Analysis of Subdivision Control Technology of Micro Motors in spur gear motor factory
Micro-motors are widely used actuators that are used in a variety of automated control systems with nanometer-level accuracy. Micro-motor structures have very high requirements for system stability. The traditional motor control technology can not meet the design requirements, and the motor subdivision technology solves the potential problems of the micro motor factory to a certain extent.
First, know the micro motor
A micromotor is an actuator that converts electrical pulses into angular displacement. When the micro-driver receives a pulse signal, it drives the micro-motor to rotate a fixed step angle in a set direction, and its rotation is operated step by step at a fixed angle. Therefore, we can easily control the angle of the motor rotation by controlling the number of pulses, and control the speed and acceleration of the motor rotation by controlling the pulse frequency.
There are three main types of commonly used micro motors: variable reluctance type, permanent magnet type and hybrid type.
Second, the reasons for subdivision
I have seen many people say that the micro-motor is subdivided to improve the positioning accuracy. In fact, this is not the most important factor. At the same time subdivided, the output torque of the motor is actually increased, especially for the three-phase reaction motor, the torque is increased by about 30-40% than without subdivision, which improves the resolution of the motor and reduces the step size. The angle increases the uniformity of the step size, so subdividing the micro motor is really a lot of benefits.
Third, the subdivision control technology implementation method
Taking a two-phase reactive micromotor as an example, if the number of beats of the motor is N, when f pulses are input every second, the rotational speed of the rotor is, and if f is constant, the speed is changed, and the rotational speed is changed. Increase, increase the number of running shots, thereby reducing the step angle, so that the motor running speed is reduced, in order to maintain the normal working speed of the motor, it is necessary to increase the corresponding number of pulses.
If each input pulse is switched, only a part of the rated current in the corresponding winding is changed, then each step of the rotor will only be part of the original step angle. How many levels of rated current are switched, how many steps the rotor takes to complete an original step angle, and the phase current of the micro motor is stepped to control the motor to run at a smaller unit step angle. Thereby reducing the step size and low frequency oscillation. In short, the idea of subdivision driving is to change the original on-off process of the rotor current to gradually change the current magnitude and direction of each phase winding, so that the spatial synthesis magnetic field inside the motor is gradually changed, so that the original The energization mode of one step angle is changed to become a step wave following the current, and becomes a multi-step. Since the frequency of the commonly used chopper is very high, the current fluctuation at each stage can be ignored, which can be regarded as a DC output.
