1W Boost


2004-08-04 8:42 pm
I am evaluating some solutions to have a step-up for a 1kW three phase inverter.
I have an input mains voltage of 165-265Vrms and I need a "stabilizied" at least 300Vdc for the inverter or better I could accept the low frequency ripple voltage of a simple bridge but I need at least to increase of 100V when I am at 165Vrms.
I prefer to have higher efficiency than better regulated output.
I do not need a PFC controll so I can have a direct feedback from the optput voltage.
At the moment there are two solutions in my mind:

-Low frequency Boost
a simple boost where the switching frequency could be not higher that 1kHz and the switch is driven for short time only some times before the normal charging of the bridge to have the requested 100V increase; the feedback is realized with the DSP used for the inverter, having a sensing of the ouput voltage and perhaps a sensing of the switch current.

-High frequency Boost with ZVT
I see that for this power many projects use the ZVT method in order to reduce the switching power dissipation allowing use of high frequency like e.g. 100kHz. This solution allow to have higher efficiency, better regulated output a small magnetic component but I need to pay attention of frequency ripple voltage that can disturb the current sense of the inverter.

Anyone have suggestions? Are there other interesting solutions?
Thank to anyone can help me, i do not want ready solutions but only some suggestions and possibilities to discuss about.