How to regulate the speed of a DC motor_Speed ​​regulation formula of a DC motor

How to regulate the speed of DC motor

The speed of a DC motor can be controlled by adjusting the power supply voltage, changing the connection method of the armature winding, changing the number of magnetic poles, changing the load of the motor, etc.

Specifically, the speed regulation methods of DC motors mainly include the following:

Voltage speed control method: The motor speed is adjusted by changing the power supply voltage. When the power supply voltage increases, the motor speed also increases, and vice versa, the motor speed decreases.

Armature speed control method: The speed of the motor is changed by changing the connection method of the armature winding. In the series connection method, the armature and the power supply are connected in series, which can reduce the speed of the motor as the load increases. In the shunt connection method, the armature and the power supply are connected in parallel, which can increase the speed of the motor as the load increases.

Magnetic pole speed regulation method: The motor speed is changed by changing the number of magnetic poles of the motor. When the number of magnetic poles increases, the motor speed will decrease, and vice versa, the motor speed will increase.

Load speed regulation method: Change the motor speed by changing the load of the motor. When the load increases, the motor speed will decrease, and vice versa, the motor speed will increase.

In addition, precise speed regulation of the motor can be achieved by adding a speed regulator to the circuit. Common speed regulators include adjustable resistors, voltage regulators, PWM controllers, etc. Different speed regulators can be selected according to specific speed regulation requirements.

In short, there are many methods for speed regulation of DC motors. The specific method to be selected depends on the motor's working requirements, control accuracy, cost and other considerations.

Speed ​​regulation formula of DC motor

The speed regulation formula of DC motor can be expressed as:

N = （U - IaRa） / kφ

Among them, N is the speed of the motor, U is the power supply voltage of the motor, Ia is the armature current of the motor, Ra is the armature resistance, k is the torque constant of the motor, and φ is the magnetic flux of the motor.

According to this formula, it can be seen that the speed of the DC motor is related to the power supply voltage, the armature current of the motor and the magnetic flux. When the power supply voltage or the armature current increases, the speed of the motor will also increase. Conversely, when the power supply voltage or the armature current decreases, the speed of the motor will also decrease. At the same time, when the magnetic flux increases, the speed of the motor will decrease, and conversely, when the magnetic flux decreases, the speed of the motor will increase.

It should be noted that this formula is a theoretical formula. In practical application, it is necessary to consider the actual working conditions of the motor and the motor's characteristic curve and other factors, and make appropriate corrections and adjustments. At the same time, it is also necessary to select the corresponding controller and control algorithm according to the specific speed regulation method to achieve accurate speed regulation control.