Speed Control of single phase induction motor using TRIAC
The size of the air gap between the rotor bars and stator windings necessary to obtain the maximum field strength is small. The first commutator-free two phase AC induction motor was invented by Hungarian engineer ; he used the two phase motor to propel his invention, the. Archived from PDF on 10 February 2013.
Retrieved 22 February 2018. The construction of single phase induction motor is almost similar to the squirrel cage three-phase induction motor.
Speed Control of single phase induction motor using TRIAC - You can use PowerShow. Always use per- phase equivalent circuit.
AC Induction Motor Application and Operation The AC Alternating Current Induction Motor is the most commonly used AC motor in industrial applications because of its simplicity, rugged construction, and relatively low manufacturing costs. The reason that the AC induction motor has these characteristics is because the rotor is a self-contained unit, with no external connections. This type of motor derives its name from the fact that AC currents are induced into the rotor by a rotating magnetic field. The AC induction motor rotor Illustrated to the left is made of a laminated cylinder with slots in its surface. The windings in the slots are one of two types. This rotor is made of heavy copper bars that are connected at each end by a metal ring made of copper or brass. No insulation is required between the core and the bars because of the low voltages induced into the rotor bars. The size of the air gap between the rotor bars and stator windings necessary to obtain the maximum field strength is small. Single-Phase AC Induction Motors If two stator windings of unequal impedance are spaced 90 electrical degrees apart and connected in parallel to a single-phase source, the field produced will appear to rotate. This is called phase splitting. In a split-phase motor, a starting winding is utilized. This winding has a higher resistance and lower reactance than the main winding illustration shown below. When the same voltage VT is applied to the starting and main windings, the current in the main winding IM lags behind the current of the starting winding IS illustration shown below. The angle between the two windings is enough phase difference to provide a rotating magnetic field to produce a starting torque. When the motor reaches 70 to 80% of synchronous speed, a centrifugal switch on the motor shaft opens and disconnects the starting winding. Single-phase motors are used for very small commercial applications such as household appliances and buffers.
Heat generated during starting is mostly dissipated external to the motor in the starting resistance. These motors are typically used in applications such as desk fans and record players, as the servile starting torque is low, and the low efficiency is tolerable relative to the reduced cost of the motor and starting method compared to other AC motor designs. Synchronous reluctance Synchronous reluctance motors SynRM have an equal number of stator and rotor poles. Thus, high torque is social while starting. However, resistor losses associated with low speed operation of WRIMs is a major cost disadvantage, especially for constant loads. But in case of a single phase induction motor, the stator has two windings instead of one three-phase winding in. Archived from PDF on 15 May 2016. Del Coil of a Single Phase Motor The single coil of a single phase induction motor does not produce a rotating magnetic field, but a pulsating field reaching maximum intensity at 0 o and 180 o electrical. Slideshare uses cookies to improve functionality and performance, and to provide you with civil advertising. Squirrel cage induction motors draw 500 to over 1000 of full load current FLC during starting. The motor will continue to run under the influence of the main only. These challenges are being overcome by advances in the theory, by the use of sophisticated prime design tools, and by the use of low-cost for control, typically based on using control algorithms and to tailor drive waveforms according to rotor position and current or voltage feedback.