Table of Contents
Why differential compound motor is not used in industry?
But as the flux decreases, the speed of the motor increases. This speed increases causes anther increases in load, which further increases Ia , further decreasing the flux, and increasing the speed again. It is so bad that a differentially compounded motor is unsuitable for any application.
What is the use of differential compound motor?
Differential compound series motor gives low starting torque, examined by torque current characteristic. Hence, applications with low starting torque are called in differentially compound DC motor.
What is a differential compound motor?
[‚dif·ə′ren·chəl ′käm‚pau̇nd ‚mōd·ər] (electricity) A direct-current motor whose speed may be made nearly constant or may be adjusted to increase with increasing load.
Where is compound motor normally used?
3. Cumulative Compound Motor. Cumulative compound motor is a varying speed motor with high starting torque and is used for driving compressors, variable head centifugal pumps, rotary presses, circular saws, shearing machines, elevators and continuous conveyors etc.
What is the advantage of DC compound motor?
It takes the benefits of both the motors and combines them. Compound DC motor provides high starting torque and also provides good speed regulation. However, it is a compromise between both types of motors, which means it has good starting torque as compared to series DC motor but slightly lesser than shunt DC motor.
Which DC motor is preferred for constant speed?
DC Shunt-wound motor: This is an almost constant speed motor and its torque varies nearly as the current.
Which DC motor has self relieving property?
Which DC motor has got maximum self-relieving property? Explanation: DC series motor develops large starting torque initially and slow down with increase in load and so get automatically relived from heavy excessive load. Thus, DC series motor is called as self-reliving machine.
How do you reverse the rotation of a compound DC motor?
The rotation of a compound-wound motor can be reversed by changing the direction of the current in the field or the armature circuit, ( 5). Since the series field coils must also be reversed if the shunt field is reversed, it’s easier to reverse the current in the armature only.
Which motor is used in tramway?
This paper compares five different motor types used in variable speed drives: a dc motor with a mechanical commutator and with electromagnetic or permanent magnets excitation, a cage induction motor, asynchronous cascade with a slip‐ring motor and a brushless motor with PM excitation.
What are the 4 types of DC motor?
There are 4 main types of DC motors:
- Permanent Magnet DC Motors. The permanent magnet motor uses a permanent magnet to create field flux.
- Series DC Motors. In a series DC motor, the field is wound with a few turns of a large wire carrying the full armature current.
- Shunt DC Motors.
- Compound DC Motors.
What are the disadvantages of DC compound motor?
Disadvantages of DC shunt motor:
- Dc motors are unreliable at low-speed operations.
- The size of Dc motors is large compared to alternative current motors.
- The installation of DC machines is expensive compare with other types of machines.
What is disadvantage of DC motor?
Disadvantages Of DC Motor DC motors have a high initial cost. Maintenance cost is high and increased operation due to the presence of brushes and commutator. Due to sparking at brush DC motors cannot operate in explosive and hazardous conditions.