Kabushiki Kaisha Toshiba

Tokyo Shibaura Denki Kabushiki Kaisha

Yukihiko Hatano

Tadashi Takahashi

Hiroshi Mochikawa

Ryuta Hasegawa

Masami Hirata

An inverter apparatus according to one embodiment includes switching elements and freewheel diodes which are connected to a direct-current power supply, a temperature detector provided near at least one of the switching elements, and a temperature estimation unit. The temperature estimation unit estimates temperatures of switching elements not provided with the temperature detector, based on an estimated-temperature increase value calculated by a loss model of the switching elements and freewheel diode and others, and a temperature of the switching element detected by the temperature detector.

Inverter apparatus

An opposite phase detecting device for alternating current electrical equipments includes a zero cross circuit synchronizing positive half waves of first and second line voltages of a three-phase AC supply supplied to an AC electrical equipment and generating first and second synchronizing pulses each having a pulse width corresponding to an electrical angle of approximately 180 degrees, a counter circuit counting the first synchronizing pulses from the zero cross circuit, a one-shot multivibrator triggered by the second synchronizing pulse to thereby generate a reset pulse having a relatively short time interval, and an AND circuit generating a reset signal based on a logical multiplication of the reset pulse generated by the pulse generating circuit and the first synchronizing pulse generated by the synchronous circuit. The counter circuit is reset when supplied with the reset signal from the AND circuit. The counter circuit generates an opposite phase detection signal when the count value thereof reaches a predetermined value.

Opposite phase detecting device for alternating current electrical

An optical gate signal generating apparatus for firing a plurality of thyristors in a thyristor converter apparatus, including a circuit for generating an electrical gate signal, a plurality of first light emitting elements, each being connected to receive the electrical gate signal for generating a first optical signal. The apparatus also includes a plurality of auxiliary circuit, each including a series connection of a second light emitting element and a nonlinear element and being connected to receive the electrical gate signal for generating a second optical signal, each of the auxiliary circuits being connected in parallel with each of the first light emitting elements, and a plurality of light guides, each having a first, a second and a third branches, each of the light guides being connected to receive the first and second optical signals at ends of the first and second branches, respectively and for guiding the first and second optical signals to an end of the third branch to produce the optical gate signal. The thyristor converter apparatus including the optical gate signal generating apparatus is also disclosed.

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Ichinomiya, Japan

Yukihiko Hatano