Toshiba Mitsubishi-electric Industrial Systems Corporation

Mitsubishi Denki Kabushiki Kaisha

Tmeic Corporation

The Ritsumeikan Trust

Hiroshi Masunaga

Masahiro Kinoshita

Kazuki Nishimura

Tomohiro Tanaka

Ryoji Tsuruta

Takeshi Tanaka

Masaru Toyoda

Keisuke Ohnishi

Kazunori Sanada

Takeaki Asaeda

Takao Kawabata

Yoshitaka Kawabata

Tingan Lee

Akihiro Yamanishi

This uninterruptible power supply includes a switch that is turned off while an AC power supply is normal and turned on during power failure, a converter that converts AC power supplied from the AC power supply into DC power to supply resultant DC power to a DC link portion while the AC power supply is normal, and that supplies DC power supplied from a battery through the switch to the DC link portion during power failure, an inverter that converts DC power from the DC link portion into AC power to supply resultant AC power to a load, and a chopper circuit that allows DC power from the DC link portion to be stored in the battery while the AC power supply is normal.

Uninterruptible power supply

A power conversion device includes: a dead time application unit which applies a dead time to only one of a pair of pulse signals; a current polarity detection unit which detects a polarity of an output current; and a gate signal selection unit which, if the polarity of the output current is positive, selects the one pulse signal, to which the dead time has been applied, as a gate signal for a positive arm and selects the other pulse signal as a gate signal for a negative arm, and, if the polarity of the output current is negative, selects the one pulse signal, to which the dead time has been applied, as the gate signal for the negative arm and selects the other pulse signal as the gate signal for the positive arm.

Power conversion device

When an abnormality occurs in a first voltage detector (), a control circuit () in an uninterruptible power supply device controls an inverter () in synchronization with an output signal (VID) from a second voltage detector () to match a phase of a two-phase AC voltage (VO, VO) output from the inverter () with a phase of a two-phase AC voltage (VI, VI) supplied from a commercial AC power supply (), and then turns on a semiconductor switch pair (S, S) and a bypass switch pair (S, S). Accordingly, even when an abnormality occurs in the first voltage detector (), the two-phase AC voltage can be supplied to a load () without instantaneous interruption.

Uninterruptible power supply device

A power supply system includes a plurality of uninterruptible power supplies provided for a load in parallel. The uninterruptible power supplies each include a power supply unit configured to supply the load with power and being larger in capacitance than the load, and a switch provided between the power supply unit and the load. The power supply system further includes a control unit selecting a first uninterruptible power supply of the plurality of uninterruptible power supplies, and setting the switch of the first uninterruptible power supply to the on state.

Power supply system

An uninterruptible power supply device () does not have a wire connecting a bidirectional chopper () to a neutral point (NP). The bidirectional chopper () includes first and second capacitors (C, C), first to fourth transistors (Q-Q), and a normal mode reactor (). In a discharging mode, a controller () causes the second and third transistors (Q, Q) to be complementarily turned on and controls the ON period of each of the second and third transistors (Q, Q) so that terminal-to-terminal voltages (V, V) of the first and second capacitors (C, C) are equal to each other.

Uninterruptible power supply device and uninterruptible power supply system using the same

An uninterruptible power supply device (U) includes a converter (), an inverter (), a bidirectional chopper (), and a controller (). The bidirectional chopper () includes first to fourth transistors (Q-Q), first to fourth diodes (D-D), and first and second, coils (). In a charging mode, the controller () causes the first and fourth transistors (QQ) to be complementarily turned on and controls the ON period of each of the first and fourth transistors (QQ) so as to cause respective detected values of first current and second current () flowing through the first coil and the second coil () to be equal to each other.

A bidirectional insulated DC/DC converter narrows a pulse width of an AC fundamental wave voltage corresponding to a higher DC voltage of two DC voltages, to cause effective values of the AC fundamental wave voltages to coincide with each other, and then, sets a phase difference between the AC fundamental wave voltages in accordance with a value and a direction of a current that is desired to flow. Accordingly, even when the difference between the two DC voltages greatly varies, DC power can be stably transmitted and received.

Bidirectional insulated DC/DC converter and smart network using the same

Provided is an uninterruptible power supply apparatus that can properly adjust the capacity of cooling a heat radiation source. A housing for housing an uninterruptible power module is provided with a cooling fan for cooling the internal space of the housing. The housing is further formed with an opening. The opening formed in one housing and the opening formed in an adjacent housing for housing another uninterruptible power module are configured to face each other. Furthermore, each uninterruptible power module includes a fan control circuit for controlling the cooling fan. The fan control circuit controls the actuation and suspension of the cooling fan on the basis of a total load of the plurality of uninterruptible power modules.

Uninterruptible power supply apparatus

A power module including a self arc-extinguishing type semiconductor such as an IGBT and having a function to protect the semiconductor, i.e., to protect the IGBT against a short-circuit current. Even the IGBT having a collector-emitter saturation voltage VCE (sat) set low can be protected against the short-circuit current, by charging a collector-gate junction capacitor ( ) quickly, when a sense current IS to flow through a current sense exceeds a set value, to raise a collector voltage VCE quickly thereby to prevent a collector current IC from increasing, by keeping a gate voltage VGE of the IGBT ( ) at a voltage rather higher than a threshold voltage, and by turning OFF the IGBT ( ) after a predetermined time.

Power module

In a gate control device for four self-arc extinction elements connected in series and two self-arc extinction elements connected in reverse parallel between the respective terminals of clamp diodes, individually, there is provided a PWM circuit that generates conduction control commands, and a gate control circuit including a delay circuit group that generates gate signals with respect to the respective self-arc extinction elements on the basis of respective conduction control commands. A pair of the self-arc extinction elements are rendered conductive at the same time, and another pair of the self-arc extinction elements are rendered conductive at the same time.

Growing community of inventors

Chuo-ku, Japan

Hiroshi Masunaga