BLDC motor commutation and controls
標(biāo)簽： commutation controls motor BLDC
上傳時(shí)間： 2014-11-17
上傳用戶：exxxds
General Description The LM621 is a bipolar IC designed for commutation of brushless DC motors. The part is compatible with both three- and four-phase motors. It can directly drive the power switching devices used to drive the motor. The LM621 provides an adjustable dead-time circuit to eliminate ``shootthrough'' current spiking in the power switching circuitry. Operation is from a 5V supply, but output swings of up to 40V are accommodated. The part is packaged in an 18-pin, dual-in-line package.
標(biāo)簽： 621 LM 無(wú)刷電機(jī)
上傳時(shí)間： 2013-07-24
上傳用戶：sdq_123
單相橋式逆變電路為例：S1～S4是橋式電路的4個(gè)臂，由電力電子器件及輔助電路組成。S1、S4閉合，S2、S3斷開(kāi)時(shí)，負(fù)載電壓uo為正S1；S1、S4斷開(kāi)，S2、S3閉合時(shí)，uo為負(fù)，把直流電變成了交流電。改變兩組開(kāi)關(guān)切換頻率，可改變輸出交流電頻率。圖5-1 逆變電路及其波形舉例電阻負(fù)載時(shí)，負(fù)載電流io和uo的波形相同，相位也相同。阻感負(fù)載時(shí)，io滯后于uo，波形也不同（圖5-1b）。t1前：S1、S4通，uo和io均為正。t1時(shí)刻斷開(kāi)S1、S4，合上S2、S3，uo變負(fù)，但io不能立刻反向。io從電源負(fù)極流出，經(jīng)S2、負(fù)載和S3流回正極，負(fù)載電感能量向電源反饋，io逐漸減小，t2時(shí)刻降為零，之后io才反向并增大 （2）換流方式分類換流——電流從一個(gè)支路向另一個(gè)支路轉(zhuǎn)移的過(guò)程，也稱換相。開(kāi)通：適當(dāng)?shù)拈T(mén)極驅(qū)動(dòng)信號(hào)就可使其開(kāi)通。關(guān)斷：全控型器件可通過(guò)門(mén)極關(guān)斷。半控型器件晶閘管，必須利用外部條件才能關(guān)斷，一般在晶閘管電流過(guò)零后施加一定時(shí)間反壓，才能關(guān)斷。研究換流方式主要是研究如何使器件關(guān)斷。本章?lián)Q流及換流方式問(wèn)題最為全面集中，因此在本章講述1、器件換流利用全控型器件的自關(guān)斷能力進(jìn)行換流（Device commutation）。2、電網(wǎng)換流由電網(wǎng)提供換流電壓稱為電網(wǎng)換流（Line commutation）。可控整流電路、交流調(diào)壓電路和采用相控方式的交交變頻電路，不需器件具有門(mén)極可關(guān)斷能力，也不需要為換流附加元件。3、負(fù)載換流由負(fù)載提供換流電壓稱為負(fù)載換流（Load commutation）。負(fù)載電流相位超前于負(fù)載電壓的場(chǎng)合，都可實(shí)現(xiàn)負(fù)載換流。負(fù)載為電容性負(fù)載時(shí)，負(fù)載為同步電動(dòng)機(jī)時(shí)，可實(shí)現(xiàn)負(fù)載換流。
上傳時(shí)間： 2013-10-15
上傳用戶：qingdou
介紹了采用ATmega48單片機(jī)實(shí)現(xiàn)三相無(wú)刷直流電機(jī)控制器的方法。利用Atmega48獲得帶死區(qū)的脈寬調(diào)制（PWM）、霍爾傳感器的換相處理、正弦驅(qū)動(dòng)信號(hào)的產(chǎn)生和電機(jī)轉(zhuǎn)速的控制等功能。采用該方法的優(yōu)點(diǎn)是所需的外圍器件少，成本低。 Abstract: The method of 3-phase brushless DC motor control based on ATmega48 is presented in this paper.The system uses ATmega48 to generate PWM signals with dead-time, hall sensors signals commutation，sine driving signal and rotational speed of motor.Using this method，the needed external devices are few, the cost is low.
標(biāo)簽： ATmega 48 無(wú)刷電機(jī) 控制方法
上傳時(shí)間： 2013-12-09
上傳用戶：330402686
Agenda■Motor Types Overview■BLDC Motor Applications■Comparison of DC to Brushless DC Motors■Hall Sensors■Six-Step commutation■Sensorless commutation with Back-EMFVector Motor Control basicsClosed-Loop Speed Control■Introduction to BLDC Motor Control Evaluation Kit■SummaryAll the popular motor types have their specific applications, and all can be controlled with microcontrollers.We wll talk about Brushless DC motors as it is the fast growing motor type today.Motors used in modern Air conditioners, home appliances, tools, even electric bikes are all going to Brushless DC.
標(biāo)簽： bldc 電機(jī)驅(qū)動(dòng)
上傳時(shí)間： 2022-07-07
上傳用戶：
3-phase Sensor-less Fan Motor DriverAM2355NThe AM2355N is a 3-phase sensor-less DC fan motor driver IC. It senses the BEMF (BackElectro-Motive Force) of the motor in rotation and provides corresponding commutation current tothe motor. Rotation speed can be controlled by PWM input signal. The drivers include LockDetection, Thermal Shutdown, and Over-current Protection. Forward and Reverse control.www.junmintech.com
標(biāo)簽： am2355n
上傳時(shí)間： 2022-07-26
上傳用戶：
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