In this simulation we observe the power quality problems such as unbalanced voltage and current, harmonics by connecting non linear load to 3p4w system with unified power quality conditioner. The conventional devices or equipment is not sufficient for enhancing the power quality. These quantities are illustrated for an electrical system represented in abc coordinates. It eliminates the harmonics in the supply current, thus improves utility current quality for nonlinear loads. In this, the design configuration is right series and left shunt with the current source converter csc 3, 4. Conditioner introduction unified power quality conditioners upqcs allow the mitigation of voltage and current disturbances that could affect sensitive electrical loads while compensating the load reactive power. Keywords power quality pq, unified power quality conditioner upqc, inverter, power flow controller pfc, series and shunt converter i. Both voltage source and current source inverter are in use for fabrication of upqc. The upfc is employed in power transmission system, where as the upqc is employed in a power distribution system. Compensation of voltage unbalance using unified power quality. The unified power quality conditioner upqc is connected between two different feeders lines, hence this method of connection of the upqc is called as interline upqc iupqc. Control of interline unified power quality conditioner for. Unified power quality conditioner for improving power quality. The upqc is the most versatile and complex of the facts devices, combining the features of the statcom and the sssc.
In this project presents a design of a unified power quality conditioner upqc connected to three phase four wire system 3p4w. In upqc, shunt apf is overburdened when it alone supplies total load reactive power. This depends upon the loads and their sensitivity to supply voltage fluctuations. Figure 1 shows the upqc, and it has a dual voltage source inverters having one shunt and other is series active power filter. Simulation and analysis of power quality improvement using multilevel unified power quality conditioner. The generalized upqc consists of both series and shunt voltage current compensation elements.
Unified power quality conditioner comprises of two bidirectional converters connected back to back through an energy storage element as shown in fig. One modern and very bright solution that deals with both load current and supply voltage imperfection is the unified power quality conditioner. Basic components of a dvr during voltage sag, the dvr injects a voltage to restore the load supply voltages. Due to vast implementation of power electronics based equipment power quality has turned into essential and important factor. To this end, a upqc controller is designed to meet four control objectives. Fuzzy logic controlled unified power quality conditioner for. The unified power quality conditioner upqc is one of the major custom power solutions, which is capable of mitigating the effect of supply voltage sag at. Analysis the performance of new control strategy for. A unified power quality conditioner upqc is considered to ensure satisfactory electrical energy quality. Unified power quality conditioner upqc controller and normal power converter to be used for dfig control system. Unified power quality conditioner for improving power quality using ten switch inverter 1 s.
Request pdf interline unified power quality conditioner this paper proposes a new connection for a unified power quality conditioner upqc to improve the power quality of two feeders in a. Power quality is one of the major problems in the todays scenario. Narayanamma institute of technology and science,india. Unified power quality conditioner in grid connected. In this paper the design of combined operation of unified power quality conditioner. Interline unified power quality conditioner iupqc, specifically aims at the integration of series vsc and shunt vsc to provide high quality power supply by means of voltage sagswell compensation, harmonic elimination and power factor correction in a power distribution network, so that improved power quality can be made available at the. One of the inverters is controlled as a variable voltage source in series apf and the other as variable current. Subramaniam2 1pg student, department of eee, pondicherry engineering college, pondicherry, india 2. When the power system is nonlinear then d and q axis currents ii. Unified power quality conditioner upqc for nonlinear and a voltage sensitive load has following facilities. Fuzzy logic control methodology has been demonstrated to allow solving uncertain and vague problems.
Improved performance of chaotic model of ac electric arc. In this paper a upqc controlled by srf theory is used to compensate current harmonics and voltage distortion in line due to nonlinear loads and fault conditions. Optimal location of unified power quality conditioner in. Various devices are available for power quality improvement. Compensation of voltage unbalance using unified power. Dynamic modeling and simulation of unified power quality. By using a unified power quality conditioner upqc it is possible to ensure a regulated voltage for the loads, balanced and with low harmonic distortion and at the same time draining undistorted currents from the utility grid, even if the grid voltage and the load current have harmonic contents. Better power quality is required for various electronics and electrical devices to perform efficiently. This paper discusses the compensation principle and control strategy of the upqc. Power quality improvement using unified power quality conditioner.
