Tutorial on static var compensators san francisco, june 12, 2005 outline module 1 reasons for reactive power compensation module 2 basic characteristics of svc module 3 svc configurations and implications module 4 main components in existing installations module 5 thyristor valves module 6 regulation, control and protection system. In this paper, the load flow models for the static var compensator distribution d svc are presented. Shunt connected reactors fixed or mechanicallyswitched are applied to minimize line over voltageunder light load conditions. Static var compensator a static var compensator is a parallel combination of controlled reactor and fixed shunt capacitor shown in the figure below. The electronic reactive power compensator uses fast switching action than the conventional relay. It is based on a power electronics voltagesource converter and can act as either a source or sink of reactive ac power to an electricity network. Objectives of shunt compensation steadystate transmittable power can be increased. A static synchronous compensator statcom, also known as a static synchronous condenser statcon, is a regulating device used on alternating current. Analyses of static and dynamic reactive power allocation between synchronous compensators and shunt capacitors to counter commutation failures. The firing angle of the thyristor controls the voltage across the inductor and thus the current flowing through the inductor. Shunt capacitor slope correction capacitor damping. If connected to a source of power it can also provide active ac.
Consequently, there is a need to improve the use of shunt compensators in view of the prior art. Static var compensators are shuntconnected static var generators or absorbers whose outputs are varied to control specific parameters of the system. Various options of shunt compensators considered are mscs, svc, and statcom. Shunt compensation an overview sciencedirect topics. An svc will typically regulate and control the voltage to the required set point under normal steady state and contingency conditions and thereby provide dynamic, fast response reactive power following system contingencies e. The effective reference vfir controlling the terminal voltage thus becomes vfirt. Static var compensators or statcoms can be used in special circumstances for fast continuous control. Design of microcontroller based thyristor controlled three. Principles of conventional reactivepower compensators voltaae with shunt and capacitors capacitors capacitive current. Pdf shunt compensator as controlled reactive power sources. The reactive power supplied by the shunt capacitor banks is directly proportional to the bus voltage. Static shunt pe voltagequality controllers springerlink. The use of shunt compensators such as facts for example svc in power systems gives possibility of fast.
A static var compensator is a set of electrical devices for providing fastacting reactive power on highvoltage electricity transmission networks. Power transfer stability index and qv curve sensitivity were considered to acquire list ranking location of shunt compensator. Voltage stability variable impedance type series compensation by different kind of. Static compensators statcoms in power systems by farhad. To design a static var compensator with capacitor bank in.
Increased efficiency in power systems the svc is a solidstate reactive power compensation device based on. Svc and statcom inductive current is positive is derived and summed to the reference vp1. The usage of shunt capacitor banks suffers from the following drawbacks. This paper discusses the design and performance of static var compensators with harmonic filters and tcr, and al so gives specific guidelines for the design of svcs. Voltage stability of a system is affected by reactive power limit of the system. Download pdf download citation view references email request permissions export to collabratec alerts. Effect of static shunt compensation on power system dynamic. Shunt compensators such as the static synchronous compensator statcom and. Its objectives includes, among other things, the modeling and simulation study of the use of svc in the nigeria. Blaabjerg, a novel control algorithm for static series compensators by use of pqr instantaneous power theory, ieee trans.
The power flow problem may be related to the length of the transmission line. It is in this perspective attempt is made to develop an advanced shunt compensator as could be made applicable on mass scale for the distribution transformers. The static var compensator svc is the arrangement of thyristor switched capacitor tsc and thyristor controlled reactor tcr. The primary difference is that its injected voltage is not related to the line intensity and can be managed independently. Variable shunt impedance connected to a line causes a variable current flow by injecting a current into the system. Hingorani and others published static shunt compensators. Development of the unified seriesshunt compensator for.
Placement of shunt var compensator based on sensitivity. Application of the posicast control method to static shunt. View static var compensators ppts online, safely and virusfree. The abb static var compensator includes the following major components. In general, there are three types of static shunt pe voltagequality controllers. Shunt compensation for improvement of voltage stability. The thyristor switch assembly in the svc controls the reactor. The design and performance of static var compensators for particle accelerators. The design and performance of static var compensators for. A shunt connected static var generator or absorber whose output is adjusted to exchange capacitive or inductive current so as to maintain or control bus voltage of the electrical. The work proposed aims at developing a static var compensator with the following technical features. The static synchronous series compensators in power electronics mainly involve in series and shunt devices. Shunt compensator as controlled reactive power sources. Series compensation series compensation is basically a powerful tool to improve the performance of ehv lines.
Svc can be realised from a tcr and one or more tsc parallel connected, fig. A static synchronous compensator statcom, also known as a static synchronous condenser statcon, is a regulating device used on alternating current electricity transmission networks. The svc regulates voltage at its terminals by controlling the amount of reactive power injected into or absorbed from the power system. Static var compensators svcs are devices that can quickly and reliably control line voltages. The term static is used to indicate that svcs, unlike synchronous compensators have no moving or rotating main components. A static var compensator has no significant moving parts other than internal switchgear. Seriesshunt compensator ussc which can mitigate a wider range of power quality problems. Placement of shunt var compensator based on sensitivity analysis muhammad nurdin, fathin saifur rahman, rizky rahmani, nanang hariyanto.
