Direct Input Power Control for Drive System of Single-Phase to Three-Phase Power Converter Without Electrolytic Capacitor

TLDR: In order to keep the dc-link voltage higher than the inverter output line-to-line voltage, the flux-weakening control that varies synchronously with the double frequency of the AC input voltage is adopted.

Abstract: The electrolytic capacitor is the key component that not only lowers the reliability of single-phase to three-phase power converter for drive system, but also makes high current harmonics at the AC grid. Recently, the drive system with a film capacitor has been researched for its long lifetime and the characteristics of small volume and low cost. However, the input power factor is reduced and the AC input current waveform is distorted when the motor is driven at light load conditions. In order to deal with this problems, the direct input power control method that related to the AC input voltage and current is proposed in this paper. Furthermore, in order to keep the dc-link voltage higher than the inverter output line-to-line voltage, the flux-weakening control that varies synchronously with the double frequency of the AC input voltage is adopted. The results verified the correctness and effectiveness of the proposed method.