The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform

Moncef Gossa - One of the best experts on this subject based on the ideXlab platform.

  • pwm switching pattern based diagnosis scheme for single and multiple open switch damages in vsi fed induction motor drives
    Isa Transactions, 2012
    Co-Authors: Mohamed Trabelsi, M Boussak, Moncef Gossa
    Abstract:

    Abstract This paper deals with a fault detection technique for insulated-gate bipolar transistors (IGBTs) open-circuit faults in Voltage source inverter (VSI)-fed induction motor drives. The novelty of this idea consists in analyzing the pulse-width modulation (PWM) switching signals and the Line-to-Line Voltage levels during the switching times, under both healthy and faulty operating conditions. The proposed method requires Line-to-Line Voltage measurement, which provides information about switching states and is not affected by the load. The fault diagnosis scheme is achieved using simple hardware and can be included in the existing inverter system without any difficulty. In addition, it allows not only accurate single and multiple faults diagnosis but also minimization of the fault detection time to a maximum of one switching period ( T c ). Simulated and experimental results on a 3-kW squirrel-cage induction motor drive are displayed to validate the feasibility and the effectiveness of the proposed strategy.

  • an improved diagnosis technique for igbts open circuit fault in pwm vsi fed induction motor drive
    International Symposium on Industrial Electronics, 2011
    Co-Authors: Mohamed Trabelsi, M Boussak, P Mestre, Moncef Gossa
    Abstract:

    This paper deals with an improved technique for insulated-gate bipolar transistors (IGBTs) open-circuit fault diagnoses in Voltage source inverter (VSI) fed induction motors. The extraction of the fault information is based on the combining of the switching pattern and the electric drive Line-to-Line Voltage measurements. The combined diagnosis signals make possible to detect and identify the single and multiple open-circuit faults of the inverter switches. Furthermore, only one Line-to-Line Voltage is necessary to diagnose two inverter legs simultaneously. For simplicity and cost-effectiveness, the fault detection is carried out by a simple circuit. To avoid the false diagnosis alarms, the time delays due to turn-on and turn-off process of the power switches are compensated while acting on the switching pattern. Different from the conventional method, the proposed technique was marked by a better time delay between the fault occurrence and its detection. The Simulation results are displayed to confirm the proposal.

N Farokhnia - One of the best experts on this subject based on the ideXlab platform.

  • closed form Line to Line Voltage thd of the cascade multilevel inverter including device Voltage drops
    Energy Conversion Congress and Exposition, 2013
    Co-Authors: N Farokhnia, Muneer Mohammad, M Ehsani
    Abstract:

    The previously published formulas showed the Line to Line Voltage THD of the cascade multilevel inverter's staircase Voltage waveform with unequal DC sources. This article explains/demonstrates how these formulas have been revised to show new expressions that include the device Voltage drops. The device Voltage drops exist across the diodes and switches in power converters during conduction. The new set of formulas is fast, accurate, and simple. They make it very simple to compute the THD in real time and in a fraction of second. Simulation results are presented to show the difference between the previous ideal case and present practical case. Experimental results are presented to verify the obtained analytical formulas as well as simulation results.

  • fast closed form solution of Line to Line Voltage total harmonic distortion for three level inverters
    Iet Power Electronics, 2013
    Co-Authors: N Farokhnia, Hadi Vadizadeh, Hamidreza Toodeji, M Ehsani, Muneer Mohammad
    Abstract:

    Harmonic emission to the network must be restricted below the predefined limits, avoiding power quality problems. Total harmonic distortion (THD) is a well-known criterion, which is used to determine harmonic content of each waveform, and extracting its exact value is very important. Three-level inverters produce a significant amount of harmonics and the exact closed-form expression for their Line-to-Line Voltage THD has not yet been derived. All presented methods in this regard are based on an approximate approach. This study calculates Line-to-Line Voltage THD of a three-level inverter by two different methods and presents their relevant formulas. The first method is usable for any number of controlled PWM switching angles, but the second method is limited to low number of switching angles. By the presented mathematical formulas in this study, the THD is computed simply, accurately and rapidly. The proposed methods are compared with the conventional methods and their advantages are verified by simulation and experimental results.

  • thd minimization applied directly on the Line to Line Voltage of multilevel inverters
    IEEE Transactions on Industrial Electronics, 2012
    Co-Authors: Nima Yousefpoor, N Farokhnia, Seyed Hamid Fathi, Hossein Askarian Abyaneh
    Abstract:

    In this paper, total harmonic distortion (THD) minimization of the output Voltage of multilevel inverters is discussed. An efficient approach in reducing the harmonic contents of the inverter's output Voltage is THD minimization. In multilevel inverters with a fundamental frequency switching strategy (each switch turning on and off once per output cycle), the switching angles can be selected so that the output THD is minimized (such as the so-called optimal-minimization-of-THD strategy). To obtain the optimum switching angles, an optimization algorithm is applied to the output-Voltage THD. In three-phase multilevel inverters, the optimization algorithm is commonly applied to the phase Voltage of the inverter. This results in the minimum THD in phase Voltage but not necessarily in the Line-to-Line minimum THD, whereas in three-phase applications, the Line-Voltage harmonics are of the main concern from the load point of view. In this paper, using the genetic algorithm, a THD minimization process is directly applied to the Line-to-Line Voltage of the inverter. This paper is based on a seven-level inverter. To verify the simulation results, a seven-level-cascaded-H-bridge-inverter-based hardware prototype, including an ATMEGA32 AVR microcontroller, has been implemented. Both simulation and experimental results indicate superiority of this approach over the commonly used phase-Voltage THD minimization approach.

