Which is the best brushless stepper motor manufacturer?
"Brushless stepper motor? Is it the very small stepper motor?" The brushless stepper motor manufacturer Bangtuo Transportation Control Xiaobian was asked this question a few times by mechanical and electrical Xiaobai, today the brushless stepper motor manufacturer Bangtuo ’s “Brushless Stepper Motor” is introduced by a model brushless stepper motor. And the answers that people often want to know, "Which brushless stepper motor is better?" For your reference!
Nowadays, the general configuration of the brushless stepper motors for aeromodelling on the market basically adopts the "brushless motor" plus ESC combination scheme. We mostly call such motors "brushless motors", and some people call them BLDCM. Related work experience, this type of motor is described as immature.
First of all, there is a certain problem in calling it a DC brushless motor. The data shows that the back electromotive force of BLDCM adapted to square wave drive is similar to a trapezoidal wave. The back electromotive force of trapezoidal wave is not formed by accident, but is controlled manually. Whole distance concentrated winding, the shape of the permanent magnet is tile, multi-radial magnetization, etc. This type of motor is suitable for square wave control, that is, the commonly used control mode of aeromodelling ESC.
The brushless stepper motor manufacturer Bangtuo Transportation Control has actually tested a variety of manufacturers and different models of aeromodel brushless motors. The back-EMF is a sine wave. By querying the winding methods of the brushless motors disclosed and the motors disassembled by yourself, it can be determined that this type of motor is a fractional slot concentrated winding permanent magnet synchronous motor. A synchronous motor with a sinusoidal back-EMF can be controlled by a square wave inverter, which has caused some people to think that the motor is BLDCM.
Of course, if the motor is classified by control method, it belongs to BLDC, and it is not impossible. A very rigorous definition has not been found for the time being. Therefore, a complete description of this type of motor should have the following keywords: outer rotor (only the outer rotor is studied, the inner rotor is not studied), fractional slots, concentrated winding, permanent magnet synchronous machine.
The model brushless stepper motor has sinusoidal drive, but this drive requires precise motor parameters. It is not easy to change the motor. The sensorless algorithm is not very mature, but it has a current loop and the response speed is very fast. The entire hardware cost can also be about twice the former, and the cost of the algorithm is even higher. The current common control algorithm is FOC. DTC will take some time. Sensorless rotor position estimates are mostly injected at high frequencies. Only one of these technologies is known on the multi-rotor. The control chip is ground, but the model is easy to guess. It feels that sinusoidal driving is the development direction of mid-to-high-end aircraft models in the future. After all, response speed and accuracy are necessary guarantees for flexible movement.