AC motor vs DC motor

First, the advantages of DC motors

1. DC motor has good starting characteristics and speed regulation characteristics

2. The torque of the DC motor is relatively large

3. Maintenance is cheaper.

4. The DC of the DC motor is more energy-saving and environmentally friendly than ac.

Second, the disadvantages of DC motors

1. DC motor manufacturing is more expensive
 

2. There is a carbon brush

 Third, the advantages of AC motors

1. AC motor is cheaper to manufacture.

2. The development of vector frequency conversion technology can already be simulated into direct current with frequency conversion motors

3. Compared with the DC motor, it has sufficient advantages in terms of simple structure, easy maintenance, low environmental requirements, energy saving and productivity improvement, so that AC speed regulation has been widely used in industrial and agricultural production, transportation, national defense and daily life.

Fourth, the disadvantages of AC motors

1. The starting and speed regulation of the AC motor are poor

AC motors can be divided into synchronous motors and asynchronous motors according to the speed.
 First, synchronous motor

There are three main modes of operation of synchronous motors, namely as generators, motors and compensators. Running as a generator is the most important way of running a synchronous motor, and running as a motor is another important way of running a synchronous motor. The power factor of the synchronous motor can be adjusted, and the application of large synchronous motors can improve the operating efficiency in the absence of speed regulation. In recent years, small synchronous motors have begun to be more widely used in frequency conversion speed regulation systems.

Synchronous motors can also be connected to the grid as synchronous compensators. At this time, the motor does not carry any mechanical load, and the inductive or capacitive reactive power required is sent to the grid by adjusting the excitation current in the rotor to achieve the purpose of improving the power factor of the power grid or adjusting the grid voltage.
Second, asynchronous motor

An asynchronous motor is an AC motor whose speed at load is not a constant ratio to the frequency of the connected grid. It also changes with the size of the load. The greater the load torque, the lower the speed of the rotor. Asynchronous motors include induction motors, doubly-fed asynchronous motors, and AC commutator motors. Induction motors are the most widely used, and without causing misunderstanding or confusion, induction motors can generally be called asynchronous motors.

Advantages: simple structure, easy manufacturing, cheap price, easy to run.

Disadvantages: power factor lag, light load power factor is low, speed regulation performance is slightly worse.

Mainly for electric motors, generally do not do generators!

Three-phase asynchronous motor is divided into cage type and winding type according to the rotor structure form; According to the shell structure, it can be divided into open type, protective type, closed type and explosion-proof type; According to the installation form, it can be divided into vertical and horizontal.