How to solve the problem of stepper motor overheating

One of the most significant advantages of stepper motor is that it can be controlled accurately in open loop system because the rotor position can be determined only by tracking the input step pulse, but overheating problem occurs easily in stepper motor, so how to solve this problem if such condition occurs?

1. Reduce the heat radiated from motor, which is to reduce copper loss and iron loss. There are two ways to reduce copper loss: reduce the resistance and the current, which requires us to choose the motor with small rated current as much as possible. For 2-phase stepper motor, do not use parallel-motor unless serial-motor cannot use, but this often contradicts the requirements of torque and speed.
2. For selected motor, automatic half-flow control function and offline function of the driver should be fully utilized. The former will reduce the current automatically while the latter will cut off the current directly when the motor is in static condition.
3. Besides, the current waveform is close to sine, so harmonic of subdividing stepper motor driver is less and heat from motor is less. There are not many ways to reduce iron loss. Voltage grade is related with the loss. High-voltage drive motor can improve the high speed characteristic, but also causes the heat increasing.
4. Proper drive motor voltage grade should be selected and those indexes, such as high speed characteristic, smoothness, heat and noises, etc. should be also taken into account.