A brief description of fractional horsepower motors

The definition of fractional horsepower motors
Fractional horsepower motor is powered by 220V AC source for a class of motors, it applies to only a single-phase power supply (single-phase power) of the small-scale industrial equipment and household appliances.
Single-phase asynchronous motor works
In the AC motor, when the stator winding through the exchange of current, established the armature magnetomotive force, its electrical energy conversion and the running performance has a significant impact. Therefore, single-phase AC single-phase AC winding access generated pulsating magnetic momentum, the magnetic motive force can be decomposed into two equal amplitude, opposite speed MMF and to create a true story in the air gap and reverse magnetic field and. The two rotating magnetic field cutting the rotor conductors, and conductors were generated in the rotor induced voltage and induced current.
The current and the magnetic interaction of positive and negative electromagnetic torque. Positive torque is an attempt to turn the rotor; reverse torque of an attempt to reverse the rotor. Superposition of the two torque motors turning up is to promote the synthesis of torque.
Whether or their size and the relationship between slip and three-phase asynchronous motor is the same. If the motor speed is
Is being transferred to the magnetic field, the slip rate:
On the reverse magnetic field, the slip rate:
Single-phase asynchronous motor T-s curve, see left
By the single-phase asynchronous motor patterns that the main features are:
(1) n = 0, s = 1, T = T + + T-= 0, shows no single-phase induction motor starting torque, if not to take other measures, the motor can not start.
(2) When s ≠ 1 时, T ≠ 0, T has no fixed direction, it depends on s, the positive and negative.
(3) The existence of reverse torque, so that torque is also decreased synthesis, so single-phase asynchronous motor overload low.
Capacitance-phase start working principle
Startup switch K closed so that the two winding current I1, I2 phase of about 90 °, resulting in rotating magnetic field, electrical switch up; rotation is
After the centrifugal switch is bypassing the often start the winding is cut off.
Shaded pole single phase motor works
Access after the stator current, part of the magnetic flux through the circuit loop, and in which the induced current. Short-circuit loop in the current impede flux changes, causing a short circuit ring section and not short-circuit ring part of the magnetic flux generated with the phase difference to form the rotating magnetic field, so that the rotor turn up.
Diagram above the direction of motor rotation: instantaneous clockwise. Because there is no short-circuit ring part of the flux than the flux short circuit some of the leading ring.