Ac motor, dc motor & # 8203; Ac motor, it is an alternating current of electrical energy into mechanical energy of a machine. Ac motor by a magnetic field to happen first electromagnet or distribute of stator windings and a rotating armature or rotor. Motor using electric coil in the magnetic field force made the phenomenon of rolling. Dc motor (直流机)Refers to direct current (dc) can transform into mechanical energy (Dc motor)Or mechanical energy transform into direct current (dc) can (Dc generator)The rotation of the motor. It is to be able to complete a direct current motor and mechanical energy transform. When run it as a motor is a dc motor, electrical energy transform into mechanical energy. Make generator operation is a dc generator, the mechanical energy transform into electricity. During the primary include: the power of the input type is different, ac motor with ac power source (Has the branch of single-phase and three-phase)Using the dc power supply, and dc motor (Have a safe dc and pulsating dc ~ ~)。 Motor structure is different, usually have for dc motor brush and commutator, and ac motor is generally not! This is why than ac motor use dc motor is widely! Dc motor brush and commutator often have spark between present, cause the commutator surface oxidation and insulation. Use different: first used for dc motor speed regulation is widely,Demand for smooth speed regulation)Machinery or other equipment, planing machine, rolling mill, electric rail traction (For electric locomotive, the subway), and first used for ac motor speed control scale is not too big machinery or other devices, for example, the general fan, water pump, machine tool, crane at the construction site, etc. , of course, with the development of power electronic technology in recent years, such as door can turn off thyristor (GTO）, insulated gate bipolar transistor (IGBT）Rendering of ac motor speed adjustment easier a lot! Speed adjustment scale expands unceasingly, also some bag yesterday called for speed wide scale mechanical equipment start gradually choose ac motor, for example, in the railway now prevailing harmonious high-power electric locomotive, is the use of three-phase ac asynchronous motor instead of the traditional dc motor. Is both work the basic principle of electromagnetic induction law, and both have their own defects, that a lot of materials are introduced. Anatomy, dc motor, dc motor perhaps the defects of the operation is very important one reason about it is just because of the commutator, it is decided to a dc motor and ac motor operation method is the most primary cause different. Or in the motor as an example, the motor to work, it is necessary to rely on the rotor winding induced electromagnetic force to drive the rotor rotate, so want to ensure that the motor safe to continue rotating, rotor winding induction electromagnetic force is necessary to adhere to the direction of the common, about dc motor, the stator magnetic field direction remains the same, so if the current in the rotor without reversing, so in the process of spinning rotor by electromagnetic force direction will change, can't ensure the rotor continuous rotation. The electromagnetic force of rotor winding direction together, the rotor will continue to rotate. And ac motor is to use it, in the job, not after reversing, but after a change of the stator magnetic field direction method to ensure that, because of ac motor stator magnetic field is not fixed, but in accordance with the laws must be in the rotation, so can make sure the electromagnetic force direction of the rotor winding was unchanged. Ac motor stator coil according to the phase distribution, natural happens can ensure rotor rotating magnetic field. There is a demand attention to local, although the operation principle of dc, ac motor, all is the law of electromagnetic induction, but both also have differences, can pass the different understanding of a method. Dc motor rotor rolling (The armature winding movement may force)Because the electricity of the armature winding in the magnetic field by electromagnetic force, so the condition is in the armature current, to launch requirements are so dc motor armature current; And only when the ac motor launch on stator flux into alternating current (ac), can produce a rotating magnetic field, the magnetic field by so movement, so rotor winding induction electromotive force, only the rotor winding can constitute a closed loop, current occurs, will drag the rotor induction of electromagnetic force on rolling, so the condition of ac motor rotor movement is in rotating magnetic field, which is both in the sports with different initial conditions. The process of the dc motor start is: magnetic field + armature winding of a current & rarr; The electromagnetic force in the winding induction & rarr; Drag the rotor rolling; And ac motor waged called: stator three-phase alternating current (ac) and access rarr; The stator rotating magnetic field & rarr; The rotor winding occurs in the rotating magnetic field induction electromotive force & rarr; Because of the rotor winding constitute closed loop (Conditions)Happened, so in the rotor winding current & rarr; Rotor winding in electromagnetism induction & rarr; Drag the rotor rotate.
