Analysis and Design of the Control Circuit of Three - phase High Frequency Chopping AC/AC Converter

This essay is based on the development of a practical Three - phase high frequency chopping AC/AC converter , which replaced traditional basic frequency compensation techniques with a high frequency PWM technique. This technique can not only minimize the size and weight but also raise efficiency and reaction speed. This essay mainly analyze and design the controlling circuit, including output sampling circuit, close loop feedback circuit and driving circuit. It also analyzes the stability of controlling circuit and gives a system frame, transporting function and Poter diagram. The essay adopts some methods as followings: a). using stable RMS data to realize the stability of output voltage, b). Using active filtering technique to reduce the higher harmonic wave interference in controlling circuit, c). Utilizing positive temperature character of Zener diode to reduce the temperature instability and compensate negative rectifying diode in sampling circuit d). adopting driving circuit of programmable adjusting dead time to completely meet the needs of interval and time order of three-phase chopping AC/AC converter.