FIVE LEVEL INVERTER

摘要

A five level inverter comprises six switch tubes, two inductors, four capacitor units and two reverse current preventing devices. The common terminal of the third capacitor unit and the fourth capacitor unit is connected with the common terminal of the first capacitor unit and the second capacitor unit. The third capacitor unit and the fourth capacitor unit are used as the output filter circuit of the inverter, and the common terminal of the third capacitor unit and the fourth capacitor unit is used as the midpoint of the DC bus.

主权项

1. A five-level inverter, comprising: a first switch, a second switch, a third switch, a fourth switch, a fifth switch, a sixth switch, a first capacitor unit, a second capacitor unit, a third capacitor unit, a fourth capacitor unit, a first inductor, a second inductor, a first reverse flow preventive element and a second reverse flow preventive element; wherein
a positive pole of a direct-current power supply is connected to a first terminal of the first switch and a first terminal of the first capacitor unit; a negative pole of the direct-current power supply is connected to a first terminal of the second switch and a second terminal of the second capacitor unit; a second terminal of the first switch is connected to a first terminal of the first reverse flow preventive element, a first terminal of the third switch and a first terminal of the fifth switch; a second terminal of the first reverse flow preventive element is connected to a second terminal of the first capacitor unit, a first terminal of the second capacitor unit and a first terminal of the second reverse flow preventive element; a second terminal of the second reverse flow preventive element is connected to a second terminal of the second switch, a first terminal of the fourth switch and a first terminal of the sixth switch; a second terminal of the third switch is connected to a first terminal of the first inductor and a second terminal of the fourth switch; a second terminal of the fifth switch is connected to a first terminal of the second inductor and a second terminal of the sixth switch; a second terminal of the first inductor is connected to a first terminal of the third capacitor unit; a second terminal of the second inductor is connected to a second terminal of the fourth capacitor unit; a second terminal of the third capacitor unit and a first terminal of the fourth capacitor unit are connected to the second terminal of the first capacitor unit; the first reverse flow preventive element is configured to prevent a current from flowing from the first terminal of the first reverse flow preventive element to the second terminal of the first reverse flow preventive element in a case that the first switch is turned on; the second reverse flow preventive element is configured to prevent a current from flowing from the first terminal of the second reverse flow preventive element to the second terminal of the second reverse flow preventive element in a case that the second switch is turned on; and the second terminal of the first inductor and the second terminal of the second inductor are alternate-current output terminals of the inverter.