How do you control the speed of a DC shunt motor?

How do you control the speed of a DC shunt motor?

In the shunt motor, speed can be controlled by connecting a variable resistor Rc in series with the shunt field winding. In the diagram below resistor, Rc is called the shunt field regulator. Figure: (a) Speed control of a D.C. shunt motor by variation of field flux.

How do you change the speed of a DC shunt motor?

Speed Control of DC Shunt Motor by Flux Control In order to change the speed, we have to change flux. This can be achieved by changing the field current. The field current can be changed by changing the rheostat R connected in series with the field.

What will happen if DC shunt motor is connected?

1. What will happen if DC shunt motor is connected across AC supply? Explanation: In case of parallel field connection, it won’t rotate at all and will start humming and will create vibrations, as a torque produced by positive and negative cycle will cancel out each other. DC motor will be heated up and it may burn.

How can you control the speed of a separately excited DC motor?

2.2. 2 Speed control techniques in separately excited dc motor: i) Varying the armature voltage in the constant torque region. ii) In the constant power region, field flux should be reduced to achieve speed above the rated speed.

How can PWM be used to control the speed of a DC motor?

The circuit is used to control speed of DC motor by using PWM technique. Series Variable Speed DC Motor Controller 12V uses a 555 timer IC as a PWM pulse generator to regulate the motor speed DC12 Volt. IC 555 is the popular Timer Chip used to make timer circuits.

Which speed can be obtained from field control of DC shunt motor?

6. Which speeds can be obtained from field control of DC shunt motor? Explanation: Speeds greater than rated speeds can be obtained by lowering the flux of shunt field motor.

Which speed control method offers below normal speed in DC shunt motor?

Shunt motor is a special type of DC motor which runs at a constant speed. But using field and armature rheostat control method we can make it more versatile. Field rheostat provides above normal speed and armature rheostat provides wide range of below normal speed.

What are the common methods of speed control for a separately excited DC motor there are any alternative methods for these motors?

There are three main ways to achieve speed regulation in series DC motors–flux control, voltage control, and armature resistance control.

  • Flux Control Method.
  • Voltage Regulation Method.
  • Armature Resistance Control Method.

How can a separately excited DC motor be controlled using a chopper?

The speed of Separately Excited DC motor is controlled to a maximum of its rated speed using chopper as a converter. The speed controller used is Proportional Integral type which reduces steady state error and provides fast control. The parameters of the speed controller have been designed using control system theory.

Why do we need to do speed control of DC motors What are the possible methods for the same?

The output voltage of generator G can be varied from zero to its maximum value by means of its field regulator and, hence, the armature voltage of the motor M2 is varied very smoothly. Hence, very smooth speed control of the dc motor can be obtained by this method.

How is the speed of a DC shunt motor controlled?

Armature Resistance Control Method for DC Shunt Motor With this method, the speed of the DC motor can be controlled by controlling the armature resistance to control the voltage drop across the armature. This method also uses a variable resistor in series with the armature.

What are the disadvantages of a shunt motor?

Disadvantages of Field Rheostat Controlled DC Shunt Motor 1 Creeping speeds cannot be obtained. 2 Top speeds only obtained at reduced torque. 3 The speed is maximum at minimum value of flux, which is governed by the demagnetizing effect of armature reaction on the… More

How is speed adjustment of a DC motor done?

Speed adjustment of DC series motor by armature control may be done by any one of the methods that follow, Armature Resistance Control Method: This is the most common method employed. Here the controlling resistance is connected directly in series with the supply of the motor as shown in the fig.

Can a field regulator be used in a shunt motor?

By reversing the field current of generator G by controller Fc, the voltage applied to the motor may be reversed. Sometimes, a field regulator is included in the field circuit of shunt motor M for additional speed adjustment.

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