General stepper motor drivers are constant current chopping. So, in practical applications, what effect does the driver drive voltage and driver set current have on the performance of the stepper motor?
In general: voltage affects speed and current affects torque.
The torque frequency characteristics of stepper motors are all tested under a certain current and voltage. When the current and voltage changes, the moment frequency characteristics will also change accordingly.
For example, for 85 motors with a wide voltage fluctuation range, the driver from 24V to 220V can be applied. The torque of FY86EC502A is 6N.m, which is the static torque in the environment of DC80V<, average current 5A. At 300 rpm, the torque is about 5.2 Nm; if we increase the current to 6 A, the static torque is increased to 6.3 Nm, and the torque at 300 rpm is increased to 5.4 Nm; if the voltage is reduced to DC 24 V, the current remains at 5 A. The static torque is only 5.7Nm, and the torque at 300 rpm is only 4.3Nm.
Relatively speaking, in the case of the same current, the voltage affects the speed of the stepping motor more. For example, a motor, at DC24V, idling up to 2100 rpm, if using DC48V, idling up to 3200 rpm; at the same voltage In this case, the effect of adjusting the current on the stepper motor torque is more prominent.
In fact, only the current affects the moment, and the voltage affects the speed is not correct. The current and voltage changes will change the torque frequency characteristics of the stepper motor. Changing the voltage also changes the torque of the stepper motor. Changing the current also changes the stepper motor. High speed performance.
What needs to be noted is:
First, increasing the voltage or increasing the current will increase the heating of the stepper motor. If the temperature of the stepper motor is too high, thermal demagnetization will occur, so try to choose a motor with a certain margin;
Second, when the motor torque is sufficient, we try to set the current to a slightly smaller gear than the rated current, which can extend the service life of the stepper motor and the driver;
Third, a driver with a rated voltage of 80V, we try to use about 70V, rated voltage AC18-80V, but there is a certain voltage fluctuation range for civil and industrial electricity, the instantaneous peak current of the machine power-on and power-off The voltage will be high, so leaving some margin will greatly reduce the repair rate. Some small brands of stepper motor drivers will give a nominal voltage range of C24-0V for drivers using 100V capacitors. If the user really supplies power at 80V, it is a bit dangerous.