Patent attributes
A three-phase converter and a control method thereof are provided. The three-phase converter includes an AC terminal, three filter circuits, three bridge arm circuits, a capacitor module and a DC terminal connected in sequence and a controller. The midpoints of the filter circuits are connected to the midpoint of the capacitor module. The controller controls each bridge arm circuit to work in the first and second modes at different time in one line voltage cycle of the AC source. In the first mode, the bridge arm circuit works in a clamping state. In the second mode, the bridge arm circuit selectively works in a DCM mode or a TCM mode. A switching frequency is limited to be lower than a preset frequency. When the three-phase converter works with over 80% of a rated load, a time length of working in the second mode is ⅓˜⅔ of the line voltage cycle.
