Tmeic Corporation

Toshiba Mitsubishi-Electric Industrial Systems Corporation

Xiaochen Zhang

Toshihide Nakano

Yousuke Hayashi

Haruyoshi Mori

A plurality of semiconductor switches and a mechanical switch are connected in series between a first terminal and a second terminal. A plurality of voltage detectors are provided corresponding to the plurality of semiconductor switches, respectively, and detect terminal-to-terminal voltages of the corresponding semiconductor switches. A plurality of drivers are provided corresponding to the plurality of semiconductor switches, respectively, and turn off the corresponding semiconductor switches in response to control signals from a main controller. Each driver determines whether or not a terminal-to-terminal voltage of the corresponding semiconductor switch matches a terminal-to-terminal voltage of another semiconductor switch of the plurality of semiconductor switches, and outputs a result of determination. The main controller detects a cutoff abnormality in which the plurality of semiconductor switches are not turned off normally, based on the result of determination provided from each of the plurality of drivers.

Power supply device comprising a plurality of semiconductor switches and a mechanical switch connected in series

At least one first power converter of a plurality of power converters has a charging mode and a standby mode, the charging mode being a mode of converting AC power supplied from an AC power supply through a switch into DC power and storing the DC power in a corresponding power storage device, the standby mode being a mode of generating a control signal for power conversion and awaiting the power conversion. When an AC voltage supplied from the AC power supply is normal, a controller turns on the switch and alternately switches the at least one first power converter between the charging mode and the standby mode. When the AC voltage is not normal, the controller turns off the switch and controls the plurality of power converters such that each of the plurality of power converters converts DC power of the power storage device into AC power and supplies the AC power to a load.

Power supply device

An AC switch that includes a semiconductor switch and a snubber circuit connected in parallel between a first terminal connected to an AC power supply via a circuit breaker and a second terminal connected to a load. The power converter is connected between a power storage device and the second terminal. The current detector detects a current flowing through the AC switch. When the AC power supply is normal, the controller turns on the semiconductor switch. When an open state of the circuit breaker is detected, the controller controls the power converter to supply a current having a phase opposite to that of the current detected by the current detector to flow through the semiconductor switch and supply the AC power to the load. The controller further turns off the semiconductor switch in response to that the amplitude of the current detected by the current detector is 0.

An uninterruptible power supply includes a plurality of vacuum circuit breakers and a bypass circuit connected in series between a commercial AC power supply and a load, a control device that turns on both of the plurality of vacuum circuit breakers and the bypass circuit when the commercial AC power supply is normal and turns off a vacuum circuit breaker different from a vacuum circuit breaker turned off on the occurrence of previous power failure of the plurality of vacuum circuit breakers and turns off the bypass circuit when the commercial AC power supply fails, and a power converter that converts DC power of a battery into AC power and supplies AC power to the load when the commercial AC power supply fails.

Uninterruptible power supply using vacuum circuit breaker

The uninterruptible power supply device includes a switch () that includes first to Nth IGBT units (Uto UN) connected in series, and a controller that turns on the switch by turning on the first to Nth IGBT units, and turns off the switch by firstly turning off the first to nth IGBT units and then turning off the (n+1)th to Nth IGBT units. Compared with the case where the first to Nth IGBT units are turned off at the same time, it is possible to reduce a surge voltage generated between the terminals of the switch ().

A switch circuit includes n switching elements (n&#x2265;2) connected in series between an input node and an output node. A control device is configured to convert DC power in a power storage device into AC power synchronized with AC power supplied from an AC power supply during a normal state and supply the AC power to the output node, by controlling a power converter, when an abnormality of at least one of the AC power supply and the switch circuit is sensed in a state where the control device outputs conduction commands for the n switching elements. The control device is further configured to produce cutoff commands for cutting off the n switching elements during execution of power conversion in the power converter, and sense a cutoff abnormality of the switch circuit based on terminal-to-terminal voltages of the n switching elements during production of the cutoff commands.

Growing community of inventors

Chuo-ku, Japan

Xiaochen Zhang