The Experts below are selected from a list of 321 Experts worldwide ranked by ideXlab platform
D. Alexa - One of the best experts on this subject based on the ideXlab platform.
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Rectifiers with near Sinusoidal Input currents - MATLAB/Simulink model case studies
2015 International Symposium on Signals Circuits and Systems (ISSCS), 2015Co-Authors: Adriana Sirbu, D. Alexa, T.c. GorasAbstract:The concept of the rectifiers with near Sinusoidal Input currents (RNSIC) has caught increasing attention, different topologies been designed and analyzed. Even though the OrCAD/PSpice simulation package has proved its merits in the design and study of this type of converters, in order to analyze their integration in complex power electronic systems (such as: wind generator systems, photovoltaic power systems, electric drives), the most powerful simulation tool has proved to be MATLAB/Simulink. The present paper proposes a MATLAB/SimulinK simulation model for RNSIC converters, compares the simulation results with reported OrCAD/PSpice simulation and experimental results and analyzes a complex drive system which includes RNSIC-1 converter.
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Wind energy conversion into electricity by means of the rectifier with near Sinusoidal Input current-1 converter
IET Renewable Power Generation, 2013Co-Authors: D. Alexa, Adriana Sirbu, I.v. Pletea, Alexandru Georgian LazarAbstract:The study presents a wind generator system based on a new converter configuration with a rectifier with near Sinusoidal Input currents (RNSICs-1 converter with DC capacitors connected in parallel with diodes). A detailed analysis of the system for different values of the load current is presented and the advantages of the solution are emphasised. The new converter configuration is characterised by smaller power losses, reduced electromagnetic interference (EMI) problems, low harmonic Input currents, high reliability, as well as reduced costs. This original configuration could also be used for small hydro interconnection with squirrel cage induction generator (SCIG) and partial variable-speed wind turbine (typically 60–100% synchronous speed).
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Hybrid Rectifier With Near-Sinusoidal Input Currents
IEEE Transactions on Industrial Electronics, 2012Co-Authors: D. Alexa, Adriana Sirbu, I.v. Pletea, T.c. GorasAbstract:This paper presents a new hybrid rectifier with near-Sinusoidal Input currents (RNSIC) converter which increases the performances of classic RNSIC converters. The proposed solution is technically and economically competitive with three-phase diode rectifiers with passive filters. Simulation and experimental results from a laboratory prototype are shown to confirm the validity of the proposed converter.
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Variants of rectifiers with near Sinusoidal Input currents - a comparative analysis with the conventional diode rectifier
IET Power Electronics, 2011Co-Authors: D. Alexa, I.v. Pletea, Constantin Filote, A. Sarbu, R. ChiperAbstract:Based on the characteristics of the rectifiers with near Sinusoidal Input currents [rectifier with near Sinusoidal Input current-1 (RNSIC-1), with capacitors connected on the DC side and RNSIC-2, with capacitors connected on the AC side], the study proposes a comparative analysis between the performances (generated capacitive current, costs, efficiency, dimensions and other considerations) of the two variants of RNSIC converters with three-phase six-pulse full-bridge diode rectifiers with passive filters. Therefore the technical and economical advantages of the RNSIC converters are demonstrated. The inductors and the capacitors of the RNSIC converters do not belong to the category of resonant circuits tuned to specific frequency. This is the reason why the design requirements for the capacitors are not very stringent as they can have a tolerance range of ±10% without inflicting severe performance degradations. These converters can be used for a wide power range, practically mitigating the current harmonics generated by a three-phase diode rectifier, without being influenced by the harmonics generated by other consumers.
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Analysis of the two-quadrant converter having rectifier with near Sinusoidal Input currents and capacitors connected on the AC side
2009 International Symposium on Signals Circuits and Systems, 2009Co-Authors: D. Alexa, I.v. Pletea, T.c. Goras, R. Buzatu, M. Moisa, R. ChiperAbstract:A new topology for a two-quadrant converter is presented. In the AC/DC transfer mode, the converter works as a rectifier with near Sinusoidal Input currents and capacitors connected on the AC side (RNSIC-2), whereas in the DC/AC transfer mode, it works as a square-wave pulse switching inverter. The converter is characterized by smaller power losses and reduced electromagnetic interference problems. Possible applications in adjustable speed drive with regenerative braking, wind energy conversion systems and small hydro interconnections with induction generators.
