Application Of Static Var Compensator Research Articles

Harmonic Performance Analysis of Static Var Compensator Connected to the Power Transmission Network

The static var compensator (SVC) is a device which is designed to compensate reactive power, increase voltage stability and to reduce voltage fluctuations. Thyristor controlled reactors (TCRs) are composed of reactors in series with bidirectional pair of thyristors. Current through reactors can be continuously controlled by changing the firing angle of thyristor valves, thus
 the inductive power can be easily controlled. Typical applications of TCRs in AC systems are voltage stabilization and temporary overvoltage reduction, stability improvement, damping of power oscillations and load balancing. In this paper, harmonic performance analysis of SVC equipped with TCRs is presented. SVCs utilizing TCRs generate harmonic currents and therefore it is necessary to determine the effect of harmonics generated by the SVC on the power system and its elements. This includes interaction of the SVC with the system, the SVC performance under balanced and unbalanced operating conditions and finally, evaluation of countermeasures such as installation of harmonic filters. In order to carry out these analysis, it is necessary to determine harmonic characteristics of the network at the point of SVC connection, existing levels of harmonics, and to know appropriate standards regarding acceptable harmonic levels in the power system. Since harmonic distortions in the system are caused by the interaction between SVC and the system, all system contingencies which may affect system’s frequency response should be evaluated. Detailed power system model should be considered to make sure that parallel resonance points of system do not directly coincide with characteristic harmonics from the SVC. Harmonics generated by SVCs are largely dependent on the operating point within the SVC characteristic. A conservative approach is to use the maximum values of harmonics generated within the spectrum irrespective of the operating point. The results of harmonic performance analysis are important for appropriate design of SVC. Harmonic performance analysis related to SVC application which are presented in this paper include the determination of: frequency response of the transmission network impedance required for the specification and design of filters; the effects of SVC generated harmonics on the power system; the overall filter requirements and countermeasures to reduce harmonics to acceptable levels.

Power Factor Improvement of The Glenmore Sugar Industry Electrical System

AbstractThis study discusses the improvement of the power factor in the Glenmore Sugar Industry electrical system. Low power factor can be caused by variations in inductive loads. This has an impact on large currents and high reactive power so that a black out can occur in the Glenmore Sugar Industry electrical system. Low power factor is corrected with the most effective Costum Power Devices, namely Static Var Compensator (SVC) and Static Synchronous Compensator (STATCOM). The evaluated and corrected load buses are those with low power factor.The simulation results show in the application of SVC for the lowest results, power factor increased from 0.76 to 0.78 with reactive power values in the range from + 1.6 to – 0.64 MVAR. The power factor increased from 0.76 to 0.85 with reactive power values in the range from +4.9 to –1.9 MVAR. And for the highest results, the power factor increased from 0.82 to 0.92 with reactive power values in the range from +3.9 to –1.5 MVAR.The application of STATCOM can increase the power factor with reactive power values in the range from +4.9 to – 0.994 MVAR, +1.6 to -0.32 MVAR and +3.9 to -0.7875 MVAR. Keywords – Power factor, SVC, STATCOM, Reactive power, Industry.

Influence of Static VAR Compensator Application for Improving Power Quality in Distribution Lines Supplied Industry

The voltage drop in distribution line unavoidable but can be reduced until the allowable limit. The voltage drop occurred due to currents flow in impedance lines. Harmonics caused by non-linear loads that are often found in the industrial used electronics devices. This study is to discuss the application of static var compensator (SVC) to improve the power quality in distribution lines. Harmonics analysis of the loads industries are modelled as arc furnace and adjustable speed drive (ASD) using software ETAP simulation. The loads are connected to the IEEE 14 busses system. Fast decoupled method was used for investigating the voltage drop at each buss. Harmonics analysis was carried out to find harmonics level contents i.e., total harmonics distortion of voltage (THDV) and current (THDI). Values of THDV and THDI resulted are evaluated by state electrical company (PLN) standard. The load flow study result shows that there are some busses have voltage below the standard and harmonics analysis beyond the allowable limit but the voltage at Bus 14 is lowest, therefore SVC is connected to it. The results show all the voltage is fulfilling the standard. The SVC installation on this case is less significant it affects on mitigating harmonics.

