UTILITY INTERACTIVE INVERTER DEVICE

Both ends of a direct-current power source 1 are connected with capacitors C1, C2 which are connected in series. The interconnection point of the capacitors C1, C2 is connected with one end of an electric power system 2 and one end of a reactor L. Both ends of the electric power system 2 are connected with a capacitor C3. One end of a first switch section (S1, D1) is connected to the positive electrode of the direct-current power source 1, while the other end of the first switch section is connected to the other end of the reactor L. One end of a second switch section (S2, D2) is connected to the negative electrode of the direct-current power source 1, while the other end of the second switch section is connected to the other end of the reactor L. One end of a third switch section (S3, D3) is connected to the other end of the reactor L, while the other end of the third switch section is connected to the other end of the electric power system 2. One end of a fourth switch section (S4, D4) is connected to the other end of the reactor L, while the other end of the fourth switch section is connected to the other end of the electric power system 2.