IMPROVEMENT OF POWER QUALITY USING UNIFIED POWER QUALITY CONDITIONER (original) (raw)
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Unified Power Quality Conditioner (UPQC) in Alleviation of Power Quality Issues
Due to vast implementation of power electronics based equipment power quality has turned into essential and important factor. The conventional devices or equipment is not sufficient for enhancing the power quality. The UPQC is the new design for improving the power quality and moreover it attends to both voltage deformity and current deformity simultaneously. In this paper new FACTs (flexible Alternating current Transmission) circuit called UPQC (unified power quality conditioner) is developed to compensate the voltage and current imperfections. The two different control strategies are used for it. The voltage sag and swells together with current harmonic compensation are shown. Index Terms-unified power quality conditioner, flexible ac transmission, power quality.
Design of a Unified Power Quality Conditioner (UPQC)
Sagging and swelling of line voltage and harmonic currents are two major problems of power quality. The communication, microcontroller and microprocessor based industry is much more affected by power quality (PQ) problems as their requirement for working and stability is compromised without high quality of power. By mitigation of voltage and current such problems of power quality can be reduced. For optimization and control of power quality in electrical power distribution system, The Unified Power Quality Conditioner (UPQC) is the most complex and versatile power electronic equipment to enhance the power quality of system. This paper presents improvement of power quality through a UPQC placed at load side. The proposed UPQC is integration of shunt and series converters. The series converter can compensate voltage fluctuation in the ac source due fault. Also, it can be used to regulate voltage sag and the under voltage situations. On the other hand, the shunt converter can compensate the current harmonic and improve the power factor. UPQC was simulated and demonstrated at 220V distribution level. Amount of active and reactive power of system can be controlled by installing the UPQC.
International Journal of Computer Applications, 2016
In recent years, there is tremendous growth in the use of power electronic devices in every sphere but in nonlinear loads, it has problem of drawing the two important limitations; draws the non-sinusoidal current and reactive power from source which in turn effects the power quality. This paper presents the performance evaluation of unified power quality conditioner (UPQC) for current and voltage harmonic elimination and improved power factor. The combined operation of shunt active power filter and series active power filter ensures THD of source current and load voltage within the permissible limits set by various regulatory agencies and near unity supply power factor. The effectiveness of the UPQC has been verified by the extensive simulation results carried out in MATLAB/Simulink and SimPowerSystem software. The results have been obtained with PI Controller and Fuzzy Logic Controller and then compared.
Power Quality Improvement by UPQC based on Voltage Source Converters
ISSN: 2349-0845, Vol 2, Issue 1
In modern power system consists of wide range of electrical, electronic and power electronic equipment in commercial and industrial applications. Since most of the electronic equipment’s are nonlinear in nature these will induce harmonics in the system, which affect the sensitive loads to be fed from the system. These problems are partially solved with the help of LC passive filters. However, this kind of filter cannot solve random variation in the load current wave form and voltage wave form. Active filters can resolve this problem. However, the cost of active filters is high. They are difficult to implement in large scale. Additionally, they also present lower efficiency than shunt passive filters. One of the many solutions is the use of a combined system of shunt and active series filters like Unified Power Quality Conditioner (UPQC) which aims at achieving a low cost under highly effective control. The UPQC device combines a shunt active filter together with a series active filter in a back-to-back configuration, to simultaneously compensate the supply voltage and the load current or to mitigate any type of voltage and current fluctuations and power factor correction in a power distribution network, such that improved power quality can be made available at the point of common coupling. The control strategies are modeled using MATLAB/SIMULINK. The performance is also observed under influence of utility side disturbances such as harmonics and voltage sags. The simulation results are compared without and with UPQC for the verification of results.
IMPROVEMENT OF POWER QUALITY BY USING MULTICONVERTER UNIFIED POWER QUALITY CONDITIONER
To meet Power Quality (PQ) standard cutoff points, including some kind of compensation might be essential. Modern arrangements can be tracked down as dynamic correction or dynamic filtering. A shunt dynamic power filter is reasonable for the suppression of negative load impact on the supply organization, however in the event that there are supply voltage defects, a series dynamic power filter might be expected to give full pay. As of late, arrangements based on Adaptable AC Transmission Systems (Realities) have showed up. The use of Realities ideas in distribution systems has brought about another generation of repaying devices. A Brought together Power Quality Conditioner (UPQC) is the expansion of the Brought together Power-Stream Controller (UPFC) idea at the distribution level. It comprises of consolidated series and shunt converters for concurrent pay of voltage and current flaws in a supply feeder.
