hey guys. I'm working on a project, a sine-wave inverter for powering home appliances. Its mostly just to learn from, if i wanted something reliable and easy i would just buy one. My setup is a boost converter converting 12 Vdc to 170Vdc. this feeds a small capacitor bank of around 900 or so microfarads. this feeds into a mitsubishi PS11036 IPM (6 igbt's with drives in an integrated device). im using some simple code to feed a sine wave pwm into it. two igbt's one one pwm, two igbt's on the other. this forms an h-bridge where an increase in one creates 170vdc, and an increase in the other creates -170vdc. the trouble I'm having is filtering out high frequency noise from the output, and im also having alot of signal distortion when running resistive loads (40 watt light bulb) and inductive loads (36 watt shaded pole motor fan). These are the oscilloscope traces taken from a 9 volt ac step down transformer (i dont have any good probes). https://picasaweb.google.com/118171524369413679019/SineWaveInverter?feat=directlink#
you can see that the wave is severely distorted and there is much high frequency noise. I've read that a combination of inductors and capacitors can filter out this kind of noise, but i would like to hear the opinion of someone who has worked with this kind of filtering before. Thanks-Andres