How to solve the vibration noise problem?
In this regard, each family has its own means. Some focus on solving problems through the process, some focus on the design of the motor body, some focus on solving problems from the perspective of the controller, and more comprehensive strategies are adopted by the masters.
Solving from the routing is a passive solution. A common method is to improve the quality of the dipping paint, such as increasing the amount of paint and the depth of soaking by secondary dipping. A similar approach is to improve the quality of the core stack, reduce the amount of shrapnel, improve the length of the winding ends and the quality of the lashing. The essence of these means is to increase the stiffness and damping of the structural system, thereby reducing the amplitude of the vibration.
Solving from the ontology design route is an essential solution. The main idea is to reduce the electromagnetic force by weakening the electromagnetic force from the source of the vibration. If the attenuation is not enough, the frequency of the problem electromagnetic force avoids the natural frequency of the structure. . The corresponding means has a slot ratio option, which can significantly change the frequency distribution of the electromagnetic force; improve the uniformity of the air gap, and can control the electromagnetic force component, and the uneven air gap will cause additional harmonics and generate additional electromagnetic force. There are many other methods, not to mention one.
The control route is solved. In the case that the motor body problem cannot be eliminated, the subjective initiative of the controller can also be exerted, and the hardware cannot be supplemented by the software. A common method is harmonic management. It can solve the problem from both sides. For example, if it has been clearly analyzed that the five armature harmonics are the main source of vibration noise, then the 5th harmonic is separately suppressed during control, thus reducing the noise. If, in turn, the main noise is caused by the 1st-order tooth harmonic, and the 5th armature harmonic can just offset the electromagnetic force generated by the 1st-order tooth harmonic, then we will actively inject the 5th armature harmonic, just like Attack with poison. In foreign countries, solving the vibration and noise problem from the control side has become a research hotspot because it is flexible and does not require an increase in cost.
Below I will first give three foreign scholars the solution to the problem from the motor ontology in order to open up ideas and inspire.
The first example is for the noise caused by the cogging harmonics of the concentrated winding. Some people have modified the stator teeth as shown in the following figure, and the arc surface is flattened. Parametric calculations were made with the width of the crest and the height of the crest as variable parameters. The result of the final optimization is to reduce the vibration of the motor by 7%.
The second example is about torsional vibration and oblique poles. The first motor of this predecessor divided the rotor into two sections with a half-slot between the two sections. In this way, the torque ripple is reduced, and the vehicle is more stable during the starting process, but the noise of the motor at 3000-4000HZ is found to be particularly large. The problem lies in the torsional resonance. The third-order torsional mode frequency of the stator of the motor is 3725HZ, and the vibration shape is stretched up and down, and the upper and lower phases are just opposite. The two-stage oblique pole causes the cogging torque phases of the upper and lower sections to be opposite. This is highly consistent with the vibration mode, which inevitably leads to torsional resonance at a certain speed. The solution is to improve the oblique pole mode. The two new oblique pole modes are as follows. The noise improvement effect is obvious.
The third example uses asymmetrical deformation and recombination of the rotor to achieve a similar slanting pole effect. As shown in the figure below, there are two types of rotor punching, the left pole arc of the A punch is smaller than the right pole arc, and the B punch is just the opposite. The two kinds of punches are combined into one rotor by means of A-B-A, and the effect is very good after the measurement. Not only has the 1000-2000HZ noise been significantly reduced, but the cogging torque has also decreased considerably.
If you want to buy a food processing processor motor, please pay attention to high speed mixer motor.