In other words, the upqc keeps critical loads beside voltage disturbance propagating through the power system, and compensates the current of these pro. Jun 11, 2014 the unified power quality conditioner is commonly called upqc. Analysis the performance of new control strategy for single phase unified power quality conditioner p. Abstractthis paper presents of unified enhancement power quality conditioner upqc using hysteresis controller. The design configuration is based on the connection of series and shunt inverters. Pdf improvement of power quality by unified power quality. The distribution system, have numerous nonlinear loads, which severely affect the quality of power supplies. In this paper fuzzy logic controller is used for generation of. Realization of unified power quality conditioner for. Design of unified power quality conditioner upqc to improve.
Power quality the quality of electrical power supply is a set of parameters which describe the process of electric power delivery to the user under normal operating conditions, determine the continuity of supply short and long supply interruption. The unified power quality conditioner is commonly called upqc. Pdf power quality improvement by unified power quality. Analysis the performance of new control strategy for single. The upqc, like a upfc, employs two voltage source inverters vsis that are connected to a common dc energy storage capacitor. May 26, 2019 a unified power quality conditioner upqc is considered to ensure satisfactory electrical energy quality. Power quality management using unified power quality conditioner. The unified power quality conditioner upqc is a solution to mitigate current and voltage issues. Presented by introduction in recent years increase of nonlinear loads results in. This is to certify that the project entitled power quality improvement using unified power quality conditioner upqc submitted by piyush anand 214ee4241 in partial fulfilment of the requirements for the award of master of technology degree in power electronics and drives, department of electrical engineering at national institute of. The proposed controller is capable of reducing total harmonic distortion and to provide constant switching frequency and it has the capability of improving power quality at the point of installation on power distribution systems or. Here we have done simulation of shunt active power. Simulation and analysis of power quality improvement using.
Active power filters are classified into two types that is shunt active power filter apf and series active power filter apf and combination of both is known as upqc unified power quality conditioner. It consists of photo voltaic pv source and ultracapacitor with a buckboost converter which is utilised for maintaining the constant dclink current. Upqc provides the var requirement of the load, so that the supply voltage and current are always in phase. In recent years unified power quality conditioner upqc is being used as universal active power conditioning device to mitigate both current as well as voltage harmonics in a polluted power system network. In a powers system network there are many problems related to power quality. The unified power quality conditioner upqc is a facts device that is used in the distribution system to. Unified power quality conditioner for improving power. They are applicable to power distribution systems, being connected at the point of common coupling pcc of loads that generate harmonic currents. An unified power quality conditioner for load sharing and power quality improvement, ieee, pp. Power quality refer to delivery of sufficiently high. Unified power quality conditionerupqc there are to voltage source inverters in upqc, they are connected back to back with a common dc link. This paper proposes a new connection for a upqc to improve the power quality of two feeders in a.
Fuzzy logic controlled unified power quality conditioner. An improved control method for unified power quality. Unified power quality conditioner for enhancement of power. The unified power quality conditioner is a custom power device that is employed in the distribution system to mitigate the. Unified power quality conditioner upqc inverteri compensates for sag through a tuned filter and voltage transformer inverterii slcvc synchronous link converter var compensator provides var to the load, isolates load current harmonics, makes input power factor unity slcvc maintains the charge of the dc link capacitor low pass filter. The unified power quality conditioner upqc aims at integrating both shunt and series apfs through a common dc link capacitor. This study describes a new configuration of unified power quality conditioner upqc based on current source converters csc topology with left shunt configuration. Implementation of unified power quality conditioner upqc. The unified power quality conditioner upqc is a flexible methodology for simultaneously active filtering the supply voltage and the load current. Design of unified power quality conditioner upqc to.
