• Energy Research

L'objectif principal de cet article est de concevoir et d'évaluer l'étude des caractéristiques du nouveau générateur synchrone à aimant permanent pseudo-polaire à double stator (NDSPPFP-PMSG) pour l'application de l'énergie éolienne.Le générateur proposé a un double stator et deux ensembles de cinq enroulements de phase qui améliorent sa densité de puissance et sa capacité de tolérance aux pannes.La nouveauté de ce générateur est basée sur le fait que huit pôles magnétiques sont formés en utilisant seulement quatre pôles d'aimants réels sur les deux surfaces du rotor.Pour la conception et les performances électromagnétiques optimales du générateur proposé, un générateur dynamique Le modèle de circuit magnétique (DMCM) est rapporté.Pour valider les résultats obtenus à partir du DMCM, la méthode des éléments finis (FEM) a été choisie en raison de sa grande précision.Pour montrer la supériorité des performances, le générateur proposé est comparé à deux générateurs conventionnels à savoir, DSEPFP (Dual Stator Embedded-Pole Five Phase) et SSSRFP (Single Stator Single Rotor Five Phase) PMSG.Pour comparer leurs performances, les résultats du FEM sont pris en compte.La performance électromagnétique à savoir, la force électromotrice générée (EMF), pourcentage(%) Distorsion harmonique totale (THD) de la EMF générée, EMF générée vs la vitesse, la tension aux bornes en fonction du courant de charge, le couple électromagnétique développé sur le rotor en fonction du temps, le % de contenu d'ondulation dans le couple et le % d'efficacité en fonction du courant de charge sont étudiés pour les trois générateurs. De ces études, il ressort que la densité de puissance (rapport puissance/poids) du générateur proposé est maximale. El objetivo principal de este documento es diseñar y evaluar la investigación de características del nuevo generador síncrono de imanes permanentes de seudopolos de doble estator (NDSPPFP-PMSG) para la aplicación de energía eólica. El generador propuesto tiene un estator dual y dos conjuntos de devanados de cinco fases que mejoran su densidad de potencia y su capacidad de tolerancia a fallos. La novedad de este generador se basa en el hecho de que, ocho polos magnéticos se forman utilizando solo cuatro polos de imanes reales en ambas superficies del rotor. Para el diseño y el rendimiento electromagnético óptimo del generador propuesto, un Se informa el Modelo de Circuito Magnético (DMCM). Para validar los resultados obtenidos de DMCM, se ha optado por el Método de Elementos Finitos (FEM) debido a su alta precisión. Para mostrar la superioridad del rendimiento, se compara el generador propuesto con dos generadores convencionales, a saber, Dual Stator Embedded-Pole Five Phase (DSEPFP) y Single Stator Single Rotor Five Phase (SSSRFP) PMSG. Para comparar sus rendimientos, se consideran los resultados de FEM. El rendimiento electromagnético, a saber, la Fuerza Electromotriz generada (EMF), porcentaje(%) Distorsión Armónica Total (ThD) de EMF generada, EMF generada vs se investigan la velocidad, el voltaje terminal frente a la corriente de carga, el par electromagnético desarrollado en el rotor frente al tiempo, el % de contenido de ondulación en el par y el % de eficiencia frente a la corriente de carga para los tres generadores. A partir de estas investigaciones, se encuentra que la densidad de potencia (relación potencia-peso) del generador propuesto es máxima. The main focus of this paper is to design and assess the characteristics investigation of Novel Dual Stator Pseudo-Pole Five Phase Permanent Magnet Synchronous Generator (NDSPPFP-PMSG) for wind power application.The proposed generator has a dual stator and two sets of five phase windings which enhance its power density and fault tolerant capability.The novelty of this generator is based on the fact that, eight magnetic poles are formed using only four poles of actual magnets on both the surfaces of the rotor.For the designing and optimal electromagnetic performance of the proposed generator, a Dynamic Magnetic Circuit Model (DMCM) is reported.To validate the results obtained from DMCM, Finite Element Method (FEM) has been opted owing to its high accuracy.For showing the performance superiority, the proposed generator is compared with two conventional generators namely, Dual Stator Embedded-Pole Five Phase (DSEPFP) and Single Stator Single Rotor Five Phase (SSSRFP) PMSG.To compare their performances, FEM results are considered.The electromagnetic performance namely, generated Electromotive Force(EMF), percentage(%) Total Harmonic Distortion(THD) of generated EMF, generated EMF vs speed, terminal voltage vs load current, electromagnetic torque developed on rotor vs time, %ripple content in the torque, and %efficiency vs load current are investigated for all the three generators.From these investigations, it is found that the power density (power to weight ratio) of the proposed generator is maximum. ينصب التركيز الرئيسي لهذه الورقة على تصميم وتقييم التحقيق في خصائص المولد المتزامن للمغناطيس الدائم ثنائي القطب الزائف (NDSPPFP - PMSG) لتطبيق طاقة الرياح. يحتوي المولد المقترح على عضو ساكن مزدوج ومجموعتين من اللفات خماسية الطور التي تعزز كثافة طاقته وقدرته على تحمل الأخطاء. تعتمد حداثة هذا المولد على حقيقة أنه يتم تشكيل ثمانية أقطاب مغناطيسية باستخدام أربعة أقطاب فقط من المغناطيس الفعلي على كل من أسطح الدوار. للتصميم والأداء الكهرومغناطيسي الأمثل للمولد المقترح، تم الإبلاغ عن نموذج الدائرة المغناطيسية (DMCM). للتحقق من صحة النتائج التي تم الحصول عليها من نموذج الدائرة المغناطيسية (DMCM)، تم اختيار طريقة العناصر المحدودة (FEM) نظرًا لدقتها العالية. لإظهار تفوق الأداء، تتم مقارنة المولد المقترح مع اثنين من المولدات التقليدية وهما، المرحلة الخامسة للجزء الثابت المضمن (DSEPFP) و PMSG للجزء الثابت المفرد. لمقارنة أدائها، يتم النظر في نتائج FEM. الأداء الكهرومغناطيسي أي القوة المحركة الكهرومغناطيسية المتولدة (EMF)، النسبة المئوية (٪) التشوه التوافقي الكلي (THD) من المجال الكهرومغناطيسي المتولد، المجال الكهرومغناطيسي المتولد مقابل يتم فحص السرعة والجهد الطرفي مقابل تيار الحمل وعزم الدوران الكهرومغناطيسي المطور على الدوار مقابل الوقت ومحتوى التموج في عزم الدوران و ٪الكفاءة مقابل تيار الحمل لجميع المولدات الثلاثة. من هذه التحقيقات، وجد أن كثافة الطاقة (نسبة الطاقة إلى الوزن) للمولد المقترح هي الحد الأقصى.

