Electric Machine


Also found in: Dictionary, Wikipedia.

Electric Machine

 

a machine that converts mechanical energy into electric energy, converts electric energy into mechanical energy, or transforms electric energy by changing the type of current or by altering such parameters as voltage and frequency. The operation of electric machines is based on electromagnetic induction and the laws governing the interaction of electric currents and magnetic fields.

Electric generators convert mechanical energy into electric energy, whereas electric motors convert electric energy into mechanical. In accordance with Lenz’s law, generators and motors are reversible—that is, can operate both as a generator and as a motor. Commercially produced electric machines, however, are usually intended for specific duty (seeALTERNATING-CURRENT MACHINE; DIRECT-CURRENT MACHINE; ASYNCHRONOUS ELECTRIC MACHINE; SYNCHRONOUS MACHINE; and COMMUTATOR MACHINE).

The conversion of current, frequency, number of phases, and voltage is achieved with rotary amplifiers, transformers, and rotary converters (seeCONVERSION TECHNOLOGY).

Electric machines also include special-purpose machines, such as magnetos, welding generators, tachometer generators, and traction motors.

Table 1. Characteristics of the electric locomotives most commonly used in the USSR (1977)
SeriesCurrent SystemType of serviceNumber of wheel pairsWeight (tons)Power rating of motors1 (kW)Tractive effort (tons)Maximum speed2 (km/hr)
11-hr rating, as determined by, for example, motor design and cooling conditions
2Maximum speed in service, as determined by locomotive design
VL80K, VL80T, VL80R ...............25-kV single-phase AC at 50 HzFreight81846,52045.1110
VL60K ...............sameFreight61384,45031.8100
ChS4T ...............samePassenger61265,10017.4160
ChS4 ...............samePassenger61265,10017.4160
VL10 ...............3-kV DCFreight81845,20039.5100
VL8 ...............3-kV DCFreight81804,20035.2100
VL22M ...............3-kV DCFreight61322,40023.975
ChS2T ...............3-kV DCPassenger61264,62019.4160
ChS2 ...............3-kV DCPassenger61234,20016.5160

REFERENCES

Kostenko, M. P., and L. M. Piotrovskii. Elektricheskie mashiny, 3rd ed., part 2. Leningrad, 1973.
Vol’dek, A. I. Elektricheskie mashiny, 2nd ed. Leningrad, 1974.

M. D. NAKHODKIN

References in periodicals archive ?
Offers Nadem line of hybrid electric machines with hydromechanical clamp, as well as MC line of horizontal fully hydraulic machines.
The influences of the current and voltage constraints in the torque-versus-speed profile of electric machines operated with an electric drive
Using a conventional distributed stator winding, the Ricardo synchronous reluctance electric machine is a highly innovative design that makes use of low-cost materials, simple manufacturing processes and uncomplicated construction.
In June 2011, CD-adapco acquired the electric machine software, SPEED.
With this product, Magsoft expands its highly technical suite of numerical tools and opens new horizons for its electric machine customers.
This machine technology has direct applicability to both military and civilian hybrid electric vehicle applications as an ISG and/or traction motor, and represents a technology advancement compared to the Toyota Prius electric machine technology.
The electric machine course alone costs $3500 ($2599 for owners of the PIM course until July 30.
Battenfeld's other electric machine, the Microsystem 50, is also being redesigned but the new machine will not be ready for Fakuma and is to be unveiled at the Hanover Fair in April next year.
Assigned: Hakko Electric Machine Works and Kazuyuki Shimomura
The electric machine leads to a further cut in energy consumption because it does not have any oil reserves for cooling; moreover, the machine's use of water is reduced by as much as 70%, says Toshiba.
The firm added a specially designed screw with a precise backflow valve, a special barrel and its accurate temperature control module to ensure the exact heating of the mold to its electric machine and created the EC-LSM.
The company has also added closed-loop feed control, only possible with the e-motion LIM electric machine.