What are tooth pulsation losses?

Tooth pulsation loss: In motors with open type slots, slot opening effects on air gap reluctance. The slots should be so proportioned that minimum variations in the air gap reluctance are produced which results in tooth pulsation losses and noise. This effects can be minimized by using large no. of narrow slots.

What is pulsation loss in induction motor?

Explanation: In the rotating electrical machine, the armatures are slotted and there is movement of rotor which leads to changes of local gap reluctance. This change leads to flux pulsations which causes additional losses called pulsating losses. Explanation: The pulsation losses occurs in the teeth of the machine.

Which loss occurs in induction motor?

Mechanical losses occur at the bearing and brush friction loss occurs in wound rotor induction motor. These losses are zero at start and with increase in speed these losses increases. In three phase induction motor the speed usually remains constant. Hence these losses almost remains constant.

What is the range of BAV for 50 Hz machine?

0.35 – 0.6 Tesla
For 50 Hz machine, 0.35 – 0.6 Tesla. The suitable values of Bav can be selected from design data hand book. Normal range 10000 ac/m – 450000 ac/m. The suitable values of q can be selected from design data hand book.

What is the use of skin effect in the induction motor?

Skin effect yields an increase of the effective resistance with frequency and a decrease of the effective inductance with frequency.

What are the factors the Permeance depends upon?

Permeability is largely dependent on the size and shape of the pores in the substance and, in granular materials such as sedimentary rocks, by the size, shape, and packing arrangement of the grains.

What are the factors the Permeance depends upon the zigzag leakage?

What are the factors the permeance depends upon in the zigzag leakage? Clarification: The permeance for the path of zigzag leakage will depend upon the relative position of stator. The permeance for the path of zigzag leakage will depend upon the relative position of rotor.

What are the 2 main types of losses in a motor?

Intrinsic losses are of two types: fixed losses – independent of motor load, and variable losses – dependent on load. Fixed losses consist of magnetic core losses and friction and windage losses. Magnetic core losses (sometimes called iron losses) consist of eddy current and hysteresis losses in the stator.

What are the losses in motors?

There are two main kinds of losses in electric motors, which are often referred to as iron losses and copper losses. Dealing first with iron losses, these are made up of two ‘components’, namely eddy current losses and hysteresis losses.

Is the speed of a DC shunt motor is increased the back EMF of the motor will?

So, the back emf is directly proportional to speed. Hence, when the speed of a DC shunt motor is increased, then the back emf of the motor will increase.

What causes tooth pulsation loss in a large air gap length motor?

Tooth pulsation loss: The tooth pulsation loss reduces in a large air gap length motor because of small variation in the reactance of air gap. Unbalanced Magnetic Pull (UMP): An unequal air gap causes unbalanced magnetic pull.The unbalanced magnetic pull acts in the direction of shortest air gap.

What is tooth pulsation loss?

This loss is called the tooth pulsation loss. The method consists in using metallic electrodes shaped like the teeth of a machine and an electrolyte or mercury to represent the air. Voltage is applied between the two members and the current through the tooth under consideration is measured.

What are pulsation losses?

This pulsation will create eddy current losses on the surface of pole shoe. These losses are known as Pulsation Losses. To reduce this losses, pole shoes are laminated. The frequency of this pulsation is mainly dependent on. Rotor speed. Number of slots and teeth available.