Advantages of DC Series Motor:
The series motor has the highest starting torque for a given power rating. When the motor is overloaded, the speed drops and the torque increases. While delivering high torque during an overload, the series motor draws less current and power from the source compared to a shunt or compound DC motor.
The main applications where series motors are best suited are for traction applications. Torque of the series motor is proportional to square of the field current i.e. T α I2. Therefore Starting torque for the series motor is quite high. Because of this property series motors are widely used in electric traction and in crane application.
Disadvantages of DC Series Motor:
- Speed regulation in the series motor is quite poor. With the increase in the load speed of the machine decreases, DC shunt motor maintains almost constant speed from no load to full load.
- With increase in the speed, torque of the dc series motor drops sharply.
- DC series motor should always require being loaded before starting the motor. Therefore series motors are not suited for the application where load on the motor is completely removed and where motors are driving the belts. Mishap to the belt leads to motor operates on no load and attains dangerous speeds which damage the motor.
You’ve said that with decrease in speed torque drops but it’s not true. In fact, opposite of it is true.
Thank you for pointing the error. Your feedback is very important to me as it helps to make the content flawless.
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