閉環(huán)控制在無(wú)刷直流電機(jī)系統(tǒng)中的應(yīng)用

　　無(wú)刷直流電機(jī)因其可靠性高、效率高、噪音低而取代傳統(tǒng)的直流電機(jī)。這些產(chǎn)品在幾乎所有領(lǐng)域都很流行，如消費(fèi)電子、家用電器和工業(yè)控制。高性能無(wú)刷直流電機(jī)控制系統(tǒng)的開(kāi)發(fā)需要更高的精度。這是通過(guò)在大多數(shù)BLDC控制系統(tǒng)中使用閉環(huán)控制來(lái)實(shí)現(xiàn)的。

　　無(wú)刷直流電機(jī)

　　直流無(wú)刷電機(jī)在直流電機(jī)上的優(yōu)點(diǎn)是：

　　效率高

　　更可靠和無(wú)電弧換向-無(wú)刷維修

　　更高的速度和功率大小比

　　定子內(nèi)產(chǎn)生熱量-易于去除。

　　低慣量無(wú)換向器

　　更高的加速率

　　BLDC motors are more efficient than brushed DC motors. For the same input power， a BLDC motor converts more electrical power into mechanical power than a brushed motor because of the absence of friction due to brushes. In a brushed motor design， the brushes are used to change the poles of the electromagnet in order to keep the motor spinning. Due to this lack of brushes， there is nothing to mechanically handle the polarity changes. As a result， an electronic controller is required to continuously switch the phase of the winding which will keep the motor spinning. To do this， the stator windings are energized in a particular sequence as seen in Figure 1. BLDC motors have three phases. With this topology， to move the motor， two phases are driven during each commutation cycle. One phase is driven high （VMotor） and the other is driven low （GND）。 The remaining phase is left floating. With every commutation step， the motor will move 60 degrees. Upon completion of all cycles， the motor will have moved a complete 360 degrees.