Power quality management using unified power quality. It uses a pair of threephase controllable bridges to produce current that is injected into a transmission line using a series transformer. The paper discusses the topology and control of a unified power quality conditioner upqc that can be used simultaneously in voltage or current control mode in a power distribution system. The upqc is similar in construction to a unified power flow controller upfc 9. Pavani and devi improved performance of chaotic model of ac electric arc furnace using unified power quality conditioner between 10 to 90 % at a power frequency for durations from 0. This paper proposes an improved control method for unified power quality conditioner upqc with unbalanced load. Recent research has shown that unified power quality conditioner upqc can simultaneously fulfill different objectives, such as maintaining a sinusoidal voltage at the bus at which it is connected, maintaining voltage when there are voltage sags and swells in the system, eliminating harmonics in the source currents,, voltage sag. A unified power flow controller upfc is an electrical device for providing fastacting reactive power compensation on highvoltage electricity transmission networks. Unified power quality conditioner upqc this system proposes about the 3phase source coupled to a power system feeding non linear load. Velumani 1 pg scholar, 2assistant professor, 3 pg scholar 1 department of electrical and electronics engineering, 1 sona college of technology, salem, tamilnadu, india. Interline unified power quality conditioner iupqc, specifically aims at the integration of series vsc and shunt vsc to provide high quality power supply by means of voltage sagswell compensa tion, harmonic elimination and power factor correction in a power distribution network, so that improved power quality can be made. So to improve power quality of a system we use different devices such as active power filters. Dvr is dynamic voltage restorer and is used for improving voltage profile of line.
Unified power quality conditioners upqcs consist of combined series and shunt active power filters apfs for simultaneous compensation of voltage and current disturbances and reactive power. Unified power quality conditioner upqc with voltage dips. Design of interline unified power quality conditioner for. A survey on unified power quality conditioner for power. A unified power quality conditioner upqc is a device that is similar in construction to a unified power flow conditioner upfc.
The unified power quality conditioner upqc is one of the major custom power solutions, which is capable of mitigating the effect of supply voltage sag at the load end or at the point of common. In this era of industrialization, the power quality is important for any. In this is paper a broad overview on the different possible intelligent controls is given which is used with upqc. Introduction electricity is the most famous form of energy which becomes compromised due to power quality problems. Power quality problems the power quality problems are classified into. Implementation of unified power quality conditioner upqc in wind energy conversion system wecs more performance improvement is observed than the normal power converter system. It aims at the integration of seriesactive and shuntactive power filters. When both these active power filters are combined then the combination is known as unified power quality conditioner. We can use dc capacitor bank, fuel cell, pvarray, flywheel, supercapacitor, etc. The main purpose of a upqc is to compensate for voltage imbalance, reactive power, negativesequence current and harmonics.
One of the inverters is controlled as a variable voltage source in series apf and the other as variable current source in shunt apf. Generally, poor power quality results into increased power losses, abnormal and undesirable behaviour of equipments and interference of communication lines. Different devices are suitable for different power quality disturbances or deviations. Comparative evaluation of vsi and csi based unified power. The controller can control active and reactive power flows in a. Active power filters are classified into two types that is shunt active power. A control scheme for dual unified power quality conditioner. The main motive of power utilities is to provide uninterrupted sinusoidal voltage of constant amplitude to their customers.
Power quality improvement using unified power quality. Upqc is custom power device, designed to compensate both source current and load voltage imperfections. Simulation of unified power quality conditioner should be done in matlab. Pdf power quality improvement using interline unified. It is very difficult to maintain electric power quality at sufficient limits. This paper deals with unified power quality conditioner upqc, which aims at the integration of seriesactive and shuntactive power filters. Unified power quality conditioner upqc, distribution static compensator dstatcom, dynamic voltage restorer dvr, pulse width modulationpwm, active power filterapf introduction power electronic based power processing offers higher efficiency, compact size and better controllability. The power components power and quality are related to the same alpha and beta voltages and currents, and can be written together. Power quality the quality of electrical power supply is a set of parameters which describe the process of electric power delivery to the user under normal operating conditions, determine the continuity of supply short and long supply interruptions and characterize the supply. Pdf design of a unified power quality conditioner upqc. Abstract unified power quality conditioner upqc is an effective device to solve the power quality problems. Power quality improvement by unified power quality. Power quality improvement of wind energy conversion. Department of electrical engineering national institute of technology, rourkela certificate this is to certify that the project entitled power quality improvement using unified power.
Each element consists of a bidirectional switch to accommodate for. Assistant professor, department of eee, pondicherry engineering college, pondicherry, india. This paper presents a configuration for mitigation of all power quality problems together named as unified power quality conditioner upqc. Interline unified power quality conditioner request pdf. The neutral of series transformer used in the fourth wire for the 3p4w system.
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