Showing 8 results for Analytical Model
A. Rana, N. Chand, V. Kapoor,
Volume 7, Issue 2 (6-2011)
Abstract
In this paper, novel hybrid MOSFET(HMOS) structure has been proposed to reduce the gate leakage current drastically. This novel hybrid MOSFET (HMOS) uses source/drain-to-gate non-overlap region in combination with high-K layer/interfacial oxide as gate stack. The extended S/D in the non-overlap region is induced by fringing gate electric field through the high-k dielectric spacer. The gate leakage behaviour of HMOS has been investigated with the help of compact analytical model and Sentaurus Simulation. The results so obtained show good agreement between model and simulation data. It is found that HMOS structure has reduced the gate leakage current to great extent as compared to conventional overlapped MOSFET structure. Further, the proposed structure had demonstrated improved on current, off current, subthreshold slope and DIBL characteristic.
A. Jabbari,
Volume 13, Issue 4 (12-2017)
Abstract
A 2D analytical method for magnetic vector potential calculation in inner rotor surface mounted and surface inset permanent magnet machines considering slotting effects, magnetization orientation and winding layout has been proposed in this paper. The analytical method is based on the resolution of Laplace and Poisson equations as well as Maxwell equation in quasi- Cartesian coordinate by using sub-domain method and hyperbolic functions. The developed method is applied on the performance computation of two prototypes surface mounted permanent magnet motors and two prototypes surface inset permanent magnet motors. A radial and a parallel magnetization orientation is considered for each type of motor. The results of these models are validated through FEM method.
A. Jabbari,
Volume 14, Issue 3 (9-2018)
Abstract
Brushless permanent magnet surface inset machines are interested in industrial applications due to their high efficiency and power density. Magnet segmentation is a common technique in order to mitigate cogging torque and electromagnetic torque components in these machines. An accurate computation of magnetic vector potential is necessary in order to compute cogging torque, electromagnetic torque, back electromotive force and self/mutual inductance. A 2D analytical method for magnetic vector potential calculation in inner rotor brushless segmented surface inset permanent magnet machines is proposed in this paper. The analytical method is based on the resolution of Laplace and Poisson equations as well as Maxwell equation in a quasi- Cartesian polar coordinate by using sub-domain method. One of the main contributions of the paper is to derive an expression for the magnetic vector potential in the segmented PM region by using hyperbolic functions. The developed method is applied on the performance computation of two prototype surface inset magnet segmented motors with open circuit and on load conditions. The results of these models are validated through FEM method.
A. Jabbari, F. Dubas,
Volume 16, Issue 1 (3-2020)
Abstract
In this research work, an improved two-dimensional semi-analytical subdomain based method for performance computation in IPM machine considering infinite-/finite-magnetic material permeability in pseudo-Cartesian coordinates by using hyperbolic functions has been presented. In the developed technique, all subdomains are divided into periodic or non-periodic regions with homogeneous or non-homogeneous boundary conditions (BCs), respectively. Taking into account the appropriate interfaces conditions in the presented coordinates system, the machine performances including magnetic flux density, cogging/electromagnetic torque, back-EMF, and self-/mutual induction have been calculated for three distinct values of soft-magnetic material relative permeability (viz, 200, 800 and ∞). The semi-analytical results are compared and confirmed by the FEA results.
A. Jabbari,
Volume 17, Issue 1 (3-2021)
Abstract
In this paper, we present a semi-analytical model for determining the magnetic and electromagnetic characteristics of spoke-type permanent magnet (STPM) machine considering magnet segmentation and finite soft-material relative permeability. The proposed model is based on the resolution of the Laplace’s and Poisson’s equations in a Cartesian pseudo-coordinate system with respect to the relative permeability effect of iron core in a subdomain model. Two different magnet-segmented STPM machine was studied analytically and numerically. The effect of the iron core relative permeability on the STPM machine performances was investigated at no-load and on-load conditions with respect to certain values of iron core relative permeability by comparing cogging torque, electromagnetic torque ripple, and reluctance torque ripple waveforms. In order to validate the results of the proposed analytical model, the analytical and numerical results were compared. It can be seen that the analytical modeling results are consistent with the results of numerical analysis.
