Any advice for automatic power backup system

[kag79]

I am trying to implement the automatic power backup system .The system should transfer from utility power supply to generator when the utility power is black out and from generator to utility power automatically.I want to use PIC in this project .
Can I get any theories, circuit diagrams ,the modle of the PIC and any advice for my project.

 

[x_zoli]

Hi

the topology of the circuit is depending on what kind of backup you need. If you are using it for a computer or a device that souldn't sense any voltage drop or "switching time" between the drop of main power supply and the start of the backup system, you need a so-called "on-line" backup, like a UPS, otherwise all you need is to sense the voltage drop and start the backup generator. The second option is pretty simple, and don't need a lot of philosophy. For the first one, you may opt for a readily available device, or you may build your own. To build it, you will need a DC-DC SMPS, from the mains to a low voltage that usually is near the backup battery voltage (12V, in most cases). At this level you interface the DC-DC converter and the battery with an DC-AC converter, that must rise your voltage from the battery DC voltage to the mains AC voltage. For this, you can use the PIC and implement a sinusoidal PWM output with some feedback, to generate a sinusoidal power output.

Best Regards

 

[bimbla]

PICREF-1 and PICREF-2 on the Microchip website will give you all that you are looking for.

bimbla.