VOLTAGE STABILITY ANALYSIS IN POWER SYSTEM BY OPTIMAL PLACEMENT OF SVC (original) (raw)
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Improvement of Voltage Stability in Power System by Using SVC and STATCOM
The increase in power demand has forced the power system to operate closer to its stability limit. Voltage instability and line overloading have become challenging problems due to the strengthening of power system by various means. The nature of voltage stability can be analysed by the production, transmission and consumption of reactive power. One of the major causes of voltage instability is the reactive power unbalancing which occurs in stressed condition of power system. Flexible AC transmission system (FACTS) devices play an important role in improving the performance of a power system, but these devices are very costly and hence need to be placed optimally in power system. FACTS device like static var compensator (SVC) and thyristor controlled series compensator (TCSC) can be employed to reduce the flows in heavily loaded lines, resulting in a low system loss and improved stability of network. In this paper, a method based on line stability index, real power performance index and reduction of total system VAR power losses has been proposed to decide the optimal location of TCSC. Now a day, Voltage Stability has become a major concern in power systems planning and operation. This problem has become very complex due to the continuous growing on system interconnections and demand for electricity and also due to economical and environmental constraints to properly expand the system. This has increased the importance of implementing suitable and efficient techniques for improving voltage stability of stressed power system. FACTS are one aspect of the power electronics revolution that is taking place in all areas of electric energy. KEYWORDS: Flexible AC Transmission System (FACTS), Static Var Compensator (SVC), PSAT, Voltage Stability, Voltage Stability Index (VSI). I.INTRODUCTION Most of the large power system blackouts, which occurred worldwide over the last twenty years, which are caused by heavily stressed system with large amount of real and reactive power demand and low voltage condition. When the voltages at power system buses are low, the losses will also to be increased. This study is devoted to develop a technique for improving the voltage and eliminate voltage instability in a power system. Application of Flexible AC Transmission System (FACTS) devices are currently pursued very intensively to achieve better control over the transmission lines for manipulating power flows. They can provide direct and flexible control of power transfer and are very helpful in the operation of power network. The power system performance and the power system stability can be enhanced by using FACTS device [1]. FACTS devices, which are power electronic based devices can change parameters like impedance, voltage and phase angle. They also helps to reduce flows in heavily loaded lines, resulting in an increased load ability, low system loss, improved stability of the network, reduced cost of production and fulfilled contractual requirement by controlling the power flows in the network. They provide control facilities, both in steady state power flow control and dynamic stability control [2]. The possibility of controlling Power flow in an electrical power system without generation rescheduling or topological changes can improve the performance considerably. Static Var Compensator (SVC) is one of the most effective device for enhancing the power stability and power transfer capability of transmission network, for this the SVC should be properly installed in the system with appropriate parameter setting. The some factors considering for optimal installation and the optimal parameter of SVC , which are the stability margin improvement, power loss reduction, power blackout prevention and the power transmission capacity enhancement [3].
Voltage Stability Improvement using Static VAR Compensator (SVC) in Power System
— Now a days the power system are operated nearer to their stability limits due to economics and environmental reason and due to of this, the secure operation of power system is very important and challenging issue. A system enters a state of voltage instability when a disturbance occurs, increase in load demand & change in system conditions because of voltage collapse. Based on review, to compensate this problem the SVC is used in transmission system. These papers investigate the effect of Static Var Compensator (SVC) on voltage stability and improvement of that stability in power system. In this paper shunt FACTS devices SVC is used in a transmission line for improving a voltage profile and stability. MATLAB Simulink platform has been used in this study. The voltage at various buses is calculated and weak buses are identified to place the FACTS devices to improve the voltage stability limits are analyzed before and after the placement of svc.
Improvement of voltage stability in power system using SVC and STATCOM
International Journal of Industrial Electronics and Drives, 2015
The increase in power demand has forced the power system to operate closer to its stability limit. Voltage instability and line overloading have become challenging problems due to the strengthening of power system by various means. The nature of voltage stability can be analyzed by the production, transmission and consumption of reactive power. One of the major causes of voltage instability is the reactive power unbalancing which occurs in stressed condition of power system. Flexible AC transmission system (FACTS) devices play an important role in improving the performance of a power system, but these devices are very costly and hence need to be placed optimally in power system. In this paper, a method based on line stability index, real power performance index and reduction of total system VAR power losses has been proposed to decide the optimal location of TCSC. Now a day, Voltage Stability has become a major concern in power systems planning and operation. This problem has become very complex due to the continuous growing on system interconnections and demand for electricity and also due to economical and environmental constraints to properly expand the system.
