Design and Implementation of a Novel Phase-Shift Pulse Width Modulation Automatic Voltage Regulator

• Main Authors: Jing-Heng Hong, 洪敬恆
• Other Authors: Kuo-Kai Shyu
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/19087237113877184370

碩士 === 國立中央大學 === 電機工程研究所 === 92 === Abstract In this paper, a novel pulse width modulation (PWM) switching strategy for single-phase inverter is proposed. It is applied to the automatic voltage regulator (AVR) to improve its performance. In contrast with conventional PWM switching strategy of the inverter, the proposed strategy uses phase-shifted control to the PWM switching signals. Though those switches have the same switching frequency, the output switching frequency in the inverter is doubled due to the phase-shifted control. It reduces the total harmonic distortions and the filter size for system output. The novel AVR is made up of an AC chopper with reversible voltage control and a compensation transformer in series with AC line. To obtain an inphase or reverse voltage with respect to AC line to compensate the variations, one only needs to control the duty ratio of switches by using the proposed phase-shifted PWM. The AVR uses a fully digital controller, which is implemented by a fixed-point digital signal processor(DSP) (TMS320F240). Therefore, the proposed AVR gives high efficiency and reliability. It is also shown via some experimental results that the presented novel AVR gives fast response for high quality control of the output voltage.