Influence of voltage and current on motor performance
RELEASE：admin TIME： 2018-08-11 BROWSING： 1029SECOND
General stepper motor drivers are constant current chopper, so in practical applications, the drive voltage, and the driver set the current, what impact on the performance of stepper motor?
Abstract we can say that voltage affects speed and current affects torque.
The torque-frequency characteristics of stepper motors are measured under a specific current and voltage. When the current and voltage change, the torque-frequency characteristics will also change.
For 85 motors with a wide range of voltage fluctuations, drives from 24V to 220V can be used, with 85HB118-504 torque of 6N.m. This is static torque at DC80V and average current of 5A, about 5.2N.m at 300 rpm; if we increase the current to 6A, the static torque will be 6.3N.m, 300 rpm. The torque is increased to 5.4N.m. If the voltage is reduced to DC24V, the current remains 5A, the static torque is only 5.7N.m, and the torque at 300 is only 4.3N.m.
Relatively speaking, the same current, the voltage more affect the speed of the stepping motor, such as 57HB76-304, in DC24V, idling up to 2100 revolutions, if DC48V, idling up to 3200 revolutions;
Under the same voltage, the influence of adjusting current on stepper motor torque is more prominent.
But one-sided talk about the current influence torque, voltage influence speed is not correct, regardless of the current or voltage changes will change the stepper motor torque-frequency characteristics, change the voltage also changes the stepper motor torque, change the current also changes the high-speed performance of the stepper motor.
Users need to pay attention to, first, increase the voltage or increase the current, will increase the stepper motor heating, stepper motor temperature too high will produce thermal demagnetization, so try to choose a certain margin of motor specifications; second, in the case of sufficient motor torque, we try to set the current to a little less than the rated current. Third, a driver with a rated current of 80V should be used below 70V. Although the driver with rated current of 80V usually uses the capacitance of DC110V, there is a certain range of voltage fluctuation in both civil and industrial power. The peak current voltage will be very high at the moment of power failure, so leaving some margin will greatly reduce the repair rate. Some small brands of stepper motor drives give drivers with 60V capacitors a nominal voltage range of DC24-60V, which can be dangerous if the user actually powers them at 60V.
Abstract we can say that voltage affects speed and current affects torque.
The torque-frequency characteristics of stepper motors are measured under a specific current and voltage. When the current and voltage change, the torque-frequency characteristics will also change.
For 85 motors with a wide range of voltage fluctuations, drives from 24V to 220V can be used, with 85HB118-504 torque of 6N.m. This is static torque at DC80V and average current of 5A, about 5.2N.m at 300 rpm; if we increase the current to 6A, the static torque will be 6.3N.m, 300 rpm. The torque is increased to 5.4N.m. If the voltage is reduced to DC24V, the current remains 5A, the static torque is only 5.7N.m, and the torque at 300 is only 4.3N.m.
Relatively speaking, the same current, the voltage more affect the speed of the stepping motor, such as 57HB76-304, in DC24V, idling up to 2100 revolutions, if DC48V, idling up to 3200 revolutions;
Under the same voltage, the influence of adjusting current on stepper motor torque is more prominent.
But one-sided talk about the current influence torque, voltage influence speed is not correct, regardless of the current or voltage changes will change the stepper motor torque-frequency characteristics, change the voltage also changes the stepper motor torque, change the current also changes the high-speed performance of the stepper motor.
Users need to pay attention to, first, increase the voltage or increase the current, will increase the stepper motor heating, stepper motor temperature too high will produce thermal demagnetization, so try to choose a certain margin of motor specifications; second, in the case of sufficient motor torque, we try to set the current to a little less than the rated current. Third, a driver with a rated current of 80V should be used below 70V. Although the driver with rated current of 80V usually uses the capacitance of DC110V, there is a certain range of voltage fluctuation in both civil and industrial power. The peak current voltage will be very high at the moment of power failure, so leaving some margin will greatly reduce the repair rate. Some small brands of stepper motor drives give drivers with 60V capacitors a nominal voltage range of DC24-60V, which can be dangerous if the user actually powers them at 60V.