V. Rajagopalan - One of the best experts on this subject based on the ideXlab platform.
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Analysis and design of single-controlled switch three-phase rectifier with unity power factor and Sinusoidal Input current
IEEE Transactions on Power Electronics, 1997Co-Authors: K. Al-haddad, G. Olivier, V. RajagopalanAbstract:This paper describes a new low-cost three-phase AC-DC high-power/low-harmonic-controlled rectifier and its analysis, design, and performance. The circuit consists of a three-phase diode-bridge rectifier, followed by a boost stage containing only one switch and one boost inductor. The proposed converter is used to automatically draw Sinusoidal Input-current waveforms with high efficiency. This is achieved with discontinuous-Input voltage to the rectifier and with a discontinuous-inductor-current mode of operation of the boost converter. By using a simplified single-phase model and symbolic analysis method, analytical equations are obtained and used for design.
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Analysis and design of single controlled switch three phase rectifier with unity power factor and Sinusoidal Input current
Proceedings of 1995 IEEE Applied Power Electronics Conference and Exposition - APEC'95, 1995Co-Authors: K. Al-haddad, G. Olivier, V. RajagopalanAbstract:This paper describes a new low cost three-phase AC-DC high power/low harmonic controlled rectifier and its analysis, design and performance. The circuit consists of a three-phase diode bridge rectifier followed by a boost stage containing only one switch and one boost-inductor; the proposed power converter is used to automatically draw Sinusoidal Input current waveforms, with high efficiency. This is achieved with discontinuous Input voltage to the rectifier and with a discontinuous inductor current mode of operation of the boost power converter. By using a simplified single-phase model and symbolic analysis method, analytical equations are obtained and used for design.
K. Al-haddad - One of the best experts on this subject based on the ideXlab platform.
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Analysis and design of single-controlled switch three-phase rectifier with unity power factor and Sinusoidal Input current
IEEE Transactions on Power Electronics, 1997Co-Authors: K. Al-haddad, G. Olivier, V. RajagopalanAbstract:This paper describes a new low-cost three-phase AC-DC high-power/low-harmonic-controlled rectifier and its analysis, design, and performance. The circuit consists of a three-phase diode-bridge rectifier, followed by a boost stage containing only one switch and one boost inductor. The proposed converter is used to automatically draw Sinusoidal Input-current waveforms with high efficiency. This is achieved with discontinuous-Input voltage to the rectifier and with a discontinuous-inductor-current mode of operation of the boost converter. By using a simplified single-phase model and symbolic analysis method, analytical equations are obtained and used for design.
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Analysis and design of single controlled switch three phase rectifier with unity power factor and Sinusoidal Input current
Proceedings of 1995 IEEE Applied Power Electronics Conference and Exposition - APEC'95, 1995Co-Authors: K. Al-haddad, G. Olivier, V. RajagopalanAbstract:This paper describes a new low cost three-phase AC-DC high power/low harmonic controlled rectifier and its analysis, design and performance. The circuit consists of a three-phase diode bridge rectifier followed by a boost stage containing only one switch and one boost-inductor; the proposed power converter is used to automatically draw Sinusoidal Input current waveforms, with high efficiency. This is achieved with discontinuous Input voltage to the rectifier and with a discontinuous inductor current mode of operation of the boost power converter. By using a simplified single-phase model and symbolic analysis method, analytical equations are obtained and used for design.
Adriana Sirbu - One of the best experts on this subject based on the ideXlab platform.
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Rectifiers with near Sinusoidal Input currents - MATLAB/Simulink model case studies
2015 International Symposium on Signals Circuits and Systems (ISSCS), 2015Co-Authors: Adriana Sirbu, D. Alexa, T.c. GorasAbstract:The concept of the rectifiers with near Sinusoidal Input currents (RNSIC) has caught increasing attention, different topologies been designed and analyzed. Even though the OrCAD/PSpice simulation package has proved its merits in the design and study of this type of converters, in order to analyze their integration in complex power electronic systems (such as: wind generator systems, photovoltaic power systems, electric drives), the most powerful simulation tool has proved to be MATLAB/Simulink. The present paper proposes a MATLAB/SimulinK simulation model for RNSIC converters, compares the simulation results with reported OrCAD/PSpice simulation and experimental results and analyzes a complex drive system which includes RNSIC-1 converter.
