Search for: unified-power-quality-conditioners
Article Iranian Journal of Electrical and Computer Engineering ; Volume 12, Issue 1-2 , 2013 , Pages 13-22 ; 16820053 (ISSN) ; Varjani, A. Y ; Mokhtari, H ; Sharif University of Technology
Iranian Research Institute for Electrical Engineering 2013
This paper presents a novel flexible control strategy for Unified Power Quality Conditioner (UPQC), which achieves more flexibility in compensation of power quality disturbances as compared to the existing methods. The proposed control strategy provides priority-based compensation as well as full and standard-based compensation considering the rating of series and shunt parts of a UPQC. The priority-based compensation is done based on the compensation priority among different power quality disturbances. In this control strategy, an on-line estimation of different voltage and current disturbances is required. For this purpose, a Unified Adaptive Power Quality Estimator (UAPQE) has been...
Article IEEE Transactions on Power Delivery ; Volume 24, Issue 3 , 2009 , Pages 1679-1686 ; 08858977 (ISSN) ; Yazdian Varjani, A ; Mokhtari, H ; Sharif University of Technology
This paper presents a new unified power-quality conditioning system (MC-UPQC), capable of simultaneous compensation for voltage and current in multibus/multifeeder systems. In this configuration, one shunt voltage-source converter (shunt VSC) and two or more series VSCs exist. The system can be applied to adjacent feeders to compensate for supply-voltage and load current imperfections on the main feeder and full compensation of supply-voltage imperfections on the other feeders. In the proposed configuration, all converters are connected back to back on the dc side and share a common dc-link capacitor. Therefore, power can be transferred from one feeder to adjacent feeders to compensate for...
Article Energy Conversion and Management ; Volume 50, Issue 6 , 2009 , Pages 1578-1585 ; 01968904 (ISSN) ; Shayanfar, H. A ; Fotuhi Firuzabad, M ; Sharif University of Technology
This paper presents modeling of unified power quality conditioner (UPQC) in load flow calculations for steady-state voltage compensation. An accurate model for this device is derived to use in load flow calculations. The rating of this device as well as direction of reactive power injection required to compensate voltage to the desired value (1 p.u.) is derived and discussed analytically and mathematically using phasor diagram method. Since performance of the compensator varies when it reaches to its maximum capacity, modeling of UPQC in its maximum rating of reactive power injection is derived. The validity of the proposed model is examined using two standard distribution systems consisting...
Application of the unified power quality conditioner for mitigating electric arc furnace disturbances, Article International Journal of Power and Energy Systems ; Volume 28, Issue 4 , 2008 , Pages 363-371 ; 10783466 (ISSN) ; Parniani, M ; Emadi, A ; Mokhtari, H ; Sharif University of Technology
This paper discusses the application of unified power quality conditioner (UPQC) for improving power quality of a system supplying an electric arc furnace (EAF). The UPQC includes combined series and shunt active filters sharing a common DC link. It is used to mitigate voltage disturbances and compensate for reactive power, harmonics and interharmonics. A novel control strategy for the UPQC is presented. As voltages at the point of common coupling contain low-frequency interharmonics, conventional methods cannot be used for extracting voltage reference signals. In the proposed method, voltage references are extracted using a phase-locked loop to generate sinusoidal waveforms. Current...