Patent ID: 7706163

Claim:
A three-level ac generating circuit, comprising: a three-level boosting circuit connected to an input source and including a positive boosting portion and a negative boosting portion; and a three-level inverting circuit connected to the three-level boosting circuit and including a positive inverting portion, a negative inverting portion and at least two inverters connected in parallel, wherein each inverter includes a first switch component and a second switch component connected in reversed series via a first midpoint, the first switch component has an end connected to a second midpoint between a first metal oxide semiconductor field effect transistor (MOSFET) and a second MOSFET, the second switch component has an end connected to a third midpoint between a third MOSFET and a fourth MOSFET, a fourth midpoint is between the second MOSFET and the third MOSFET and provides a single phase output, wherein while the input source is a relatively low voltage, the relatively low voltage is boosted via the three-level boosting circuit, and inverted and output via the three-level inverting circuit, while the input source is a relatively high voltage, the relatively high voltage is inverted and output via the three-level inverting circuit, and the output of the three-level ac generating circuit is a power grid.