A. Jabbari, F. Dubas,
Volume 17, Issue 2 (6-2021)
Abstract
In this paper, we present a mathematical model for determining the optimal radius of the iron pole shape in spoke-type permanent-magnet (PM) machines (STPMM) in order to minimize the pulsating torque components. The proposed method is based on the formal resolution of the Laplace’s and Poisson’s equations in a Cartesian pseudo-coordinate system with respect to the relative permeability effect of iron core in a subdomain model. The effect of PM width on the optimal radius of the iron pole has been investigated. In addition, for initial and optimal machines, the effect of the iron core relative permeability on the STPMM performances was studied at no-load and on-load conditions considering three certain PM widths. Moreover, the effect of iron pole shape on pulsating torque components with respect to certain values of iron core relative permeability was studied by comparing cogging torque, ripple and reluctance torque waveforms. In order to validate the results of the proposed analytical model, three motors with different PM widths were considered as case studies and their performance results were compared analytically and numerically. Two prototype spoke-type machines were fabricated and the experimental results were compared to analytical results. It can be seen that the analytical modeling results are consistent with the numerical analysis and experimental results.
A. Jabbari,
Volume 18, Issue 2 (6-2022)
Abstract
Low-speed brushless permanent magnet machines are ideal for use in gearless propulsion systems. It is important to provide a precise analytical model to determine the performance characteristics of these machines. One of the challenges in designing permanent magnet machines is the elimination of the pulsating torque due to the presence of cogging torque and torque ripple components. The use of dummy slots (auxiliary teeth) is one of the most common methods of reducing pulsating torque phenomenon. In this paper, an accurate two-dimensional analytical model for calculating the magnetic vector potential in brushless permanent magnet machines is presented, taking into account the effect of stator slots, stator dummy slots, the magnetic direction of permanent magnets and phase winding style. The proposed analytical method is based on solving Laplace’s and Poisson’s equations using the separation of variables method for given regions in the subdomain approach. In the proposed method, to achieve a simpler analytical model, by changing the variable, the polar coordinate system is converted to a quasi-Cartesian coordinate system. Therefore, in mathematical terms, the hyperbolic functions are used instead of exponential ones. To validate the proposed model accuracy, the performance of a 14 kW low-speed brushless permanent magnet motor is calculated analytically and compared with the results of the numerical method and the experimental tests. Comparison of the performance results of this motor shows the consistency of analytical, numerical, and experimental results.
Ali Jabbari, Ali Badran,
Volume 19, Issue 3 (9-2023)
Abstract
Cost reduction, increased efficiency and reliability, extended service life, reduced noise and vibration, and environmental friendliness are critical for new generation wind turbines and electric vehicles. Segmented Hybrid Permanent Magnet (SHPM) machines, on the other hand, which are primarily segmented PMs combined with different materials, dimensions, and magnetization directions, offer a way to meet these needs. In this study, we present nine topologies of segmented PM-rotor SHPM generators based on the Taguchi experimental design method, while presenting a simple and accurate model based on subdomain method for estimating the magnetic performance characteristics of SHPM machines. An analytical model is provided. Magnetic partial differential equations (MPDEs) are represented in a pseudo-Cartesian coordinate system, and with appropriate boundary conditions (BC) and interface conditions (IC), the general solution and its Fourier coefficients are extracted using a variable separation approach. The performance characteristics of nine of the SHPM machines studied were compared semi-analytically and numerically. Two prototype SHPM machines were manufactured and semi-analytical modeling results were compared with finite element analysis (FEA) methods and experimental testing (load mode) on a generator. The FEA simulation and experimental test results have a maximum error rate of about 3, confirming the high accuracy of the provided semi-analytical model. We compare the induced voltage, torque ripple and magnetic torque among the investigated topologies.
