inverter transformer with integrated resonant inductor

Look up patents on the Sola regulaing transformer aks ferroresonant transformer.

Sounds like the Baxandall class D oscillator. Jim Williams of Linear Technology has written a series of application notes on the circuit (though he doesn't credit it to Baxandall).

I've got a couple of pages of discussion of the circuit on my web- site, including a couple of literature references

-- Bill Sloman, Nijmegen

i am not referring to ferro's. inverter transformer for 3 level pwm inverter with two parallel magnetic paths and only one winding surrounding both cores

thanks for the info but i am afraid i am referring to something different

Also, search for 'Paraformer' or 'Parametric Transformer'.

RL

thanks, but this is not paraformer

Ams

If you say so.

Inverters don't inherently need transformers, never mind ones 'with integrated resonant inductor'. If the silicon can manage the environment, you'd be better off avoiding one.

A three-phase inverter is probably the last place you'd find one used.

RL

[snip] [snip]

Gawd! You sound like a marketing cretin. Without energy storage elements your "environment" will be substantially dissipative.

...Jim Thompson

-- | James E.Thompson, P.E. | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona Voice:(480)460-2350 | | | E-mail Address at Website Fax:(480)460-2142 | Brass Rat | |

| 1962 | America: Land of the Free, Because of the Brave

As you said it is possible to design invertors(3 or 1 phase) without transformer,the stuff i am talking about is a old technique,the tfr plus choke isolates the power switches and also functions to filter the hf carrier wave in pwm

shef

A transformer is not normally an energy storage medium. The intention of an electronic inverter is to transform energy to suit the load. If this is done without using pounds of steel and copper (of an isolating or autotransformer), even if discrete inductive elements are used, there are distinct advantages.

RL

Sounds like an old Exide UPS system. About 5 Watts per pound, not including the batteries.

RL

Ever heard of a flyback power supply? I'd say there's a very "normal" application of a transformer used as an energy storage medium.

Transformers store energy in their magnetizing inductance whether you like it or not. Granted, a regular "AC" transformer just stores it and gives (most) of it back on every cycle. However, the energy storage in a transformer is a significant parameter when it comes to their design.

Without knowing more about the design parameters, you can't claim that a transformer-based design would necessarily use more "pounds of steel and copper" than a non-transformer-based design.

---Joel

'Inverters don't inherently need transformers, never mind ones 'with integrated resonant inductor'. If the silicon can manage the environment, you'd be better off avoiding one.'

The OP indicates the application is a 3ph inverter, using the same transformer for LF coupling and for the HF filter element, similar, it seems to those employed in stationary applications, or mounted on large wheeled trolleys in the 70's and 80's by Exide and others for UPS installations.

One of the few assumptions that CAN be made about this low frequency application is that an electronic version using only HF storage elements will weigh less, simply because the LF coupling magnetics are not used.

RL