Abstract: A voltage drop Vzs is calculated based on an output current detection value Iac and a virtual synchronous impedance Zs or a corrected virtual synchronous impedance Zs?, and a value obtained by subtracting the voltage drop Vzs from an internal induced voltage Ef is output as a grid voltage command value Vac*. Zs calculation unit 7 limits an output current phase ? so that the output current phase ? is within an effective range by a phase limiter 12a, and calculates the corrected virtual synchronous impedance Zs? based on a limited output current phase ?, the internal induced voltage Ef, a grid voltage detection value Vac and a current limit value Ilim. Accordingly, in grid interconnection power conversion device that controls a virtual synchronous generator, it is possible to continue operation while suppressing an overcurrent and possess a synchronizing power generated by action or working of a virtual synchronous impedance.

Abstract: A method for reinforcing a structure with a sheet containing reinforcing fiber yarns is disclosed, by which method separation of the sheet is sufficiently prevented, maximum use of the sheet strength is achieved, and existing structures are effectively reinforced. The method includes the step of providing a sheet containing reinforcing fiber yarns over the surface of a structure selected from the group consisting of concrete and steel structures, with a flexible material interposed therebetween, the flexible material having a tensile elongation of 10 to 200% at maximum load at 23° C., and a tensile strength of 0.1 to 50 N/mm2 at 23° C.

Abstract: A method for reinforcing a structure with a sheet containing reinforcing fiber yarns is disclosed, by which method separation of the sheet is sufficiently prevented, maximum use of the sheet strength is achieved, and existing structures are effectively reinforced. The method includes the step of providing a sheet containing reinforcing fiber yarns over the surface of a structure selected from the group consisting of concrete and steel structures, with a flexible material interposed therebetween, the flexible material having a tensile elongation of 10 to 200% at maximum load at 23° C., and a tensile strength of 0.1 to 50 N/mm2 at 23° C.