Generators are usually composed of parts such as stator, rotor, end cap and bearing. The stator is composed of the stator core, the wire winding, the base, and the other structural parts that are fixed. The rotor consists of a rotor core (or magnetic pole, a choke) winding, a retaining ring, a central ring, a sliding ring, a fan and a hinge.
By the bearings and end caps the stator, the rotor connection assembled, so that the rotor can rotate in the stator, do cutting the movement of magnetic field lines, resulting in inductive potential, through the wiring terminal leads, and then in the loop, then produced an electric current.
for turbo-generator and turbine In order to obtain higher efficiency, the turbine is generally made of high-speed, usually 1500 rpm/sub (frequency of 50 khz) or 1800 RPM/sub (frequency of 60 khz). The turbine speed of the nuclear power plant is low, but also in 1500 rpm/Sub. In order to reduce the mechanical stress caused by centrifugal force and reduce wind friction, the rotor diameter is generally smaller, the length is larger, that is, the slender rotor is used.
Especially in 3000 rpm/sub high-capacity high-speed unit, due to the relationship of material strength, the rotor diameter is strictly limited, generally cannot exceed 1.2 meters. The length of the rotor body is constrained by the critical speed. When the body length reaches 6 times times the diameter, the second critical speed of the rotor will be close to the speed of the motor, and the larger vibrations may occur in the operation. So the size of large high-speed turbo-generator rotor is strictly limited.
0-kilowatt% of the air cooled motor rotor size has reached the above limit size, to increase the motor capacity, only by increasing the electromagnetic load of the motor to achieve. Therefore, the cooling of the motor must be strengthened. Therefore, the turbine generators with more than 5~10 10,000 kw are using hydrogen cooled or water-cooled technology with better cooling effect. Since the 70 's, the maximum capacity of turbo generators has reached 130~150 10,000 kw. Since 1986, a major breakthrough has been made in the research of HTS materials with high critical temperatures. Superconducting technology is expected to be used in turbo-generators, which will produce a new leap in the development of turbo-generators.
A motor that converts mechanical energy into electrical energy. Usually driven by steam turbines, turbines or internal combustion engines. Small generators are also useful for windmills or other machines driven by gears or belts.
Generators are divided into two main types of DC generators and AC generators. The latter can be divided into synchronous generators and asynchronous generators two kinds. The most common use of modern power stations is synchronous generators. This generator is characterized by DC current excitation, both to provide active power, but also to provide reactive powers to meet the needs of various loads. Because there is no independent excitation winding, the asynchronous generator is simple in structure, easy to operate, but does not provide power to the load, but also needs to absorb the hysteresis magnetizing current from the network.
Therefore, the asynchronous generator must run in parallel with other synchronous motors, or a considerable number of capacitors. This restricts the application range of asynchronous generators, which can only be used in small automation. Urban tram, electrolytic, electrochemical and other industries used DC power supply, in in the 1950 of the 20th century before the use of more DC generators. But DC generators have commutator, complex structure, manufacturing time-consuming, more expensive, and easy to malfunction, maintenance difficulties, efficiency is not better than AC generators. Since the advent of high-power controllable rectifier, the use of AC power supply through the semiconductor rectifier to obtain DC power to replace DC generators trend.