服务热线 18660772233
0531-55536261
联系在线客服

无刷电机磁场的变化会带来哪些作用?

来源:http://www.jnmcd.com 发布时间:2019-01-29 浏览:
直流无刷电机是同步电机的一种,也就是说电机转子的转速受电机定子旋转磁场的速度及转子极数(P)影响:N=120.f / P。在转子极数固定情况下,改变定子旋转磁场的频率就可以改变转子的转速。直流无刷电机即是将同步电机加上电子式操控(驱动器),操控定子旋转磁场的频率并将电机转子的转速回授至操控中心反复校对,以期达到接近直流电机特性的方式。也就是说直流无刷电机可以在额定负载范围内当负载改变时仍可以操控电机转子保持必定的转速。  直流无刷驱动器包含电源部及操控部如图 (1) :电源部供给三相电源给电机,操控部则依需求转化输入电源频率。
Brushless DC motor is a kind of synchronous motor, that is to say, the speed of motor rotor is affected by the speed of stator rotating magnetic field and the number of rotor poles (P): N = 120.f/P. When the poles of the rotor are fixed, the speed of the rotor can be changed by changing the frequency of the stator rotating magnetic field. Brushless DC motor is a synchronous motor with electronic control (driver), which controls the frequency of stator rotating magnetic field and feeds the speed of motor rotor back to the control center for repeated proofreading, in order to achieve close to the characteristics of DC motor. That is to say, the brushless DC motor can control the motor rotor to maintain a certain speed when the load changes in the rated load range. The DC brushless driver includes power supply and control unit as shown in Figure (1): The power supply unit supplies three-phase power to the motor, while the control unit converts the input power frequency according to the demand.
向左转|向右转
Turn left | right
电源部可以直接以直流电输入(一般为24V)或以交流电输入(110V/220 V),如果输入是交流电就得先经转化器(converter)转成直流。不论是直流电输入或交流电输入要转入电机线圈前须先将直流电压由换流器(inverter)转成3相电压来驱动电机。换流器(inverter)一般由6个功率晶体管(Q1~Q6)分为上臂(Q1、Q3、Q5)/下臂(Q2、Q4、Q6)衔接电机作为操控流经电机线圈的开关。操控部则供给PWM(脉冲宽度调制)决议功率晶体管开关频度及换流器(inverter)换相的时机。直流无刷电机一般期望使用在当负载改变时速度可以稳定于设定值而不会改变太大的速度操控,所以电机内部装有能感应磁场的霍尔传感器(hall-sensor),做为速度之闭回路操控,同时也做为相序操控的依据。但这只是用来做为速度操控并不能拿来做为定位操控 。
The power supply can be directly input by direct current (usually 24V) or alternating current (110V/220 V). If the input is alternating current, it must be converted to direct current by converter. Whether DC or AC input is to be converted into motor coil, the DC voltage must be converted from a converter (inverter) to a three-phase voltage to drive the motor. Converter (Inverter) generally consists of six power transistors (Q1-Q6) which are divided into upper arm (Q1, Q3, Q5) / lower arm (Q2, Q4, Q6) connected motor as a switch to control the flow through the motor coil. The control unit provides PWM (pulse width modulation) to determine the switching frequency of power transistors and the timing of commutation of converters. DC brushless motor generally expects that the speed can be stabilized at the set value without changing too much speed control when the load changes, so the motor is equipped with Hall-sensor which can induce magnetic field, as a closed-loop control of speed, but also as a basis for phase sequence control. But this is only used as speed control, not positioning control.
山东无刷电机
直流无刷电机的操控原理
Control Principle of DC Brushless Motor
要让电机滚动起来,首先操控部就必须依据hall-sensor感应到的电机转子目前所在方位,然后依照定子绕线决议敞开(或封闭)换流器(inverter)中功率晶体管的次序, inverter中之AH、BH、CH(这些称为上臂功率晶体管)及AL、BL、CL(这些称为下臂功率晶体管),使电流依序流经电机线圈发生顺向(或逆向)旋转磁场,并与转子的磁铁相互作用,如此就能使电机顺时/逆时滚动。当电机转子滚动到hall-sensor感应出另一组信号的方位时,操控部又再敞开下一组功率晶体管,如此循环电机就可以依同一方向持续滚动直到操控部决议要电机转子停止则封闭功率晶体管(或只开下臂功率晶体管);要电机转子反向则功率晶体管敞开次序相反。
In order to make the motor roll, the control unit must first base on the current orientation of the motor rotor induced by hall-sensor, then open (or close) the power transistors in the converter according to the stator winding resolution, AH, BH, CH (these are called upper arm power transistors) and AL, BL, CL (these are called lower arm power transistors) in inverter, so that the current flows through the motor in sequence. The coil produces a forward (or reverse) rotating magnetic field and interacts with the magnet of the rotor, so that the motor can roll clockwise/counter-clockwise. When the motor rotor rolls to the Hall-sensor to sense the orientation of another set of signals, the control unit opens the next set of power transistors, so that the circulating motor can continue to roll in the same direction until the control unit decides to stop the motor rotor, then the closed power transistor (or only open the lower arm power transistor); if the motor rotor is reversed, the power transistor opens in reverse order.
