Abstract: An electric power conversion device according to an embodiment includes: a converter circuit that converts direct current power to alternating current power; a circuit breaker one end of which is connectable to an external system and another end of which is connected to the converter circuit via a filter circuit; and an injector that, before injecting the circuit breaker during activation, sets the converter circuit to an operating state, determines whether a voltage at the one end and a voltage at the other end meet a synchronization condition, and injects the circuit breaker when the synchronization condition is met.

Abstract: A power conversion device includes a conversion circuit, a grid forming control circuit, a grid following control circuit, a modulation circuit, a switching circuit, a phase synchronization processing circuit, an initial value computing circuit, and a synchronization adjusting circuit. When a switching signal instructing switching from grid forming control to grid following control is received, the phase synchronization processing circuit computes a synchronous phase by phase synchronization processing for which an amplitude of a grid voltage is used as input. The initial value computing circuit computes an initial amplitude command value based on the amplitude of the grid voltage and the synchronous phase. The synchronization adjusting circuit sets the initial amplitude command value to be an initial value of a command value of an amplitude of an output voltage in the grid following control after switching from the grid forming control.

Abstract: A power conversion device is disclosed in which a grid following amplitude command value and a grid following phase command value are output in response to receiving a switching signal instructing switching from grid following control to grid forming control. The grid following amplitude command value indicates a target value of an amplitude computed by the grid following control. The grid following phase command value indicates a target value of a phase computed by the grid following control. When the grid following control is switched to the grid forming control, an initial value of the target value of the amplitude in the grid forming control to be the grid following amplitude command value is set, and an initial value of the target value of the phase in the grid forming control to be the grid following phase command value is set.

Abstract: A startup method and startup program for microgrid that enable to stably start up the microgrid without producing frequency fluctuation is provided. An embodiment of the present disclosure is a startup method for microgrid configured by a plurality of inverter power supplies independently sharing a load and divided into a master that starts up first and a slave that starts up secondly and later, the startup method comprising: a master initial startup step of initially starting up the master in a CVCF mode; a slave initial startup step of initially starting up the slave in a grid interconnection mode; and a control mode changing step of the master and the slave changing control modes thereof when output fluctuation of the master and the slave becomes a predetermined threshold or less or when the master and the slave or other inverter power supplies become a predetermined operation state while output voltage of said master and said slave becomes a predetermined threshold or less.

Abstract: A power conversion device is disclosed in which a first command to change amplitude and phase of AC-power by grid forming control (GFM) is generated. A second command to change amplitude and phase of the AC-power by grid following control (GFL) is generated. A modulation circuit changes amplitude and phase of the AC-power in response to the first or second command. The first command is corrected before input to the modulation circuit is switched from the second command to the first command such that a difference between target amplitude of the first command and amplitude of a given grid voltage becomes a threshold or smaller, a difference between target frequency of the first command and frequency of the grid voltage becomes a threshold or smaller, and a difference between target phase of the first command and phase of the grid voltage becomes a threshold or smaller.

Abstract: This invention provides a matrix adhering to the nasal mucosa which allows improved transfer into the brain of a drug exerting its effect in the brain and is capable of continuously supplying the drug into the brain. This matrix contains a polyglycerol fatty acid ester, the drug exerting its effect in the brain, and a viscogenic substance.