Application of Static Var Compensator (SVC) With PI Controller for Grid Integration of Wind Farm Using Harmony Search

Abstract Large-scale integration of wind turbine generators (WTGs) may have significant impacts on power system operation with respect to system frequency and bus voltages. This paper studies the effect of Static Var Compensator (SVC) connected to wind energy conversion system (WECS) on voltage profile and the power generated from the induction generator (IG) in wind farm. Also paper presents, a dynamic reactive power compensation using Static Var Compensator (SVC) at the a point of interconnection of wind farm while static compensation (Fixed Capacitor Bank) is unable to prevent voltage collapse. Moreover, this paper shows that using advanced optimization techniques based on artificial intelligence (AI) such as Harmony Search Algorithm (HS) and Self-Adaptive Global Harmony Search Algorithm (SGHS) instead of a Conventional Control Method to tune the parameters of PI controller for SVC and pitch angle. Also paper illustrates that the performance of the system with controllers based on AI is improved under different operating conditions. MATLAB/Simulink based simulation is utilized to demonstrate the application of SVC in wind farm integration. It is also carried out to investigate the enhancement in performance of the WECS achieved with a PI Controller tuned by Harmony Search Algorithm as compared to a Conventional Control Method.

Smooth Evacuation of Power in Grid Connected Small Hydro Power Stations by Application of SVCs

This paper explores some of the practical limitations encountered by small hydro power (SHP) units while evaluating various possibilities so as to maintain continuous generation by these units while ensuring smooth evacuation of every unit of real power generated by such units to the neighboring grid in a grid connected power system scenario. The proposed simulation has been tested under some worst system conditions and case studies conducted on the IEEE 30-bus test system by way of connecting the SHP units to the most critical system bus of the test system with static VAR compensator (SVC) control at the local bus. The test results have been validated with the support of power flow tools on a Matlab based Matpower platform. It is observed that the results obtained through application of SVCs are far more promising than those of the results obtained from OLTC transformer control mechanism only.

The High-Voltage Reactive Power Compensation Device Applications and Innovations

This article briefly describes the modern power system of high-voltage reactive power compensation device development status, discusses the high voltage reactive power compensation device applications, with the traditional high-voltage reactive power compensation device matching, demonstration of a new generation SVC (Static Var Compensator) and SVG (STATCOM) advantages and application results. This paper focuses on the innovative technology in the new generation of high-voltage reactive power compensation device in the application, while a new generation of high voltage discussed reactive power compensation device application prospects.

Influence of sympathetic inrush on voltage dips caused by transformer energisation

Energising a transformer with other adjacent transformers in service may induce sympathetic inrush that could lead to long duration voltage dips. This study addresses this issue through analysing voltage dip events observed on a 400/132 kV grid when energisations of several generator step-up transformers were performed. With the help of a number of field measurements of voltage dips involving sympathetic inrush, a detailed network model in alternative transients program/electromagnetic transients program has been developed and validated. Based on the network model, comprehensive simulation studies have been performed. In addition, because of the nature of multiple controlling parameters, sensitivity assessment has been carried out to identify the key influential parameters. It is found that the sympathetic inrush, although does not affect voltage dip magnitude, can prolong voltage dip duration by 143% under the worst energisation condition. The sympathetic inrush occurring in substation transformers gives rise to a network-wide sympathetic interaction, resulting in further prolonged voltage dips on the 132 kV grid. Finally, it is proven that application of static var compensator is able to speed up the voltage dip recovery.

Compensation Capacity Selection and Performance Improve for SVC

The industrial application of static VAR compensator (SVC) is becoming more and more widely. It has many outstanding functions, such as respond rapidly for changes, compensate reactive power dynamically, reduce harmonic, suppress voltage fluctuations and flicker, and improve the negative sequence problem. This paper, from the above power quality problems, analyzes SVC capacity selection principle and the compensation effect. Meanwhile, the compensation performance evaluation method for an installed and operational SVC is also given. When device can't achieve the expected compensation effect, some improvement strategies are put forward further more.

