How is torque control achieved?

Hello esteemed colleagues,

Torque control in motors can be achieved through various methods, depending on the type of motor and the application.

(Before we start, it would be useful to review our article on What is torque control?)

Here are some common methods:

For DC Motors:

    Voltage Control: In DC motors, the torque is directly proportional to the armature current. By controlling the voltage across the motor, the current and hence the torque can be controlled.

    Current Control: Pulse Width Modulation (PWM) techniques can be used to control the armature current to maintain a constant torque.

    Field Control: For separately excited DC motors, the field current can be adjusted to control torque.

For AC Motors:

    V/f Control (Volts by Frequency Control): In AC induction motors, the torque is indirectly controlled by adjusting the voltage and frequency applied to the motor. (What is V-F Control?)

    Vector Control (or Field Oriented Control): This advanced method allows separate control of the motor's speed and torque by dynamically adjusting the currents in the rotor and stator windings. (What is vector control (with vfd) ?)

    Direct Torque Control (DTC): This is another advanced method that directly calculates and controls the torque by using advanced algorithms and feedback systems. (What is Direct Torque Control (DTC)? )

For Servo Motors:

    PID Control: Proportional-Integral-Derivative (PID) controllers are widely used in servo systems to maintain a constant torque based on error signals. (PID Control With servo?)

    Feedforward Control: In this method, the control algorithm predicts the torque requirements based on load and speed conditions and adjusts the voltage or current accordingly.

Other Methods:

    Gear Ratios: Mechanical methods like using different gear ratios can also be employed to control torque in various applications. (What should I consider when buying a reducer?)

    Software Algorithms: In electric vehicles and robotics, advanced algorithms can adjust torque to optimize performance, range, and efficiency.

    Hydraulic/Pneumatic Systems: In hydraulic or pneumatic systems, pressure can be adjusted to control the torque generated by motors. (FAQ Hydraulic Pumps)

    Slip Control: In certain applications like wound rotor induction motors, adding resistance to the rotor circuit can control the slip, and hence the torque. (what is slip compensation?)

Each of these methods has its pros and cons, and the choice of method often depends on the specific requirements of the application. Factors like required accuracy, dynamic conditions, efficiency, and cost are some of the considerations that influence the choice of torque control method.

"Torque and motors that produce torque are present in every aspect of our lives, whether in electrical or mechanical forms. We've tried to answer the most frequently asked questions about the torque capacities of electric motors below.

- What is torque motor?

- What is torque?

- What is torque boosting?

- What is torque control?

- What is the difference between torque and power?

- How is torque measured?

- What are the units of torque?

- Why is torque important when selecting a motor?

- What advantages does a high-torque motor provide?

- What disadvantages does a low-torque motor bring?

- How is a balance between torque and speed achieved?

- What is the relationship between torque and horsepower in cars?

- What is a torque curve?

- Why do electric vehicles generally produce high torque?

- How can torque be increased?