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My name is Maziyar Fakhraei and I am graduated in M.S of Power Electrical engineering at Shiraz University of Technology in Iran.
Currently, most electro-mechanical drive systems that require speed control use pulse-width modulated (PWM) variable frequency drives known as adjustable speed drives (ASD). The high switching speeds of the electronics switches are essential for proper operation of the ASD. Common mode voltage (CMV) has its origin in the PWM switching. The CMV increases the stress on the coils and windings, reduces the life of the bearing and, therefore, has a significant impact on motor life cycle. In this paper, a variant of a PWM-based space vector modulation (SVPWM) switching algorithm is proposed to control both the shoot-through intervals and the dead time of the power switches that could be compensated. The proposed algorithm is implemented on a platform consisting of an impedance source network in the DC side of the topology with the purpose of mitigating the CMV and capability of voltage boosting. Since similar methods have achieved a CMV reduction of 1/6 of the DC link voltage so far, in this paper, while surpassing the disturbing current harmonics, the high efficiency is fully accessible. The presented experimental results verify the effectiveness of the proposed approach by slightly increasing the total harmonic distortion (THD) and reducing the converter losses.
Mehrdad Mahmoudian; Maziyar Fakhraei; Edris Pouresmaeil; Eduardo M. G. Rodrigues. An Impedance Source Multi-Level Three Phase Inverter with Common Mode Voltage Elimination and Dead Time Compensation. Electronics 2020, 9, 1639 .
AMA StyleMehrdad Mahmoudian, Maziyar Fakhraei, Edris Pouresmaeil, Eduardo M. G. Rodrigues. An Impedance Source Multi-Level Three Phase Inverter with Common Mode Voltage Elimination and Dead Time Compensation. Electronics. 2020; 9 (10):1639.
Chicago/Turabian StyleMehrdad Mahmoudian; Maziyar Fakhraei; Edris Pouresmaeil; Eduardo M. G. Rodrigues. 2020. "An Impedance Source Multi-Level Three Phase Inverter with Common Mode Voltage Elimination and Dead Time Compensation." Electronics 9, no. 10: 1639.
Since high voltage transmission line towers or wind turbines structures are installed in high-altitude areas, it is essential to achieve a high overvoltage protection system against direct and indirect lightning strikes collisions. The lightning current must be discharged quickly into the protective earth, to prevent the dangerous over-voltages formation and define a reference voltage node. This paper presents a novel model to assess the behavior of the grounding system, based on Pocklington integral equations under lightning magnetic fields and variations in soil ionization, in which an explicit circuit-based vector fitting RLC admittance branches are proposed. The frequency-dependent behavior of grounding system frequency response and soil ionization effect is modeled in time domain, straightly to implement into the electro-magnetic transient program (EMTP). The model verification contains horizontal, vertical, and their combinations of grounding grids to represent the complete investigations under lightning strikes. The harmonic impedance mathematical formulations and principles are derived based on a rational function, that could be applicable on ground potential rise (GPR) investigation.
Maziyar Fakhraei; Mehrdad Mahmoudian; Eduardo Manuel Godinho Rodrigues. Grounding System Modeling and Evaluation Using Integrated Circuit Based Fast Relaxed Vector Fitting Approach, Considering Soil Ionization. Applied Sciences 2020, 10, 5632 .
AMA StyleMaziyar Fakhraei, Mehrdad Mahmoudian, Eduardo Manuel Godinho Rodrigues. Grounding System Modeling and Evaluation Using Integrated Circuit Based Fast Relaxed Vector Fitting Approach, Considering Soil Ionization. Applied Sciences. 2020; 10 (16):5632.
Chicago/Turabian StyleMaziyar Fakhraei; Mehrdad Mahmoudian; Eduardo Manuel Godinho Rodrigues. 2020. "Grounding System Modeling and Evaluation Using Integrated Circuit Based Fast Relaxed Vector Fitting Approach, Considering Soil Ionization." Applied Sciences 10, no. 16: 5632.