Motor Encyclopedia: the difference between DC motor and AC motor

According to the types of power, the motor can be divided into DC motor and AC motor, the Encyclopedia of the motor, Wannan motor will simply introduce DC motor and AC motor and their difference:

DC motor is able to achieve the DC motor and mechanical energy conversion of each other, when the mechanical energy conversion to electric energy. The principle of the DC electromotive force to the working principle of the DC generator is to the alternating electromotive force induced in the armature coil, by the commutator with brush of the role, so that leads from the brush end.

Working principle of DC motor

DC motor inside is fixed on the annular permanent magnet, the current through the coils in the rotor generated ampere force, when the rotor coil and the magnetic field is parallel, and then continue to by the direction of the magnetic field will change, so at this time, at the end of the rotor brush to switching sheets alternately contact and thus on the coil current also changes the direction, produce the Lorents force in the same direction, so the motor can keep a direction of rotation.

The principle of the DC electromotive force to the working principle of the DC generator is to the alternating electromotive force induced in the armature coil, by the commutator with brush of the role, so that leads from the brush end.

Direction of induction electromotive force by the right-hand rule to determine (magnetic induction line point to palm, thumb pointing in the direction of movement of the conductor, the other four fingers pointing is the direction of the induced electromotive force in a conductor).

The conductor the direction of force with the left hand dingze sure. This pair of electromagnetic force to form a torque on the armature, the torque in the rotary motor is referred to as the electromagnetic torque, the direction of the torque is counter clockwise, in an attempt to make the armature counter clockwise rotation. If the electromagnetic torque can overcome the resistance torque on the armature (for example, the resistance torque caused by friction and other load torque), the armature can be rotated counter clockwise.

Alternating current dynamo：

AC motor is a machine used to realize mechanical energy and AC motor. Due to the great development of AC power system, AC motor has become a commonly used motor. Compared with DC motor, AC motor has simple structure, easy manufacture, high speed, high voltage, high current, high current and large capacity. AC motor power coverage is very large, from a few watts to hundreds of thousands, or even millions of watts.

Difference between DC motor and AC motor:

1, speed and voltage proportional to the motor is a DC motor, speed and frequency of the motor is directly proportional to the AC motor.

2, the DC motor is the coil commutation, and the AC motor is the phase change group.

3, DC motor is adjustable speed, and the AC motor is the frequency conversion, which is the DC motor and AC motor of the watershed.

4, the fundamental difference between the DC motor and the AC motor is the equation of electric potential balance:

1), electromotive force balance equation of DC motor is U=C n

2), electromotive force balance equation of AC motor is: U=C f

3) DC motor with a response to rapid, large starting torque, from zero speed to rated speed with torque performance, but the advantages of DC motor is its disadvantages, because DC motor to produce the rated load under constant torque performance, armature magnetic field and the magnetic field of the rotor must be constant to maintain 90 or, this is the book by a carbon brush and commutator motor rotates in will produce sparks, toner so in addition to cause damage to components, use the occasion is restricted. AC motor without carbon brush and commutator, maintenance free, sturdy, and wide range of application, but property if you want to reached a considerable in the performance of DC motor shall be with complex control technology to achieve. Three phase asynchronous motor has the advantages of simple structure, reliable operation, low cost, etc..