New Research on AC-AC Converters without Intermediate Storage and Their Applications in Power-Electronic Transformers and AC Drives

Advantages of ac-ac power converters based on ANPC topology for wind applications

Wind energy conversion systems (WECS) are increasingly higher due to the great demand of wind energy. Thus, the power converter will play a more important role in the next generation of large WECS. Currently, the most accepted ac-ac power converter for WECS is the conventional twolevel back-to-back (2L-B2B). However, 2L-B2B is expected not to provide an acceptable performance for the largest of...

A Combined Vector and Direct Power Control for AC/DC/AC Converters in DFIG Based Wind Turbine

The doubly-fed generators (DFIG) have clear superiority for the applications of large capacity and limited-range speed control case due to the partially rated inverter, lower cost and high reliability. These characteristics enable the doubly-fed wound rotor induction machine to have vast applications in wind-driven generation.In this paper Combined Vector and direct power control (CVDPC) strate...

AC Circuits with Transformers

Direct Buck-type AC-AC Converters using VSC Method

The researches on direct AC-AC converters have been an important field. The DC-modulated method, which was used in DC-DC converters before, is used in AC-AC converters to realize a direct AC-AC converting now. The traditional control method regulates the output by adjusting the duty ratio. Its’ core is the PWM technology. In this paper, the variable structure control (VSC) strategy was utilized...

A Novel Multilevel Ac–Dc-Ac Converters with Improved Efficiency

Multilevel inverter technology has emerged recently as a very important alternative in the area of high power medium-voltage control and also for improving the total harmonic distortion by reducing the harmonics. Generally, the poor quality of voltage and current of a conventional inverter fed induction machine is obtained due to the presence of harmonics and hence there is a significant level ...