pdf difference between ac and dc motor

Pdf difference between ac and dc motor

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Types of DC Machines

What is Alternating Current (AC)?

What is Alternating Current (AC)?

What is the difference between an AC motor and a DC motor?

Types of DC Machines

The conversion of this mechanism is known as the commutator, thus these machines are also named as commutating machines. DC machine is most frequently used for a motor. The main benefits of this machine include torque regulation as well as easy speed.

The applications of the DC machine is limited to trains, mills, and mines. For example, underground subway cars, as well as trolleys, may utilize DC motors. In the past, automobiles were designed with DC dynamos for charging their batteries. A DC machine is an electromechanical energy alteration device. The working principle of a DC machine is when electric current flows through a coil within a magnetic field, and then the magnetic force generates a torque that rotates the dc motor.

The AC motor is frequently used in industrial applications for altering electrical energy to mechanical energy. Some of the parts of the DC machine is discussed below. Another name of a yoke is the frame. The main function of the yoke in the machine is to offer mechanical support intended for poles and protects the entire machine from moisture, dust, etc.

The materials used in the yoke are designed with cast iron, cast steel otherwise rolled steel. The pole of the DC machine is an electromagnet and the field winding is winding among pole. Whenever field winding is energized then the pole gives magnetic flux. The materials used for this are cast steel, cast iron otherwise pole core. It can be built with the annealed steel laminations for reducing the power drop because of the eddy currents.

Pole shoe in the DC machine is an extensive part as well as to enlarge the region of the pole. Because of this region, flux can be spread out within the air-gap as well as extra flux can be passed through the air space toward armature. The materials used to build pole shoe is cast iron otherwise cast steed, and also used annealed steel lamination to reduce the loss of power because of eddy currents. Whenever current is supplied through field winding than it electromagnetics the poles which generate required flux.

The material used for field windings is copper. Armature core includes a huge number of slots within its edge. The armature conductor is located in these slots. It provides the low-reluctance path toward the flux generated with field winding. The materials used in this core are permeability low-reluctance materials like iron otherwise cast.

The lamination is used to decrease the loss because of the eddy current. The armature winding can be formed by interconnecting the armature conductor.

Whenever an armature winding is turned with the help of prime mover then the voltage, as well as magnetic flux, gets induced within it.

This winding is allied to an exterior circuit. The materials used for this winding are conducting material like copper. The main function of the commutator in the DC machine is to collect the current from the armature conductor as well as supplies the current to the load using brushes.

And also provides uni-directional torque for DC-motor. The commutator can be built with a huge number of segments in the edge form of hard drawn copper. The Segments in the commutator are protected from the thin mica layer. Brushes in the DC machine gather the current from the commutator and supply it to the exterior load.

Brushes wear with time to inspect frequently. The materials used in brushes are graphite otherwise carbon which is in rectangular form. The excitation of the DC machine is classified into two types namely separate excitation, as well as self-excitation. In a separate excitation type of dc machine, the field coils are activated with a separate DC source. In the self-excitation type of dc machine, the flow of current throughout the field-winding is supplied with the machine.

The principal kinds of DC machines are classified into four types which include the following. In Shunt wound DC Machines, the field coils are allied in parallel through the armature. In series-wound D. Machines, the field coils are allied in series through the armature. As series field winding gets the armature current, as well as the armature current is huge, due to this the series field winding includes few twists of wire of big cross-sectional region.

A compound machine includes both the series as well as shunt fields. The two windings are carried-out with every machine pole. The series winding of the machine includes few twists of a huge cross-sectional region, as well as the shunt windings, include several fine wire twists.

The connection of the compound machine can be done in two ways. The DC machine e. In a generator, the e. A is the no. The voltage produced E can be decided with the no. We know that the main function of a DC machine is to convert mechanical energy to electrical energy. Throughout this conversion method, the whole input power cannot be changed into output power because of the power loss in different forms. The type of loss may change from one apparatus to another. These losses will decrease the apparatus efficiency as well as the temperature will be increased.

The DC machine energy losses can be classified into Electrical otherwise Copper losses, Core losses otherwise Iron losses, Mechanical losses, Brush losses, and Stray load losses.

