Yes it is, but VERY heavy, VERY expensive, and much less efficient.Hie, I want to build a pure sinewave inverter. Most pure sinewave inverters use small ferrite core transformers at high frequencies. Is it possible to build a pure sinewave inverter using a low frequency soft iron core transformer
High frequency is much more efficient, and uses high frequency PWM to create the low frequency sinewave - a crude squarewave inverter followed by a brute force low-pass filter is going to be a great deal less efficient.What affects the efficiency, provided the square wave types employing the same types of transformer are quite efficient
Do any? - how would they possibly compete with switch-mode designs?.So what topology is used by those manufacturers who make pure sinewave inverters with heavy soft iron core transformers
I don't see why it would be significantly different compared to a linear amp.A class-D audio amplifier with a sinewave input that drives a transformer will probably not be able to use negative feedback from the output of the transformer.
How is that different from a linear audio amp?The class-D audio amplifier will already have its own negative feedback so it must be disconnected and replaced with negative feedback from the output of the transformer with compensation.
True, but that was mostly due to the difficulty of keeping the feedback negative over the full audio range.It is complicated resulting in many vacuum tube audio amplifiers not having any negative feedback from the output of their transformer.
Just a quick look at that link, it seems like that chip could be used to make a single phase VFD. What would your thoughts be on doing that?https://www.lz2gl.com/data/power-inverter-3kw/eg8010_datasheet_en.pdf Read this lot, this is how some of the commercial pure sinewave inverters work. The driver board is avalable on Ebay quite cheap, then all you need is the switching Mosfets & transformer. I agree with Nigel its cheaper to buy a ready made one.
I doubt that phase-shift is significant at 50-60Hz, where you need the feedback correction.If you add negative feedback from the transformer output of a class-D amplifier then the phase shift caused by the switching-frequency-filter must be compensated for, because you do not want to feed the switching frequency into the negative analog feedback.
Acording to the data sheet you can. I just used the board to make a replacement inverter for a generator. But it did not last very long before the switching MOSFETs were destroyed. Just gave up on that project.Just a quick look at that link, it seems like that chip could be used to make a single phase VFD. What would your thoughts be on doing that?