hi ,
i am a student of electronics and i want some information on a sine wave ups ............ i want to design a 1.5 kva ups but the problem i am facing is in the design of a PWM controller that can derive 4 mosfets.... plz help me its urgent i need a circuit diagram can any one help me?

 

hi ,
the problem i am facing is in the design of a PWM controller that can derive 4 mosfets....

Are they an H-bridge or are they some other configuration?

Will you be using some type of microprocessor or do you require discreet components?

Also, what frequency do you wish to run at?

If you can provide more information, such as what you've tried so far, we will be better equipped to assist.

plz help me its urgent i need a circuit diagram can any one help me?

We are happy to assist you as you design your own schematic, as we all believe that students learn best when doing their own work. I'm afraid I don't understand what "urgent" means, but we are willing to help.

 

hi and thaks for replying...
well actually my teacher told me to design a ups of 1.5 kva which gives a complete sine wave, the shitching speed must be high so that there is no interuption...... what i have been told so far by my teacher is u have to connect 10 12v dc batteries to get a dc input of 120v then using the inverter u have to change it into a complete sine wave.
actually we are not using any transformers we have to use boost converters instead....
about the mosfets i dont know on which frequecncy should they be operated e.t.c so starting from scratch i need some help but i have to start from the pwm controller which will be driving 4 mosfets thats all i know ....
help me plz

 

You'll want to review MOSFET driver circuits. http://www.powersystems.eetchina.com/PDF/2007JUL/PSCOL_2007JUL26_DROP_TA_101.PDF?SOURCES=DOWNLOAD

Control will depend on the topology of the MOSFETs. Why four of them?

Also, does your teacher know that 120Vac is RMS value, and that 170Vdc will be needed from the batteries?

 

4 mosfets because the ups is supposed to be a single plase and full wave. the input dc 120v connecting 10 batteries in series of 80AH , in Pakistan we have 220vac so we have to use a booster which will boost up 120 ac after inverter to 220v ac . hope u understand any way thanx for ur reply i will study the matter u have just send me and will reply u after that , tomorrow i will give u all the scematics and detailed i have studied so for....
take care.