inverter efficiency

Most power losses come from to the switch used to control the current flow. Even in the "on" condition, there's some voltage drop, with a fixed loss of E X I watts. E is usually constant, so at a higher switched voltage, the overall efficiency is higher. There's a trade off between switch device voltage ratings and costs.

The way the current "switch" is controlled, digital or otherwise does not have much to do with the over-all efficiency, assuming the switches are controlled in an intelligent manner.

You can go to the manufacturers' web sites and get the figures for various types and models.

But, generally, the better approximation to a sine wave output you need, the greater the losses. Some "inverters" intended for powering equipment with smpsu, only, run at 98% efficiency - but have a dc output..

| snipped-for-privacy@ipal.net wrote: |> While looking for larger inverters, I found these: |> |>

|> |> But the efficiency is not very good, only in the 87% to 90% range. I would |> think that with today's digital techniques, much better, like 96%, would be |> possible. Can anyone reliably or authoritatively comment on what kinds of |> efficiency is really possible from the different inverter technologies, |> especially the digital ones? |> | Most power losses come from to the switch used to control the current | flow. Even in the "on" condition, there's some voltage drop, with a | fixed loss of E X I watts. E is usually constant, so at a higher | switched voltage, the overall efficiency is higher. There's a trade off | between switch device voltage ratings and costs. | | The way the current "switch" is controlled, digital or otherwise does | not have much to do with the over-all efficiency, assuming the switches | are controlled in an intelligent manner.

What about the amount of power far away from 60 Hz that is filtered out by the low pass filter?

I found another inverter at 96% efficiency. But this one has a very low fault current capability. Maybe they all do. Maybe I need to design my own.

On Wed, 08 Nov 2006 22:01:16 +0000 Palindr?me wrote: | snipped-for-privacy@ipal.net wrote: |> While looking for larger inverters, I found these: |> |>

|> |> But the efficiency is not very good, only in the 87% to 90% range. I would |> think that with today's digital techniques, much better, like 96%, would be |> possible. Can anyone reliably or authoritatively comment on what kinds of |> efficiency is really possible from the different inverter technologies, |> especially the digital ones? |> | You can go to the manufacturers' web sites and get the figures for | various types and models.

For some you can. Many have rather poor web sites and make this info hard to find.

| But, generally, the better approximation to a sine wave output you need, | the greater the losses. Some "inverters" intended for powering equipment | with smpsu, only, run at 98% efficiency - but have a dc output..

I think I need to find some inverter schematics for typical modern designs and see just what they are doing at least to compare against what I think they should be doing.