The speed regulation performance of dc motor is very good. Why need ac motor?
One is that the dc motor needs a powerful dc power supply, while the ac motor is not needed. Second, the electric brush system of dc motor is mechanical friction, which requires constant maintenance (changing the brush, cleaning commutator), ac motor without it. Third, the spark of a carbon brush can cause electromagnetic interference in a large number of electronic systems. Four is that the volume of dc motors with power is larger than the ac motor. Five is that the current frequency converter is mature enough to meet most of the speed adjustment requirements.
Because dc motors require a powerful dc power supply, ac motor is not needed. 2, dc motors (direct current machine) is to point to to direct current (dc) can be converted into mechanical energy (dc motor) or can convert mechanical energy into direct current (dc generator) the rotation of the motor. It is an electric motor that can convert direct current and mechanical energy. When it is running on an electric motor, it is a direct current motor, converting electrical energy to mechanical energy. The generator is run by a dc generator that converts mechanical energy into electricity. "Ac motor" is a machine used to realize mechanical energy and exchange electrical energy. Ac motor has become the most commonly used electric motor due to the huge development of ac power system. Compared to the ac motor and dc motor, with no commutator (see dc motor commutator), so the simple structure, easy fabrication, quite strong, easy to make a high speed, high voltage, high current, the large capacity motor. Ac motor power covers a wide range, ranging from a few watts to several hundred thousand kilowatts and even a million kilowatts.
Compared with ac motor, dc motor is very good at the speed of adjustment, but it is difficult to maintain the high cost and high cost.
