The Experts below are selected from a list of 303 Experts worldwide ranked by ideXlab platform
Predrag Pejovic - One of the best experts on this subject based on the ideXlab platform.
-
Three-phase rectifiers with suboptimal Current Injection and improved efficiency
IET Power Electronics, 2014Co-Authors: Milan Darijevic, Predrag Pejovic, Johann W. Kolar, Marija M. Janković, Yasuyuki NishidaAbstract:Three-phase diode bridge rectifiers that apply suboptimal Current Injection and active resistance emulation are analysed. Two types of Current Injection devices (CIDs) are in the focus, and rectifiers with each CID are analysed for two cases of active resistance emulation: one that applies low-frequency filtering of the emulator output, and another that does not. Models that cover both continuous and discontinuous conduction mode are developed. To minimise the input Current total harmonic distortion (THD), optimisation is performed, showing that in each case the THD is about the same when the emulated resistance takes its optimal value. The results are experimentally verified on a 1.5 kW rectifier.
-
Hybrid three-phase rectifier with switched Current Injection device
2012 15th International Power Electronics and Motion Control Conference (EPE PEMC), 2012Co-Authors: Marija M. Janković, Predrag Pejovic, Johann W. Kolar, Milan Darijevic, Yasuyuki NishidaAbstract:A hybrid three-phase rectifier with switched Current Injection device and high frequency switching Current Injection network is analyzed in this paper. The rectifier applies suboptimal Current Injection. Optimization of the injected Current amplitude is performed, resulting in the minimum of the input Current THD of 4.36%. Ratings of applied semiconductor devices are derived. Effects caused by finite values of the inductance applied in the Current Injection network are analyzed. It is shown that increased values of the inductance require reduced amplitude of the injected Current, and result in slightly increased values of the input Current THD. A new structure of the Current Injection network that provides filtering of the switching ripple is proposed. The results are experimentally verified on a low-power converter model.
-
A Current Injection based twelve-pulse rectifier
2008 IEEE Power Electronics Specialists Conference, 2008Co-Authors: Predrag Pejovic, Yasuyuki NishidaAbstract:A three-phase twelve-pulse rectifier that applies Current Injection to reduce the input Current total harmonic distortion (THD) is proposed. In absence of losses, the input Currents are the same as in conventional twelve-pulse rectifiers, with the THD equal to 15.22%. The Current Injection system applies a voltage-loaded resistance emulator, consisting of a transformer and two diodes. Piecewise linear model of the rectifier, suitable for numerical simulation, is developed. Optimization of the resistance emulator transformer turns ratio is performed. It is shown that losses in the Current Injection system considerably affect the input Current THD and volt-ampere ratings of applied magnetic components. The results are experimentally verified on a rectifier with the rated power of 3 kW.
-
Application of optimal and suboptimal Current Injection in twelve-pulse three-phase diode rectifiers
2008 IEEE Power Electronics Specialists Conference, 2008Co-Authors: M. Ivkovic, Predrag Pejovic, Zarko JandaAbstract:Two methods of Current Injection applied to reduce input Current THD of twelve-pulse three-phase diode rectifiers are proposed in this paper. The methods are optimal and suboptimal Current Injection. In the case of the optimal Current Injection, THD of the input Currents is zero, and the Currents are in phase with corresponding input voltages. In the case of suboptimal Current Injection, THD of the input Currents is 1.016%, while the power factor is 0.9999. In comparison to conventional twelve-pulse three-phase rectifiers, that provide THD of the input Currents of 15.22%, significant improvement is achieved for the price of two additional transformers with low VA rating, and dissipation of less than 2.5% of the output power in the Current Injection system. Proposed solutions are analyzed and compared. Both of the methods are verified by simulation. Experimental verification of the suboptimal Current Injection is performed on an 1.8 kW rectifier model.
-
Current-Injection-based 12-pulse rectifier using a single three-phase diode bridge
IET Electric Power Applications, 2007Co-Authors: P. Bozovic, Predrag PejovicAbstract:A three-phase rectifier that applies Current Injection to reduce the input Current total harmonic distortion (THD) is proposed. The rectifier injects rectangular Current, which results in the waveforms of the input Currents the same as in the case of 12-pulse rectifiers, with the THD equal to 15.22%. The Current Injection system applies a voltage-loaded resistance emulator. To simplify the rectifier analysis, an equivalent circuit of the rectifier is derived, which significantly reduces the number of nonlinear elements. Analytical optimisation of the resistance emulator transformer turns ratio is performed for the case when the losses in the Current Injection system can be neglected. Influence of the losses in the Current Injection system is analysed numerically, and it is shown that they considerably affect the rectifier performance and design. Numerical optimisation of the resistance emulator turns ratio in the presence of losses is performed. Analytical results are experimentally verified on a rectifier with a rated power of 3 kW.
