نتایج جستجو برای: ac machinery
تعداد نتایج: 66915 فیلتر نتایج به سال:
a few papers have been interested by the fixed switching frequency direct torque control fed by direct matrix converters, where we can find just the use of direct torque controlled space vector modulated method. In this present paper, we present an improved method used for a fixed switching frequency direct torque control (DTC) using a direct matrix converter (DMC). This method is characterized...
The matrix converter has many advantages in wind power system applications. Matrix converter is compact and highly efficient because it directly converts generated power from AC generator to AC grid without intermediate DC bus while conventional back-to-back converter systems requires many electrolytic capacitors in DC link bus which are bulky and have short life-time. Matrix converter has both...
Abstract: A three-phase to single-phase matrix converter is investigated in the present paper. Based on the state matrix vector, a mathematical analysis of the converter is performed giving the relation between the sinusoidal line voltage (current) and the output voltage (current). The results of the investigation are confirmed using computer simulation of the converter by the program product C...
Solid-state transformer (SST); Medium frequency transformer; AC/AC converter; Matrix converter Abstract This paper presents a novel topology of solid-state transformer (SST). In the design process, the AC/DC, DC/AC and AC/AC converters have been integrated to achieve higher efficiency. To obtain higher efficiency from other SST with DC-link topologies, the AC/DC and DC/AC converters have been i...
Rotating machinery is the most common machinery in industry. The root of the faults in rotating machinery is often faulty rolling element bearings. This paper presents a technique using optimized artificial neural network by the Bees Algorithm for automated diagnosis of localized faults in rolling element bearings. The inputs of this technique are a number of features (maximum likelihood estima...
The researches on direct AC-AC converters have been an important field. The DC-modulated method, which was used in DC-DC converters before, is used in AC-AC converters to realize a direct AC-AC converting now. The traditional control method regulates the output by adjusting the duty ratio. Its’ core is the PWM technology. In this paper, the variable structure control (VSC) strategy was utilized...
this study investigated the status of mechanized power and self-propelled rice cultivation machinery in guilan province in northern iran. the raw data was obtained from 2013 statistics of the agricultural jihad organization of guilan province. power per unit of area, mechanization level, area per unit of self-propelled machinery, and mechanization requirement were calculated for eastern, wester...
در برخی کاربردها از جمله کنترل سرعت موتورهای الکتریکی، کنترل روشنایی، کنترل گرمایش صنعتی و ... نیاز به ولتاژ ac با دامنه متغیر می باشد. از آنجا که ولتاژ ac در دسترس دارای دامنه و فرکانس ثابت است، لذا مبدل های مختلفی برای تبدیل یک مرحله ای ولتاژ ac به ac معرفی شده اند. برخی از این مبدل ها از توانایی تغییر دامنه و فرکانس برخوردار هستند اما دسته ای دیگر فقط توانایی تغییر دامنه را دارند. در این میا...
This paper presents the choice between the utilizing a lower cost die cast or fabricated aluminium rotor versus the more expensive copper bar rotor. In industrialized countries Induction motors account for approximately 50% of the overall electricity use. In every field whether it is agricultural sector or the economical sector. The power consumption by a.c motors is quite enough. On an average...
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