30-08-2011, 09:43 AM
Abstract:
The number of industry applications in which induction motors are fed by static frequency inverters is growing fast and, although much has already been done within this field, there is still a lot to be studied/understood regarding such applications. The advance of variable speed drives systems engineering increasingly leads to the need of specific technical guidance provision by electrical machines and drives manufacturers, In this paper we have studied and developed a simulink model with PWM inverter and find out the various characteristics and analysis them.
Keywords: ASM (Asynchronous Machine), PWM (pulse width modulation)
I. INTRODUCTION
A three-phase The Direct Current (D.C.) machine, the synchronous machine, and the asynchronous machine, also known as an three phase induction machine. Induction machine are the major electromechanical conversion devices in industry. The merits of the squirrel cage induction machine are: lightness, simplicity, ruggedness, robustness, less initial cost, higher torque-inertia ratio, capability of much higher speeds, ease of maintenance, etc. The most important feature which declares it as a tough competitor to D.C. machines in the drives field is that its cost per KVA is approximately one fifty of its counter-part and it possesses higher suitability in hostile environment. Unfortunately, induction machines suffer from the drawback that, in contrast to D.C. machines, their speed cannot be easily and effectively adjusted continuously over a wide range of operating conditions. On the other hand, the synchronous machine has the merit of being operated under a wide range of power factors, both lagging and leading, and are much better suited for bulk power generation. In the induction motor, alternating current is applied to the stator and alternating currents are induced in the rotor by transformer action. In the synchronous machine, direct current is supplied to the rotor and Alternating Current (A.C.) flows in the stator. On the other hand, a D.C. machine is a machine that is excited from D.C. sources only or that itself acts as a source of D.C. It is a common practice in industry to employ A.C. motors whenever they are inherently suitable or can be given appropriate characteristics by means of power electronics devices. Yet, the increasing complexity of industrial processes demands greater flexibility from electrical machines in terms of special characteristics and speed control. It is in this field that the D.C. machines, fed from the A.C. supply through rectifiers, are making their mark.
Download full report
http://googleurl?sa=t&source=web&cd=1&ve...-IJAET.pdf&ei=FGNcTsn3J4jOrQeVqOi6Dw&usg=AFQjCNHwJ1YlWtVp0P78JaSngl_DONsu1w