郑州航空工业管理学院
毕 业 论 文（设 计）外文翻译
  2016 届  电子信息工程  专业  1213081  reactor 翻译班级
姓    名      王兴宇    学号121308128
指导教师      王义琴    职称  讲师 
二О一 六 年 三 月 十 日
The Design of the Vector Control System of Asynchronous Motor
Abstract: Among various modes of the asynchronous motor speed control, vector control has the advantages of fast response, stability, transmission of high-performance and wide speed range. For the need of the asynchronous motor speed control, the design uses 89C196 as the controller, and introduces the designs of hardware and software in details. The Design is completed effectively, with good performance simple structure and good prosp
ects of development.
Keywords: Asynchronous motor, 89C196, Vector control
1. Introduction
AC asynchronous motor is a higher order, multi-variable, non-linear, and strong coupling object, using the concept of parameters reconstruction and state reconstruction of modern control theory to achieve decoupling between the excitation component of the AC motor stator current and the torque component, and the control process of AC motor is equivalent to the control process of DC motor, the dynamic performance of AC speed regulation system obtaining notable improvement, thus makes DC speed replacing AC speed possible finally. The current governor of the higher production process has been more use of Frequency Control devices with vector-control.
2. Vector Control
With the criterion of producing consistent rotating magneto motive force, the stator AC current, , by3S/2S conversion in the three-phase coordinate system, can be equivalent to AC current，， in two-phase static coordinate system, through vector rotation transformation of the re-orientation of the rotor magnetic field, Equivalent to a synchronous rotation coordinates of the DC current，. When observers at core coordinates with the rotation together, AC machine becomes DC machine. Of these, the AC induction motor rotor total flux, it has become the equivalent of the DC motor flux, windings equivalent to the excitation windings of DC motor , equivalent to the excitation current, windings equivalent to false static windings, equivalent to the armature current proportional to torque. After the transformation above, AC asynchronous motor has been equivalent to DC motor. As a result, imitating the control method of DC motor, obtaining the control variable of DC motor, through the corresponding coordinates anti-transformation, can control the asynchronous motor. As a result of coordinate transformation of the current (on behalf of magnetic momentum) space vector, thus, this control system achieved through coordinate transformation called the vector control system,
referred to VC system. According to this idea, could constitute the vector control system that can control and directly, as shown in Figure 1. In the figure a given and feedback signal through the controller similar to the controller that DC speed control system has used, producing given signal of the excitation current and given signal of the armature current, after the anti-rotation transform VR-1 obtaining and, obtains, , by 3S/2S conversion. Adding the three signals controlled by current and frequency signal obtained by controller to the inverter controlled by current, can output three-phase frequency conversion current that asynchronous motor needs for speed.
3. The Content and Thought of the Design
This system uses 80C196 as controller, consists of detection unit of stator three-phase current unit of keyboard input, LCD display modules, given unit of simulation speed detection unit of stator three-phase voltage, feedback unit of speed and output unit of control signals. System block diagram shown in Figure 2, the system applies 16 bits MCU 80C196 as control core, with some hardware analog circuits composing the vector control s
ystem of asynchronous motor. On the one hand, 80C196 through the A/D module of 80C196, speed gun and the given speed feedback signals has been obtained, obtaining given torque of saturated limiting through speed regulator, to obtain the given torque current; Use a given function generator to obtain given rotor flux, through observation obtaining real flux, through flux regulation obtaining given excitation current of given stator current, then the excitation current and the torque current synthesis through the K/P transformation, obtaining amplitude and phase stator current, after amplitude of stator current compared to the testing current , control the size of stator current through current regulator.; on the other hand, the stator current frequency is calculated by the simultaneous conversion rate for the time constant of the control inverter, regularly with timer, through P1,submitting trigger word to complete the trigger of the inverter.

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