| Variable frequency speed control technology has become one of the main technology to improve energy conservation, technological process, product quality and production efficiency for the enterprises. With the continuous development of the power electronic devices, microprocessor and AC motor control theory, variable frequency speed control technology will also make huge progress. Research and development of high performance vector control inverter has important significance to improve the speed range, speed control precision and dynamic response ability for induction motor.Firstly, the development and status of variable frequency speed control technology, and the induction motor speed control strategy are introduced. According to simplified mathematical model, the induction motor vector control system is established by the rotor field orientation and speed sensorless technology. The rotor flux observation is realized by improved voltage model method, and the rotor speed is obtained by PI adaptive speed estimation method in this control system. The correction of current and speed closed loop system is realized by the design of the regulator.The principle and realization of SVPWM is given. The dead time effect of the inverter is analyzed, then a dead time compensation method based on SVPWM is proposed. Motor parameters are obtained by the response signal which stimulated by DC and AC signals generated in the inverter.The hardware structure of vector control inverter with the DSP as the core is introduced in detail, and the system software design process is given. Finally, tests of performance and function for the inverter are carried out based on the experimental platform. The results show out that the vector control inverter has good control performance. Compared with the traditional general inverter, the design in this paper makes the induction motor has better speed range, the dynamic response ability and anti-interference ability. |
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