Accurate Angle Control System Of Three - Phase Asynchronous Motor Based On

Angle control is widely used by industrial control.Angle control is generally use stepper motor as control object, and the control device is also mostly use miniature computer or a digital signal processor DSP, but the power capacity of stepper motor is restricted, microprocessor and DSP also have special requirements for the environment, for drilling in the field away from the city, that is difficult, and the oil drilling is an important part. Adopting ordinary asynchronous motor with unrestricted drive capacity as the control object and using PLC programmable logic controller with high reliability and low work environment requirement as control method to achieve precise angle control, that is the goal people always want to achieve. This paper researched on a three-phase asynchronous motors precise angle control system based on PLC, and it has good performance.Firstly, a dynamic mathematical model of three-phase asynchronous motors and coordinate transformation principle are introduced in this paper. For asynchronous motor with nonlinear, strong coupling, multivariable, using a vector control technology of high dynamic speed performance, and the principle of vector control and the voltage space vector pulse width modulation (SVPWM) are introduced in details. Combining with the vector control, an accurate control system of induction motor rotation angle based on fuzzy control is introduced to achieve precise positioning of the motor.Secondly, the system is modeled and simulated by the use of MATLAB/Simulink software. According the mathematical model of three-phase asynchronous motor, the technology of vector control and the theoretical knowledge of fuzzy control technology, the every part of the system is modeled and simulated, and do a large number of simulation experiments. The feasibility and correctness of the control algorithm is demonstrated by analyzing simulation result to make a theoretical basis for building hardware platforms.Finally, an accurate angle control system is built that consists with Siemens S7-315PLC and Siemens S120drive system. PLC communicates with S120by using PROFIBUS-DP field bus. By using the STEP7software, hardware is configured and the parameters of S120drive system are deployed, and then the whole system is programmed.Based on the analysis of experimental data, the system designed meets the design requirements.