Since a series motor develops high starting torques at low speeds and low torque at high speeds, therefore, speed – torque characteristics of a DC series motor is a hyperbola. High starting torque enables, even a small series motor to start a heavy load.
Why is a DC series motor used to start heavy loads?
Heavy load requires heavy starting torque and DC series motor can provide that Torque. Torque in a DC motor depends on product of field current and armature current. Again higher the load, higher will be the armature current and hence higher torque. That’s why DC series motor is suitable for pulling out heavier load.
Which motor is best suited for heavy traction loads?
Explanation: DC motors are used for traction as, according to the characteristics of DC motors speed is inversely proportional to torque and square of armature current as well, if linear magnetization is concerned. Thus, DC motors are perfectly suitable for traction. 2.
Can a DC shunt motor run at heavy loads?
DC shunt motors should never be started on heavy loads because such loads need heavy starting current.
Which motor has highest no load speed?
Explanation: At no load, armature current tends to zero, flux φ tends to zero, where speed is inversely proportional to the flux, speed will tend to infinity. Thus, no load speed of DC series motor is highest.
Which type of motor is used for traction Why?
AC traction motors have replaced DC motors in many traction applications. The motors used are induction or asynchronous motors designed to have characteristics suitable for traction. The speed and torque of the motor are controlled by varying the frequency, voltage and current applied to the stator coils.
Which type of following motors are most efficient?
BLDC motors are typically 85–90% efficient or more. Efficiency for a BLDC motor of up to 96.5% have been reported, whereas DC motors with brushgear are typically 75–80% efficient.
Which motor is suitable for traction?
3. AC Series Motor: Many single phase ac motors have been developed for traction purposes but only compensated series type commutator motor is found to be best suited for traction. Single phase induction motors have been abandoned as they are not capable of developing high starting torque.
How do you select a motor for a particular application?
5 steps to choose the best motor for your application
- Step 1: Know the load characteristics. …
- Step 2: Get a handle on horsepower. …
- Step 3: Getting started. …
- Step 4: Adjust for duty cycle. …
- Step 5: The last consideration, motor hypoxia.
Which motor is used in tramway?
Dc motor (Ma) and induction motor (Mc) are currently manufactured and used in 105 N tram drive, their parameters are available. Dc motor (Mb), brushless motor (Me) and slip-ring motor (Md) pa- rameters have been determined by analysis.
Which DC motor has maximum self loading property?
Which DC motor has got maximum self-loading property? Explanation: A differentially compound DC motor, flux reduces so sharply at small increase in load at higher values of load.