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Wind energy conversion into electricity by means of the rectifier with near Sinusoidal Input current-1 converter
IET Renewable Power Generation, 2013Co-Authors: D. Alexa, Adriana Sirbu, I.v. Pletea, Alexandru Georgian LazarAbstract:The study presents a wind generator system based on a new converter configuration with a rectifier with near Sinusoidal Input currents (RNSICs-1 converter with DC capacitors connected in parallel with diodes). A detailed analysis of the system for different values of the load current is presented and the advantages of the solution are emphasised. The new converter configuration is characterised by smaller power losses, reduced electromagnetic interference (EMI) problems, low harmonic Input currents, high reliability, as well as reduced costs. This original configuration could also be used for small hydro interconnection with squirrel cage induction generator (SCIG) and partial variable-speed wind turbine (typically 60–100% synchronous speed).
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Hybrid Rectifier With Near-Sinusoidal Input Currents
IEEE Transactions on Industrial Electronics, 2012Co-Authors: D. Alexa, Adriana Sirbu, I.v. Pletea, T.c. GorasAbstract:This paper presents a new hybrid rectifier with near-Sinusoidal Input currents (RNSIC) converter which increases the performances of classic RNSIC converters. The proposed solution is technically and economically competitive with three-phase diode rectifiers with passive filters. Simulation and experimental results from a laboratory prototype are shown to confirm the validity of the proposed converter.
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Parametric design and optimization platform — Case study: Rectifiers with near Sinusoidal Input currents
ISSCS 2011 - International Symposium on Signals Circuits and Systems, 2011Co-Authors: Adriana SirbuAbstract:The paper presents and analyzes the functionality of a software platform aiming to offer a generous framework for parametric optimal design of electronic systems. We describe the role of the platform components and we provide an overview of the steps required by a design procedure. The utilization of the platform using PSpice and genetic algorithms optimization is illustrated by a case study focusing on the design of rectifiers with near Sinusoidal Input currents.
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Analysis of the two-quadrant converter with rectifier with near Sinusoidal Input currents
IET Power Electronics, 2008Co-Authors: D. Alexa, Adriana Sirbu, I.v. Pletea, T.c. Goras, Constantin Filote, F. IonescuAbstract:A new topology for a two-quadrant converter is presented. In the AC/DC transfer mode, the converter works as a rectifier with near Sinusoidal Input currents, whereas in the DC/AC transfer mode, it works as a square-wave pulse switching inverter. The converter is characterised by smaller power losses and reduced electromagnetic interference problems. Possible applications in adjustable speed drive with regenerative braking, wind energy conversion systems and small hydro interconnections with induction generators are also discussed.
Okko Bosgra - One of the best experts on this subject based on the ideXlab platform.
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experimental characterization of the stick sliding transition in a precision mechanical system using the third order Sinusoidal Input describing function
Mechatronics, 2008Co-Authors: Pwjm Pieter Nuij, M Maarten Steinbuch, Okko BosgraAbstract:In this paper a new, non-parametric frequency domain based measurement technique is introduced that enables capturing the stick to gross sliding transition of a mechanical system with dry friction. The technique is an extension of the Sinusoidal Input Describing Function theory (SIDF) to Higher Order Describing Functions. The resulting Higher Order Sinusoidal Input Describing Functions (HOSIDF) relate the magnitude and phase of the higher harmonics in the periodic response of a non-linear system to the magnitude and phase of the Sinusoidal excitation. A non-linear mechanical system with dry friction is analyzed using both the classical Frequency Response Function (FRF) technique and the newly developed HOSIDF technique. Where the FRF technique is not able to identify the stick/sliding transition of the system, the third order SIDF clearly displays this transition. From the third order SIDF the pre-sliding displacement of the system is determined. The first order SIDF is used to generate information about the resonance frequency of the system due to the friction-induced stiffness. From the pre-sliding displacement and the friction-induced stiffness, the friction force is calculated which must be present in the stick-phase. Validation with force measurements shows excellent agreement.
