無刷直流馬達之自動相角調整晶片的設計與實現

Abstract

本文針對單相及三相無刷直流馬達研製出自動相角調整晶片以改善震動和噪音：在單相無刷直流馬達方面，我們利用霍爾元件所偵測到的霍爾訊號搭配週邊電路送至場效型可規劃邏輯陣列元件(FPGA)處理，再根據不同情形下製造一個適當的假霍爾訊號送至驅動IC，以達到不同轉速下的自動相角調整的目的。而三相無刷直流馬達方面，我們是以無感測換相為基礎，藉由馬達的相電壓訊號進行驅動與控制，改良傳統的120度六步方波驅動，並克服脈波寬度調變(PWM)訊號對無感測換相和震動的影響，設計降低震動與噪音的機制，並且利用此設計開發一個三相無刷直流馬達的自動相角調整之無感測控制晶片。

本文係利用場效型可規劃邏輯陣列元件(FPGA)和硬體描述語言(VHDL)系統層級模組化進行設計。在單相馬達方面，設計出一個數位自動換相器，以精準地估測馬達換相點。而在三相馬達方面，除了設計數位自動換相器外，還設計出一個數位濾波器以克服PWM訊號對無感測換相的影響。不管是單相或者是三相無刷直流馬達透過自動相角調整機制，都可以達到提高功率和改善降低震動與噪音的效果，並且從震動頻譜上探討其改善原因，確實為改善激磁頻下的震動。

An automatic phase adjustment chip for 1-phase or 3-phase BLDCM is mentioned in this paper. In this paper, it is used to reduce the vibration and noise. In respect of 1-phase BLDCM, a Hall signal detected by a Hall device is sent to FPGA (Field Programmable Gate Array) and then a pseudo Hall signal is produced according to different situation to sent drive IC. As a result, automatic phase adjustment under different rotating speed is achieved. In respect of 3-phase BLDCM, based on sensorless commutating, the phase voltage signal is applied to drive and control, in order to improve traditional 120 degree six-step square-wave actuation. Moreover, the effect of PWM(Pulse Width Modulation) signal on sensorless commutating and vibration is overcome. By designing a mechanism to suppress vibration and noise, a 3-phase BLDCM automatic phase adjustment chip with sensorless control chip is implemented.

In this paper, FPGA is design by VHDL(Very High Speed Integrated Circuit Hardware Description Language) on system level module. In respect of 1-phase motor, a digital automatic commutator is design to estimate the commutating point of a motor. By the way, a digital automatic commutator is also used on 3-phase motor and a digital filter is also designed to overcome the effect from PWM signal on sensorless commutating. Automatic phase adjustment can be used not only on 1-phase BLDCM but 3-phase BLDCM, and the effect on raising power and suppress vibration and noise can achieve. With respect to vibration frequency spectrum, the improvement is actually due to reduce exciting frequency vibration.