I'm going down the ferrite route because I know the losses at the switching PWM frequency are going to be better and I've done this before on similar jobs. I have no idea if I'll stumble upon a core that is suitable for the OP's requirements but, the process is going to be the same whether it is a ferrite, iron or powder core. I'm going to make a semi-educated guess at a suitable ferrite material (and core shape) to see how it pans out. If you need some reference values: RMS output voltage is 230V at 50Hz and RMS output current can be in the order of 10A-20A.įeel free to ask for clarifications if needed. I mean, in nowadays with solar inverters for instance, I don't think they are using laminated steel for the output inductor because the whole inverter seems to be quite small. I know laminated steel works because I used it for a project but I was just wondering if there are alternatives to it. Therefore which materials could be used for the output inductor of a PWM inverter (50Hz fundamental-wave current plus some high frequency ripple) and how to use them?

Laminated steel -> Works but its very bulky, pricey and heavy.

Tape wound cores -> May work (NiFe cores) but still cannot find any application notes on how to design/wind your inductor at 50Hz.

Probably just used for common mode chokes or the likes. Sometimes in the application notes they say 'line filter' but I'm not sure that means they support a very high current before going into saturation.

Powder cores -> Still trying to understand them.

I've been struggling for a very long time to find a reference book or paper to explain how to design a PWM inverter output inductor but couldn't find any. The high frequency allows for smaller magnetic cores and for these applications there is a huge amount of application notes. In DC/DC converters applications you have a mostly DC component plus some 10kHz-500kHz current ripple. I'm talking about how you could (and if) wind your own inductor like you do for DC/DC converters (buck, boost. I don't mean how you compute its value in uH/mH nor its current rating in A. Given a SMPS PWM inverter (for example an UPS) supplying voltage/current at 50/60Hz, how do you design an output inductor?

Ferrite core inductor calculator