies ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 3292 ◽  
Author(s):  
Andres Tarraso ◽  
Ngoc-Bao Lai ◽  
Gregory N. Baltas ◽  
Pedro Rodriguez

The variable and unpredictable behavior of renewable energies impacts the performance of power systems negatively, threatening their stability and hindering their efficient operation. Flexible ac transmission systems (FACTS) devices are able to emulate the connection of parallel and series impedances in the transmission system, which improves the regulation of power systems with a high share of renewables, avoiding congestions, enhancing their response in front of contingencies and, in summary, increasing their utilization and reliability. Proper control of voltage and current under distorted and unbalanced transient grid conditions is one of the most critical issues in the control of FACTS devices to emulate such apparent impedances. This paper describes how the synchronous power controller (SPC) can be used to implement virtually synchronous FACTS. It presents the SPC functionalities, emphasizing in particular the importance of virtual admittance emulation by FACTS devices in order to control transient unbalanced currents during faults and attenuate harmonics. Finally, the results demonstrate the effectiveness of SPC-based FACTS devices in improving power quality of electrical networks. This is a result of their contribution to voltage balancing at point of connection during asymmetrical faults and the improvement of grid voltage quality by controlling harmonics flow.


Author(s):  
Hanuman P. Agrawal ◽  
Hariom Bansal

Background: The power industry has been evolving continuously and influenced by a competitive deregulated market. The crucial demand to maximize the efficiency of the existing equipment requires it’s proper management. Flexible AC Transmission System (FACTS) are flexible devices, which provide dynamic control over the power system to cope with its dynamic nature. Methods: An extensive review is carried out on FACT devices covering its classification, importance, optimal placement and influence on the power systems. Results: In this paper, different techniques to identify the optimal location of placing FACT devices have been discussed and compared, as the placement of these devices in the power system is of utmost importance for its efficiency. Conclusion: This paper summarizes techniques available for optimal placement of FACTS devices in order to improve power system performance. It will serve as a ready reference for the future researchers in this field and help them in selecting the proper devices to carry out their work.


Energies ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1976 ◽  
Author(s):  
Samuel Marrero Vera ◽  
Ignacio Nuez ◽  
Mario Hernandez-Tejera

Power system stability is a topic which is attracting considerable interest due to the increase of both electrical demand and distributed variable generation. Since Flexible AC Transmission Systems (FACTS) devices are an increasingly widespread solution to these issues, it is important to study how their allocation procedure should be done. This paper seeks to assess the influence of load share in FACTS devices allocation. Despite this interest, researchers, as well as system planners, have mainly focused on studying single power system configuration rather than using a wider approach. Keeping this in mind, we have iteratively created several load share scenarios based on an IEEE 14-bus test system. Subsequently, we have applied an heuristic procedure in order to demonstrate how load share may affect the results of the FACTS devices allocation procedure. Additionally, we have compared results from two different objective functions so as to evaluate our proposal. Finally, we have proposed a solution to FACTS allocation which takes load share into account. Our tests have revealed that, depending on the distribution of load within the power system, the optimal location for a FACTS device may change. Furthermore, we have also found some discrepancies and similarities between results from distinct objective functions.


2013 ◽  
Vol 385-386 ◽  
pp. 872-876 ◽  
Author(s):  
Wen Lei Li ◽  
Wei Xing Lin

For the single machine connected to infinite bus power system with uncertainties, one nonlinear coordinated control scheme for Static Synchronous Compensator (STATCOM) and excitation is proposed in this paper. Firstly, in order to avoid solving the differential algebraic equations (DAEs) model of system, we simplify the DAEs into the classical differential equations, and then a new nonlinear parameter strict feedback model is given. Secondly, in order to make the system achieve the desired results, the controller is designed in two parts based on improved dynamic surface control method (IDSC) and passive control techniques. The theoretical analysis shows that the derived controller can not only attenuate the influences of external disturbances, but also has strong robustness for system parameters variety. The control law obtained is more effective and the system globally and uniformly ultimately bounded can be achieved using full nature of nonlinear dynamic. Lastly, the further simulation results indicate that the proposed controller can ensure transient stability of the power system under large sudden fault.


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