Abstract This paper describes a methodology based on Gaussian distribution approach for generating capacity reliability evaluation of a power system. The presented methodology has developed using continuous probability distribution function. The failure probability evaluation of generating system accounts the load models as load duration curve and is based on maximum average generation capacity. The probability of load exceeding the generating capacity has also been considered in LOLP evaluation. The described methodology in this paper is based on safety factor concept and peak load considerations. The test results using proposed methodology and various discussions have been presented for various generating capacity and load data available at Vijay Wada super thermal power plant, A. P.; India. Obtained results from extensive testing of the proposed method at different generating capacity and load demand considerations of Indian power system confirm the validity of the developed approach.

AbstractThis paper describes the controller design aspects of DFIG‐based wind turbine system (WTS) using gravitational search algorithm (GSA). The appropriate control schemes are required for efficient and reliable functioning of the DFIG‐based wind energy conversion system (WECS). The control algorithms are implemented in converters which are placed in the rotor end and grid side of the WECS. The controller design schemes are optimized for accurate, reliable and stable operations of WECS using GSA. The most commonly used other design techniques are bacterial foraging optimization (BFO), and particle swarm optimization (PSO). Moreover, the transfer function modeling of DFIG is also described in this paper. The results show that the proposed GSA technique with sixths order transfer function model of DFIG improves the transient performance including time of rising the response to 90%, settling time, and amplitude of peak overshoot. The proposed GSA technique is compared with the techniques already implemented in the previous research works including PSO and BFO. The DFIG‐based WTS's output waveforms of voltage at dc‐link, reactive power, and active power are improved using GSA based design technique. Finally, it is concluded that the GSA technique gives better results as compared with the PSO and BFO techniques.

