Search results
Results from the WOW.Com Content Network
Small variable-frequency drive Chassis of above VFD (cover removed). A variable-frequency drive (VFD, or adjustable-frequency drive, adjustable-speed drive, variable-speed drive, AC drive, micro drive, inverter drive, variable voltage variable frequency drive, or drive) is a type of AC motor drive (system incorporating a motor) that controls speed and torque by varying the frequency of the ...
In vector control, an AC induction or synchronous motor is controlled under all operating conditions like a separately excited DC motor. [21] That is, the AC motor behaves like a DC motor in which the field flux linkage and armature flux linkage created by the respective field and armature (or torque component) currents are orthogonally aligned such that, when torque is controlled, the field ...
A variable frequency drive (VFD) or variable speed drive (VSD) describes the electronic portion of the system that controls the speed of the motor. More generally, the term drive, describes equipment used to control the speed of machinery. Many industrial processes such as assembly lines must operate at different speeds for different products.
Thus it is not possible to control the motor if the output frequency of the variable frequency drive is zero. However, by careful design of the control system it is possible to have the minimum frequency in the range 0.5 Hz to 1 Hz that is enough to make possible to start an induction motor with full torque from a standstill situation.
A control strategy for variable frequency drives that models the magnetic field of the motor to control its torque. filter A circuit that selectively alters a signal based on its frequency components. filter capacitor In a power supply, a capacitor that smooths the DC voltage produced by a rectifier stage. finite impulse response
Vortex mixers are quite commonplace in bioscience laboratories. In cell culture and microbiology laboratories they may be used to suspend cells. In a biochemical or analytical laboratory they may be used to mix the reagents of an assay or to mix an experimental sample and a dilutant.
CCVs are used for driving mine hoists, rolling mill main motors, [4] ball mills for ore processing, cement kilns, ship propulsion systems, [5] slip power recovery wound-rotor induction motors (i.e., Scherbius drives) and aircraft 400 Hz power generation. [6] The variable-frequency output of a cycloconverter can be reduced essentially to zero.
chemistry (ratio of activation energy to thermal energy) [1] Atomic weight: M: chemistry (mass of one atom divided by the atomic mass constant, 1 Da) Bodenstein number: Bo or Bd = / = chemistry (residence-time distribution; similar to the axial mass transfer Peclet number) [2]