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The waveform of 230 V and 50 Hz compared with 120 V and 60 Hz. The utility frequency, (power) line frequency (American English) or mains frequency (British English) is the nominal frequency of the oscillations of alternating current (AC) in a wide area synchronous grid transmitted from a power station to the end-user.
Single-phase 60 Hz 1800 RPM synchronous motor for Teletype machine, non-excited rotor type, manufactured from 1930 to 1955. In non-excited motors, the rotor is made of steel. It rotates in step with the stator's rotating magnetic field, so it has an almost-constant magnetic field through it.
An induction generator produces electrical power when its rotor is turned faster than the synchronous speed. For a four-pole motor (two pairs of poles on stator) powered by a 60 Hz source, the synchronous speed is 1800 rotations per minute (rpm) and 1500 RPM powered at 50 Hz. The motor always turns slightly slower than the synchronous speed.
Synchronous speeds for synchronous motors and alternators depend on the number of poles on the machine and the frequency of the supply. ... Speed (rpm) at 60 Hz 2 ...
For example, for a four-pole, three-phase motor, = 4 and = = 1,500 RPM (for = 50 Hz) and 1,800 RPM (for = 60 Hz) synchronous speed. The number of magnetic poles, , is the number of north and south poles per phase. For example; a single-phase motor with 3 north and 3 south poles, having 6 poles per phase, is a 6-pole motor.
The rating of a brushless motor is the ratio of the motor's unloaded rotational speed (measured in RPM) to the peak (not RMS) voltage on the wires connected to the coils (the back EMF). For example, an unloaded motor of K v {\displaystyle K_{\text{v}}} = 5,700 rpm/V supplied with 11.1 V will run at a nominal speed of 63,270 rpm (= 5,700 rpm/V ...
For example, a 100 HP, 460 V, 60 Hz, 1775 RPM (4-pole) induction motor supplied with 460 V, 75 Hz (6.134 V/Hz), would be limited to 60/75 = 80% torque at 125% speed (2218.75 RPM) = 100% power. [26] At higher speeds, the induction motor torque has to be limited further due to the lowering of the breakaway torque [a] of the motor. Thus, rated ...
This is because as long as the motor torque is constant, I 2 R or winding resistance losses are the same at 50 Hz and 60 Hz. The motor output power, however, increases linearly with speed, increasing by 20% when the frequency is increased from 50 Hz to 60 Hz. In general, the 60 Hz efficiency is about 2.5% to 0.5% greater than the 50 Hz values.