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1

Study of electro-thermal stress of IGBT devices

Shaban M. A., Ettomi Y.

Poznan University of Technology Academic Journals. Electrical Engineering

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2013

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No. 76

275--284

EN

The aim of this paper is to present a new approach which consists to correlate or coupled the functional and electrical stress with temperature. This approach can be extremely useful in the predicting the stressing effect and the impact of IXGH-IGBT I-V characteristics on circuit degradation. Moreover, this new approach significantly improves such parameters likes (threshold voltage Vth, collector saturation current, the stress and enhanced collector leakage current) and provides new capability for use this power device IXGH-IGBT in an actual circuit environment and modules. We also explain the physical reasons behind the improvement obtained using functional electrical stress on the IGBTs for IXYS constructor with temperature. Moreover, the forward blocking capability of IXGH-IGBT under a coupled Functional - Electro stress at high temperature was analyzed using simulation. This paper gives a straight comparison in term of the stress for improving the switching speed of IGBT device. This study is essential to ensure product reliability and to the evaluation of hot carrier reliability in the early stages. Furthermore, our reliability study permits us to improve the implantation of the device in a circuit, as well as its use in industrial operating conditions. The need for good simulator (Spice, Spice) to carry out a reliability study is pointed out in this paper.

2

Efficiency control of inverter fed induction motor drives

Shaban M. A.

Poznan University of Technology Academic Journals. Electrical Engineering

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2012

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No. 72

291--295

EN

Induction motor losses at partial loads can be significantly reduced by operating an adjustable frequency drive at the optimum slip which yields maximum efficiency. The present investigation quantifies the potential improvement in induction motor efficiency for both standard and energy efficient motors operating on a six-step voltage-source inverter supply. The analysis employs a comprehensive model of the induction motor which incorporates the frequency - dependent nature of the motor parameters and effects of stray load loss. Efficiency contours are plotted on a torque- speed plane for constant volts/hertz operation and for optimum slip frequency control plotted as a contour map.

3

An optimization model for reactive power control of super high voltage grid systems

Shaban M. A.

Poznan University of Technology Academic Journals. Electrical Engineering

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2012

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No. 69

89--93

EN

This paper develops an optimization model to control the excessive (MVAR) generation by super high voltage gird systems for maintaining the nodal voltages within the required acceptable margin. The model enhances an approximate solution on the condition of balanced real power. The pseudo-inverse method of optimization is implemented as an optimal optimization is implemented as an optimal means of solving non-square systems of equations based on LaGrange's theory of optimization. It recommends the locations and ratings of the minimum required reactors from the preinstalled ones that to be in service for optimum nodal reactive power and voltage controls.

4

Synthesis of some novel nitrogenous furocoumarin derivatives

Elgamal M.H.A., Shalaby N.M.M., Shaban M.A.

Polish Journal of Chemistry

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1998

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Vol. 72, nr 4

735-745

EN

Reaction of 5-chloro-6-formylfurocoumarins (3 and 4) withheterocyclic amines and hydrazine derivatives yields corresponding 5-N-substituted and 5-chloro-6-hydrazine derivatives 7a-h and 8a-h, respectively. Bergapten (5,6-c)isoxazole (9) or 6-oxime derivative 10 were obtained by reaction of 3 and 4 with hydroxylamine hydrochloride. Also, reaction of 5-hydroxybergapten (1) and 5-hydroxyisopimpinellin (2) with aliphatic, heterocyclic and aromatic amines beside benzenesulphonamide derivatives affords some novel 5- and 6-substituted aminofurocoumarins 11a-o, 12 a-f, and 13 a-f.The antimiocrobial activity of all compounds was studied.