Tcsc, the first generation of facts, can control the line impedance through the introduction of a thyristor controlled capacitor in series with the transmission line. Thus, the statcom needs to absorb teactive power in the. Facts devices such as static var compensator svc, static synchronous compensator statcom, and thyristor controlled series capacitor tcsc, are included into the test system as. In this letter, a static synchronous compensator statcom is included with the purpose of analyzing its behavior on the improvement of voltage stability margins. Compensator, when connected to a weak ac system which has the stability enhancement for power insta bility and commutation failures. Threephase power flows and modal analysis are employed to the voltage stability margin calculation by means of the pv curves for different power systems operating conditions. Synchronous compensator statcom is applied to a power network which includes a scig driven by a wind turbine, for steady state voltage regulation. Voltage stability of the power system is the ability of the system to retain system voltages within acceptable limits when subjected to disturbance 1, 2. Benefits of svc and statcom for electric utility application. The choice of the location,sizing and cost comparison of these facts devices with traditional reactive powervoltage stability devices are. But due to presence of an svc or a statcom this type of instability can be avoided. Facts, statcom, voltage stability, pv curve, stability margin, voltagevar control 1. Pdf this paper examines the application of flexible ac transmission system facts technologies to enhance system steady state voltage.
The results of vsi based d statcom system are compared with those of push pull inverter based d statcom system. Statcom is connected to improve the voltage stability of entire sstem for a. The statcom is modeled by a voltage source connected to the system through a coupling transformer. Direction of power flow can be changed very quickly. An adaptive controller for a static compensator statcom to enhance voltage stability comprises an outer voltage regulator loop and an inner current regulator loop. Fast control of power flow, which implies stability improvements. In addition to stability improvement, the controller is also found to maintain the postfault steady state voltage of the point of connection i. Installing a statcom at one or more suitable points in a grid will increase power transfer capability by enhancing voltage stability and maintaining a smooth voltage profile under different network conditions. An attempt on enhancing the steadystate voltage stability using facts. A power system is steady state stable for a particular steady state op.
Controller design of statcom for power system stability improvement using honey bee mating optimization, a. An ieee 39bus test system is built using matlab and psat. Mostly a statcom is installed to endorse electricity networks that partake of a bad muscle cause and habitually bad voltage regulation. Study of a statcom application for voltage stability evaluated by. Dstatcom is studied with respect to the voltage stability improvement at the load busses. This paper examines the potential for improved steady state voltage stability margins by means of facts technologies.
Hence the rotor angle stability limit under steady state conditions is coincident with steady state voltage stability limit. Statcom is connected to improve the voltage stability of entire sstem for a contingency of a threeterminal line outage. Voltage stability enhancement in large power system by. Bhole and prateek nigam, journalinternational journal of advanced. This lindex determines how any system is close to its instability limit. The voltage stability at steady state is also affected by the load. Statcom has the capability of improving stability and damping by dynamically controlling its reactive power output.
A statcom is a voltage cause converter vscbased device, with the voltage spokesperson behind a reactor. The overall impact leads to a voltage rise to higher than 1. D statcom is studied with respect to the voltage stability improvement at the load busses. Figure 3 shows the structure diagram of a compensator statcom, static var. Steady state voltage stability enhancement using shunt and series. It shows that, at steady state stability limit, the reactive power becomes infinite.
Impact of statcom and opf on power system voltage stability using modal analysis and quadratic programming a. Us20207620a1 adaptive controller for statcom to enhance. During steady state working condition, the voltage v 2 produced by vsc is in phase with v 1 i. In the normal operating condition the voltage of a power system is stable, but when the fault or disturbance occurs in the system, the. Statcom is the shunt connected solid state switching computer capable of. Abstractthreephase power flows and modal analysis are em ployed to the voltage stability margin calculation by means of the. The evolving power generation scene is becoming ever more challenging for transmission system operators a larger share of renewables, retirement of baseload plants, increased. The analysis process is performed using a steady state voltage stability index. The results of vsi based dstatcom system are compared with those of push pull inverter based dstatcom system. Coordinated application of facts devices to enhance steady. Controller design of statcom for power system stability.
Compensator statcom, and thyristor controlled series capacitor tcsc, are. This voltage stability index considers both active and reactive powers to evaluate voltage stability, which provides information about the stability condition of the lines and also determines the. Voltage stability in industrial plant requirement voltage stability. Voltage stability in industrial plant requirement voltage stability remote and weak grid conditions in kazakhstan 3 gearless mill drives at one bus bar generalized statcom performance. Voltage stability in the power system is defined as the ability of a power system to maintain acceptable voltages at all bus in the system under normal condition and after being subjected to a disturbance. Role of statcom for steady state voltage stability margin enhancement in power systems conference paper pdf available april 20 with 191 reads how we measure reads. Steady state voltage stability improvement by determination. Introduction one of the main criteria, deciding the power system operation and control is its voltage stability. This point is substantiated by looking at an accepted definition of the steady state stability of a power system 3.
