[foruhar]

Tesla was the real power grid guy. The scope of his invention from the generators at Niagara Falls power generation to the transformers to the motors is pretty impressive. More so given that he was eventually given the patents (originally issued to Marconi) for radio transmission.

[yummypaint]

The fact that Edison is pervasively over-credited is really another example of the highly visible executive claiming personal credit for the labors of employees.

[MisterTea]

Two others who come to mind are https://en.wikipedia.org/wiki/Charles_Proteus_Steinmetz and https://en.wikipedia.org/wiki/Charles_F._Scott_(engineer)

Steinmetz contributed heavily to AC systems theory which helped understand and expand transmission. while Scott contributed a lot to transformer theory and design (I have to find his Transformer book.)