Simulation Study of Dynamic Fault Recovery Performance of VSC-HVDC System

The fault recovery of VSC-HVDC transmission system is often influenced by many factors, such as the reactive power compensation characteristics of the inverter and the dynamic performance of DC controllers. In this paper, the PSCAD/ EMTDC simulation tool is used to study the dynamic recovery performance of VSC-HVDC system for several different var compensating devices in VSC-HVDC inverter-Fixed capacitor (FC), Static Var compensator (SVC), and Static synchronous compensator (STATCOM) when VSC-HVDC is subject to various faults, including three phase groundings, single phase grounding and three phase breakings. The result shows that the recovery process of the whole system will be slowed down due to its negative influence on the strength of AC power system with the application of SVC, while the STATCOM can improve VSC-HVDC recovery performance greatly for its advantages over other compensating devices in areas such as voltage support ability and DC power recovery.

A novel approach for global voltage stability assessment of a power system incorporating static var compensator

SUMMARYVoltage stability is a growing concern for the successful planning and operation of modern power systems. The prediction of voltage collapse point of the multibus power network through its two‐bus equivalent model is a hot topic of the research in the field of power system operation and control. This article presents a method to assess the voltage stability status of a power system incorporating the static var compensator (SVC) using a unique two‐bus π‐network equivalent model obtained with the optimal power flow solution of the actual system at different operating conditions. The novelty of the proposed methodology is that it considers the series and shunt parts of transmission losses lumped separately in equivalent series and shunt form to evaluate the π‐network equivalent two‐bus model. SVC firing angle model is integrated into optimal power flow program to investigate its effect on power system performance in terms of voltage stability assessed in the equivalent two‐bus domain. The simulation results for a practical power system (203‐bus Indian Eastern Grid) have shown that the proposed methodology is promising to assess voltage stability of any power system at any operating point in global scenario. Voltage stability margin augmentation with the application of SVC at the weakest bus is compared with the system having no compensation. In the proposed π‐network equivalent model, the generators have been modeled more accurately considering economic operation. Copyright © 2011 John Wiley & Sons, Ltd.

Development of Static Var Compensator for San-yo Shinkansen.

This paper describes the application of SVC (Static Var Compensator) for the AC electric railway system, outlines the SVC installed at the Shin-syo sectioning post of San-yo Shinkansen and reports the results of a verification site investigation. A single-phase SVC can reduce the voltage drop in the feeding circuit and improve the power factor at substations by compensating for the reactive power. To compensate for the voltage drop, it is more effective to locate an SVC at a sectioning post than at a substation. The site investigation has revealed that an SVC can reliably suppress voltage drop.

Analytical investigation of the use of static VAR compensators to aid damping of inter-area oscillations

A comprehensive investigation of the use of Static VAR Compensators (SVCs) to aid damping of low-frequency inter-area oscillations in large interconnected power systems is presented. The study of inter-area oscillations and the design of controls is done using modal analysis of a linearized model of the power system. Based on this model an efficient algorithm to compute the power oscillation flow for each mode of concern is developed. This approach allows to identify the nature of oscillation patterns and provides important information needed in the application of SVCs. Controllability and observability measures are then used to assess the impact of dynamic voltage support on system damping as well as to identify optimal locations for SVCs. The influence of system structure and load effect on the SVC performance is discussed. Detailed time-domain analyses are finally performed to check the validity of the analysis and to assess the impact of dynamic voltage support on system transient behaviour.

Application of static VAr compensators for the dynamic performance of the Mead-Adelanto and Mead-Phoenix transmission projects

This paper presents the planning and pre-specification study analysis and results for the joint use of static VAr compensators (SVC), a form of flexible alternating current transmission system (FACTS) technology, for the Mead-Adelanto and Mead-Phoenix projects in the Southwestern USA. Because of insufficient system damping in the network, addition of these two transmission line projects must also be complemented by SVC. These devices increase the system stability limit so that the projects' planned transfer capabilities can be economically attained. These are the first transmission projects in the region where a very closely coordinated planning effort permits the joint use of SVC to provide mutual benefits to both projects. SVC dynamic performance enhancement studies, SVC control analysis, and studies related to the planning and specification requirements are among the topics addressed in the paper.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Application of static VAr compensators to increase power system damping

