DC COMPOUND MOTOR
A compound wound DC motor is a self-excited motor it is a combination of Dc series motor and shunt Dc motor it has both shunt and series field windings with the help of field coils the required amount of magnetic flux which helps the armature coil to rotate at desired speed with the necessary flux
The compound wound DC motor is created by the combination of the shunt wound DC motor and series wound DC motor so that it could achieve both of their properties a shunt wound Dc motor has better speed regulation characteristics while the DC series motor has high starting torque so that the compound wound Dc motor has achieved both of these characteristics so it has higher starting torque and better speed regulation ability so it can be used for industrial applications such as rolling mills, freight elevators, stamping presses, mixers, and metal shears
The compound wound Dc motor can be classified into two types according to their field winding connection with respect to the armature winding
• Long shunt compound motor
In this case, the shunt field winding is connected in parallel across both the armature and to the series field coil’s
• Short shunt compound wound DC motor
In the case of short shunt compound wound of DC motor, the field winding is connected across the armature winding only in parallel and the field coil which is series is exposed to the supply current
• Cumulative compound DC motors
In this type the polarity of the shunt winding adds to the series fields it can be either short shunt in which the shunt is parallel only to the armature or long shunt in which the shunt would be parallel to both armature and series field and thus it will create a cumulative effect
• Differential compound motor
In this type the armature polarity and shunt field oppose each other and the negative terminal of the shunt field is connected to the positive terminal of the armature here an opposite effect is created, if the load is reduced differential compound motor will act as a series motor and it will over speed if we increase the load its speed will reduce