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Becoz it use frequecy to start
What else can I help you with?
Drawing of speed-torque curve for synchronous machine?
Theoritical torque speed curve for a synchronous machine will be a vertical line located vertical to the synchrounous speed at x axis, from starting torque to stalling torque value. This is because theoritically synchronous motors are not self starting. Practically however they start as induction motors and at near synchrounous speed the excitation is switched on. Anand Sekhar
Why use clutch plate in single phase motor?
induction motors have very little starting torque as the motor come up to speed it reduces the torque load until it gets near synchronous speed
Principle and working of synchronous motor?
Principle of synchronous motor is as given below:"when a 3 phase winding is fed by a 3 phase supply, then a magnetic flux of constant magnitude but rotating at synchronous speed, is produced."
Difference between synchronous and asynchronous motors?
1)Synchronous motors are those that run only at Synchronous speed i.e. constant speed. But Motor can run in various speeds. 2)Synchronous motors runs at same speed of magnetic filed. but if one consider case of induction motor the rotor rotates at different speed than revolving magnetic field. there is slip between field and rotor.
Why ac motors are not used in railways?
Ac motor has a low starting torque so that DC series motor used in railways cause DC motor has high starting torque
Drawing of speed-torque curve for synchronous machine?
Theoritical torque speed curve for a synchronous machine will be a vertical line located vertical to the synchrounous speed at x axis, from starting torque to stalling torque value. This is because theoritically synchronous motors are not self starting. Practically however they start as induction motors and at near synchrounous speed the excitation is switched on. Anand Sekhar
Why use clutch plate in single phase motor?
induction motors have very little starting torque as the motor come up to speed it reduces the torque load until it gets near synchronous speed
Why is the speed of synchronous motor is more then induction motor?
Synchronous motors run at synchronous speed. An induction motor that has the same number of poles must run at a sub-synchronous speed to create a second magnetic field (a field that is at a different phase angle) to generate torque.
What is a synchronous motor?
Synchronous motors are those that run only at Synchronous speed ie.. constant speed.
What is reluctance torque?
torque of synchronous motor with out feild exitation
Where theSlip ring induction motors are used?
The slip ring induction motors are usually used in the application requiring the low starting current or the high starting torque.
Why the synchronous machine rotate at synchronous speed?
The spatial distribution of the windings in the armature is designed in a way such that it produce a rotating field when a three phase source is applied to its terminals. The field windings have a DC field applied to it and it is rotated mechanically by a prime mover. If the prime mover tried to rotate the synchronous machine at speed higher than its synchronous value then the power output of the generator will increase and this causes the speed to "lock" again to the synchronous one. If the prime mover applied less torque then the machine will slow down but the power output will decrease DUE TO DECEASE in the applied torque and this cause the machine to "lock" again to synchronous speed of the grid. The same principle can be applied to synchronous motors except that torque is negative (i.e. the prime mover is applying negative torque)
What is the most efficient electric motor?
The most efficient electric motors are synchronous motors, which can achieve efficiency rates of up to 99%. This high efficiency is due to their ability to convert electrical energy into mechanical energy with minimal losses. Synchronous motors operate at a constant speed that matches the frequency of the electrical supply, eliminating slip and reducing energy waste. In addition to their efficiency, synchronous motors are designed to be compact while providing higher power output. They also deliver superior torque at lower speeds, making them ideal for various industrial applications. This combination of efficiency, power, and compact design makes synchronous motors a top choice for businesses looking to optimize energy use and performance. Overall, if you're seeking an electric motor that maximizes energy efficiency and reliability, synchronous motors are an excellent option for powering your operations effectively.
Principle and working of synchronous motor?
Principle of synchronous motor is as given below:"when a 3 phase winding is fed by a 3 phase supply, then a magnetic flux of constant magnitude but rotating at synchronous speed, is produced."
Difference between synchronous and asynchronous motors?
1)Synchronous motors are those that run only at Synchronous speed i.e. constant speed. But Motor can run in various speeds. 2)Synchronous motors runs at same speed of magnetic filed. but if one consider case of induction motor the rotor rotates at different speed than revolving magnetic field. there is slip between field and rotor.
Why ac motors are not used in railways?
Ac motor has a low starting torque so that DC series motor used in railways cause DC motor has high starting torque
How much is skewing angle in three phase induction motor?
the skew angle varies from 0 degrees, depending on how much torque you want at near synchronous speed and how smoothly you want to transition with varying loads most motors all the shorting bars are parallel to shaft. skew is more often for lower current starting in motors that will turn on an off a lot