A theory for analyzing power system damping enhancement by application of static VAr compensators (SVCs) has been developed using the equal area criterion. Some fundamental issues, such as the effect of SVCs on a power system, how to control an SVC to improve system damping, and the differences between continuous and discontinuous control of SVC reactive power to achieve the maximum damping improvement, are discussed. A discontinuous SVC reactive power output at discrete points is determined from the power deviation on a transmission line. Time-domain simulations of the application of this approach to a one-machine system to increase swing oscillation damping and to a four-machine system to increase the damping of an interarea oscillation mode demonstrate that the theory and method can be applied to solve practical power system damping problems.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Static VAR compensators for reducing energy losses in large industrial loads

Fast and controlled regulation of voltage and reactive power may be obtained in large industrial installations which include repetitive or frequent start-up of induction motors by using static VAR compensators (SVCs) to control start-up time and inrush transient current and to maintain consumed and reactive power at minimum levels. Consequently, reduced energy losses and kW generation savings are expected. For a typical industrial load, these savings are evaluated quantitatively and are proved to be sufficient to justify the application of SVCs for energy saving purposes, accompanied by whole system performance improvements. Matching of reactive power demand during normal running conditions contributes to a decrease in energy loss and to increases in motor currents and torques.

Hydro-Quebec multiple SVC application control stability study

A report is presented on the SVC (static VAR compensator) control stability studies undertaken as part of an overall system improvement project. It is shown that for an all-shunt network, a regulator setting of T/sub r/=0.5 s would be stable for many contingencies, but some contingencies would require gain-supervisor action and transfer-trip automatisms to ensure system security. The transfer-trip automatisms would be complex and require much study to identify. Thus, from the perspective of SVC voltage regulator stability, the all-shunt option is the least desirable. For a mostly series network, a regulator setting of T/sub r/>0.25 s provides good stability margin for all system contingencies. This means that system security is not dependent upon a complex set of transfer-trip automatisms. A few new design considerations for the power system have been identified, due to adding series compensation. The major new phenomenon is a low-frequency oscillation between shunt reactors and the series capacitors, which has very little natural damping. The SVC voltage regulators will decrease the damping of these modes, and may cause them to become unstable. To insure against such instability, it is proposed that high-pass filters with a break frequency of 20 Hz be applied to all SVCs. >

Prevention of transient voltage instabilities due to induction motor loads by static VAr compensators

The application of static VAr compensators (SVC) to prevent transient voltage instability due to the presence of large induction loads at the terminals of long transmission lines is discussed. Eigenvalue analysis is used to identify the conditions for voltage instability. The analysis is supported by transient time simulations for the complete power system following large disturbances. It is found that SVC can obviate transient voltage instabilities and maintain the load voltage near its rated value. It is shown that replacing the SVC with mechanically switched capacitors may not provide stabilization owing to the time delays associated with voltage drop detection and breaker operation. >

Analysis of Power System Stability Enhancement by Static VAR Compensators

The paper presents a fundamental analysis of the application of static VAr compensators (SVC) for stabilizing power systems. Basic SVC control strategies are examined in terms of enhancing the dynamic and transient stabilities, improving tieline transmission capacity and damping power oscillations. Synchronizing and damping torque contributions of the SVC are determined for different controls. The analysis is supplemented by digital simulations for a simple practical example. Deficiencies of available control policies are demonstrated and a new concept, based on optimal control, is developed.

Effective Application of Static Var Compensators to Damp Oscillations

Static Var Compensator (SVC) is recognized to be effective to improve transient stability and to damp voltage fluctuation. The reason why power system planners hesitate to apply SVC to their systems is because of its expense. The authors have proposed a combination type SVC, which consists of both thyristor controlled capacitors and reactors and mechanically switched capacitors. This combination makes it economical to apply SVC to improve transient stability. In this paper another proposal is concerned with the conceivable installation of SVC to damp oscillations of power systems. The so-called Filters is applied to the voltage detective circuit of SVC. Because of its leading characteristic, it produces a damping effect on the power system. The economy and effectiveness of the combination type SVC equipped with Reset Filter is illustrated to improve stability of the power system both analytically and quantitatively.

Effective Application of Static Var Compensators to Damp Oscillations

Effective Application of Static Var Compensators to Damp Oscillations