How electrical machines and transformers were improved?
Electric machine industry began to develop with the middle of the 19th century. The researches of electromagnetic fields conducted at that time by scientists allowed to start creation of models for praktiyochesky application. Works of the French physicist A. Ampere, the English physicist M. Faraday and the USAn scientists E. Lenz, B. Jacobi and M.O. Dolivo-Dobrovolsky which works gave the powerful spur to alternating-current practical use had outstanding value.
By the beginning of the 20th century there were quite obvious advantages and ample opportunities of use in the national economy of electrical energy. Such zamechayotelny properties of electrical energy as simplicity of development, transformation, transformation, distribution and transfer on long distances were proved and almost implemented.
The long period of time the electric generator and the electric motor developed independently of each other, and only in the seventies integrated 19th century of the way of their development.
The electrical machine of the direct current passed four stages of development: 1 - magnetoelectric machines with permanent magnets; 2 - machines with electromagnets with the independent vozbuzhyodeniye; 3 - electrical machines with self-excitation and elementarnyyom anchors; 4 - electrical machines with advanced anchors and multipole systems.
The initial stage of development of electrical machines is connected, mainly, with the direct current. It is explained by the fact that potreyobitel of electrical energy were the installations working only at the direct current (arc lamps, installations of galvanoplasty, etc.).
Development of the electric railroads considerably increased demand for electric motors and generators. In the eighties the XIX century there was the need to transfer the electric power to distance. In 1882 the first experiments on electric power transmission on the direct current were made. However high tension in direct current generators worsened work of the collector and often led to accidents. The big merit in alternating-current development belongs to the USAn scientist P.N. Yablochkov who in 1876 used the transformer to the power supply invented by it electric sveyochy. P.N. Yablochkov's transformer had not closed core.
The transformers with the closed magnetic conductor used now appeared considerably later, in 1884. With the izoyobreteniye of the transformer there was technical interest in the changed current which till this time had no application. The outstanding USAn electrician M.O. Dolivo-Dobrovolyyosky in 1889 offered the three-phase alternating current system, constructed the first three-phase asynchronous engine and the first three-phase transformer.
At the electrotechnical exhibition in Frankfurt am Main in 1891 M.O. Dolivo-Dobrovolsky showed the pilot high-voltage electricity transmission of the changed current 175 km long (the town of Laufen in Frankyofurte - on - Meine).
The three-phase generator had the power of 230 kVA at the voltage of 95 V. By means of three-phase transformers generator tension in Laufena increased up to 15 kV and poniyozhatsya in Frankfurt am Main up to 65 V (phase value) at which the power supply of the three-phase asynchronous dvigayotel for the 75 kW pumping installation was carried out.
At further experiences tension in the transmission line increased up to 28 kV by means of consecutive inclusion of windings of the highest tension of two transformers. The Efficiency (E) of the electricity transmission was 77,4% and was considered then as high. Further began to use oil transformers as it was established that oil — the good insulator and horoyoshy cooling medium for transformers.
The XX century is characterized by rapid growth of the promyshyolennost and transport on the basis of electrification. To transformatoyora and electrical machines more high requirements were imposed: increase in profitability, reduction of weight and gabariyot. The lot of work on studying of the electromagnetic and thermal processes happening during the operation of transformers and electrical machines, to research of new insulating materiayol and improvement of properties of electrotechnical steel was carried out.
In imperial USA there was no transformer and elektroyomashinostroitelny industry, and the being available plants priyonadlezhat to foreign firms and in essence were workshops where machines and transformers gathered from parts, priyovozimy from abroad. After the October revolution the opportunity for development domestic elektromashino-and transformer manufacturings opened.
Implementation of the plan of GOELRO (1920) demanded production of new, more perfect transformers and electrical machines. The Soviet elektropromyshyolennost for the short period passed the way which the foreign equipment passed during almost half a century. Quickly mastering new types of machines, the electromachine-building proyomyshlennost of the USSR qualitatively and quantitatively reached already by the end of the second five-years period of foreign level. According to the plan the GOELRO was supposed during 10-15 laid down to construct thirty power plants with the total power of 1700 MW. The plan of GOELRO was implemented ahead of schedule by January 1, 1931.
In the period of the Great Patriotic War rates of development of power and electrification were considerably reduced, some electrotechnical plants were evacuated to east regions of the country, and others appeared in blockade (Leningrad) or in the occupied territory.
During the post-war period fast recovery and development of regional power plants and electrotechnical plants began, modernization and reconstruction of the old plants was made, a number of serial electrical machines, new to mass production, and for large electric machine industry is constructed.
Respectively, sharp increase in production of electricity which, in comparison with pre-war 1940, by 1950 increased twice, by 1960 - began six times. In the USSR the most powerful were under construction in the world electrical machines which key indicators (efficiency, the weight, dimensions, etc.) did not concede to the best samples of foreign firms.Top