Full-Bridge Inverter

dc-acfull-bridgeh-bridgeinverter

enter image description hereenter image description hereCircuit Setup with connection of power supply to circuit and drivers, line 48 is where output voltage is being measured.All four IGBT have their own drivers with setting shown for one.

I'm building a Full-bridge inverter with input of up to 36V, Four IGBT are used for switching and embed micro controller for PWM. To drive IGBT I'm using four HCPL-3120 chips. After testing the circuit, I'm having an issue of very low output voltage somewhere around 1V irrespective of input voltage however I got something close to a sine wave. Also I want to know if it is necessary for opto-couplers to have isolated supplies.

Best Answer

Here's the data sheet for the driver and here's a typical circuit used to drive IGBTs: -

enter image description here

You should be able to see where you have gone wrong - you haven't coupled pin 5 to the emitter of IGBT1. Step and repeat for the other devices.

Also i wanted to know is it necessary for optocouplers to have isolated supply.

Absolutely!