I'm interested to know, too. Every time I bump into needing an IEEE spec, it's big money. When I was in college, I was a student member, and could get the specs for free. Many of them are in college libraries, if you have a good university nearby that you can sneak into the library.
Try a manufacturers rep that has an interest in that standard.
For example, 1547 has to do with protection for paralleling engines, so check with Basler, SEL, Multilin, Woodward, Beckwith, etc.
We have a IEEE membership that allows us to download standards, I think it cost $1525.00 a year. IMO not worth it, as I may download maybe $200.00-$500.00 worth a year. You can also purchase on an as needed basis online.