Brief performance history of electric drive development

The course THEORY OF ED

Function of automatic control system

- automatization of starting control;

- automatization of braking and reverse control;

- automatization of coordinate regulation;

- automatization of maintenance of coordinates stability (speed, moment, power efficiency);

- automatization of monitoring;

- automatization of operation cycle.

The course THEORY OF ED comprises 3 parts.

The 1^st part. It is general theory of ED, that studies general physical regularities, that are typical for different technical realization of any ED designation, has general methods and recommendations, using when designing, checkout and operation of ED.

The 2^nd part. Involves theory of ED individual systems differed by technical realization, for example:

- theory of thyristor ED;

- theory of Ed valve frequency;

- theory of discrete ED and others.

The 3^rd part. Theoretical questions concerning the ED application in definite industrial installation, for example:

- rolling mills;

- metal cutting lathes;

- load-lifting cranes;

- excavators and other.

This theory is based on specific requirements for typical production installations.

The course proposed to your attention is mainly about the 1^st part of ED;2^nd and 3^rd parts are used if required.

The factors that limited the expansion of ED in XIX century were the absence of first of all reliable power suppliers, particularly its non-efficiency (virtually the least power supply by that time were the galvanic cells). The second factor was the imperfection of electric motors.

The event that assisted the introduction of Ed was the creation of industrial type of economic power source that is electromechanical generator. At the same period the electric motor of the same designing (particularly with self-excitation) were being created.

The next drag of further ED expansion became the problems of transmission and distribution of DC systems existing by that time, all mentioned above electrical machines were the DC machines. For a long time the direct current was used mainly for lighting.

The appearance of one-phase alternative current played a significant role in development of electricity in whole, but practically nothing had been changed in Ed (absence of initial starting moment in electromechanical systems with one-phase power supply).

The development in 80^th years of XIX century of rotating magnetic field put forth the creation of multiphase electromechanical systems.

The most economical, simple and reliable was the system of 3-phase currents basis for which were developed in 1889 - 1890 by Dolivo-Dobrovolsky. System of three-phase current became that new technical mean, with the help of which the whole complex of production problems, transmission, distribution and consuming of energy was solved. The development of three-phase system was stipulated the prerequisites for development of electrification of any country, irrespectively of particulars of its territory.

The creation of asynchronous motor with short-circuited and phase rotors by M.O. Dolivo-Dobrovolsky opens the road to further perfection of ED, industrial using of electricity.

The first three-phase industrial installations in Russian empire were installations in city of Shepetivka (Ukraine) in 1893.

The appearance of direct current ED in Empire industry falls at the same time.

On Morozov weaving-mills (famous by that time as capitalist-manufacturer and supporter) the EDs on a base of direct current motors were already work in 1896. The first electric tram in Empire appeared in Kyiv, then in Kotel, Nijni Novgorod, Moscow, Petersburg, Odessa.

Distinctive electric motor advantages comparatively with mechanical sources of mechanical energy allowed it to became the first in all manufacturer areas.

Pe – total power of all mounting electric motors;

P – total power of all types of installed motors.

Дата добавления: 2014-01-05