Also known as: “we removed the rare earths and added software.”
The Dolivo-Dobrovolsky motor is the ancestor of all high-power induction motors, while the Tesla motor can be considered the ancestor of the single-phase induction motors that have been used (more frequently in the past than today) for several household appliances, like washing machines (or reel-to-reel magnetic tape recorders, a half of century ago).
In 1891, the three-phase induction motor was invented by Mikhail Dolivo-Dobrovolsky, combining the principles of the three-phase synchronous motor previously invented by Mikhail Dolivo-Dobrovolsky with the principle of the induction motors invented by Nikola Tesla and Galileo Ferraris.
Like any inventions, the induction motors of Nikola Tesla and Galileo Ferraris had not sprung out of nothing, but they were based on the experimental observation that had been known for many decades that if you rotate some magnets around a disk of copper, the disk will rotate, even if the magnets do not have any action on the disk when stationary.
Because of the symmetry, it is easier to generate electromechanically three-phase currents than two-phase currents where the phase difference must be precisely of one right angle.