What is the excitation winding of a shunt-excited DC motor connected in parallel with?

A shunt DC motor is a common type of DC motor in which the field winding is connected in parallel with the armature winding. In this article, we will discuss in detail the working principle of a shunt DC motor, the parallel connection of the field winding with the armature winding, and the applications of shunt DC motors.

1. Working principle of shunt-excited DC motor

1. Basic Principles of DC Motors

A DC motor is a device that converts DC electrical energy into mechanical energy. Its working principle is based on the law of electromagnetic induction and the Lorentz force law. When a DC current passes through the coil of the motor, a magnetic field is generated around the coil. This magnetic field interacts with the magnetic field generated by the permanent magnet or electromagnet of the motor to generate torque, causing the rotor of the motor to rotate.

1. Characteristics of Shunt-excited DC motors

A shunt-excited DC motor is a special type of DC motor in which the field winding is connected in parallel with the armature winding. This type of motor has the following characteristics:

(1) The excitation current is the same as the armature current, the excitation magnetic field and the armature magnetic field reinforce each other, and the output torque of the motor is increased.

(2) The field winding and the armature winding are connected in parallel, making the field current and the armature current independent of each other, making it easier to adjust the speed and torque of the motor.

(3) Since the excitation magnetic field and the armature magnetic field reinforce each other, the efficiency of the motor is higher and it is suitable for occasions requiring larger torque and higher efficiency.

2. Parallel connection of field winding and armature winding

1. Basic Concepts of Parallel Circuits

A parallel circuit is a circuit in which two or more circuit elements are connected at both ends and are subject to the same voltage. In a parallel circuit, the currents of the components can be different, but the voltages are the same.

1. Parallel connection of field winding and armature winding

In a shunt-excited DC motor, the field winding is connected in parallel with the armature winding. Specifically, the two ends of the field winding and the armature winding are connected together to bear the input voltage of the motor together. In this way, the field current and the armature current can be independent of each other, making it easy to adjust the speed and torque of the motor.

1. Advantages of connecting the field winding in parallel with the armature winding

(1) The excitation current and armature current are independent of each other, which makes it easy to adjust the speed and torque of the motor.

(2) The excitation magnetic field and the armature magnetic field reinforce each other, increasing the output torque of the motor.

(3) Since the excitation current is the same as the armature current, the efficiency of the motor is higher.

3. Application of Shunt-excited DC Motor

1. Industrial field

Shunt-excited DC motors are widely used in industrial fields, such as cranes, conveyor belts, elevators, etc. These devices require large torque and high efficiency, and shunt-excited DC motors just meet these requirements.

1. Transportation

Shunt-excited DC motors are also widely used in the transportation field, such as electric vehicles, subway trains, etc. These devices require higher starting torque and higher efficiency, and shunt-excited DC motors can meet these requirements.

1. Aerospace

In the aerospace field, such as satellites, spacecraft, etc., shunt-excited DC motors are also used. These devices require higher efficiency and longer service life, and shunt-excited DC motors have these advantages.

4. Advantages and disadvantages of shunt-excited DC motors

1. advantage

(1) The excitation magnetic field and the armature magnetic field reinforce each other, increasing the output torque of the motor.

(2) The excitation current and armature current are independent of each other, which makes it easy to adjust the speed and torque of the motor.

(3) Since the excitation current is the same as the armature current, the efficiency of the motor is higher.

1. shortcoming

(1) Since the field winding is connected in parallel with the armature winding, the motor is larger in size and weight.

(2) In some special occasions, such as equipment that needs to start quickly or start and stop frequently, additional control circuits may be required to adjust the excitation current.

5. Development trend of shunt-excited DC motor

1. Application of high performance materials

With the development of high-performance materials, such as high-performance permanent magnet materials and high magnetic permeability materials, the performance of shunt-excited DC motors can be further improved, such as increasing output torque and reducing energy consumption.

1. Innovation in control technology

With the development of control technologies, such as digital control and intelligent control, the control accuracy and response speed of shunt-excited DC motors can be further improved to meet the needs of more special occasions.

1. System Integration

With the development of system integration technology, shunt-excited DC motors can be integrated with other devices, such as sensors and controllers, to achieve more efficient control and wider applications.

VI. Conclusion

Shunt-excited DC motors are DC motors with high efficiency and large output torque, and are widely used in industries such as industry, transportation, and aerospace. By connecting the field winding and the armature winding in parallel, the field current and the armature current are independent of each other, making it easier to adjust the speed and torque of the motor. With the development of high-performance materials and control technology, as well as the innovation of system integration technology, the performance of shunt-excited DC motors will be further improved, and their application areas will be more extensive.