In this paper a technical review of the integration of a Unified Power Quality Conditioner (UPQC) in a distributed generation network is presented.. The increasing use of the Nonlinear devices, such as power electronics converters, inject harmonic currents in the AC system and increase overall reactive power demanded by the equivalent load. Also, the number of sensitive loads that require ideal sinusoidal supply voltages for their proper operation has increased. This paper deals with the shunt APF, series APF and the unified power quality conditioner (UPQC) which aims at the integration of series and shunt active filters. The main purpose of a UPQC is to compensate for voltage flicker/imbalance, reactive power, negative sequence current and harmonics. In other words, the UPQC has the capability of improving power quality at the point of installation on power distribution systems or industrial power systems. & reduce the THD of voltage & current level.
Improvement in Power Quality Problems Using Unified Power Quality Controller (UPQC
This paper deals with conceptual study of unified power quality conditioner (UPQC) during voltage sag and swell on the power network.Power quality has become an important factor in power systems, for consumer and household appliances with production of various electric and electronic equipment and computer systems. The main causes of a poor power quality are harmonic currents, poor power factor, supply voltage variations etc. The Unified Power Quality Conditioner (UPQC) is a custom power device, which diminishes voltage and current related power quality issues. It also prevents load current harmonics from entering the utility and corrects the input power factor of the load. The system performance for current harmonics, voltage harmonics, voltage sag and voltage swell will be evaluated. The MATLAB / Simulink based simulations will be provided which support the functionality of the UPQC.
Al-Rafidain Engineering Journal (AREJ)
The power quality (PQ) is a major issue for both electrical utilities and their customers. The nonlinear loads cause PQ problems like current harmonics, voltage harmonics, frequency deviation, voltage sag and voltage swell. A unified power quality conditioner (UPQC) is utilized in this research to minimize these PQ problems. The UPQC is made up of two active power filters (APFs), one of which is connected to the line in series and the other in parallel. The Unit Vector Template Generation (UVTG) approach is used to control the series APF, whereas the Synchronous Reference Frame (SRF) technique is used to control the shunt APF. The compensating properties of a series-shunt APFs when the loads become imbalanced have been explored. The system performance has been tested under conditions current harmonics, voltage harmonics, voltage sag, and voltage swell. The voltage harmonics are identified and reparation in a series APF using the UVTG technique, whereas the harmonics and unbalanced currents are identified and reparation in a shunt APF using the SRF method. An IEEE-519-compliant THD (Total Harmonic Distortion) of less than 5% is achieved by UPQC in simulations with unbalanced loads. The findings indicate that harmonic currents and supply voltage fluctuations were lessened by UPQC.
RESOLVEMENT OF POWER QUALITY PROBLEMS BY UNIFIED POWER QUALITY CONDITIONER (UPQC
In this project presents a Design of a Unified Power Quality conditioner (UPQC) connected to three phase four wire system (3P4W). The neutral of series transformer used in the fourth wire for the 3P4W system. The neutral current that may flow toward transformer neutral point is compensated by using a four-leg voltage source inverter topology for shunt part. The series transformer neutral will be at virtual zero potential during all operating conditions. 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. A new control strategy such as unit vector template is used to design the series APF to balance the unbalanced current present in the load currents by expanding the concept of single phase P-Q theory.
Power Quality Management using Unified Power Quality Conditioner
International Journal of Engineering Research and, 2015
In this paper, a unified power quality conditioner (UPQC) is used for simultaneous compensation of current harmonics and voltage variations due to fault conditions in to grid. For improving power quality series and shunt compensation is provided in form of UPQC, in which series APF and shunt APF are connected through a common DC link. Synchronous reference frame theory is used to generate reference signals for both series and shunt active power filters. Series active power filter is used to compensate voltage related distortions and shunt active power filter is used to compensate current related problems. PI controller is used to stabilize the level of DC link voltage.