Single‐phase PWM converter using balanced two‐phase rectification

AbstractEnergy storage devices, such as inductors or capacitors, are needed in single‐phase ac to dc converters because instantaneous power flow of input single‐phase ac is inherently pulsating and output dc power must have as little ripple as possible. Energy storage devices (such as smoothing inductors or capacitors) are usually inserted on the dc side. In those converters, energy storage ability of the devices cannot be used effectively, especially when dc power ripple is required to be very small.To solve such a problem, this paper presents novel single‐phase ac/dc conversion circuits, in which energy storage devices are used at the ac rather than at the dc side. That is, after converting single‐phase ac into balanced (rectangular) two‐phase ac using variable reactance element, reconversion of it into dc is carried out.This paper presents a control method for the converters and the variable reactance devices, and performance of the proposed circuits is confirmed using computer simulation.