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Measuring the higher order Sinusoidal Input describing functions of a non-linear plant operating in feedback
Control Engineering Practice, 2008Co-Authors: Pwjm Pieter Nuij, M Maarten Steinbuch, Okko BosgraAbstract:In this paper two measuring techniques are presented for measuring the higher order Sinusoidal Input describing functions (HOSIDF) of a non-linear plant operating in feedback. The HOSIDF relate the magnitude and phase of the harmonics of the periodic response of a non-linear system to the magnitude and phase of the Sinusoidal excitation. In a controlled system the harmonics generated by the non-linear system will be fed back to the Input changing the Sinusoidal excitation into a harmonic excitation. The first method applies linear techniques to compensate the bias caused by the harmonic components in the excitation signal. The second method uses a modified repetitive control scheme to suppress the harmonic components in the excitation signal. The effectiveness of both methods is tested in simulations of a mass subjected to Coulomb friction, Stribeck effect and hysteresis in the pre-sliding regime. The friction forces are modeled with the modified Leuven friction model. The results are compared with the HOSIDF simulated under open-loop condition. Both methods prove able to produce reliable results.
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Bias Removal in Higher Order Sinusoidal Input Describing Functions
2008 IEEE Instrumentation and Measurement Technology Conference, 2008Co-Authors: Pwjm Pieter Nuij, M Maarten Steinbuch, Okko BosgraAbstract:In this paper a novel method is presented for the reduction of bias caused by harmonic excitation in the identification of higher order Sinusoidal Input describing functions (HOSIDF). HOSIDF are a recently introduced generalization of the theory of the describing function. HOSIDF describe the magnitude and phase relations between the individual harmonic components in the output signal of a non-linear system and the Sinusoidal excitation signal. In the presented method, the output signal of a non-linear system subjected to harmonic excitation is numerically split up into a fraction caused by the non-linear response due to the fundamental Input signal component and the fraction caused by the quasi-linear response due to the harmonic Input signal components. This separation is based on the assumption that the non-linear effects of intermodulation can be neglected, compared to the the effects caused by the generation of harmonics and gain compression/expansion. The method is demonstrated with real measurements on a mechanical system with friction.
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Experimental characterization of the stick/sliding transition in a precision mechanical system using the third order Sinusoidal Input describing function
Mechatronics, 2008Co-Authors: Pwjm Pieter Nuij, M Maarten Steinbuch, Okko BosgraAbstract:In this paper a new, non-parametric frequency domain based measurement technique is introduced that enables capturing the stick to gross sliding transition of a mechanical system with dry friction. The technique is an extension of the Sinusoidal Input Describing Function theory (SIDF) to Higher Order Describing Functions. The resulting Higher Order Sinusoidal Input Describing Functions (HOSIDF) relate the magnitude and phase of the higher harmonics in the periodic response of a non-linear system to the magnitude and phase of the Sinusoidal excitation. A non-linear mechanical system with dry friction is analyzed using both the classical Frequency Response Function (FRF) technique and the newly developed HOSIDF technique. Where the FRF technique is not able to identify the stick/sliding transition of the system, the third order SIDF clearly displays this transition. From the third order SIDF the pre-sliding displacement of the system is determined. The first order SIDF is used to generate information about the resonance frequency of the system due to the friction-induced stiffness. From the pre-sliding displacement and the friction-induced stiffness, the friction force is calculated which must be present in the stick-phase. Validation with force measurements shows excellent agreement.
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Higher-order Sinusoidal Input describing functions for the analysis of non-linear systems with harmonic responses
Mechanical Systems and Signal Processing, 2006Co-Authors: Pwjm Pieter Nuij, Okko Bosgra, M Maarten SteinbuchAbstract:For high-precision motion systems, modelling and control design specifically oriented at friction effects is instrumental. The Sinusoidal Input describing function theory represents an approximative mathematical framework for analysing non-linear system behaviour. This theory, however, limits the description of the non-linear system behaviour to a quasi-linear amplitude-dependent relation between Sinusoidal excitation and Sinusoidal response. In this paper, an extension to higher-order describing functions is realised by introducing the concept of the harmonics generator. The resulting higher-order Sinusoidal Input describing functions (HOSIDFs) relate the magnitude and phase of the higher harmonics of the periodic response of the system to the magnitude and phase of a Sinusoidal excitation. Based on this extension two techniques to measure HOSIDFs are presented. The first technique is FFT based. The second technique is based on IQ (in-phase/quadrature-phase) demodulation. In a simulation, the measurement techniques have been tested by comparing the simulation results to analytically derived results from a known (backlash) non-linearity. In a subsequent practical case study both techniques are used to measure the changes in dynamic behaviour as a function of drive level due to friction in an electric motor. Both methods prove successful for measuring HOSIDFs.
