PWM GENERATION TO CONTROL VARIABLE FREQUENCY POWER SOURCE
International Journal of Research in Engineering and Technology
The efficient use of available power for various types of demand has remained an important issue in electrical engineering domain. The focus has very often been to develop dedicated types of power sources according to specific, tailor-made demands. Very often, such requirements are specified in the form of generation of AC sources having variable magnitude, variable frequency and different types of waveform shapes. Depending on requirement, there may be design and development of single phase
... of single phase and /or three phase power sources. Presently available power generation sources have no real time implementation. Moreover these are not cost effective. The quality of electrical power developed is gradually becoming a matter of major concern as the new generation equipment installed for increasing productivity very often turn out to be the major sources of creating additional power quality problems. Hence, in an overall consideration, design of high quality, variable voltage variable frequency power source with a wide range of peak-topeak alternating waveforms, with a wide range of frequency and with minimum distortion in the generated waveform, still remains a major challenge. The present work describes the development of a microcontroller-based variable voltage variable frequency power source, which is a necessity for various applications. The power source is developed using H-bridge inverter, which uses four MOSFETs for this purpose. The design utilizes the concept of generating a special kind of signals for the driver circuit. This special signal is nothing but a pulse width modulated signal which is provided as an input to the driver. The H-bridge inverter along with the microcontroller incorporates a memory that is based on a table. The memory used in this case is a Read Only Memory (ROM) that uses Look-Up- Table.