Multi-input power converter and online uninterruptible power supply including multi-input power converter

A multi-input power converter, wherein the multi-input power converter obtains power from a three-phase alternating current power supply or a rechargeable battery and outputs direct current power to a positive direct current bus and a negative direct current bus, wherein a first capacitor and a second capacitor are connected in series between the positive direct current bus and the negative direct current bus, and a first node formed by connecting the first capacitor to the second capacitor is connected to a neutral point;

• the multi-input power converter comprises a first bridge arm unit, a second bridge arm unit, and a third bridge arm unit, and each bridge arm unit comprises an inductor and a bidirectional switch unit that are connected in series, and a current direction control bridge arm connected between the positive direct current bus and the negative direct current bus, wherein a first end of the inductor is connected to a corresponding phase of the three-phase alternating current power supply, a second node formed by connecting a second end of the inductor to a first end of the bidirectional switch unit is connected to a corresponding current direction control bridge arm, and a second end of the bidirectional switch unit is connected to the first node;
• wherein, a first end of an inductor of the first bridge arm unit is connected to a positive electrode of the rechargeable battery via a first direct current switch, and a first end of an inductor of the second bridge arm unit is connected to a negative electrode of the rechargeable battery via a second direct current switch, so that the positive direct current bus and the negative direct current bus can be powered by the rechargeable battery;
• and
• a first end of an inductor of the third bridge arm unit is connected to the neutral point via a bidirectional conductive switch, and a current direction control bridge arm of the third bridge arm unit comprises a bidirectional controllable element, wherein the bidirectional controllable element is controlled to enable a second end of the inductor of the third bridge arm unit to alternately connect to one of the positive direct current bus and the negative direct current bus.