Nikola Tesla and His Works - On the Occassion of the Eightieth Anniversary Page 10

production, transmission, and use of electrical energy. These Tesla patents include:

1. Discovery of rotating magnetic fields;
2. Discovery of multiphase alternating current systems;
3. Invention of the asynchronous motor; and
4. Solution to the problem of long-distance transmission of electrical energy for mechanical work.

The collection of these discoveries and inventions represents a unified, grand work that spans the entire electrical industry, covering all three of its main branches: production, transmission, and use of electrical energy. It should be emphasized here that Tesla not only discovered the rotating field and invented the asynchronous motor, but, in addition, he was the first to build multiphase generators, multiphase transformers, discovered multiphase systems of alternating currents, and, based on all of this, created a new system for long-distance transmission of electrical energy for mechanical work. Tesla completely and at once resolved this great and complex work, leaving nothing for others to do, and if any work could ever be called genius, it is Tesla’s work.

In the jubilee issue of the prominent journal Electrical Engineering [3] in the May 1932 volume, the development of electrotechnics for the last 50 years was outlined, and on that occasion, full recognition was given to Nikola Tesla for this work with the following words: “At a time when there was commercial rivalry between direct current and alternating current systems, Nikola Tesla independently discovered the polyphase system of alternating currents and built the first small polyphase motor, thus opening a new era in the electrical industry.”

All the above Tesla patents were purchased, in early 1888, by the Westinghouse company (Westinghouse Electric and Manufacturing Company). At its request, Tesla during 1888 and

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energy no. 382 281; finally on December 23, 1887, 2 patents: Method of converting and distributing electric currents no. 381 970 and 382 282. He received protection for all seven above-mentioned patents, of which 2 patents (no. 381 969 and 382 281) refer to the polyphase synchronous motor, on May 1, 1881.

During 1888 and several following years, Tesla filed 34 more patents in this field. Among them, two are particularly significant: The System of Electrical Distribution, No. 390 413, filed on April 10, 1888, and issued on October 2, 1888, and Dynamo-Electric Machine, No. 390 414, filed on April 23, 1888, and issued on October 2, 1888. In the first one, Tesla proves that, for a polyphase system, the order of the number of line conductors can be reduced without any difficulty from 2p to (p + 1); in the second, he describes how a direct current generator can be easily converted into a polyphase generator and explains the principle of the commutator and polyphase generator; in this same patent, he indicates a star coupling of three-phase electromotive forces with a line of only 3-phase conductors.