Search results
Results from the WOW.Com Content Network
Synchronous motors use electromagnets as the stator of the motor which create a magnetic field that rotates in time with the oscillations of the current. The rotor with permanent magnets or electromagnets turns in step with the stator field at the same rate and as a result, provides the second synchronized rotating magnet field.
If the field current is increased beyond this point, the armature current becomes leading, power factor decreases, and grows again. [4] The data from the V curves can be used to set up the synchronous motor to correct the power factor of the overall system, as the power factor of the motor can be changed by simply adjusting the field current. [3]
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 field coil may be connected in shunt, in series, or in compound with the armature of a DC machine (motor or generator). For a machine using field coils, as is the case in most large generators, the field must be established by a current in order for the generator to produce electricity.
A field coil is an electromagnet used to generate a magnetic field in an electro-magnetic machine, typically a rotating electrical machine such as a motor or generator. It consists of a coil of wire through which the field current flows.
The sequence of events is similar for manual or automatic synchronization. The generator is brought up to approximate synchronous speed by supplying more energy to its shaft - for example, opening the valves on a steam turbine, opening the gates on a hydraulic turbine, or increasing the fuel rack setting on a diesel engine. The field of the ...
As in a synchronous motor, the stator of the machine is connected to a three-phase supply of voltage (assumed to be constant), and this creates a rotating magnetic field within the machine. Likewise, the rotor is excited with a DC current I e {\displaystyle I_{e}} to act as an electromagnet.
A generator in which current and magnetic field direction are constant as the machine rotor revolves. homopolar motor A motor that produces torque from a current and magnetic field that does not change direction. horsepower A unit of power, equivalent to around 746 watts. hot wire barretter