Application of dc motors pdf

Shunt motor: This motor runs at a constant speed when the supply voltage is fixed. This motor can be also reversed by reversing the connections of motor same as a series motor. In this motor, torque can be increasing, without a decrease in speed by increasing motor current. Compound motor: Compound motor characteristics depend upon type whether it is cumulatively compound or differential compound.

Characteristic of the compound motor is the combination of both series dc and shunt dc motor. A cumulative compound can develop high starting torque at low speed like a series motor. This motor can run at reasonable speed and will not run with dangerously high speed like series motor, on light or no load condition. We can also run this motor at a constant speed. Hope now you understand well about the everyday uses of DC motors. We saw some examples of applications of DC motors also above.

Dc shunt motors are used in constant speed applications. It has the good starting torque and nearly constant speed also. So it is used in Presses, Shears, Conveyors, Elevators etc. Clear concept by your article. Thank you for this complete solution related to application of DC motor. Thank you sir.

Above all information is very helpful for me to better understanding the concept of DC motor……. Your email address will not be published. Skip to content Search for:. So one end of the voltage source is attached to the winding and the other end is attached to the armature through the brush.

Initially at the motor starts with a voltage source attached to the motor, it forms a large amount of current because both the winding and the armature of the motor are made up of large conductors, providing minimal resistance to the current path. The large current through the winding produces a strong magnetic field.

This strong magnetic field gives high torque to the armature shaft, thus exerting the spinning action of the armature. Hence the motor starts rotating at its maximum speed in the beginning. A rotating armature in the presence of a magnetic field occurs in a counter EMF, limiting the current build-up in a series combination of armature and winding. Thus the series motors will offer maximum speed and torque once started but with increasing speed gradually, its torque will come down due to its low current.

In practice, this is required from motors. Due to the high torque provided by the armature, the load on the shaft is initially set to rotate. Consequently, the low torque will drive the load forward. This further helps to increase the heat dissipation of the motor. But, the amount of torque generated by the motor is directly proportional to the winding current. A compound wound DC motor is a type of self-excited motor, and consists of both series of field coils and shunt field coils are attached to the armature winding.

Both field coils provide for the expected amount of magnetic flux, which links with the armature coil and delivers about the torque required to facilitate rotation at the desired speed. As we know, a compound wound motor is basically formed by the amalgamation of a shunt wound DC motor and series wound DC motor to obtain better closure properties of both these types.

Like a shunt wound, a DC motor is offered with a highly efficient speed regulation characteristic, while a DC series motor has high starting torque.

So the compound wound DC motor makes a compromise in terms of both these characteristics and has a good combination of proper speed regulation and high starting torque. However, its initial torque is not as high as in the case of a DC motor, nor is its speed regulation as good as a DC shunt motor.

The overall characteristics of a DC shunt motor come in between these 2 extreme limits. If the shunt field flux assisted main field flux, which is produced by the main field connected in series to the armature winding, is called a cumulative compound DC motor. If the shunt and series winding is arranged in such a way that the field flux generated by the shunt field winding reduces the effect of flux by the main series field winding, then it is called differential compound DC motor.

Both types of compound DC motors can be of short or long shut type according to the nature of the arrangement. When the shunt field winding of the motor is connected in parallel to the armature winding it is known as a short shunt DC motor. The diagrammatic representation of the short shunt motor is shown in the figure above. When the shunt field winding of the motor is connected parallel to both armature winding and series field winding then it is known as a long shunt DC motor.

The diagrammatic representation of the long shunt motor is shown in the figure above. If you found this article helpful then please share it with your friends.

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Hence, the use of DC machines, i. They are mainly used in supplying excitation of small and medium-range alternators. Nowadays, the alternating current is generated first and then it is converted into DC by the rectifiers. Thus, DC generator has generally been suppressed by a rectified AC supply for many applications.

Direct current motors are very commonly used as variable speed drives and in applications where severe torque variations occur.