At present, the generation of electrical energy can be done in bulk in the form of AC an alternating current. In industries, DC machines are used for different processes like welding, electrolytic, etc. Generally, the AC is generated and after that, it is changed into DC with the help of rectifiers. Therefore DC generator is suppressed through an AC supply which is rectified to use in several applications. Thus, this is all about DC machines. Whereas DC motor drives some devices like lathes, fans, centrifugal pumps, printing presses, electric locomotives, hoists, cranes, conveyors, rolling mills, auto-rickshaw, ice machines, etc.

Here is a question for you, what is commutation in dc machine? What is a DC Machine? Share This Post: Facebook. What is Admittance : Units and Its Equation. DC motor is one kind of rotatory motor used to change the energy from DC to mechanical.

The armature characteristics of ac motors are the armature is inactive whereas the magnetic field turns. The armature characteristics of dc motors are, the armature turns whereas the magnetic field remains inactive.

The DC motor speed control can be done by changing the current of the armature winding.

What is Alternating Current (AC)?

Electrical Academia. An electric motor is a machine that converts electric energy into mechanical energy. An electrical signal voltage is applied to the input terminals of the motor, and the output of the motor output generates a specific torque according to the motor characteristics. AC motors and DC motors perform the same function which is to convert electric power into mechanical power, however, they are powered, manufactured and controlled in a different manner. The most primary difference between two of them is the source of power. Maintenance Requires less maintenance because of absence of brushes and commutation process Demands extensive maintenance frequently.

DC is the kind of electricity made by a battery with definite positive and negative terminals , or the kind of charge generated by rubbing certain types of materials against each other. Certain sources of electricity most notably, rotary electromechanical generators naturally produce voltages alternating in polarity, reversing positive and negative over time. Whereas the familiar battery symbol is used as a generic symbol for any DC voltage source, the circle with the wavy line inside is the generic symbol for any AC voltage source. One might wonder why anyone would bother with such a thing as AC. It is true that in some cases AC holds no practical advantage over DC.


DC motors are typically utilized in applications where the speed has to be controlled by some external source. AC motors operate better in such applications where.


What is Alternating Current (AC)?

Latest Articles in "Industry News". Electricity comes in two forms—alternating current AC and direct current DC. Both are essential to enable the functioning of our electronics, but do you know the difference between the two and what they apply to? Alternating current AC power is the standard electricity that comes out of power outlets and is defined as a flow of charge that exhibits a periodic change in direction. AC 's current flow changes between positive and negative because of electrons—electrical currents come from the flow of these electrons, which can move in either a positive upward or negative downward direction.

What is the difference between an AC motor and a DC motor?

There are direct current or DC and alternating current or AC motors. The reference of DC or AC refers to how the electrical current is transferred through and from the motor. Difference between AC and DC motor somewhat lies in the name as their name reflect their working style.

The AC Motor and the DC Motor are differentiated on the various factors like the source or the nature of the power used in the motor. The commutation process, types, starting of the motor, a number of terminals. Applications of the motor, usage of brushes and the maintenance cost of the motor. In an AC Motor , an alternating current passes through the coils. When an alternating current is passed on the electromagnets is a magnetic field is generated. Stationary parts consist of the electromagnets. The magnetic field which is created changes constantly.

AC and DC Motors | Types of Electric Motors and Applications

4 comments

  • Charlotte K. 20.05.2021 at 07:58

    A C Motor works on the concept of alternating current, whereas DC Motor works of the Direct Current. DC Motor are self-starting motors. The Armature is stationary, and the magnetic field rotates in the AC Motor but in DC Motor the armature rotates, and the magnetic field is stationary.

    Reply
  • Comlimasap1963 23.05.2021 at 13:19

    The conversion of this mechanism is known as the commutator, thus these machines are also named as commutating machines.

    Reply
  • Jeffrey H. 27.05.2021 at 12:59

    Typically, engineers can choose between direct-current (DC) or alternating-​current (AC) motors. Machine Design has covered the difference between basic.

    Reply
  • Noah D. 27.05.2021 at 16:15

    Electric motors play an essential role in almost every industry.

    Reply

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