Toshiba Mitsubishi-electric Industrial Systems Corporation

Tmeic Corporation

Kenta Yamabe

Yoshihiro Tawada

Masahiro Kinoshita

Issei Fukasawa

Tomoya Katsukura

Yoshinori Tsuruma

A control device for a power conversion apparatus that can prevent a rush current from flowing into a power converter. In a power conversion apparatus with a power converter connected with a DC power supply, a filter, and a switch connected with an AC power supply are connected in series in that order, a control device for the power conversion apparatus includes: a calculation unit configured to calculate, from a value of an AC current flowing between the power converter and the filter and impedance of the filter, an estimated value for AC power to be outputted by the power converter; and a control unit configured to control an action of the power converter in a state that the switch is open such that a difference between a target value for AC power and the estimated value falls within an allowable range set in advance.

Control device for power conversion apparatus

A power conversion device including a power conversion circuit, an AC filter circuit, and a calculation unit. The power conversion circuit converts DC input power from a DC power supply to output a first AC output current and a first AC output voltage. The AC filter circuit filters the first AC output current and the first AC output voltage to generate a second AC output current and a second AC output voltage. The calculation unit calculates an estimated value of an upper impedance based on a difference value between a first voltage value and a second voltage value, the first voltage value being a value of the second AC output voltage at a time of stop of the power conversion circuit or at a time of zero output from the power conversion circuit or at a time of a certain amount of output from the power conversion circuit.

Power conversion device that calculates an estimated value of an upper impedance

A control system of a power converter includes a plurality of carrier wave generating units which are respectively provided for a plurality of power converters connected between a plurality of DC power supplies and a common AC power supply and which are configured to respectively generate carrier waves on the basis of an AC voltage of the AC power supply. The control system of the power converter can thereby synchronize carrier phases of a plurality of power converters.

Control system of power converter

An open phase detection system for a power conversion system includes a phase difference abnormality detection unit, an amplitude difference abnormality detection unit, and an open phase determination unit. The phase difference abnormality detection unit outputs a phase difference abnormality signal when an absolute value of a phase difference between a current flowing through a reactor and a current flowing through a capacitor is equal to or smaller than a phase threshold value. The amplitude difference abnormality detection unit outputs an amplitude difference abnormality signal when an absolute value of a value based on an amplitude difference between the current flowing through the reactor and the current flowing through the capacitor is equal to or smaller than an amplitude threshold value. The open phase determination unit outputs an open phase signal when receiving inputs of both the phase difference abnormality signal and amplitude difference abnormality signal.

Open phase detection system for power conversion system

A power conversion system includes: a storage battery; a first power conversion device configured to implement grid-connection operation with an electric power grid, converting electric power of the storage battery, outputting converted power to a connection point between load equipment and the electric power grid to supply electric power to the load equipment; and a controller transmitting a load adjusting signal to a load control part in the load equipment for reducing electric power supply to the load equipment if a state of the storage battery matches a remaining power shortage condition which is set in advance, during stand-alone operation in which the electric power grid is disconnected from the first power conversion device.

Growing community of inventors

Tokyo, Japan

Kenta Yamabe