Abstract: A system interconnecting facility is connected to a power system, and includes a plurality of power converters connected to the power system, a plurality of transformers provided between the power system and the power converters, a plurality of switches provided between the transformers and the power converters, and a controller that controls the opening and closing of the switch. The controller outputs, to the switches, open and close commands in so that the number of closed switches is out of a closed switch number range where a harmonic voltage of the system interconnecting facility increases, based on a harmonic voltage containing rate characteristic that is a relation between the number of closed switches and a harmonic voltage containing rate of the system interconnecting facility. The system interconnecting facility is capable of suppressing a harmonic voltage even if a circuit structure differs depending on a situation.

Abstract: A system interconnecting facility is connected to a power system, and includes a plurality of power converters connected to the power system, a plurality of transformers provided between the power system and the power converters, a plurality of switches provided between the transformers and the power converters, and a controller that controls the opening and closing of the switch. The controller outputs, to the switches, open and close commands in so that the number of closed switches is out of a closed switch number range where a harmonic voltage of the system interconnecting facility increases, based on a harmonic voltage containing rate characteristic that is a relation between the number of closed switches and a harmonic voltage containing rate of the system interconnecting facility. The system interconnecting facility is capable of suppressing a harmonic voltage even if a circuit structure differs depending on a situation.

Abstract: According to one embodiment, a system includes modules to detect a node voltage and an output current of a converter, a detector to obtain an effective power value, a system condition detector to detect a power supply condition in the electric system or the operating conditions of devices included in the electric system and then output a first signal, a setting unit to switch a set value to a preset first or second value and then output the set value, a unit to calculate an angular frequency of an output voltage of the converter on the basis of an output of the detector, the value, and an output of the system condition detector, and a unit to calculate a target value of the converter.

Abstract: According to one embodiment, a system includes modules to detect a node voltage and an output current of a converter, a detector to obtain an effective power value, a system condition detector to detect a power supply condition in the electric system or the operating conditions of devices included in the electric system and then output a first signal, a setting unit to switch a set value to a preset first or second value and then output the set value, a unit to calculate an angular frequency of an output voltage of the converter on the basis of an output of the detector, the value, and an output of the system condition detector, and a unit to calculate a target value of the converter.