What Are The Advantages And Disadvantages Of Dc Machines?

DC Motor Advantages & Disadvantages

Advantages	Disadvantages
Inexpensive controls for speed regulation	Cogging at speeds of less than 300 rpm
Generally a low-cost motor option	Significant power loss on full wave rectified voltage
Easily pairs with gear reducers	High starting torque can damage reducers

What are the advantages and disadvantages of DC shunt motor?

The installation of DC machines is expensive compare with other types of machines. Shunt motor is a constant speed motor, it would be disadvantages where it’s necessary to operate under variable speed. For the same current input, its starting torque is not a high as that of a DC series motor.

What are the disadvantages of DC machines?

Disadvantages of DC motors

• High initial cost.
• Increased operation and maintenance cost due to the presence of commutator and brush gear.
• Cannot operate in explosive and hazard conditions due to sparking occur at brush (risk in commutation failure)

What is the advantage of DC machine?

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 are the advantages and disadvantages of AC and DC motors?

AC motors are generally considered to be more powerful than DC motors because they can generate higher torque by using a more powerful current. However, DC motors are typically more efficient and make better use of their input energy.

What is the one disadvantage of Series DC motor?

The series motor has poor speed regulation. When the load speed of the machine increases, the DC shunt motor keeps its constant speed from no load to full load. The dc series motor’s Torque drops sharply when the speed increases.

What are the disadvantages of DC series motor?

Disadvantages of DC Series Motor

• Speed regulation in the series motor is quite poor. With the increase in the load speed of the machine decreases.
• With decrease in the speed torque of the dc series motor drops sharply.
• DC series motor should always require to be loaded before starting the motor.

What are the disadvantages of direct current?

If we transmit the electricity in the format of direct current within the wires, the main portion of the electricity is already reduced and wasted in the shape of heat that will cause nothing but loss. This is the basic disadvantage of the direct current.

What are the advantages and disadvantages of a separately excited generator over a self excited generator?

Separately excited DC generators have many advantages over self-excited DC generators. It can operate in stable condition with any field excitation and gives wide range of output voltage. The main disadvantage of these kinds of generators is that it is very expensive of providing a separate excitation source.

What is the difference between AC machine and DC machine?

The most obvious difference is the type of current each motor turns into energy, alternating current in the case of AC motors, and direct current in the case of DC motors. AC motors are known for their increased power output and efficiency, while DC motors are prized for their speed control and output range.

What is difference between AC and DC?

Alternating Current (AC) is a type of electrical current, in which the direction of the flow of electrons switches back and forth at regular intervals or cycles.Direct current (DC) is electrical current which flows consistently in one direction.

What’s better AC or DC?

DC power is significantly more energy efficient than AC power. DC motors and appliances have higher efficiency and power to size characteristics.The greater efficiency resulting from recent developments in DC converter technology allows improvements in electricity delivery over long distances.

What are advantages and disadvantages of a series motor?

The series motor has the highest starting torque for a given power rating. When the motor is overloaded, the speed drops and the torque increases. While delivering high torque during an overload, the series motor draws less current and power from the source compared to a shunt or compound DC motor.

What is the main disadvantage of series generator?

The main disadvantage of series generators, Output voltage varies as the load varies The e. mf induced in the armature winding is constant with . time Inter pole winding is connected in series with main poles of d.c machine Series motor maintains a more constant speed under varying load.

What are the advantages and disadvantages of speed control by armature voltage control method?

field control:

• Higher initial costs: The armature control method is often more expensive than the field control method.
• Low energy efficiency: One reason why armature control is most commonly used for shorter lengths of time is that speed variation tends to waste large amounts of power.

Which of the following are the advantages of induction machines?

Advantages of an induction motor (IM):

• The working of an induction motor is very simple.
• It is very cheap in cost to compare the other motors.
• It is a highly efficient motor.
• The brushes are not used in an induction motor.
• The maintenance of IM is very less compared to the DC motor and synchronous motor.

Where is DC series motor used?

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.

What is the main advantage of a shunt motor?

Shunt Motors
The shunt-connected motor offers good speed regulation. The field winding can be separately excited or connected to the same source as the armature. An advantage to a separately excited shunt field is the ability of a variable speed drive to provide independent control of the armature and field.

What are the disadvantages of AC and DC?

• Peak value of A.C. is high and it is dangerous to use so better insulation is required.
• It attracts person who touches it unlike D.C. which gives a repelling shock.
• An A.C. is transmitted from surface of the conductor and hence need several strands of thin wires insulated from each other.

What is the advantage of AC over DC current?

Because of the high voltages that can be generated, AC can be transmitted over long distances. Long-range transmission results in relatively low energy losses resulting from resistance. AC is cheaper to generate than DC. AC can be easily converted to DC if required.

What is the disadvantage of DC transmission system over AC transmission system?

Potential stresses developed on the insulation in the dc system are 70% as compared to the ac system. Hence, it requires less insulation. In the case of dc transmission, there is no effect of inductance and capacitance, no power factor, and surge problems.