Abstract: Provided is an additive for a chemical agent, which is capable of improving the functions of various chemical agents. The additive for a chemical agent according to an embodiment of the present invention includes a polymer (I) containing 50 mol % to 100 mol % of a structural unit derived from an N-vinyl lactam-based monomer with respect to 100 mol % of structural units derived from all monomers, the additive for a chemical agent having an average particle diameter of 100 ?m or less in a state of having been dried under a reduced pressure of 0.02 MPa or less at 100° C. for 1 hour.

Abstract: A system interconnection inverter includes a step-up converter and an inverter. Moreover, the system interconnection inverter includes a short-circuit current-interrupting diode with a cathode connected to an input terminal of a negative bus, a semiconductor switch connected to an anode of the short-circuit current-interrupting diode, a semiconductor switch drive circuit that drives the semiconductor switch, a semiconductor switch-off circuit that turns off the semiconductor switch drive circuit when negative power is applied such that electric current flows from a cathode toward an anode of the input terminal, and a control circuit that controls the semiconductor switch drive circuit.

Abstract: An interconnection inverter device includes a pair of capacitors connected in series to a pair of direct-current buses each connecting a direct-current power supply and the inverter; an opening/closing unit connected to either one of the pair of direct-current buses; voltage monitor units that monitor terminal voltages of the pair of capacitors respectively; and a controller that controls opening or closing of the opening/closing unit based on monitor voltages detected by the voltage monitor units.

Abstract: A system interconnection inverter includes a step-up converter and an inverter. Moreover, the system interconnection inverter includes a short-circuit current-interrupting diode with a cathode connected to an input terminal of a negative bus, a semiconductor switch connected to an anode of the short-circuit current-interrupting diode, a semiconductor switch drive circuit that drives the semiconductor switch, a semiconductor switch-off circuit that turns off the semiconductor switch drive circuit when negative power is applied such that electric current flows from a cathode toward an anode of the input terminal, and a control circuit that controls the semiconductor switch drive circuit.

Abstract: An interconnection inverter device includes a pair of capacitors connected in series to a pair of direct-current buses each connecting a direct-current power supply and the inverter; an opening/closing unit connected to either one of the pair of direct-current buses; voltage monitor units that monitor terminal voltages of the pair of capacitors respectively; and a controller that controls opening or closing of the opening/closing unit based on monitor voltages detected by the voltage monitor units.