What’s the most efficient DC to AC inverter topology?

[kender]

most efficient inverter

Colleagues,

What’s the most efficient topology for a 12Vdc to 110Vac@50Hz inverter rated for a few kW? So far, the best one I could think of was a Class D amplifier with a “sound” frequency set to 50Hz and switching frequency set to about 1kHz.

If anyone knows a good overview article or a book on inverter topologies, I’d really appreciate if you could post a reference.

Thanks and happy new year of 2009!

- Nick

 

[eem2am]

the most efficient topology for dc-ac inverters

well i think it is a resonant one

 

[FvM]

which inverter is the most efficent

A few kW means a few 100 A unfortunately.

For this reason you should try to achieve constant input current which involves an energy storage. It could be more effectively handled a the high DC bus voltage. So basically you get a 12 to 160 V DC/DC converter and full bridge PWM DC/AC output stage.

For DC/DC, the said resonant converter is an option for lower loses. But you most likely won't easily find suitable capacitors for a resonant circuit at the 12V level, it must be shifted to the secondary. If no bidirectional energy flow is involved, a usual push-pull two-switch power stage with a center-tapped transformer at the primary side is still most simple.

 

[Mr.Cool]

the most efficient topology

first you must boost your 12V input to 300V. what is the efficienty of this... maybe 98% if you're lucky.

then you must use an inverter to go from 300Vdc to 110Vac. with a hard-switched (basic) topology you can expect the efficiency of around 92% to 94%. this is for rated current. if your load drops or is variable, so too is your efficiency. at very light loads, you can expect an efficiency of 80%.

you can improve the situation with design complexity.

Mr.Cool