نتایج جستجو برای: اصلاح الگوی پالس pwm

تعداد نتایج: 76129  

1998
Ahmet M. Hava Russel J. Kerkman Thomas A. Lipo

This paper provides analytical and graphical tools for the study, performance evaluation, and design of the modern carrier based PWM methods which are widely employed in PWM-VSI drives. Simple techniques for generating the modulation waves of the high performance PWM methods are described. The two most important modulator characteristics, the current ripple and the switching losses are analytic...

2005
H. Azizi A. Vahedi

Voltage and current source inverter are widely used in electrical motor drives. In this drives, DC voltage (or current) are usually provided from phase control or line commutation rectifiers. Because of disadvantage & limitation of this converter, some new topologies are presented in advanced drive such as PWM rectifier. Thanks to well known capabilities of PWM rectifier, classical converter’s ...

1998
Ahmet M. Hava Russel J. Kerkman Thomas A. Lipo

In this paper, a generalized discontinuous pulsewidth modulation (GDPWM) method with superior high modulation operating range performance characteristics is developed. An algorithm which employs the conventional space-vector PWM method in the low modulation range, and the GDPWM method in the high modulation range, is established. As a result, the current waveform quality, switching losses, volt...

ژورنال: :مجله علوم پزشکی پارس 0
شهره فرشاد shohrah farshad مجتبی انوری نژاد mojtaba anvarinejad علی مهرابی توانا ali mehrabi tavana عزیز ژاپونی aziz japoni مرضیه حسینی marzeh hoseini مانلی شهیدی maneli shahidi

مقدمه: عفونت های ادراری از علل عمده مراجعه به بیمارستان ها و کلینیک ها است و درمان سریع آن به لحاظ ایجاد عوارض بسیار مهم است. از آنجا که باکتری اشریشیاکلی یکی از مهم ترین عامل های ایجاد عفونت های مجاری ادراری(uti) در کودکان می باشد،این مطالعه ابتدا به بررسی الگوی مقاومت اشریشیاکلی های جدا شده از مجاری ادراری کودکان می پردازد. از آنجائی که تغییرات زیادی در خصوصیات فنوتیپی ارگانیسمهایی همچون اشری...

1998
Ahmet M. Hava Russel J. Kerkman Thomas A. Lipo

In this paper, the overmodulation region voltagegain characteristics and waveform quality of carrier-based pulsewidth-modulated (PWM) methods are investigated. Through detailed analytical study, voltage-gain characteristics are extracted independent of carrier frequency. The influence of blanking time and minimum pulsewidth (MPW) control on the inverter gain characteristics are studied and show...

Journal: :iranian journal of basic medical sciences 0
ali reza khosravi mycology research center, faculty of veterinary medicine, university of tehran, tehran, iran hojjatollah shokri department of pathobiology, faculty of veterinary medicine, amol university of special modern technologies, amol, iran shahin eshghi department of food sciences, qazvin, iranian veterinary organization

objective(s): systemic candidiasis is an infection of candida albicans (c. albicans) causing disseminated disease and sepsis, invariably when host defenses are compromised. we investigated the histopathological changes as well as the lymphoproliferative responses and cytokine production of splenic cells after stimulation with concanavalin a (con a) and pokeweed mitogen (pwm) in mice with dissem...

Journal: :EURASIP J. Adv. Sig. Proc. 2007
Andreas Floros John Mourjopoulos

Although uniformly sampled pulse width modulation (UPWM) represents a very efficient digital audio coding scheme for digitalto-analog conversion and full-digital amplification, it suffers from strong harmonic distortions, as opposed to benign nonharmonic artifacts present in analog PWM (naturally sampled PWM, NPWM). Complete elimination of these distortions usually requires excessive oversampli...

2012
Megha Jess Mathew

Multilevel inverters have been widely applied industries. A family of optimal puisewidth modulation (PWM) methods for multilevel inverters, such as step modulation, can generate output voltage with less harmonic distortion than popular modulation strategies, such as the carrier-based sinusoidal PWM or the space vector PWM. However, some drawbacks limit the application of optimal PWM. One of suc...

2008
Huynh Ngoc Phien

This study is concerned with the estimation of the parameters of the general (or generalised) extreme value (GEV) distribution by the methods of maximum likelihood (ML) and probability-weighted moments (PWM) for complete and type I censored samples. For complete samples, the PWM provided estimators which are less biased than the ML estimators. For the variances/covariances of the parameter esti...

2014
R. Madhavi C. Harinath Reddy

In this paper, hybrid pulse width modulation algorithm for vector controlled induction motor drives is used to reduce the steady state ripple in current. Also the newly developed Hybrid PWM technique does not use angle and sector information and hence it simplifies the control algorithm. The conventional Space vector pulse width modulation (CSVPWM) algorithm gives inferior performance at higher...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید