As a digital actuator, stepper motor has been widely used in motion control system. When using a stepper motor, many of my friends feel that the motor has a lot of heat when it is working, and they have doubts about whether this phenomenon is normal. In fact, heating is a common phenomenon in stepper motors, but what kind of heating is considered normal, and how to minimize the heating of stepper motors?
　　 First of all, we must understand why stepper motors generate heat. For various stepper motors, the interior is composed of iron cores and winding coils. The winding has resistance, and power will cause loss. The loss is proportional to the square of the resistance and the current. This is the copper loss we often say. If the current is not a standard DC or sine wave, harmonic loss will also occur; the iron core has hysteresis The eddy current effect also produces loss in the alternating magnetic field, and its size is related to the material, current, frequency, and voltage. This is called iron loss. Copper loss and iron loss will be manifested in the form of heat, thereby affecting the efficiency of the motor.
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Stepper motors generally pursue positioning accuracy and torque output. The efficiency is relatively low, the current is generally relatively large, and the harmonic component is high, and the frequency of the current alternation also changes with the speed. Therefore, stepper motors generally have heat generation, and the situation is more common. The AC motor is serious. Furthermore, controlling the heating of the stepping motor within a reasonable range to what extent the heating of the motor is allowed depends mainly on the internal insulation level of the motor.
　　Internal insulation performance will be destroyed at high temperature (above 130 degrees). So as long as the interior does not exceed 130 degrees, the motor will not be damaged, and the surface temperature will be below 90 degrees at this time. Therefore, the surface temperature of the stepper motor is normal at 70-80 degrees.