How do you calculate the transfer function of a DC motor?

How do you calculate the transfer function of a DC motor?

Transfer Function of Armature Controlled DC Motor

1. Let Ra = Armature resistance,
2. La = Armature inductance.
3. Ia = Armature current.
4. Va = Armature voltage.
5. eb = Back emf.
6. Kt = Torque constant.
7. Kb= Back emf constant.

What is field controlled DC motor?

Field Controlled DC Motor. DC drives offer the ability to control the speed and torque of heavy-duty DC motors in various industrial and other similar applications. Speed control can be achieved using DC drives in a number of ways.

How do you drive a DC motor?

Thus, the speed of a DC motor can be controlled in three ways:

1. By varying the supply voltage.
2. By varying the flux, and by varying the current through the field winding.
3. By varying the armature voltage, and by varying the armature resistance.

How can the speed of a DC motor be controlled?

Thus, the speed of a DC motor can control in three ways: By varying the flux, and by varying the current through field winding. By varying the armature voltage, and the armature resistance. Through the supply voltage.

What is the speed of dc motor?

DC controls adjust speed by varying the voltage sent to the motor (this differs from AC motor controls which adjust the line frequency to the motor). Typical no load or synchronous speeds for an AC fractional horsepower motor are 1800 or 3600 rpm, and 1000-5000 rpm for DC fractional hp motors.

What are the factors that affect the speed of a DC motor?

Factors Affecting Motor Performance

• Voltage of Power Supply.
• Type of Power Supply.
• Winding Specifications.
• Environmental Temperature.
• Type of Magnet.
• Flux Yoke.
• Phase.

What are the two ways to increase the speed of a DC motor?

The speed of the motor can be increased by:

• increasing the strength of the magnetic field.
• increasing the current flowing through the coil.

What are the two factors influencing the speed of induction motor?

Motor Speed The speed of an AC motor depends on the frequency of the input power and the number of poles for which the motor is wound.

Why is it necessary to control the speed of a DC motor?

DC Motors plays an important role in energy conversion process. It is a machine which converts electrical energy into mechanical energy. In mechanical system, speed varies with number of task so speed control is necessary to do mechanical work in a proper way. It makes motor to operate easily.

How do you slow down a 12v DC fan?

Get a three 1.8 ohm 2 watt resistors, connect them in parallel and put them in series with your fan (put them in the air stream of the fan to help cool them). That should slow your fan down and reduce the load.

How do I control my 12v DC fan speed?

Just place a resistor in series with it or use a pot. The maximum current is only 104 mA with an average of 90 ma. It will start as low as 4.5 volts so slowing it down is not difficult. Start with about a 120 Ohm 2 Watt resistor or get a 100 Ohm 2 watt pot and find a speed you like.

What are the applications of DC motor?

Applications. DC motors are suitable for many applications – including conveyors, turntables and others for which adjustable speed and constant or low-speed torque are required. They also work well in dynamic braking and reversing applications, which are common in many industrial machines.

What is the working of dc motor?

The DC motor is the motor which converts the direct current into the mechanical work. It works on the principle of Lorentz Law, which states that “the current carrying conductor placed in a magnetic and electric field experience a force”.

What is the most common type of dc motor?

Mainly there are two types of DC Motors. One is Separately Excited DC Motor and other is Self-excited DC Motor. The self-excited motors are further classified as Shunt wound or shunt motor, Series wound or series motor and Compound wound or compound motor.

What are the two basic types of DC motor connections?

There are three types of electrical connections between the stator and rotor possible for DC electric motors: series, shunt/parallel and compound (various blends of series and shunt/parallel) and each has unique speed/torque characteristics appropriate for different loading torque profiles/signatures.

What are the parts of DC motor?

These components are: a stator, a rotor, a yoke, poles, armature windings, field windings, commutator, and brushes. Many of its parts are the same as parts of AC motor, but with a little change.

Why starters are required in a DC motor?

Starters are used to protect DC motors from damage that can be caused by very high current and torque during startup. They do this by providing external resistance to the motor, which is connected in series to the motor’s armature winding and restricts the current to an acceptable level.

What will happen if DC motor used without starter?

What will happen if DC motor is used without starter? Explanation: It would cause intolerably heavy sparking at the brushes which may destroy the commutator and brush-gear. Sudden development of large torque will cause mechanical shock to the shaft, reducing its life.

Which motor has the poorest speed control?

DC motor

Which DC motor is used for machine tools?

DC shunt motor

Which DC motor is preferred for constant speed?

Explanation: Rotary compressor generally demand constant speed operation throughout the load. Sometimes, DC machines are not able to produce constant speed throughout the process hence, synchronous machine is used. 4.

How do you calculate the no load speed of a DC motor?

By multiplying the velocity constant by the nominal motor voltage, obtain the theoretical no-load speed of the motor (zero torque and no-load speed) and plot it on the left vertical axis. Draw a straight line between this point and the stall torque and zero speed point on the graph.

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.

Which motor is used in traction?

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. Motors for a typical locomotive would be in the range 400 to 600 kW.

Which motor is used in metro train?

INDUCTION MOTOR

Are locomotives AC or DC?

All in all, the AC traction locomotive offers about twice the amount of adhesion as a DC unit. Therefore, a modern lightweight AC locomotive such as the RX500 can provide as much or more tractive effort than an old style DC unit like the SW1200 which weighs 60% more.

Why DC is used in trains?

Direct current, either directly supplied, or converted from AC onboard a train, is the most commonly used. The equipment in the DC traction system is less costly, lighter, and more efficient than an AC traction system. It also causes no electrical interference with nearby communication lines.”