Bidirectional cascade voltage-increasing and decreasing direct current-alternating current converter

The invention relates to a bidirectional cascade voltage-increasing and decreasing direct current-alternating current converter, belonging to the technical field of power electronics. The converter comprises a voltage decreasing level circuit, a direct current bus inductor, a voltage increasing level circuit and a control circuit. The voltage decreasing level circuit forms an H bridge structure by two fully-controlled devices and two diodes, so that a bipolar alternating current voltage can be generated on a direct current bus; and the voltage increasing level circuit forms an H bridge structure by four unidirectional fully-controlled switch devices, so that a bipolar alternating current voltage can be generated on an output end. In the converter, the control circuit is used for controlling the switch period mean value of the direct current bus current to be constant by properly changing the respective conducting mode of the voltage decreasing level circuit and the voltage increasing level circuit, so that the converter is guaranteed to have the voltage-increasing and decreasing capabilities, the bidirectional energy flow capability, and the direct current-alternating current converting capability.