See
FAQ: How to change upper/lower case of tag fields or filenames?
and refer to to
FAQ: How to replace the string “xyz” in tag-fields or filenames?
for other replacements (e.g., Tv to TV). Make sure you have the option only as whole word enabled, for all string replacements where it should not replace a substring inside a word.
You can check this post for an action for upper-case roman numbers