Shunt compensation for improvement of voltage stability using static var compensator svc in a power transmission system. Static var compensators are electrical devices that provides fastacting reactive power hence the var on highvoltage electricity transmission networks or power system. In other hand, the shunt facts devices such as the static var compensator svc and the static compensator statcom are extensively used for the local voltage control without any coordination. Use of shunt compensator to enhance power transfer. Shunt capacitors do not affect current or power factor beyond their poin t of application.
Svcs are part of the flexible ac transmission system device family, regulating voltage, power factor, harmonics and stabilizing the system. This article discusses about compensators used in power electronics, that includes static synchronous series compensator sssc, tssc, tssr, tcsc and tcsr. Static compensators statcoms in power systems farhad. Facts devices improve the reactive power flow in system thereby improving voltage stability and these are. Contrasted to generators, svcs or statcoms are designed. A static compensator statcom, also known as static synchronous compensator, is a member of the flexible alternating current transmission system facts devices. The static var compensator svc is a shunt device of the flexible ac transmission systems facts family using power electronics to control power flow and improve transient stability on power grids 1. Lessons learned in static var compensator protection. Based on static voltage analyses result, use of shunt compensators was proven to increase power transfer limit. An object of the present invention is to simplify the arrangement related to static var compensators. It consists of capacitors connected in series with the line at suitable locations. Static var compensator svc is a type of facts device.
It is a powerelectronics based regulating device which is composed of a voltage source converter vsc and is shuntconnected to. Shunt static synchronous compensator statcom shuntseries unified power flow controller upfc seriesseries interline power flow controller ipfc. Harmonic minimization in the operation of static var. Hingorani is credited with originating the concepts of facts and custom power.
Analyses of static and dynamic reactive power allocation. Pdf shunt compensation for improvement of voltage stability. Shunt capacitor banks are low cost and have virtually zero losses. Shunt compensators are generally used to reduce or cancel the phase wise unbalanced reactive power var demand and to minimize the reactive power drawn from the ac supply lines. The sssc operates like a controllable series capacitor and series inductor. Electrical loads both generate and absorb reactive power. If the reactive power of the load is changing rapidly, then a suitable fast response compensator is needed. The models of the dsvc are based instead on the variable shunt susceptance concept. In this paper, the posicast control method is used for decreasing the reactive power oscillations of static shunt compensators. A shunt compensator provided say at the middle of a line fig. Modern allfilm fuseless capacitor banks increase costeffectiveness 14,15.
Phasewise unbalanced reactive power compensations are required in distribution systems for dynamic power factor correction and terminal voltage stabilization. Static var compensator svc is a type of facts device, used for shunt compensation. As mentioned in the introduction to this manual, shuntcapacitor substations have certain drawbacks, such as the difficulty in coordinating all substations and. Static var compensators are preferred over traditional. Download for offline reading, highlight, bookmark or take notes while you read static compensators statcoms in power systems. Shunt compensator as controlled reactive power sources abstract based on the analysis of technical solutions used around the world, we present basic design features of a shunt power system. Variable impedance shunt facts controllers are also called static var generators svgs or static var compensators svcs. Dr ahmed massoud university of strathclyde 2 facts 1. Thereafter we should discuss shunt static shunt compensator a typical. Static var compensator svc static synchronous compensator statcom 2. A rapidly operating static var compensator svc can. They are thyristorcontrolled reactors andor thyristorswitched capacitors and.
Static synchronous series compensator sssc is a modern power quality facts device that employs a voltage source converter connected in series to a transmission line through a transformer. Application of the posicast control method to static shunt compensators. He is a retired vice president of electrical systems at epri and provides consulting services that help utilities plan and purchase power electronics technology. Static compensators statcoms in power systems ebook written by farhad shahnia, sumedha rajakaruna, arindam ghosh. In general, there are three types of static shunt pe voltage quality controllers. These models are incorporated into existing load flow harmonic lfh. Circuit globe power systems methods of voltage control in power system. By using a unified approach of seriesshunt compensators, it is possible to compensate for a variety of power quality problems in distribution systems including sag compensation, flicker reduction, unbalance voltage. In static shunt compensation, the shunt reactor, shunt capacitor and static var system are used, whereas the shunt compensation uses the synchronous phase. Svc static var compensator an insurance for improved grid. Static var compensators are preferred over traditional var compensators for this purpose. Shunt compensation static var compensator svc sr,tcr,fctcr,tsc. In this paper, microcontroller based threephase svc system is designed using thyristor controlled switch. Understanding facts concepts and technology by narain g.
1107 1123 649 310 1399 861 1411 951 480 372 586 496 136 295 768 1410 604 538 338 796 1152 1114 606 1028 1390 1378 795 63 1269 1350 618 1206 307 9