According to writer /artist Tony Isabella, DC didn’t want to pay him part of their cut from their licensing characters for the SUPER FRIENDS animated series. Hanna Barbara didn’t want to pay him for the right to use of Black Lightning so they created Black Vulcan to fill in that vacant spot and DC let them do it.
In response, Isabella wrote the last story of Black Lightning called “The Other Black Lightning” where a villain called Barbara Hanna used a Black Lightning impostor as part of her crime syndicate. DC published the story and Isabella has said in an interview “I don’t think they realized what I was doing there.”
Regardless of his origin, Black Vulcan still holds a place in the minds of SUPER FRIENDS fans... read Marc Tyler Nobleman's interview with the voice of Black Vulcan, Buster Jones.