The method of turning 24VDC to 24VAC 50Hz and then using a transformer to get 110VAC 50Hz or whatever is only used on old designs as there are weight,cost, efficiency and heat problems.
Transformers are much more efficient at converting voltages with high frequency square waves so as transformers are expensive and electronics cheap.
The usual method these days is to go 24VDC to 24VAC 20+KHZ to +-160VDC to 110VAC 50Hz the actual high VDC levels varying with the requirement and there can be several to get a waveform closer to a sine wave.
As an example of the advantages of doing it this way is the PC power supply. A 50Hz transformer for the sort of current required would be roughly the size of a desktop and most of that would be iron and copper. It also wouldn't retail for USD20 including the case.