Steady state voltage stability steady state voltage instability and its. For steady state voltage stability studies a large number of contingencies involving line, bus and generating unit outages were considered. Steadystate stability improvement transient stability improvement statcom features a. This index can be evaluated at each node of radial distribution system. Improvement of transient stability of power systems with. Improvement of voltage stability in power system by using svc. However, statcom in suitable location with parameters chosen using ts may help the system to retain stability even beyond that fault clearing time. Rafiee department of electrical engineering iran university of science and technology abstract.
Siddiqui, tanmoy deb, voltage stability improvement using statcom and svc int. System voltage support and stabilization by smooth control over a wide range of operating conditions. Sensitivity analysis is provided which shows the impact of svcs and statcoms with regard to network strength. Voltage stability index a new steady state voltage stability index is proposed by m. Comparison of shunt capacitor, svc and statcom in static voltage stability margin enhancement arthit sodeyome and n. Steadystate voltage stability with statcom request pdf. If the magnitude of the voltage v 2 produced by the vsc is less than. For this outage, the steadystate load level at bus n4 and bus n5 is as shown in table 2. Harmonic issues, space requirements, and price discussions are also briefly addressed. Voltage stability analysis of radial distribution networks. The outer loop adjusts proportional and integral control gains of voltage regulator. The drones play the father role in the colony that.
For this outage, the steadystate load level at bus n4 and bus n5 is as shown in. Distribution statics synchro nous compensator d statcom, voltage source inverter vsi, push pull inverter, power quality, facts. Pdf improvement of voltage stability in power system by. Major goal of the steadystate voltage stability analysis is the computation of the vp curve, also known as the nose curve see fig. Power system stability improvement using facts devices. Michael neutz, mv power converters, abb switzerland ltd. Hvdc can carry more power for a given size of conductor improved transient stability dynamic damping of the electric system oscillations require less space compared to ac for same voltage rating and size. Introduction with the ongoing deregulation of the electric utility industry. Large disturbance voltage stability can be studied by using nonlinear time domain simulations in the shortterm time frame and loadflow analysis in the longterm time frame steady state dynamic analysis the voltage stability is. Enhancement in voltage stability and reactive power. Facts, statcom, voltage stability, pv curve, stability margin, voltage var control 1.
Steadystate voltage stability with statcom ieee xplore. Bhole and prateek nigam, journalinternational journal of advanced research in electrical, electronics and instrumentation energy. Steady state voltage stability enhancement using shunt and. Impact of statcom and opf on power system voltage stability. Comparison of shunt capacitor, svc and statcom in static. Distribution statics synchro nous compensator dstatcom, voltage source inverter vsi, push pull inverter, power quality, facts. Each of the outer loop and the inner loop comprises a proportional integral controller. Study of a statcom application for voltage stability. This paper proposes application of statcom to extend steady state voltage stability margin in electric. Mar, 2015 an attempt on enhancing the steady state voltage stability using facts devices has been made in this work. The choice of the location,sizing and cost comparison of these facts devices with traditional reactive power voltage stability devices are presented. Implement phasor model of threephase static synchronous. High reliability with redundant parallel converter design and modular construction.
The transient stability improvement of the multimachine power system at different fault condition is investigated in this work. Improvement of voltage stability in power system by using svc and statcom sarita bhole1, prateek nigam 2. Pdf role of statcom for steady state voltage stability margin. Its ability to perform active filtering is also very useful for improvements in power quality. The hvdc stability problem is tackled with a statcom which not only provides a rapid recovery from power, harmonic stability and commutation failures but also offers a lower cost filter design for the hvdc system.
Pdf role of statcom for steady state voltage stability. Improvement of voltage stability in power system by using. Improving the voltage stability of electrical power systems using shunt facts devices by ahmed mostafa mohammed mohammed a thesis submitted to the. Let v 1 be the voltage of power system and v 2 be the voltage produced by the voltage source vsc. The static synchronous compensator phasor type block models an igbtbased statcom fixed dc voltage. The coordinated application of facts devices, however, requires a careful appraisal of system characteristics and expected operating conditions.
The voltage track down is produced from a modest full of zip state capability. However, as details of the inverter and harmonics are not represented, it can be also used to model a gtobased statcom in transient stability studies. The line stability index is specified by lmn, which depend on single line concept shown in fig. Statcom bus in the steady state, if the statcom is not activated. The enhancement of transient stability is achieved by adjusting line reactance with the help of tcsc and by compensating the reactive power with the help of statcom. Remote and weak grid conditions in kazakhstan 3 gearless mill drives at one bus bar generalized statcom performance. The statcom regulates voltage at its terminal by controlling the amount of. Study and simulation of the svc and statcom effect on voltage. Request pdf steadystate voltage stability with statcom threephase power flows and modal analysis are employed to the voltage stability margin calculation by means of the pv curves for. Steady state stability improvement transient stability improvement statcom features a. Improvement of voltage stability in power system by.
Analysis of steady state voltage stability in large scale. The performance curves of the system with tcsc, statcom and their combination are taken for discussion. Immediate inherent reaction providing 80% of rated current within 20ms not controlled. Voltage stability index can be used for determining the weakest line in a power system. Voltage stability enhancement in large power system by using. For the chosen pq bus of the network, this curve shows the dependence of the bus voltage magnitude vertical axis on the active power load in the bus when increased from zero to its maximum possible value.
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