When constant current drive technology is adopted, the current of NEMA 23 hybrid stepper motor will be maintained relatively constant at static and low speed to maintain constant torque output. When the speed is high to a certain extent, the internal back potential of the motor increases, the current will gradually decrease, and the torque will also decrease. Therefore, the heating due to copper loss is velocity dependent. Static and low speed generally high fever, high speed fever is low. However, the iron loss (though a small percentage) does not always vary, and the total heat of the motor is the sum of the two, so the above is only general.
NEMA 23 hybrid stepper motor heating allowed to what extent, mainly depends on the internal insulation level of the motor. Internal insulation is damaged only at high temperatures (above 130 degrees). So as long as the interior is not more than 130 degrees, the NEMA 23 hybrid stepper motor will not be damaged, and the surface temperature will be below 90 degrees. Therefore, the stepping motor surface temperature in 70-80 degrees is normal. Simple temperature measurement methods are useful for point thermometers, and can also be roughly judged: touch with hands for more than 1-2 seconds, not more than 60 degrees; With the hand can only touch, about 70-80 degrees; Drops of a few drops of water quickly gasification, it is more than 90 degrees; Of course, you can also use a temperature gun to detect.
To reduce the heating of NEMA 23 hybrid stepper motor is to reduce copper loss and iron loss. There are two directions to reduce copper loss, reduce resistance and current, which requires the selection of small resistance and small rated current motor as far as possible, for two-phase motor, can be used in series motor without parallel motor. But this often conflicts with the requirements of torque and high speed.
For the selected NEMA 23 hybrid stepper motor, full use should be made of the driver's automatic semi-current control function and off-line function, the former automatically reduces the current when the motor is static, the latter simply cut the current. In addition, the subdivision driver because the current waveform is close to sinusoidal, less harmonic, motor heating will be less. There is not much that can be done to reduce iron loss. The voltage level is related to this. While high voltage driven motors will improve high-speed characteristics, they will also increase heat. Therefore, the appropriate driving voltage level should be selected, taking into account the high speed, stability and heat, noise and other indicators.
NEMA 23 hybrid stepper motor heating although generally does not affect the life of the motor, for most customers it is not necessary to ignore. However, severe fever can have some negative effects. If the thermal expansion coefficient of each part of the motor is different, the change of structural stress and the small change of internal air gap will affect the dynamic response of the motor, and the speed will be easy to lose step. And some occasions do not allow excessive heating of the motor, such as medical equipment and high-precision test equipment, etc. Therefore, the heating of the motor should be controlled as necessary.
