Load vs Line Commutated Inverters

[bikeman1]

Hi All,

I understand that to operate a load commutated inverter it must be connected to a device supplying a leading power factor - either an overexcited synchronous motor or an induction motor with shunt capacitors connected.

I cant however understand why the line side of the converter(when operating in regeneration mode as an inverter) does not need a leading power factor to self commutate. As far as i understand the input power factor = cos (firing angle) - which i understand, however wouldnt this mean that for any line or load commutated inverter with firing angle between 90 and 180 degrees would be at a leading power factor? Can someone please explain to me why this is?

I cant seem to get my head around the concept despite reading everything i can get my hands on

Thanks

 

[cuky2000]

You probably have a better chance to get an answer if you post this question in a Power Electronic Forum.


See if the enclosed fire angle simulator could help to visualize the operation of the converter(when operating in regeneration mode as an inverter)