Static frequency converter with direct current link and active power filter

A new PWM-controlled AC/DC converter and control strategy is proposed that is able to draw nearly sinusoidal currents as unity power factor from three-phase power lines. An active power filter with capacitive storage is used for this purpose. A wide control range and a linear variation of the output DC voltage of the converter versus relative connecting duration are obtained. Such a converter can be efficiently used to get a static frequency converter with direct current link, which can feed an induction motor with adjustable voltage and frequency.