B. S. Ryvkin - One of the best experts on this subject based on the ideXlab platform.
-
Polarization stabilization in vertical-cavity surface-emitting lasers through asymmetric Current Injection
IEEE Photonics Technology Letters, 2000Co-Authors: Guy Verschaffelt, Martinus Petrus Creusen, E. Smalbrugge, T.g. Van De Roer, F Fouad Karouta, Jan Danckaert, Irina Veretennicoff, W.c. Van Der Vleuten, R.c. Strijbos, B. S. RyvkinAbstract:We present experimental evidence that asymmetric Current Injection in intracavity contacted vertical-cavity surface-emitting lasers (VCSELs) stabilizes the polarization of the emitted light. Anisotropies in the gain and loss mechanisms introduced by asymmetric Current Injection are considered to explain this effect. The design scheme opens perspectives to obtain actual polarization control in VCSELs.
-
Asymmetric Current Injection for polarization stabilization in vertical-cavity surface-emitting lasers
1999 Digest of the LEOS Summer Topical Meetings: Nanostructures and Quantum Dots WDM Components VCSELs and Microcavaties RF Photonics for CATV and HFC, 1999Co-Authors: Guy Verschaffelt, Martinus Petrus Creusen, E. Smalbrugge, T.g. Van De Roer, F Fouad Karouta, Jan Danckaert, Irina Veretennicoff, B. S. Ryvkin, Hugo Thienpont, Gerard Adriaan AcketAbstract:Intra-cavity contacted In/sub 0.17/Ga/sub 0.83/As/AlAs VCSELs with asymmetrical and symmetric contacts were fabricated and characterized. The square devices with asymmetric Current Injection emit light polarized perpendicular to the direction of the Current Injection, despite the fact that these VCSELs have higher order transverse modes. The asymmetric Current Injection scheme seems thus to be able to stabilize the polarization. We expect that smaller devices working in single mode operation will further enhance the polarization contrast.
Zarko Janda - One of the best experts on this subject based on the ideXlab platform.
-
Application of optimal and suboptimal Current Injection in twelve-pulse three-phase diode rectifiers
2008 IEEE Power Electronics Specialists Conference, 2008Co-Authors: M. Ivkovic, Predrag Pejovic, Zarko JandaAbstract:Two methods of Current Injection applied to reduce input Current THD of twelve-pulse three-phase diode rectifiers are proposed in this paper. The methods are optimal and suboptimal Current Injection. In the case of the optimal Current Injection, THD of the input Currents is zero, and the Currents are in phase with corresponding input voltages. In the case of suboptimal Current Injection, THD of the input Currents is 1.016%, while the power factor is 0.9999. In comparison to conventional twelve-pulse three-phase rectifiers, that provide THD of the input Currents of 15.22%, significant improvement is achieved for the price of two additional transformers with low VA rating, and dissipation of less than 2.5% of the output power in the Current Injection system. Proposed solutions are analyzed and compared. Both of the methods are verified by simulation. Experimental verification of the suboptimal Current Injection is performed on an 1.8 kW rectifier model.
-
Three-phase rectifiers that apply optimal Current Injection
IEEE Transactions on Aerospace and Electronic Systems, 2002Co-Authors: Predrag Pejovic, Zarko JandaAbstract:A class of Current Injection based three-phase high power factor rectifiers is proposed. Low distortion of the input Currents and high power factor are obtained applying near optimal Current Injection. The optimal Current Injection is discussed, and requirements it imposes to the Current Injection network are derived. A class of simple Current Injection networks that provide near optimal Current Injection, consisting of a transformer, two capacitors, and a number of resistors or resistance emulators is proposed. The power processed by the resistors or resistance emulators is shown to be 8.81% of the input power. Design of the Current Injection network is discussed, and dependence of the input Current distortion on capacitance of the applied capacitors is analyzed. Volt-ampere rating of the transformer is shown to be only 0.16% of the input power. Effects caused by the output Current ripple are studied, and a method for their compensation is proposed. Analytical results are experimentally verified. Switching resistance emulation is discussed and its feasibility is experimentally demonstrated.
-
An improved Current Injection network for three-phase high-power-factor rectifiers that apply the third harmonic Current Injection
IEEE Transactions on Industrial Electronics, 2000Co-Authors: Predrag Pejovic, Zarko JandaAbstract:A novel Current Injection network for low-harmonic rectifiers that apply the third harmonic Current Injection is proposed in this paper. The Current Injection network requires one inductor, two capacitors, and one 1:1 transformer with a voltampere rating of only 0.16% of the input power. The transformer is introduced to provide complete rejection of harmonic components of the injected Currents at even triples of the line frequency, resulting in significant reduction of the input Current total harmonic distortion (THD). Dependence of the input Current THD on the Current Injection network Q factor is computed. The THD is shown to be in the range 4%
-
Low-harmonic three-phase rectifier applying Current Injection
IEE Proceedings - Electric Power Applications, 1999Co-Authors: Predrag Pejovic, Zarko JandaAbstract:A low-harmonic three-phase rectifier that applies near optimal Current Injection is proposed. The rectifier utilises a novel passive Current Injection network, suitable for application at high power levels. The Current Injection method is analysed and it is shown that ideal sinusoidal waveforms of the input Currents can be obtained. Requirements imposed to the Current Injection network are derived. Structure and design of the Current Injection network are discussed. Analytical results are experimentally verified.
