What are the factors that affect the torque produced by an electric motor?

The factors affecting the torque generated by an electric motor mainly include the following aspects:

1. Power Supply Voltage

Voltage Level: The torque of an electric motor is directly proportional to the square of the supply voltage. The higher the voltage, the greater the torque produced by the motor. Conversely, a drop in voltage leads to a significant decrease in torque. For instance, if the supply voltage drops to 80% of its original value, the starting torque will decrease to 64% of its original value.

2. Current

Current: Current is the main energy source that drives the motor to operate. The larger the current, the greater the torque of the motor.

3. Number of Poles in the Motor

Pole Number: The higher the number of poles in a motor, the greater the torque it produces. This is because, under the same conditions, a motor with more poles can generate a stronger magnetic field, thereby increasing torque.

4. Motor Materials and Quality

Material Quality: High-quality motor materials and larger motor mass can improve the torque performance of the motor.

5. The heat dissipation effect of the motor

Cooling Effect: A good cooling effect can ensure that the motor operates normally at high temperatures, improving its torque performance.

6. Load Status

Load Size: The larger the load, the greater the torque required by the motor, but the speed will decrease. Conversely, the smaller the load, the less torque the motor needs and the higher the speed.

7. Environmental Conditions

Temperature and Humidity: The higher the ambient temperature, the lower the speed and torque of the electric motor; high humidity may affect the insulation performance of the electric motor, thereby affecting its performance.

8. Control Algorithm of the Controller

Control Algorithm: Different control algorithms (such as current control, speed control, position control, etc.) have varying effects on the speed and torque of an electric motor.

9. Transmission System Gear Ratio

Transmission Ratio: The larger the transmission ratio, the lower the speed of the electric motor, but the torque will increase.

10. Design Parameters of Electric Motor

Design Parameters: These include factors such as motor type, armature winding, permanent magnet material, rotor structure, etc., which directly affect the speed and torque of the electric motor.

11. Leakage Reactance

Leakage reactance：High leakage reactance (caused by leakage magnetic flux) results in low starting torque; reducing leakage reactance can increase starting torque. Leakage reactance is related to the number of turns in the winding and the size of the air gap.

12. Rotor Resistance

Rotor Resistance: Increasing the rotor resistance can enhance the starting torque. For instance, when starting a wound-rotor induction motor, adding an appropriate amount of additional resistance in series with the rotor winding circuit can increase the starting torque.

In summary, the torque of an electric motor is affected by a combination of various factors, including the supply voltage and current, the number of poles of the motor, material and mass, heat dissipation performance, load conditions, environmental conditions, control algorithms of the controller, gear ratio of the transmission system, design parameters of the motor, leakage reactance, and rotor resistance, among others. In practical applications, it is necessary to consider these factors comprehensively to select and design appropriate electric motors, ensuring that their performance and efficiency reach optimal levels.