Due to an interaction of the rotor current and the main flux, the torque is produced and the motor starts rotating. In the stator the electric energy is get converted into magnetic energy. The magnetic energy travels through the air gap of the motor. The air gap increase the reluctance of the magnetic circuit.
Why do induction motors have air gaps?
The air gap refers to an actual physical gap in an electric motor that separates the moving rotor and the stator core. This gap is a necessary part of motor design and the size of the air gap is one of the keys to motor performance and reliability.19 мая 2020 г.
What will happen if we increase the air gap in the induction motor *?
If the air gap of an induction motor is increased, the following will happen: The permeability of the magnetic circuit rotor-to-stator will decrease. … The magnetic flux in the air gap will decrease and leakage fluxes will increase. This will cause a reduction in the maximum available torque.
Why is the air gap between the stator and the rotor so small?
The smaller the air gap is, the lower that reluctance, and thus the higher the magnetic flux (which is the magnetic analog of current), allowing the motor to work more efficiently and at a higher power.
What is air gap in magnetic circuit?
A magnetic circuit is where a magnetic flux is circulated or follow through a closed area or path. An air gap is a non-magnetic part of a magnetic circuits and it is usually connected magnetically in series with the rest of the circuit. This allows a substantial part of the magnetic flux flows through the gap.
What does air gap mean?
Air-gap refers to computers or networks that are not connected directly to the internet or to any other computers that are connected to the internet.
What is air gap flux?
An air gap is a practically unavoidable part of any magnetic circuit in which there is a relative movement between different parts (e.g. in motors, generators, relays, etc). … Due to increased reluctance of an air gap the flux spreads into the surrounding medium causing the flux fringing effect.
What is the relation between the power factor and the air gap length?
What is the relation between the power factor and the air gap length? Explanation: If the air gap length is small, the dispersion coefficient decreases. As the dispersion coefficient decreases, the power factor increases.
Which starting method is the best method in induction motor?
Starting of an Induction Motor
- Direct on line starter. The direct on line starter method, of an induction motor is simple and economical. …
- Star delta starter. The star delta starter method of starting three phase induction motors is very common and widely used among all the methods. …
- Auto transformer starter.
What is overload capacity of induction motor?
Overload capacity: overload capacity decreased with high value of ac. The value of ac depends upon the size of the motor, voltage of stator winding, type of ventilation and overload capacity desired. It varies between 5000 – 450000 ampere conductors per meter.
What does an air gap do?
A common use of the term “air gap” in home plumbing refers to a fixture that provides back-flow prevention for an installed dishwasher. … When installed and maintained properly, the air gap works as described above, and prevents drain water from the sink from backing up into the dishwasher, possibly contaminating dishes.
What is difference between stator and rotor?
The stator then is the stationary part of the AC motor. The rotor is the rotating electrical component. It also consists of a group of electro-magnets arranged around a cylinder, with the poles facing toward the stator poles. The rotor is located inside the stator and is mounted on the AC motor’s shaft.
How do you measure the air gap between rotor and stator?
Capacitive sensors from Micro-Epsilon designed for non-contact displacement and distance measurements reliably monitor the operation. Therefore, the sensors are used to measure the distance between the stator and rotor and to monitor the so-called rotor gap.
What is the formula for MMF for air gap?
Magnetomotive force (mmf), Fm = NI ampere-turns (At), where N = number of conductors (or turns) and I = current in amperes. … B H = a c o n s tan t . This constant is µ0, the permeability of free space (or the magnetic space constant) and is equal to 4π × 10-7 H/m.
How is reluctance of an air gap calculated?
Reluctance is obtained by dividing the length of the magnetic path l by the permeability times the cross-sectional area A; thus r = l/μA, the Greek letter mu, μ, symbolizing the…
What is the effect of fringing on the area of an air gap?
The fringing effect results from the presence of the air gap in the magnetic circuit. The main consequence of the fringing effect is to make the magnetic flux density of the air gap different from the flux density of the core due to the path of the flux.