Electrical network stepper motor as a digital performance of the components, widely used in the motion control system. Many users friends in the use of stepper motor, the feeling machine work with larger fever, suspicious, I do not know this kind of phenomenon is normal. Fever is actually a common phenomenon of stepper motor, but how the degree of fever is normal, and how to minimize stepper motor fever? First of all, to understand why stepper motor heating on all kinds of stepping motor, internal are composed of iron core and the windings. Will happen winding resistance, electric loss, the loss is proportional to the square of the intrusive and resistance and current, this is what we call the copper loss, if the current is not a standard dc or sine wave, harmonic loss will happen; Core has hysteresis eddy current effect, can also occur in the alternating magnetic field loss, its intrusive and materials, current, frequency, voltage, this is called iron losses. Copper loss and iron loss will be displayed in the form of heat, and then influence the power of the machine. Stepper motor general pursuit of position precision and torque output, low power, the electric current is compared commonly big, high harmonic components, the frequency of the alternating current is also change with speed, thus stepping motor common heating conditions, and conditions than the general ac motor. , moreover, the stepper motor heating control in a reasonable range of fever allowed to what extent, mainly depends on the internal motor insulation class. Internal insulation at high temperature (More than 130 degrees)Will be damaged. Are no more than 130 degrees, so as long as the internal motor will not damage, while the surface temperature under 90 degrees. So, step motor surface temperature in 70 -80 degrees are normal. Simple useful point thermometers, temperature measurement method can also be roughly judging: 1 - to contact with the handMore than 2 seconds, do not surpass 60 degrees; Can only touch with the hand, around 70 -80 degrees; Drop a few drops of water gasification rapidly, more than 90 degrees; A temperature measuring gun, of course, also can be used to detect. Third, stepper motor heat change with speed condition with constant current driver skills, the stepper motor under static and low speed, the current will keep relatively constant, to adhere to the constant torque output. High speed to necessarily degree, higher motor internal counter potential, current will decline gradually, torque will decline. Therefore, because of the copper loss of heat condition is related to the speed. Generally high fever when static and low speed, high speed low fever. But the iron losses (Although the share of smaller)Change the condition of not so much, and motor of the fever is the sum of the two, so the only general situation. Fourth, the effects of heating motor fever although generally does not affect the stature, for most customers don't need to ignore. However, the severe fever will bring some negative impacts. Internal parts such as motor thermal expansion coefficient of different lead to the change of the structure stress and small changes in the internal air gap, will affect the motor dynamic echo, high-speed will simply out of step. And as some situation does not allow excessive heating of the motor, such as medical equipment and precision test equipment, etc. So for the motor heating shall carry out the necessary control. Finally, the cutting motor fever fever, cuts is to cut copper loss and iron loss. Reduce copper loss, there are two directions, cutting resistance and current, choose as far as possible when this request in the selection of small resistance and the rated current of the motor, the two-phase motor, motor without parallel in tandem. But this often conflict with the moment and the requirement of high speed. About has selected motor, should make full use of the drive active flow control function and offline function, the former voluntary reduction in current when motor is static, the latter is simply the current block. In addition, the subdivision driver because current waveform is close to sine, less harmonic, electric heating will be less. Cut iron loss method, voltage grade, with high pressure driven motor while improve the characteristic of high speed, but also brings the increase of the heat. So should choose the appropriate drive voltage grade, recommend suite, give attention to two or morethings stationarity and fever, noise, etc.
