Which motor is used in tramways?
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. length should be equal to lm 6 = mm.
What type of dc motor is used in traction?
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.
Why DC motors are preferred for traction application?
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.
Why DC series motor is suitable for goods vehicles?
⇒ DC series motors are used where high starting torque required. These motors are only used where the variation of speed is possible. series motors are not suitable for constant speed applications.
What is a DC series motor?
Series DC motors are a group of self-excited DC motors in which the field coil is connected in series to the armature winding and thus a higher current passes through it. A series DC motor mission is to turn the electrical energy into mechanical one based on electromagnetic law.
What are the applications of DC series motor?
Series DC motors are generally used where high starting torque is required, and speed variations are possible. These types of direct connection motors are, for instance, used in the traction system, cranes, air compressors, vacuum cleaners, sewing machines, etc.
Which motor is most suitable to use in the 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.
What is used to prevent high starting current in DC motor?
In order to avoid high starting current an extra resistance must be connected in series with the armature. This external resistance is known as starter resistance. The series resistance is divided into sections which are cut out one by one as the speed of the motor increases and the back emf builds up.
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.
Why is the DC motor preferred over AC motor?
DC motors have the advantage of: higher starting torque, quick starting and stopping, reversing, variable speeds with voltage input and they are easier and cheaper to control than AC. AC motor advantages include: lower power demand on start and minimal maintenance.
What is starting resistance of DC motor?
In practical DC machines, armature resistance is basically very low, generally about 0.5 Ω. Therefore, a large current flows through the armature during starting.