Power conversion system and method of operating the same

摘要

A power conversion system mainly includes an input capacitor bank, a first conversion circuit, a second conversion circuit, and a control circuit. The input capacitor bank has a first capacitor and a second capacitor. The first capacitor and the second capacitor are connected to a neutral point and receive a DC input voltage. The first conversion circuit is connected in parallel to the input capacitor bank, and has a first branch, a second branch, and a first auxiliary branch. The second conversion circuit is connected in parallel to the input capacitor bank, and has a third branch, a fourth branch, and a second auxiliary branch. The control circuit produces a plurality of control signals to correspondingly control the first conversion circuit and the second conversion circuit so as to reduce leakage current caused by parasitic capacitance voltage.

主权项

1. A power conversion system configured to convert a DC input voltage into an AC output voltage; the power conversion system comprising:
an input capacitor bank having a first capacitor and a second capacitor, and the first capacitor and the second capacitor connected to a neutral point and configured to receive the DC input voltage; a first conversion circuit connected in parallel to the input capacitor bank; a second conversion circuit connected in parallel to the input capacitor bank; a first filtering circuit connected between the first conversion circuit and the second conversion circuit, and an output side of the first filtering circuit connected to the neutral point; a second filtering circuit connected between the first conversion circuit and the second conversion circuit, and an output side of the second filtering circuit connected to the neutral point; and a control circuit configured to produce a plurality of control signals to correspondingly control the first conversion circuit and the second conversion circuit, thus reducing leakage current of the DC input voltage caused by parasitic capacitance voltage, wherein the first conversion circuit comprises a first branch, a second branch, and a first auxiliary branch; the first branch comprises a first power switch and a first diode connected to the first power switch; the second branch comprises a second power switch and a second diode connected to the second power switch; the first auxiliary branch comprises a first auxiliary power switch and a first auxiliary diode connected to the first auxiliary power switch; the first auxiliary branch is connected between the first branch and the second branch; the control circuit is configured to produce a first control signal to control the first power switch and the second power switch, and produce a first auxiliary control signal to control the first auxiliary power switch.