向左转|向右转
Turn left | right
基本上功率晶体管的开法可举例如下:
Basically, the open method of power transistors can be illustrated as follows:
AH、BL一组→AH、CL一组→BH、CL一组→BH、AL一组→CH、AL一组→CH、BL一组, 但绝不能开成AH、AL或BH、BL或CH、CL。此外由于电子零件总有开关的响应时刻,所以功率晶体管在关与开的交织时刻要将零件的响应时刻考虑进去,不然当上臂(或下臂)尚未彻底封闭,下臂(或上臂)就已敞开,结果就形成上、下臂短路而使功率晶体管焚毁。
AH, BL group AH, CL group BH, CL group BH, AL group CH, AL group CH, BL group, but must not be opened into AH, AL or BH, BL or CH, CL. In addition, because the electronic parts always have the response time of the switch, the power transistor should take the response time of the part into account when interleaving with the open. Otherwise, when the upper arm (or lower arm) has not been completely closed, the lower arm (or upper arm) has been opened, resulting in the short circuit between the upper arm and the lower arm, which causes the power transistor to burn.
当电机滚动起来,操控部会再依据驱动器设定的速度及加/减速率所组成的命令(Command)与hall-sensor信号改变的速度加以比对(或由软件运算)再来决议由下一组(AH、BL或AH、CL或BH、CL或……)开关导通,以及导通时刻长短。速度不够则开长,速度过头则减短,此部份工作就由PWM来完结。PWM是决议电机转速快或慢的方式,如何发生这样的PWM才是要达到较精准速度操控的核心。高转速的速度操控必须考虑到系统的CLOCK 分辨率是否足以把握处理软件指令的时刻,另外关于hall-sensor信号改变的资料存取方式也影响到处理器效能与判定正确性、实时性。
When the motor rolls up, the control unit compares (or calculates by software) the speed of the Hall-sensor signal with the command (Command) composed of the speed set by the driver and the acceleration/deceleration rate, and then decides whether the next group (AH, BL or AH, CL or BH, CL or... (2) Switching on, and the length of the turning on time. If the speed is not enough, it will be longer, but if the speed is too high, it will be shorter. This part of the work will be completed by PWM. PWM is the way that decides the speed of motor fast or slow. How to generate such PWM is the core to achieve more accurate speed control. High speed speed control must consider whether the CLOCK resolution of the system is enough to grasp the processing time of software instructions. In addition, the data access mode of Hall-sensor signal changes also affects the processor's efficiency, correctness and real-time performance.
至于低转速的速度操控尤其是低速起动则由于回传的hall-sensor信号改变变得更慢,怎样撷取信号方式、处理时机以及依据电机特性适当装备操控参数值就显得非常重要。或者速度回传改变以encoder改变为参阅,使信号分辨率增加以期得到更佳的操控。电机可以工作顺畅而且响应杰出,P.I.D.操控的恰当与否也无法忽视。之前提到直流无刷电机是闭回路操控,因此回授信号就等于是告诉操控部现在电机转速距离目标速度还差多少,这就是误差(Error)。知道了误差自然就要补偿,方式有传统的工程操控如P.I.D.操控。
As for the low speed speed control, especially the low speed start, the Hall-sensor signal is changed more slowly. It is very important how to pick up the signal mode, the processing time and the appropriate equipment control parameters according to the characteristics of the motor. Or the speed return change refers to the encoder change to increase the signal resolution in order to get better control. The motor can work smoothly and respond well, and the proper operation of P.I.D. can not be ignored. As mentioned earlier, brushless DC motor is closed-loop control, so the feedback signal is equivalent to telling the control unit how far the motor speed is from the target speed, which is Error. Knowing the error will naturally be compensated by traditional engineering manipulation such as P.I.D. manipulation.
以上的精彩内容已经给大家讲述完毕,如果您还有什么问题,请记住我们:山东无刷电机http://www.jnmcd.com我们将会有更多的精彩内容陆续的为大家呈现.
If you have any questions, please remember us: Shandong Brushless Electric Machine http://www.jnmcd.com, we will have more wonderful content for you one after another.
推荐新闻
  • 联系人:张经理
  • 手机:18660772233(微信同号)
  • 电 话:0531-55536261 / 0531-55536272
  • 邮 箱:911510021@qq.com
  • 地 址:山东济南市济南时代欧亚电子大厦一楼A111号
  • Copyright © 2018 济南美磁达电子有限公司 All Rights Reserved 诺商信息 网站地图 XML TXT  鲁ICP备18050301号-1

    鲁公网安备 37010502001057号