Mitsubishi Electric Corporation

Kabushiki Kaisha Toshiba

Yasuyuki Miyazaki

Yuji Watanabe

Yasuo Takagi

Takashi Hattori

Yusuke Morimoto

Yasuhiro Noro

Yoshitaka Ono

Toshiaki Asano

Yoichi Uemura

Hideyuki Miyaji

Shinji Yurino

Takahiro Shimoo

Koichi Harada

Kozo Takagi

Yoshitaka Sakaki

Shinichiro Takahashi

A phase difference correction control unit determines, based on a difference between a voltage of a first input smoothing capacitor and a voltage of a second input smoothing capacitor, a difference between a current flowing through a first switching element and a current flowing through a second switching element, or a difference between a reactor current when a gate signal of the first switching element is turned on and a reactor current when a gate signal of the second switching element is turned on, an amount of correction of a difference between a phase of switching of the first switching element and a phase of switching of the second switching element. A switching control unit switches the first switching element and the second switching element based on the amount of correction.

Double step-down chopper circuit

An air-conditioning control system includes a first inverter that drives a first driving target in accordance with commands received via a first communication network, a second inverter that drives a second driving target in accordance with commands received via the first communication network, a first controller that is capable of controlling the first inverter and the second inverter by transmitting commands via the first communication network, and a second controller that is capable of controlling the first inverter and the second inverter by transmitting commands via the first communication network. Each of the first controller and the second controller is capable of transmitting, to the first inverter and the second inverter via the first communication network, an invalidation command for invalidating the commands therefrom.

Air-conditioning control system for railroad vehicle

A detector detects physical quantities relating to an operation of a vehicle air-conditioning device at a predetermined sampling frequency to generate groups of time-series data items. A volatile tracking memory has a work area to which the groups of time-series data items for a tracking period is writable. A record holding power accumulator supplies, to the tracking memory, power used for holding in the work area the groups of time-series data items. A writer sequentially overwrites the groups of time-series data to the work area of the tracking memory and stops overwriting of the groups of time-series data items to the work area when an abnormality occurs in the vehicle air-conditioning device.

Recording device for railroad vehicle, air conditioning device for railroad vehicle, and recording method for railroad vehicle

According to an embodiment, a voltage fluctuation suppressing apparatus is provided with a power storage device connected to an electric power system, a basic control unit to control an output of the power storage device, a voltage detector to measure a voltage of a connection point to the electric power system, and an output control unit to divide a control amount to be outputted to the basic control unit into a reactive power command value and an active power command value and to output them. The output control unit is provided with a reactive power upper limit value calculation unit, a reactive power calculation/output unit, and an active power calculation/output unit.

Voltage fluctuation suppressing apparatus

To improve the resistance against external low-frequency disturbance (represented by generator output change), the power system stabilizer for a generator, for inputting a voltage regulating signal (e), as an auxiliary signal, to an automatic voltage regulator to control a generator terminal voltage at a target voltage (V.sub.o), comprises: an angular acceleration observer for calculating an estimated angular acceleration change rate (.DELTA.as) of the generator on the basis of at least one of stabilizing signal change rates (.DELTA.P and/or .DELTA..omega.) of the generator; and a power stabilizer circuit for calculating a corrected voltage regulating signal (e) applied to the automatic voltage regulator on the basis of the estimated angular acceleration change rate value (.DELTA.as) calculated by the angular acceleration observer. Further, it is preferable to provide a plurality of observers and a plurality of power stabilizer circuits, separately for each fluctuation frequency.

Power system stabilizer for generator

Growing community of inventors

Tokyo, Japan

Yasuyuki Miyazaki