The Study Of Dual-PWM Variable Frequency Speed Regulation System Based On DSP Control Technology

With the development of microcomputer control technology and Power Electric device, the AC motor variable frequency speed regulation technology also receive considerable progress, and plays an extremely important role in the production and life. AC-DC-AC variable frequency speed regulation system based on traditional diode rectifier has simple structure and can be realized into digital control, and this structure is a kind of generally adopted control form in which medium-to-high grade frequency converters at present. However, Electromagnetic Interference and harmonious wave pollute which caused by current distortion in uncontrollable rectifier have become a serious problem increasingly.Dual-PWM variable frequency speed regulation system which be put forward in this paper is based on AC-DC-AC configuration. The system adopts PWM controllable rectifier, it has several advantages such as its ac-side current like sine-wave approximately, ac-side power factor is close to 1, quicker dynamic response, bidirectional power transmit, all these realize energy-conservation speed regulation with high combination of "green environmental protection" really.Dual-PWM variable frequency speed regulation system includes PWM rectifier and PWM inverter;key technology lies in PWM rectifier. The operation principle of PWM rectifier is introduced in detail in the paper, the mathematical model based on switch function is provided and introduces the rotatory coordinates system on this basis, and then provides the mathematical model under the rotatory coordinates system of two phase. Employ feed-forward control technology, the paper designs PI regulator control of current closed-loop and voltage closed-loop. Using Power Electric toolbox offered by MATLAB to finish the simulation experiment under Simulink environment and to verify systematic exactness and feasibility.In the research of variable frequency speed regulation system on inverter side, analyzes and studies several control schemes on AC-motor variable frequency speedregulation theoretically, key in the utility of SVPWM technology in AC-motor variable frequency speed regulation system, and offer the MATLAB simulation result to verify the design of this part.The paper designs the Dual-PWM variable frequency system on the base of theory analysis. The system design includes main circuit, control circuit, sampling circuit, and provide the design project. The design adopts 2407DSP chip of TI Company to realize numerical control of PWM rectifier double closed-loop, and to realize software design to receive preliminary result. The research production of this paper will offer practical value to research and develop Dual-PWM variable frequency system.