Research On The Direct Self Control For Brushless DC Motor With High Performance

With the development of permanent magnet material, permanent magnet synchronous motor has the advantages of high efficiency,long life,small bulk,light weight,simple structure, so it was widely used in the field of aviation and spaceflight,military affairs,appliance and industry. There are two kinds of permanent magnet synchronous motor. One is the permanent magnet synchronous motor with the back-EMF of sine wave, it has the good performance, but its structure and control are complicated. The other is permanent magnet brushless DC motor. This kind of permanent magnet synchronous motor with the back-EMF of trapezoid wave has simple structure and control. But its performance was not better than PMSM.BLDCM was further impeled with the development of power electronics technology, control theory and microprocessor technology, which has higher power density than PMSM, but its performance limited its use. So if BLDC's performance was improved through the control theory, BLDCM will be further used. It is also the objective and significance of researching in this paper.The direct self control was proposed to Brushless DC Motor drive system in this papper. The simple structure was holding while the high performance was achieved. This paper analyzed the mathematic model of BLDCM and the simulation model of BLDCM was established by MATLAB. In this model, the simulation result was given with the direct self control theory. When the speed is high, neglecting the influence of the drop voltage of stator-winding resistance, the torque was first in order to get the simple control system. In order to improve the distortion of stator flux-linkage at lower speed, the stator flux-linkage should also be controlled. Therefore, the flux-linkage and torque were adjusted simultaneously. The high-speed and universal ditigtal control platform which can be replaced DSP was designed and debugged. The control software based on TMS320LF2407 was compiled and debugged, realized the experiment of the direct self control theory on BLDCM and validated the theory. Finally, the initial rotor position estimate method which used stator inductance saturation effects was researched on the surface mounted BLDCM, the experiments were carried out to validate the theory.This subject is supported by Delta education development foundation.