Patent ID: 7440300
Filing Date: 2008-10-21
Classification: H02J,H02M

Abstract:
1. A transformerless power conversion circuit for distributed generation system interconnected with an electric grid, the power conversion circuit converting an input DC power provided by a power generator into an AC power and feeding the AC power into the grid, the power conversion circuit comprising: a buck-boost converter converting the input DC power into two sets of DC power levels, wherein the buck-boost converter comprising: a first active switch having an input end connected to a positive end of the input DC power; a first inductor and a second inductor sharing a same iron core; wherein one end of the first inductor is electrically connected to a grounded end, one end of the second inductor is electrically connected to an output end of the first active switch, another end of the second inductor is electrically connected to a negative end of the input DC power and the ground; a first passive switch with a positive end connected to another end of the first inductor; a second passive switch with a negative end connected to the output end of the first active switch; a first capacitor with a positive end connected to a negative end of the first passive switch and a negative end connected to the ground; a second capacitor with a positive end connected to the ground and a negative end connected to a positive end of the second passive switch; and at least one half-bridge inverter converting the two sets of DC power levels into the AC power for feeding into the grid.