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This work represent induction motor modeling from its dynamic equations. The switching table base DTC(ST- DTC) is implemented to the dynamic machine model for 2 level and 3-level voltage source inverter. Out of 27 switching vectors of 3-level inverter, 12 active vectors are used for simulation of DTC with 12 sectors. For reduction of torque ripple a five level torque comparator is proposed. A comparison...
We study the enhancement of multisubband electron transport mobility μ as function of well width w of AlxGa1−xAs based square — parabolic double quantum well (SPDQW) in which the side barriers are delta doped with Si. We calculate μ by considering different elastic scatterings. We show that when single subband is occupied μ is mostly governed by interface roughness scattering (ir-). Whereas, under...
In this work, a normal rectangular gate AlGaN/GaN based High Electron Mobility Transistor with gate length of 150 nm and a T-shaped gate AlGaN/GaN High Electron Mobility Transistor with a gate foot print of 90 nm are designed and compared. DC and RF performance is observed for both the devices. It is shown that the DC parameters like drain current, transconductance are nearly same for both the devices...
We study enhancement of electron mobility in a MODFET by suggesting a hybrid double quantum well (HDQW) structure where one of the wells is square type while the other is parabolic. We consider the wells are of equal width w with side barriers being delta doped symmetrically. We analyze μ as function of w by considering double subband occupancy in which the intersubband effects contribute substantially...
In this work, a AlGaN/GaN based High Electron Mobility Transistor with 3 μm gate length is designed and simulated with the Silvaco TCAD software which is passivated by SiO2. A drain current of 658 mA/mm is found for a gate voltage of 2.5 V. The transconductance of the device is 123 mS/mm at the gate voltage of 2V. A maximum output conductance of 163 mS/mm is obtained at the drain voltage of 45 V....
This paper explicates the minimization of annual energy loss cost (AELC) and maximization of total economic savings cost (TESC) in the radial distribution systems (RDS) with the allocation of DSTATCOM (distribution static compensator). To determine the best size of DSTATCOM for the maximum reduction in the power loss to minimize the AELC, a certain range of size of DSTATCOM was injected at each bus...
The biotechnology business in India with an increase from USD 500 million in 1997 and reaching an estimated USD 1 billion next year health related prod ucts accounting for 60%, agro and veterinary products together 15%, and con tract R&D, reagents, devices and supplies adding up to the remaining 25% of which the diagnostics share was about 10% of the total surely presented an encouraging picture...
Modern day bipolar transistors are based on a drift based current transport in the base region in addition to a diffusion based current transport. These type of transistors are called as drift transistors. Whereas early bipolar transistors which were mainly diffusion transistors were based on a diffusion based current transport across the base. In this paper a detailed theoretical analysis of the...
This paper presents, a rotor speed and stator resistance estimation under very low speed operating region using parallel rotor speed and stator resistance estimation scheme. This scheme is an extension of rotor flux based model reference adaptive system (MRAS) scheme. In this scheme the rotor speed and parameter variation is estimated using MRAS technique. The estimated speed is incorporated as a...
This paper presents the placement of DSTATCOM (distribution static compensator) in radial distribution systems for the compensation of reactive power. The reduction in Power loss and improvement in voltage profile are examined by injecting the reactive power at every node of a distribution system, one by one using DSTATCOM. A new mathematical modelling of DSTATCOM is derived and is integrated into...
In this paper a unique AIN/GaN MOSHEMT (Metal Oxide Semiconductor High Electron Mobility Transistor) structure is reported with ultra-thin A1N barrier layer with thickness 2nm which is less than the critical thickness, so that 2-Dimentional Electron Gas (2DEG) formation is not held at zero gate bias. Suitable positive gate bias is applied for creating 2DEG at the heterointerface which leads the device...
In an inverter, the number of legs can be increased to any number. So, any number of phase voltages can be generated with proper firing pulses. In this work, a five phase machine is modeled and simulated in MATLAB / Simulink. The space vector modulation (SVM) technique is applied to the proposed model for its torque control. The torque control characteristic obtained using SVM based DTC is compared...
Soft magnetic materials rich on iron or cobalt have found vast range of usability for sensors such as fluxgates [1] and also, the recently re-invented, magneto-impedance sensors [2]. Giant magneto-impedance (GMI) has experienced huge increase of interest since the late 80's. Although the fluxgate sensor is commercially available, the easy manufacturing of GMI sensors, possibility of miniaturization...
The induction motor is generally fed from an inverter whose firing pulse can be easily modified according to the required output. The inverter fed motor drive removes the limitation of number of phases which led to the increasing application of the multiphase induction motor. In this work, a five phase induction motor with two-level inverter is mathematically modeled. The proposed model is simulated...
In this paper, a Zero-Voltage-Transition (ZVT) Pulse-width Modulated (PWM) multiphase synchronous buck converter (SBC), with an active auxiliary circuit is proposed, that reduces the stresses and enhances the efficiency abating the switching and conduction losses of the converter. The important design feature of ZVT-PWM multiphase SBC converters is placement of resonant components that pacifies the...
In this paper a new HEMT structure is proposed by replacing the barrier layer of a conventional AlGaN/GaN HEMT with InAlN material. InAlN/GaN HEMTs can obtain substantially higher polarization-induced two-dimensional electron gas (2DEG) of the order of 1014 cm−2 at the heterointerface. The spontaneous polarization in Al0.3Ga0.7N/GaN HEMT is 0.017C/m2 while for the proposed In0.17Al0.83N/GaN HEMT is...
This work compares the DC and RF performance for Single Gate(SG) field plated AlGaN/GaN High Electron Mobility Transistor (HEMT) with a Dual Gate(DG) field plated High Electron Mobility Transistor. The maximum drain current obtained for AlGaN/GaN DG field plated HEMT is 1057mA/mm at Vgs=0V and Vds=10V, which is of 396mA/mm for AlGaN/GaN SG field plated HEMT. The maximum transconductance for Dual-Gate...
This paper deals with design, modeling and characterization of a 50nm InAlGaAs/InGaAs based HEMT which is compared with a 50nm InAlAs/InGaAs based HEMT. A performance evaluation is done considering the above two HEMTs and the DC and RF characteristics are compared for the same device dimension. For a InAlGaAs/InGaAs based HEMT, a maximum drain current of 331mA/mm at Vgs=-0.2V, a cutoff frequency of...
In this research study, a new speed control scheme is proposed for direct torque and flux control (DTFC) of induction motor drive (IMD) to replace the conventional constant gain PI-speed controller (PISC). The conventional PISC offers poor dynamic response of stator current, torque and motor speed under sudden change in speed or load torque disturbances. In order to improve the dynamic as well as...
In this paper, a rotor-flux model reference adaptive system (MRAS) based speed sensorless direct torque and flux control (DTFC) of induction motor drive (IMD) using sliding-mode control (SMC) and fuzzy logic control (FLC) based adaptation mechanism schemes are implemented to replace the conventional constant gain PI-controller (PIC). The SMC is considered to minimize the error dynamics under different...
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