Thing requires more power than your 3000 watt step-up converter can provide.
Ideally appliance should not require more than 1/2 to 1/4 of the operating power of the transformer. Indeed the later should be sized about twice the rated power load for the appliance. In you case that means something along the lines of 8Kw. Transformers over 5Kw really ought to be hardwired as that is too much power for any outlet, at least those in North America to provide.
Appliances with motors such as washing machines, air conditioners, fridges, and so forth also require a heavy load of power to start those motors. IIRC this is the reason one's lights sometimes dim when such appliances kick in.
Adding the above to your situation, you would need a transformer probably around the 10Kw range.
It is a very good thing the transformer is blowing fuses. Better it goes than your house!
Know it is hard without the knobs and such, but try to see if you can run a cycle without engaging the heaters, that should take a huge load off the electrical demand.