-
A novel harmonic-free three-phase diode bridge rectifier applying Current Injection
APEC '99. Fourteenth Annual Applied Power Electronics Conference and Exposition. 1999 Conference Proceedings (Cat. No.99CH36285), 1999Co-Authors: Predrag Pejovic, Zarko JandaAbstract:A novel harmonic-free three-phase diode bridge rectifier is proposed in the paper. Low distortion of the input Currents is obtained applying optimal Current Injection. The optimal Current Injection is discussed, and requirements it imposes to the Current Injection network are derived. A class of simple Current Injection networks, consisting of a transformer, two capacitors and a number of resistors or resistance emulators is proposed. Power processed by the resistors or resistance emulators is shown to be 8.81% of the input power. Design of the Current Injection network is discussed, and dependence of the input Current distortion on the applied capacitors is analyzed. Volt-ampere rating of the transformer is shown to be only 0.16% of the input power. Analytical results are experimentally verified.
Guy Verschaffelt - One of the best experts on this subject based on the ideXlab platform.
-
Polarization stabilization in vertical-cavity surface-emitting lasers through asymmetric Current Injection
IEEE Photonics Technology Letters, 2000Co-Authors: Guy Verschaffelt, Martinus Petrus Creusen, E. Smalbrugge, T.g. Van De Roer, F Fouad Karouta, Jan Danckaert, Irina Veretennicoff, W.c. Van Der Vleuten, R.c. Strijbos, B. S. RyvkinAbstract:We present experimental evidence that asymmetric Current Injection in intracavity contacted vertical-cavity surface-emitting lasers (VCSELs) stabilizes the polarization of the emitted light. Anisotropies in the gain and loss mechanisms introduced by asymmetric Current Injection are considered to explain this effect. The design scheme opens perspectives to obtain actual polarization control in VCSELs.
-
Asymmetric Current Injection for polarization stabilization in vertical-cavity surface-emitting lasers
1999 Digest of the LEOS Summer Topical Meetings: Nanostructures and Quantum Dots WDM Components VCSELs and Microcavaties RF Photonics for CATV and HFC, 1999Co-Authors: Guy Verschaffelt, Martinus Petrus Creusen, E. Smalbrugge, T.g. Van De Roer, F Fouad Karouta, Jan Danckaert, Irina Veretennicoff, B. S. Ryvkin, Hugo Thienpont, Gerard Adriaan AcketAbstract:Intra-cavity contacted In/sub 0.17/Ga/sub 0.83/As/AlAs VCSELs with asymmetrical and symmetric contacts were fabricated and characterized. The square devices with asymmetric Current Injection emit light polarized perpendicular to the direction of the Current Injection, despite the fact that these VCSELs have higher order transverse modes. The asymmetric Current Injection scheme seems thus to be able to stabilize the polarization. We expect that smaller devices working in single mode operation will further enhance the polarization contrast.
Irina Veretennicoff - One of the best experts on this subject based on the ideXlab platform.
-
Polarization stabilization in vertical-cavity surface-emitting lasers through asymmetric Current Injection
IEEE Photonics Technology Letters, 2000Co-Authors: Guy Verschaffelt, Martinus Petrus Creusen, E. Smalbrugge, T.g. Van De Roer, F Fouad Karouta, Jan Danckaert, Irina Veretennicoff, W.c. Van Der Vleuten, R.c. Strijbos, B. S. RyvkinAbstract:We present experimental evidence that asymmetric Current Injection in intracavity contacted vertical-cavity surface-emitting lasers (VCSELs) stabilizes the polarization of the emitted light. Anisotropies in the gain and loss mechanisms introduced by asymmetric Current Injection are considered to explain this effect. The design scheme opens perspectives to obtain actual polarization control in VCSELs.
-
Asymmetric Current Injection for polarization stabilization in vertical-cavity surface-emitting lasers
1999 Digest of the LEOS Summer Topical Meetings: Nanostructures and Quantum Dots WDM Components VCSELs and Microcavaties RF Photonics for CATV and HFC, 1999Co-Authors: Guy Verschaffelt, Martinus Petrus Creusen, E. Smalbrugge, T.g. Van De Roer, F Fouad Karouta, Jan Danckaert, Irina Veretennicoff, B. S. Ryvkin, Hugo Thienpont, Gerard Adriaan AcketAbstract:Intra-cavity contacted In/sub 0.17/Ga/sub 0.83/As/AlAs VCSELs with asymmetrical and symmetric contacts were fabricated and characterized. The square devices with asymmetric Current Injection emit light polarized perpendicular to the direction of the Current Injection, despite the fact that these VCSELs have higher order transverse modes. The asymmetric Current Injection scheme seems thus to be able to stabilize the polarization. We expect that smaller devices working in single mode operation will further enhance the polarization contrast.
