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Two-phase power can be derived from a three-phase source using two transformers in a Scott connection: One transformer primary is connected across two phases of the supply. The second transformer is connected to a center-tap of the first transformer, and is wound for 86.6% of the phase-to-phase voltage on the three-phase system.
The two two-phase windings, fixed at right (90°) angles to each other on the stator, produce a sine and cosine feedback current. The relative magnitudes of the two-phase voltages are measured and used to determine the angle of the rotor relative to the stator. Upon one full revolution, the feedback signals repeat their waveforms. This device ...
Transformation of three phase electrical quantities to two phase quantities is a usual practice to simplify analysis of three phase electrical circuits. Polyphase a.c machines can be represented by an equivalent two phase model provided the rotating polyphases winding in rotor and the stationary polyphase windings in stator can be expressed in a fictitious two axes coils.
Wiring schematic for a simplified bipolar-field Gramme-ring single-phase–to–direct-current rotary converter. (In actual use, the converter is drum-wound and uses a multipolar field.) [2] Wiring schematic for a simplified two-phase–to–direct-current rotary converter, with the second phase connected at right angles to the first [3] Wiring schematic for a simplified three-phase–to ...
Since the typical two-phase load was a motor, the current in the two phases was presumed inherently equal during the Scott-T development. In modern times people have tried to revive the Scott connection as a way to power single-phase electric railways from three-phase Utility supplies. This will not result in balanced current on the three-phase ...
The rotating magnetic field is the key principle in the operation of induction machines.The induction motor consists of a stator and rotor.In the stator a group of fixed windings are so arranged that a two phase current, for example, produces a magnetic field which rotates at an angular velocity determined by the frequency of the alternating current.
In the case of a twisted line the individual conductors of an electric circuit swap places, either in their whole course (at cables) or at certain points (at overhead lines). The mutual influence of electrical conductors is reduced by transposing. The unbalance of the line, which can lead to one-sided loads in three-phase systems, is also ...
In an alternating current (AC) electric power system, synchronization is the process of matching the frequency, phase and voltage of a generator or other source to an electrical grid in order to transfer power. If two unconnected segments of a grid are to be connected to each other, they cannot safely exchange AC power until they are synchronized.