Overview of motors and applications

I. Engine classification

1. DC motor

• Brushless: is a brushless motor hybrid between a 3-phase motor and a DC motor. Have a permanent magnet rotor or stator, whose coils are supplied with 120 degrees out of phase DC current per coil. Has small capacity high speed. There is a controller (dedicated ESC). Applications in electric cars, electric motorcycles and drones.

• Brushed Motor

– Permanent magnets: is a brush DC motor whose stator is a permanent magnet. Small capacity is often used in daily life.

– Electromagnet: is a DC motor whose stator is an electromagnet. Has a large capacity. Commonly used in industry.

– Control method

2. AC Motor

• Induction Motor (IM) or Asynchronous Motor: is a motor with a stator of 3 windings placed 120 degrees apart. The rotor is copper rods connected together to form a closed circuit. When supplying 3-phase power on the stator, a rotating magnetic field is formed. Inside the rotor will appear induced current will generate force F to rotate the motor, so the rotor will move later than the stator. IM motor is easy to control, so it is widely used in all fields (eg pumps, fans, conveyors, compressors,…). Due to the principle of electromagnetic induction, the foucault current is large, so it usually only reaches the IE2 index (Efficiency: efficiency of converting electrical energy to kinetic energy).

Control: Can be used direct starter, star delta, inverter.

• Permanent Magnets (PM) or Synchronous Motor: is a motor whose stator is 3 windings placed 120 degrees out of phase. The rotor is a permanent magnet. Because of using permanent magnet, PM motor has no delay between stator and rotor, can reach IE4 index. There are 3 types of PM motors:

• PM thường: According to the way of pasting magnets divided into 2 types Interior Permanent Magnets (IPM) và Suface Permanent Magnets (SPM).

Control: It is possible to use a distributed Song Nguyen inverter running in PM mode.

• Torque Motor: Torque motor is a special brushless permanent magnet synchronous motor. Since the load is directly connected to the rotor without the use of drive elements, torque motors are classified as direct drive. The motor has many pairs of poles, so it generates large torque at low speed. Used in coil collection and discharge systems.

• Servo motor: Like the SPM motor, the servo motor has an additional encoder for position as well as speed feedback. Because of the feedback, Servo is used in high-precision applications such as printing, cutting, CNC, etc.

3. Application

• Advantages and disadvantages of different types of motors

• About application and replacement:

– Brushed DC motors used in old machines are imported with the machine to run torque and speed for the collection and discharge systems of fabric, steel, etc. DC motors can be replaced by IM motors, but the capacity must be increased. double (ignoring mechanical constraints).

– Engine IM: Easy to use should be applied in many different fields.

– Engine PM Often: Applications in coil collection and discharge systems, air compressors, etc.

– Engine Servo: Widely used in printing, oscillating cutters, and position control applications such as CNC, robotics, etc.

PM motor screw air compressor

II. Some practical applications

Stainless Steel Cutting Machine

Label press machine

Label Printer