Abstract This manuscript describes the controller design for doubly fed induction generator (DFIG) driven by a variable speed wind turbine using particle swarm optimization technique. The mathematical model of the DFIG, its power converters, and their controllers have illustrated in this paper appropriately. The lower order simple illustration of DFIG have been used for PID controller design using numerical differentiation of Simulink model. The controller design for DFIG based WECS using PSO technique and its fitness functions are described in detail. The responses of the DFIG system regarding terminal voltage, current, active-reactive power and DC-Link voltage along with generator speed have slightly improved with PSO based controller. Finally, the obtained output is equated with a standard technique for performance improvement of the DFIG based wind energy conversion system.

This paper describes the characteristic investigation of the Novel Dual-stator V-Shape Magnetic Pole Six-Phase Permanent Magnet Synchronous Generator (NDSVSMPSP-PMSG) for wind power application. The proposed generator has V-shaped embedded magnetic pole in the rotor and six-phase winding in both the stator. The proposed generator has high-power density and high efficiency. For emphasizing the significance of the proposed generator, the characteristics of the NDSVSMPSP generator are analyzed and compared to one of the traditional generators, i.e., the Dual-stator Surface Mounted Six-Phase Permanent Magnet Synchronous Generator (DSSMSP-PMSG). For the design and characteristic investigation of both the generator, Finite Element Method (FEM) is chosen because of its high accuracy. Two modes of FEM analysis are considered, namely magneto-statics and transients. The magneto static analysis is used for the study of flux line and flux density distribution, while the transient analysis is considered for the generator’s characteristic investigation. The performance characteristics such as generated Electromotive Force (EMF) for both inner and outer stator, Percentage Total Harmonic Distortion (THD) of developed voltage, Developed EMF vs rpm, terminal voltage vs. current, developed rotor torque vs time, percent (%) ripple content in torque, and percent efficiency vs current for both generators are investigated. As a result, it can be stated that the power density and reliability of the proposed generator is higher than that of the traditional generator.

AbstractEfficient maximum power point tracking (MPPT) is an important problem for renewable power generation from photovoltaic systems. In this work, a current sensor based MPPT algorithm using an adaptive step‐size for a single ended primary inductance converter (SEPIC) based solar photovoltaic system is proposed. Due to lower sensitivity of power to current perturbation as compared to the voltage one, such a scheme is shown to yield better efficiency at steady‐state. A new adaptation scheme is also proposed for faster convergence of the MPPT technique. Hence, the proposed scheme yields better transient as well as steady‐state performance. A prototype converter is used along with digital implementation of the proposed MPPT technique to demonstrate the superiority of the proposed algorithm over the fixed step‐size and voltage based ones. Simulation and experimental results corroborates the same.

This paper presents a convective dominated reliable diffusion process in an axi-symmetric tube with a local constriction simulating a stenos artery considering the porosity effects. The investigations demonstrate the effects of wall shear stress and recirculation flow on the concentration distribution in the vessels lumen and on wall mass transfer keeping the porosity in view. The flow is governed by the incompressible Navier-Stokes equations for Newtonian fluid in porous medium. The convection diffusion equation has been used for the mass transport. The effect of porosity is examined on the velocity field and wall stress. The numerical solutions of the flow equations and the coupled mass transport equations have been obtained using a finite difference method. This paper explains the reliable effects of flow porosity on the mass transport.

This paper presents the design and analysis of electromagnetic characteristics of a five phase permanent magnet synchronous generator for direct drive wind energy conversion system (WECS). In this study, simple and accurate Dynamic Reluctance Network Modeling is used for design and optimization of generator. The anisotropic structure of stator and rotor for the accurate prediction of flux distribution in the air gap and electromagnetic performance is accounted by the dynamic variation of air gap reluctance in an electrical period. This model considers the leakage flux paths for machine design optimization to achieve better performance. In this context, three permanent magnet (PM) materials namely NdFeB, SmCo and ferrite are considered to evaluate the generated voltage. The dimensions of these permanent magnets are varied and performance under normal and saturated core condition is evaluated. A prototype is developed in the machine laboratory of the IIT(BHU) Varanasi (India) and results obtained in accordance with Finite Element Method.