As the name suggests, the direct current motor uses DC as the power supply. AC motors use alternating current as power source.
Structurally, the principle of the direct current motor is relatively simple, but the structure is complex, and it is not easy to maintain. The principle of AC motor is complex, but the structure is relatively simple, and it is easier to maintain than the direct current motor.
On the price，the same power background,price of DC motor higher than the AC motor, speed control device, including speed control and DC speed regulating device is higher than that of AC speed regulation device structure and maintenance of price, of course there are also great differences.
In performance, because the DC motor speed stability, accurate speed control, AC motor can not hit, so in the strict requirements of speed, have to use DC motor instead of AC motor.
AC motor speed regulation is relatively complicated, but it is widely used because of the use of AC power supply in chemical plants.