Waldemar or Valdemar in some language is a professor of Electrical Engineering at TH Darmstadt. He was born on June 10 1880 in Athens.
It was at Darmstadt where Petersen developed still further, then young AC technology. His involvement in the Alternating Current technology led to the invention of Petersen Coil. It is a grounding reactor, used in alternating-current power transmission systems, which is designed to limit the current flowing to ground at the location of a fault almost to zero by setting up a reactive current to ground that balances the capacitive current to ground flowing from the lines.
Aside from this, he invented a watt metric ELR, developed the W metric ELR, and developed the theory of the electric field and electric punch where he wrote the first basic textbooks on these areas.
Not is much known about Waldemar "Wayne" Petersen, except his coil. One thing's for sure though, he is a pioneer, a legend, and an Electrical Engineering Hero.