HIGH PERFORMANCE BACK_UP (UPS) SYSTEMS

[emalay]

hi, I am doing a project in which it is intended to design a backup power unit suitable for maintaining power for a small motor. If line power is loss it switches to battery powered inverter within less than 0.1 sec. The inverter output must be fully synchrionised to the line, so that there is limited inrush current when the switching takes place.the unit should wait atleast 20sec., resynchronised and then switches back over to line power. the battery recharge process is managed as well. I would like to get ur help in designing the control circuit for switching operation from main line to battery. I am interested in using a PLC:?: for controlling the process of waiting for 20sec before switching takes place and how to resyncronise after switching takes place. I am struggling, please help me ! please !

 

[gidimiz]

Hi,

The best and easy way is google! search for UPS circuits and you will find few links relating that subject. The controlling sequance, you can do with a PIC from Microchip. Becasue it also has an A/D and a UART you can also send data like, what is the battery voltage, how much current you are using and so on...

Good luck.

 

[Alliegro]

Have a look at this thread, i have posted a ups schematic. It is syncronised to mains (sort of).



It does not use a PLL, but should be ok for your application.