Impact of Static Var Compensator (SVC) Installation in Power System Stability
2020
The research is proposed the modeling and analysis of Static Var Compensator (SVC) for stability improvement in power system. This is achieved by modeling a test system 220kV, 50Hz, and 100KVA base in long transmission line. Furthermore, the MATLAB/Simulink software is used to modeling the system in the normal condition and the fault condition of test system. The simulation results demonstrate the effectiveness and robustness of the proposed SVC on stability improvement in power system
International Journal of Advanced Research in Electrical, Electronics and Instrumentation Engineering, 2014
Voltage stability of a system is affected by reactive power limit of the system. FACTs devices improve the reactive power flow in system thereby improving voltage stability and these are used for controlling transmission voltage, Power flow, dynamic response and reducing reactive losses in transmission lines. This paper explores the effect of SVC on static voltage stability and presents the effect of Static VAR compensator (SVC) on Voltage Profile & Reactive Power for variable load conditions is investigated and presents static methods like Modal Analysis, Two Bus Thevenin Equivalent and Continuation Power Flow methods to predict the voltage collapse of the bus in the power system. WSCC 3-machine, 9-bus system has been used to demonstrate the ability of SVC in improving the voltage stability margin. These FACTs controllers help to increase the load ability margin of the power network. Modelling & simulation have been carried out using MATLAB/SIMULINK Software.
Power system stability is defined as the ability of power system to preserve it's steady stability or recover the initial steady state after any deviation of the system's operation. This paper will discuss how SVC has successfully been applied to control dynamic performance of transmission system and regulate the system voltage effectively. Present time power systems are being operated nearer to their stability limits due to economic and environmental reasons. Maintaining a stable and secure operation of a powersystem is therefore a very important and challenging issue. Shunt FACTS devices play an important role in improving the transient stability, increasing transmission capacity and damping low frequency oscillations. In this paper shunt FACTS device-SVC is used in a two area power system for improving the power system stability. MATLAB software has been used in this study.
Electrical Engineering, 2017
Increasing in the scale and complexity of interconnected power systems was because of the growth of electricity demands, leading to multiple electromechanical oscillations despite having support of the power system stabilizer (PSS). Therefore, the dynamic performance of the existing networks should enhance. One type of flexible alternating current transmission system devices, namely the static var compensator (SVC), can be installed at the buses to maintain and/or control particular parameters of the electrical power system by exchanging capacitive and/or inductive current. However, the performance of SVC device highly depends upon its parameters, sizes, and suitable number and location in the power network. Hence, the optimal location for SVC has become a key issue; in this paper, we propose a novel approach for the suitable number and location for SVC by using critical energy analysis based on the Gramian matrices that the solution framework applied an algorithm based on the Lyapunov equations and the balanced realization technique. The optimal placement is determined by (1) analyzing the small-signal stability to seek number of feasible loca
Performance Evaluation of Optimally Placed SVC for Dynamic Stability of the Power System
International journal of multidisciplinary research and analysis, 2023
Given the complexity of power systems, particularly in the deregulated power industry found in Nigeria, a consistent, safe, controllable, and high-quality power supply is required. The loss of the system's overall damping torque, which reduces the system's susceptibility to fluctuations and problems with dynamic stability, is one of the key downsides of network expansion. Flexible AC transmission systems (FACTS) controllers have been used to overcome problems with power system stability control. In order to improve dynamic stability, this study investigates how the generator's rotor angle, speed, voltage magnitude profile, and real power affect how well SVC operates under the effect of a three-phase fault. With a fault introduced on Bus 33 (Geregu Substation) and SVC placed optimally on Bus 21 (Jos Transmission Station) using voltage stability sensitivity factor (VSSF) after the simulation of continuation power flow (CPF), the 48-bus power system network in Nigeria was modeled using commercial PSAT software in a MATLAB environment. The power system's oscillation was significantly reduced, and the voltage profile was enhanced for power system dynamic stability, per simulation results with and without SVC.
In power system all over the world, due to increase in load demand, transmission system are being forced to operate nearer to their loading limits, stability limits. If exchanges were not controlled, some lines located on particular paths may become overloaded; this phenomenon is called as congestion. Congestion management is essential to bring power system in secured state. Congestion management can be defined as the actions taken to avoid or relieve congestion. In this deregulated power system, independent system operator has to relieve the congestion, so that the system is maintained in secure state. The Flexible AC Transmission System (FACTS) devices are found to be more useful to relieve congestion. FACTS devices enhance power transfer capabilities, power system stability and allow more flexible control of power flow. Here FACTS device used is Static VAR Compensator (SVC). For optimal location of SVC, real power flow performance index sensitivity indices method is implemented. To determine sensitivity indices for proposed metho used. IEEE-14 bus system is used here for the study purpose.
POWER FLOW MODEL OF STATIC VAR COMPENSATOR AND ENHANCEMENT OF VOLTAGE STABILITY
Voltage stability analysis is the major concern in order to operate any power system as secured. In this context there are many research work has been carried out to improve the voltage stability. This study demonstrates the use of latest Power System Analysis Toolbox (PSAT) package for network analysis of alternative means of improving existing transmission system voltage stability. This paper presents the investigation on enhancement of voltage stability using FACTS controllers such as Static Var Compensator (SVC) device. The proposed method explains how voltage stability can be improved with the continuation power flow methods in case of increasing loading of contingency. Voltage stability assessment on standard IEEE-14 system has been simulated to test the effectiveness of increasing loadability. This paper presents the simple method for identifying the weak bus and also optimal value of reactive power support needed for that. A comparative study between the base case and SVC are presented to demonstrate the effectiveness of SVC. The propose methodology found advantages because it is simple, faster and very convenient to apply for voltage stability analysis