LC FILTER

[Muhammad Owais]

i want to design a LC filter for 325v ................which is use as filter in inverter or the next step of H-bridge output (PWM) .............i designed by the formula but it's not working...............So what value i select for it.....????

 

[ccurtis]

That equation applies to the LC filter, alone. When the filter is connected in a circuit with other components (a source and a load), the whole circuit must be evaluated, not just the filter. So, without seeing the whole circuit and understanding how it is supposed to perform, your problem cannot be addressed.

 

[Muhammad Owais]

i used the following circuit ...................which is tag you as a pic

 

[ccurtis]

Okay, there is an H-bridge circuit that pulse switches 300 VDC to the output terminals in alternating polarity. But there is no indication as to what the load is, nor what the filter is supposed to do and how it is connected. If I assume the LC filter is series connected in series with the load to filter out harmonics of the switching frequency, one thing to watch out for is that the inductor does not become saturated. If the inductor becomes saturated, the LC filter will be ineffective.