How to distinguish AC and DC machines
The main difference between AC and DC motor is the power properties of different AC motors using AC generator, the AC and DC motor; using direct current, the generator is DC. Advantages of DC motor (AC motor and more): smooth speed control characteristics, can achieve economic. And AC motor need to use inverter, electromagnetic regulator and other components to achieve this function.
This also increases the manufacturing cost of DC motors to a certain extent. The alternator is concerned, it can realize direct energy feedback to the grid (but must ensure 4 conditions: the same voltage amplitude, phase and phase sequence of the same, the same frequency); but DC generator power needs to convert AC inverter (DC rectification process called, the direct current into alternating current the process that the inverter can be feedback to the power grid). So it also needs to increase the power of the inverter.
With the same power, the same speed (must be the same speed) compared with DC motor and AC motor, DC motor of the expensive price point, mainly because of its complicated structure must have the commutator to achieve AC-DC conversion.