  • calculating the formula of Line Voltage thd in multilevel inverter with unequal dc sources
    IEEE Transactions on Industrial Electronics, 2011
    Co-Authors: N Farokhnia, Hadi Vadizadeh, Seyed Hamid Fathi, F Anvariasl
    Abstract:

    Multilevel inverters introduce harmonics to the network besides their remarkable advantages. Total harmonic distortion (THD) is one of the most important indexes to evaluate the harmonic contents of waveforms. The conventional method of Line-Voltage THD calculation gives approximate answers, because high-order harmonics are ignored. In this paper, an analytical algebraic method based on formulating the Line-Voltage THD of multilevel inverters with unequal dc sources is presented. This method, which is general and applicable to each number of switching angles, is implemented to a five-level inverter with staircase waveform as a case study. The implementing process of this method can be easily repeated for each number of levels. The accuracy of the proposed method is illustrated in comparison with the approximate method. Some advantages of the extracted formulas of Line-Voltage THD are simplicity and rapidity in calculations, considering all harmonics and the possibility of finding optimal switching angles analytically. Experimental results are presented to validate the theory.

Mohamed Trabelsi - One of the best experts on this subject based on the ideXlab platform.

  • pwm switching pattern based diagnosis scheme for single and multiple open switch damages in vsi fed induction motor drives
    Isa Transactions, 2012
    Co-Authors: Mohamed Trabelsi, M Boussak, Moncef Gossa
    Abstract:

    Abstract This paper deals with a fault detection technique for insulated-gate bipolar transistors (IGBTs) open-circuit faults in Voltage source inverter (VSI)-fed induction motor drives. The novelty of this idea consists in analyzing the pulse-width modulation (PWM) switching signals and the Line-to-Line Voltage levels during the switching times, under both healthy and faulty operating conditions. The proposed method requires Line-to-Line Voltage measurement, which provides information about switching states and is not affected by the load. The fault diagnosis scheme is achieved using simple hardware and can be included in the existing inverter system without any difficulty. In addition, it allows not only accurate single and multiple faults diagnosis but also minimization of the fault detection time to a maximum of one switching period ( T c ). Simulated and experimental results on a 3-kW squirrel-cage induction motor drive are displayed to validate the feasibility and the effectiveness of the proposed strategy.

  • an improved diagnosis technique for igbts open circuit fault in pwm vsi fed induction motor drive
    International Symposium on Industrial Electronics, 2011
    Co-Authors: Mohamed Trabelsi, M Boussak, P Mestre, Moncef Gossa
    Abstract:

    This paper deals with an improved technique for insulated-gate bipolar transistors (IGBTs) open-circuit fault diagnoses in Voltage source inverter (VSI) fed induction motors. The extraction of the fault information is based on the combining of the switching pattern and the electric drive Line-to-Line Voltage measurements. The combined diagnosis signals make possible to detect and identify the single and multiple open-circuit faults of the inverter switches. Furthermore, only one Line-to-Line Voltage is necessary to diagnose two inverter legs simultaneously. For simplicity and cost-effectiveness, the fault detection is carried out by a simple circuit. To avoid the false diagnosis alarms, the time delays due to turn-on and turn-off process of the power switches are compensated while acting on the switching pattern. Different from the conventional method, the proposed technique was marked by a better time delay between the fault occurrence and its detection. The Simulation results are displayed to confirm the proposal.

K M Smedley - One of the best experts on this subject based on the ideXlab platform.

Xiangning He - One of the best experts on this subject based on the ideXlab platform.

  • equivalent switch circuit model and proportional resonant control for triple Line Voltage cascaded Voltage source converter
    IEEE Transactions on Power Electronics, 2013
    Co-Authors: Faqiang Zhou, Zhiqiang Wang, Xiangning He
    Abstract:

    This paper studies the modeling and control for a triple Line-Voltage cascaded Voltage-source converter. The unbalanced current of each cascaded unit results in complicated control algorithm and structure due to its structural characteristic, and there exists a double-frequency fluctuation for each dc-capacitor Voltage. To solve the aforementioned problems, an equivalent switch circuit model for the converter is established in this paper based on the external circuit characteristic, and a simple proportional resonant control strategy for the model is also proposed. The technique realizes the power factor regulation and the balanced stable transmission of the converter power in a two-phase stationary frame. And by adding an ac-side Voltage compensation control for each converter, the double-frequency fluctuation of each dc-link Voltage is effectively restrained. Besides, the strategy adopts a carrier phase-shifting space vector pulsewidth modulation suitable for the structural characteristics, which effectively simplifies the modulation algorithm. The proposed strategy has such advantages as less hardware and computation, simpler control structure, better dynamic and static performance, and better robustness. The experimental results have verified the feasibility and availability of the proposed model and its control method.