Mikhail Osipovich Dolivo-Dobrovolsky (Russian: ?????´? ?´??????? ????´??-???????´??????; German: Michail von Dolivo-Dobrowolsky or Michail Ossipowitsch Doliwo-Dobrowolski; Polish: Michal Doliwo-Dobrowolski; 2 January [O.S.
21 December 1861] 1862 – 15 November [O.S.
3 November] 1919) was a Russian engineer, electrician, and inventor.
As one of the founders (the others were Nikola Tesla, Galileo Ferraris and Jonas Wenström) of polyphase electrical systems, he developed the three-phase electrical generator and a three-phase electrical motor (1888) and studied star and delta connections.
The triumph of the three-phase system was displayed in Europe at the International Electro-Technical Exhibition of 1891, where Dolivo-Dobrovolsky used this system to transmit electric power at the distance of 176 km with 75% efficiency.
In 1891 he also created a three-phase transformer and short-circuited (squirrel-cage) induction motor.
He designed the world's first three-phase hydroelectric power plant in 1891.