Pros and Cons of 4 Pairs of Electric Motors

Figure 1: Different types of electric motors.

According to different structures, working principles, types of operating power, and uses, Electric motors can be divided into various types. Different motors also have their own advantages and disadvantages in terms of price, efficiency, function, energy consumption, etc. The following briefly introduces the pros and cons of direct current (DC) motors and alternating current (AC) motors, asynchronous motors and permanent magnet synchronous motors, three-phase asynchronous motors and single-phase asynchronous motors, and stepper motors and servo motor.

DC Motors vs. AC Motors

The main difference between a DC motor and an AC motor lies in the types of operating power. A DC motor is input with a direct current while an AC motor with an alternating current. The advantages and disadvantages of the two are shown in the table below:

Figure 2: Pros and cons of DC motors and AC motors.

Asynchronous Motors vs. Permanent Magnet Synchronous Motors

The asynchronous motor, also known as induction motor, is an AC motor that generates electromagnetic torque by the interaction of the air-gap rotating magnetic field and the rotor winding induced current, thereby realizing the conversion of electromechanical energy into mechanical energy. Thanks to the mature vector control speed regulation technology, asynchronous motors have obvious advantages. But they are being gradually replaced by other new brushless permanent magnet traction motors. Compared with the brushless permanent magnet synchronous motor, pros and cons of the asynchronous motor are shown in the following table:

Figure 3: Pros and cons of asynchronous motors and brushless permanent magnet synchronous motors.

Three-phase Asynchronous Motors vs. Single-phase Motors

The three-phase asynchronous motor is a kind of induction motor powered by 380V three-phase AC current (phase difference 120 degrees) at the same time. The single-phase motor uses a single-phase AC power supply. Both are asynchronous motors, but they have their own pros and cons:

Figure 4: Pros and cons of three-phase asynchronous motors and single-phase motors.

Stepper Motors vs. Servo Motors

Both stepper motors and servo motors are motor controllers. The former is a motor that converts electrical pulse signals into corresponding angular displacement or linear displacement. The latter is an engine that controls the operation of mechanical elements in a servo system, and is an auxiliary motor indirect transmission. The pros and cons of the two are compared in the following table

Figure 5: Pros and cons of stepper motors and servo motors.

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