When organizing the control of the drive thyristor frequency converter - induction motor (TFC-AD) with sufficiently high speed, wide range of speed control and good economic indicators it is necessary on the basis of information about the coordinates of the AD state to form control actions on the frequency and voltage channels of TFC in accordance with certain algorithms.
Synthesis of a transient control system in a frequency-controlled asynchronous drive directly from equilibrium equations ...
To generate transients of an induction motor, it is necessary to measure the stator or air gap flux-coupling. The most reliable flux sensor is a measuring coil located in the air gap or stator slots ...
Asynchronous motor with squirrel cage rotor - structurally the simplest electrical machine, which has caused a fairly widespread use of this motor in the drive of mining machines. However, the dynamic modes of these machines are not sufficiently studied ...
Operational experience with drilling rigs of the SBSh and BASh types demonstrates that during operation, vibrations occur in the drill string, which are transmitted to the rig platform. These vibrations limit the permissible level of technological parameters and ultimately reduce the rig's productivity. The vibration level can be reduced by adjusting technological parameters, as well as by improving the design of the rig's rotation-feed mechanism. Vibrations of the rig's centre of mass are caused by disturbance introduced into this system by the drill string. ...
Thyristor DC regulators, or, as they are called, DC pulse converters, in control systems containing electrical machines, prove to be more convenient than adjustable thyristor rectifiers in a number of cases. The use of controlled rectifiers is often complicated by distortion of the supply voltage waveform. ...
In certain cases involving the mechanisation of maintenance and auxiliary operations related to ball mills, direct frequency converters with a limited output frequency range are employed. These operate in short-term duty modes that do not require optimal converter output voltage waveform or high precision in maintaining thyristor firing angles. On the other hand, such devices typically must meet enhanced requirements regarding noise immunity and reliability, as they are installed in industrial premises with high levels of electromagnetic interference. ...
An AC induction machine can generally be represented as a dynamic system of moving and fixed circuits...
The result of research of mine electric locomotive pumping on alternating current was the scheme with the use of power magnetic amplifiers, in which the amplifier can be controlled both by the driver and automatically - by electrical signals. The traction motors of the electric locomotive are powered from the AC contact network through a magnetic amplifier with a magnetic key with a DC output. The magnetic amplifier consists of two chokes wound on toroidal cores: one choke C is a power choke, the second choke Y is a control choke. Part of the power winding of the choke C (ax) through the valve Dy is closed to the choke Y. The output voltage of the magnetic amplifier is regulated by a variable resistance Ry, shunting the valve Dy.
Mine electric locomotive pumping by contact DC electric locomotives with rheostat control has a number of significant disadvantages. The presence of a converter substation reduces the reliability of power supply of the electric locomotive rolling. Stray currents reach a significant value in the DC system of rail transportation. Underground metal structures (cables, pipelines, etc.) located in the zone of stray currents are subjected to electrolytic corrosion ...
