You can swap out the internal PSU for Either a dual output dc/dc PSU OR a 24v output dc to dc converter and a 54v output boost converter. I'm making a video explaining how.
Remember this will void your warranty and Mikrotik does not support this modification. I do repairs and modifications on my youtube channel. The video Im making this week shows you how to adapt an ac switch to a dc plant. Look me up. "Ms Fixit" or thefixitgal.