The Study Of Dual-pwm Variable Frequency Speed Regulatjon System

Because of un-controlled rectifier, general inverter has some drawbacks, such as low ac-side power factor, big current ripple and un-revisble power flow. By replacing the un-controlled rectifier of general inverter with PWM rectifier is characteristic of dual-PWM variable-frequency system.This kind of device can actively raise ac-side power factor, eliminate ac-side harmonic pollution of inverter, economize energy resources, and promote performance of inverter.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 thepaper, 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 varisble frequency speed regulation system on inverter side analyzes and studies several control schemes on AC-motor variable frequency speed regulation theoretically, key in the of SVPWM technology in AC-motor varisble 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 2812DSP chip of TI Company to realize numerical control of SVPWM .The research production of this paper will offer practical value to research and develop Dual-PWM variable frequency system.