"Current" Affairs : Question for Sun, Dec 5

The rivalry between X & Y over the use of DC or AC as the primary form of distribution of Electric Power came to be known as the "War of Currents". DC was the standard in the USA and X who was a famed inventor of the time, whose various patents worked with DC, promoted DC. Y threw his hat in the ring after partnering with the Austrian born Z aka the Wizard of the West to commercialize Z's work in generating and transmitting AC. Fierce campaigning by both parties followed to set the new standard, with X promoting the hazardous effects of AC by publically electrocuting stray dogs and cats and even horses. X even went on to invent the first Electric Chair which worked with AC. Finally Y's successful bid for the construction of the Niagara Falls power plant sealed the fate in favor of AC. However the companies they both started to distribute Electric Current still survive today.

Identify X & Y.