Difference Between Induction Motor and Synchronous Motor

Main Difference

Synchronous Motor and Induction Motor both are the two major categories of the AC motors. The induction motor is also known as an asynchronous motor. These motors have many differences in their structure, construction, working and functions. The induction motor and synchronous motor are classified as the most in-demand, preferred and desired varieties of Alternating current motors. The primary difference among both the kids would be that the synchronous motor revolves in specific synchronism together with the line frequency. The synchronous motor is not going to depend on current induction to create the rotor’s magnetic field. In comparison, the induction motor involves “slip”, the rotor need to spin marginally more slowly compared to the AC current alternations, in order to stimulate current within the rotor winding. Tiny synchronous motors are employed when it comes to timing purposes for example in synchronous timepieces, electronic timers in machines, tape recorders and precision servomechanisms where the motor need to function with an exact specific speed; speed accuracy and reliability are the capability of line frequency, which can be meticulously controlled, managed and governed when it comes to substantially connected power grid systems. mainly they differ induction motor at a very lower speed than the synchronous motor.

What is Induction Motor?

The induction motor is also referred as an asynchronous motor. An induction or asynchronous electric motor is known as an Alternating current motor unit wherein the household current within the rotor are required to create torque and is simply acquired through electromagnetic induction through the magnetic field with the stator turning. An induction motor consequently doesn’t require physical commutation, separate-excitation or self-excitation for those or perhaps portion of the power transmitted from stator to rotor, for example as in universal, DC and substantial synchronous motors. A good induction motor’s rotor could be possibly wounded kind or maybe squirrel-cage form. Squirrel-cage three phase induction motors are traditionally used when it comes to commercial drives simply because they’re durable, dependable cost-effective and affordable. Single-phase induction motors are employed and utilized substantially regarding smaller sized loads, for example, home gadgets such as fans. Despite the fact that widespread in fixed-speed assistance, induction electric motors are usually now being used in combination with variable-frequency drives (VFDs) inside changeable-speed service. VFDs provide particularly important power cost savings possibilities regarding current as well as possible induction motors in the variable-torque centrifugal fan, pump, and compressor, converter load applications. When we talk about Squirrel cage induction motors, they are incredibly popular in both fixed-speed and variable-frequency drive (VFD) purposes. induction motor works on the faraday’s law of electromagnetic induction There are generally two kinds of induction motor which rely upon the particular input supply, which are

  • Single phase induction motor
  • Three phase induction motor

WHat is Synchronous Motor?

A synchronous electric motor is known as an Alternating current motor during which, at the constant condition of the revolving of the shaft is simply synced together with the rate of recurrence of the source current; the actual revolving time period is precisely similar to an intrinsic quantity of Alternating current cycles. Synchronous motors incorporate multi-phase Alternating current electromagnets around the stator belonging to the electric motor that induces some sort of magnetic field which usually rotates over time together with the oscillations associated with the line current. The rotor along with permanent magnets or electromagnets becomes in line with the actual stator field with the exact same pace and for that reason, supplies the next synced revolving magnet field associated with an AC motor. A synchronous motor is just regarded as two times raised on in cases where it is supplied with individually excited multi-phase AC electromagnets for both the stator and rotor. Synchronous motors are available in many self-excited sizes. Whenever precise constant speed is desired, synchronous motors are used. There are generally three types of synchronous motors, which are

  • Reluctance motors
  • Hysteresis motors
  • Permanent magnet motors
  • DC-excited motors
  • Non-excited motors

Key Differences

  1. The speed of the synchronous motor is independent of the load whereas the speed of the induction motor depends upon load, it has a reciprocal relation of speed with load.
  2. Synchronous motor runs at a constant speed while the speed of induction motor is always less than the speed of the synchronous motor
  3. Synchronous motor has no self-starting torque while induction motor has its own self-starting torque
  4. The synchronous motor is comparatively far better and efficient than an induction motor
  5. The synchronous motor is doubly excited motor while induction motor is singly excited machine
  6. The synchronous motor is costly as compared to the induction motor
  7. The power factor of synchronous motor can be adjusted but induction motor has always lagging power factor
  8. Synchronous motors need Direct current excitation to be provided towards the rotor winding but, on the other hand, induction motors don’t need this
  9. Synchronous motors need slip rings and brushes to provide rotor excitation. Induction motors do not need slip rings,
  10. Synchronous motor design, structure and construction is complicated. Induction motor construction is very simple, specifically in the event of cage rotor.
  11. In synchronous motor speed control isn’t feasible. In an induction motor, Speed control is achievable though it is very challenging.
  12. In synchronous motors, Separate DC source is needed with regard to rotor excitation. Whereas Rotor becomes excited through the induced e.m.f so separate source is not necessary.

Comparison Video

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Harlon Moss

Harlon currently works as a quality moderator and content writer for Difference Wiki. He graduated from the University of California in 2010 with a degree in Computer Science. Follow him on Twitter @HarlonMoss

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