The Study On AC Motor Variable-Frequency Speed Regulating Technology Based On DSP

Energy is an important material foundation in today's society. In the known mechanical, electrical, heat, light, chemical, nuclear and other forms of primary energy, mechanical energy is the most basic energy, while electricity is used, transmission and control of the most convenient, full of energy for human research. The motor is the two energy transformation converter.Since the motor has been produced, although a wide variety of motors, but the most typical are mainly two:DC motor and three-phase AC asynchronous motor. Owing to the simple structure, the easy manufacture, the convenience of use and maintenance, the running credibility, the cheap price, the comparatively satisfied operating characteristic and the relatively high efficiency, the AC asynchronous motor is more common in transmission domain.From the current direction of the electric transmission, and with the continuous development of the electrical and electronical technology, electric drives playing an increasingly important role in modernization. To meet the requirements of high performance,environmental protection and energy conservation, AC variable frequency speeds regulating system plays the important role in the electric drives.Since the 1970s to 1980s,by in-depth study and improvement on AC speeds regulating technology,the AC variable frequency speeds regulating system with its distict advanges is replacing the traditional direct current speeds regulating system gradually, and the SVPWM technology discussed in this article has a superior practical value in thus system. The superiority of motor variable-frequency control technology shows in two aspects:One is the prominence of saving power; the other is the preeminent governing performance.The constant ratio of voltage to frequency (constant V/F) control is the most basic and most used widely in general-purpose inverter. The structure of this control system is the simple and the price is the low. It is suitable for the wind motor and water pump that changed in running more slowly and the request of dynamic performance is not very high. Currently this converter is accepted by the market because of its economy and popularity.This paper described the basic working principle of three-phase AC asynchronous motor and the general situation of AC variable frequency speeds regulating system, the area which applied, the study situation, and expatiated the methods of AC speeds regulating. According to this situation, in this paper a system of the AC motor Variable-Frequncy speed regulating used DSP is designed, the control principle is constant V/F and the control method is technique of space voltage vector PWM. Some major problems are analyzed and the realization methods are also given.Detailed speaking, the main content in this paper is:It discussed the general method of SVPWM technology. Three phase AC asynchronous motor is the controlled object, regard TMS320LF2407A as the processor, based on Intelligent Power Module (IPM) PM25RSB120, this system use SVPWM technology to realize constant V/F control of AC asynchronous motor, and the variable frequency speeds regulating control system of AC asynchronous motor based on DSP is designed. The result of experiment shows the high performance and the good precision.