Theoretical study of 3 dimensional hysteresis PWM techniques

In this paper, the theoretical study and comparison between the a-b-c hysteresis PWM technique which is proposed at 1997 and 3 dimensional (/spl alpha/-/spl beta/-0) hysteresis PWM which is proposed at 1998 are performed for 3-phase 4-wire 3-leg center-split power quality compensators. There is description on DC voltage variation control in the a-b-c hysteresis PWM technique, however, no description of DC voltage variation and no determination of error bands are performed for 3-dimensional (/spl alpha/-/spl beta/-0) hysteresis one. In this paper, a novel 3-D hysteresis control is proposed with DC voltage control by the concept of keeping the same overall error bounded volume with higher the DC control ability.