Step-up/down AC voltage regulator using transformer with tap changer and PWM AC chopper

A step-up/down AC voltage regulator is proposed, in which a tap-changing transformer and a pulsewidth modulation (PWM) AC chopper are combined. The proposed regulator can step up or down the output voltage to input voltage. Also, the proposed regulator restrains more harmonics of output voltage compared to the conventional PWM regulator. The input current flows continuously in the proposed regulator, while it flows discontinuously in the conventional PWM regulator. Through digital simulation, several characteristics are investigated theoretically and then compared with those of conventional schemes. Practical verification of the theoretical predictions is presented to confirm the capabilities of the proposed regulator.

[1]  Bimal K. Bose,et al.  Three-Phase AC Power Control Using Power Transistors , 1976, IEEE Transactions on Industry Applications.

[2]  Alan K. Wallace,et al.  An improved PWM technique for AC choppers , 1989 .

[3]  E. El-Bidweihy,et al.  Power Factor of AC Controllers for Inductive Loads , 1980, IEEE Transactions on Industrial Electronics and Control Instrumentation.

[4]  B. W. Williams.  Asymmetrically Modulated AC Chopper , 1982, IEEE Transactions on Industrial Electronics.

[5]  Gyu-Ha Choe,et al.  Asymmetrical PWM technique with harmonic elimination and power factor control in AC choppers , 1995 .

[6]  Shota Miyairi,et al.  Effects of PWM Applied in Single Phase AC Power Control Circuit , 1983 .

[7]  Gyu-Ha Choe,et al.  Improvement of input power factor in AC choppers using asymmetrical PWM technique , 1995, IEEE Trans. Ind. Electron..

[8]  G. N. Revankar,et al.  Symmetrically Pulse Width Modulated AC Chopper , 1977, IEEE Transactions on Industrial Electronics and Control Instrumentation.