Abstract
II
Research on Vector-controlled Induction Motors Based
on the Sliding Mode Variable Structure Control
ABSTRACT
The vector control system of three phase asynchronous motors without Using Speed
Sensor is a hot issue in AC drive control theory and application research. The main research
contents of this paper are: (1) improved SVPWM algorithm to control the neutral point
voltage balance of the three level NPC inverter; (2) Mathematical formula derivation and
modeling based on rotor field oriented vector control of three phase induction motor;(3)
Several methods of speed estimation were analyzed and compared. The model reference
adaptive (MRAS) method and the sliding mode observer method were discussed.
Firstly, this paper introduced the working principle of three level NPC inverter, mainly
talked about the neutral point voltage offset of the SVPWM, and on the basis of this, the
virtual SVPWM algorithm was adopted. The problem of the middle point voltage deviation
was solved from the root. So it was helpful to supply higher quality three-phase power for
three phase induction motor.
Secondly, the paper was based on the mathematical model of rotor flux oriented vector
induction motor control. By modeling the flux regulator, torque regulator and speed regulator,
there built up the whole asynchronous motor vector control system model. In order to get rid
of the speed sensor, rotor speed was estimated by sampling stator voltage and current data
which was based on the vector control system of induction motor. Two mathematical model of
simple speed calculation method was introduced in this paper, there were slip calculation
method and the direct synthesis method for the equation of state. The problem of the
parameter dependence on the pure integral saturation would seriously affect the stability of
the system. To solve this problem, this paper focused on the model reference adaptive method,
and then used the Popov super stability theory to prove the feasibility of the model reference
adaptive algorithm. The transfer function of the adaptive algorithm was derived in detail. The
adaptive algorithm PI regulator was designed based on the transfer function. Finally,
according to the motor parameter variation that was caused by the instability of the system
such as interference problem, this paper adopted sliding mode observer instead of adaptive
algorithm PI controller.
Finally, On Matlab/Simulink the software platform, the simulation of speed sensorless
vector control system of induction motor was realized. The simulation results show that:
aiming at the problem of inaccurate model and other disturbances which was caused by the
changing motor parameters, comparison of simulation results by model reference adaptive
method and sliding mode observer method, the method of mode observer can obtain a better
speed tracking effect with strong stability and anti-disturbance.
key words: three level NPC inverter; vector control; model reference adaptive; Sliding
mode observe
万方数据
5星 · 超过95%的资源 66 浏览量
2022-07-12
06:33:17
上传
评论
收藏 6.4MB PDF 举报 
2301_776724402023-04-24内容与描述一致，超赞的资源，值得借鉴的内容很多，支持！
