Electrical Drives History

Homework is a no-no here.

Do some research on the major drive manufacturer's and their history, many of them will lay claim to various innovations, usually building on previous work that might be referenced, keep digging back.

Early inverters

From the late nineteenth century through the middle of the twentieth century, DC-to-AC power conversion was accomplished using rotary converters or motor-generator sets (M-G sets). In the early twentieth century, vacuum tubes and gas filled tubes began to be used as switches in inverter circuits. The most widely used type of tube was the thyratron.

The origins of electromechanical inverters explain the source of the term inverter. Early AC-to-DC converters used an induction or synchronous AC motor direct-connected to a generator (dynamo) so that the generator's commutator reversed its connections at exactly the right moments to produce DC. A later development is the synchronous converter, in which the motor and generator windings are combined into one armature, with slip rings at one end and a commutator at the other and only one field frame. The result with either is AC-in, DC-out. With an M-G set, the DC can be considered to be separately generated from the AC; with a synchronous converter, in a certain sense it can be considered to be "mechanically rectified AC". Given the right auxiliary and control equipment, an M-G set or rotary converter can be "run backwards", converting DC to AC. Hence an inverter is an inverted converter.^[4][5]

That was a quick Wiki search. Now you try it.

if you are going to study drive history, you better start with DC speed control, series, shunt and compound DC motors and the control gear (equipment) that goes with them. While you're at it, check out Mercury Arc rectifiers. If you can't find anything come back to me.

Westinghouse Electric back in the early 20th century (around 1905) came up with a way to control large electric motors used on electric locomotives from a small controller in the cab. It eliminated the running of large high voltage and current cables inside the cab. This was important to prevent dangerous switching for varying engine speed. It also made possible the running of multiple unit (MU) trains with one controller.

Danfoss (Danfoss Drives) claim to have produced the first commercially available electronic AC motor drive (aka inverter), around 1964. Early drives were analog, using an RCs for the SCR gate drive timing. Drives went digital around the late 70's / early 80's. Modern drives use microprocessors / DSPs and/or MCU peripheral timers to produce the gate drive signals for IGBTs.

Jim