Synchronous Generator

synchronous generator

[′siŋ·krə·nəs ′jen·ə‚rād·ər]
(electricity)
A machine that generates an alternating voltage when its armature or field is rotated by a motor, an engine, or other means.The output frequency is exactly proportional to the speed at which the generator is driven.

Synchronous Generator

 

a synchronous machine that operates as a generator. Synchronous generators are usually employed as sources of alternating current of a constant frequency. They are used, for example, in power stations, electrical installations, and transportation systems. Synchronous generators came into use in the 1870’s when P. N. Jablochkov (Iablochkov) invented the arc lamp known as the Jablochkov candle.

Synchronous generators are most often used to produce commercial-frequency current. The rotors of such machines are driven by steam or water turbines. Synchronous generators are also built that are driven by gas turbines, internal-combustion engines, wind engines, and electric motors.

The rotor windings of a synchronous generator are supplied with direct current from rectifying equipment or from a separate generator (seeELECTRICAL MACHINE EXCITER), which is usually mounted on the same shaft as the synchronous generator. When the rotor turns, its magnetic field induces an alternating electromotive force (emf) in the three-phase winding of the stator. The frequency of this emf is f = pn, where P is the number of pole pairs and n is the rotational speed of the rotor. Highspeed synchronous generators (steam- and gas-turbine generators) have a small number of pole pairs: p = 1 or 2. Low-speed generators (water-turbine generators) may have several tens of pole pairs. The magnitude of the emf is regulated by varying the current in the rotor winding.

In some low-power synchronous generators, the AC winding is placed on the rotor, and the field winding on the stator. A special group is formed by generators that are provided with a large number of pole pairs in order to obtain higher-frequency currents (seeELECTROMECHANICAL MEDIUM-FREQUENCY GENERATOR).

References in periodicals archive ?
Supply of a kaplan turbine (steel spiral) of about 4 mw / 1.6 m in diameter, a 4.5 mva / 428.6 rpm three-phase synchronous generator, a butterfly valve (dn 2200) and a control system.
Synchronous generator is a widely used wind turbine generator across the globe.
Permanent magnet synchronous generator (PMSG) has started widely used according to other generator types due to its superior characteristics, such as a low wind speed and the highest power-to-weight ratio in a direct drive [3], [4].
Developed over the course of two decades by Ingersoll Rand before being acquired by FlexEnergy in 2010, Flex turbine technology features a highly robust synchronous generator for larger gas turbines.
The goal of the paper is obtaining by the results of mathematical modeling of optimal parameters of the synchronous generator, which is part of the system of electromechanical transformation of the energy of mechanical vibrations of the vehicle chassis.
Based on these assumptions and design constraints; main design parameters of the low speed, direct-drive, PM synchronous generator is given as shown in Table I.
On the other hand, in modern wind power systems, three of the most promising types of wind turbine generators are the Doubly Fed Induction Generator (DFIG), the Direct Drive Synchronous Generator (DDSG) with permanent magnet, and the Squirrel Cage Induction Generator (SCIG) [5-12].
Various investigations on wind turbine generators have shown that permanent magnet synchronous generator (PMSG) has many advantages compared to other kinds of electrical machines [6,7] and therefore becomes an attractive choice for variable speed wind turbines.
The station which has been in continuous operation since 1962 is part of the Great Glen Hydro Group and the power plant comprises a Kaplan turbine driving a 3300V, 40pole, 150rpm AC synchronous generator.
Synchronous generator equipped with a gear is used for the variable speed applications [1].
One of the paper pillars is the introduction of a sliding mode controller for the exciter, controlling the rotor field of the synchronous generator and indirectly the DC bus voltage.
The synchronous generator model considered is rated 200 kW.

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