Structurally speaking, the principle of a DC motor is relatively simple, but its structure is complex and not easy to maintain. AC motors have complex principles but relatively simple structures, and are easier to maintain than DC motors.
A DC motor introduces current into the rotor armature through brushes and commutators, causing the rotor to rotate under force in the stator magnetic field. An AC motor (taking a commonly used AC asynchronous motor as an example) is a device that applies AC power to the stator winding, generating a rotating magnetic field in the air gap between the stator and rotor. The rotating magnetic field induces current in the rotor winding, causing the rotor to rotate under the force of the stator magnetic field.
1. DC characteristics:
(1) Good speed regulation performance. The so-called "speed regulation performance" refers to the artificial change of the motor speed under certain load conditions according to needs. DC motors can achieve uniform and smooth stepless speed regulation under heavy load conditions, and the speed regulation range is wide.
(2) The starting torque is high. It can achieve uniform and economical speed regulation. Therefore, any machinery that starts under heavy loads or requires uniform adjustment of speed.
For example, large reversible rolling mills, winches, electric locomotives, trams, etc. are all driven by DC electric motors.
2. Communication characteristics:
The working efficiency of AC electric motors is high, without smoke, odor, environmental pollution, and low noise. Due to its series of advantages, it is widely used in various fields such as industrial and agricultural production, transportation, national defense, commercial and household appliances, medical electrical equipment, etc.
