Mitsubishi Electric Corporation

Mitsubishi Denki Kabushiki Kaisha

Fuji Jukogyo Kabushiki Kaisha

Masashi Kitayama

Ryosuke Uda

Kenichi Kuroda

Shigeo Hayashi

Hiroyuki Hashimoto

Masahiko Ikawa

Yoshiyuki Kono

Takumi Hasegawa

Hiroyuki Kumazawa

Takuya Ishioka

Yoshio Izui

Kazunori Washio

Miyuki Yamamuka

Each arm circuit of a power conversion device includes a plurality of cascaded cell blocks and a plurality of bypass circuits connected in parallel to the respective cell blocks. Each cell block includes: a first connection node on a high potential side and a second connection node on a low potential side for connection to another cell block; and a plurality of converter cells cascaded between the first and second connection nodes, each converter cell containing an energy storage. The plurality of converter cells include at least one first converter cell of a full-bridge (or hybrid) configuration and at least one second converter cell of a half-bridge configuration.

Power conversion device having bypass circuit protection

In a multilevel converter, three switches are connected between three arms and three reactors, and three resistive elements are connected to the respective three switches in parallel. The three switches are configured to be in a conductive state during a normal operation. The three switches are configured to come into a non-conductive state when a short circuit accident occurs between two DC power transmission lines, whereby an inter-arm direct current flowing in four arms and the like is quickly attenuated by the three resistive elements.

Power converter

In a multilevel converter, three first rectifying elements are respectively connected between three arms and a negative voltage terminal. Three second rectifying elements are respectively connected to the three first rectifying elements in antiparallel. During a normal operation, current flows in the three first rectifying elements and the three second rectifying elements. When a short circuit accident occurs between two DC power transmission lines, the three first rectifying elements are brought into the non-conductive state, thereby interrupting and quickly attenuating inter-arm direct current flowing in four arms and the like.

In a multilevel converter, three circuit breakers are respectively connected between three arms and three reactors. One circuit breaker is a DC circuit breaker configured to interrupt direct current when a short circuit accident occurs between two DC power transmission lines. Each of the two circuit breakers is an AC circuit breaker configured to interrupt alternating current when the short circuit accident occurs. When the short circuit accident occurs, the two AC circuit breakers are brought into the non-conductive state and then the DC circuit breaker is brought into the non-conductive state, thereby interrupting the short circuit current.

Each of a master node and a slave node has a safety data processing unit and a high reliability communication unit. At the time of transmission, the safety data processing unit creates a safety data packet including data about safety and the high reliability communication unit creates a communication data packet including the safety data packet and transmits the communication data packet a predetermined number of times. At the time of reception, the high reliability communication unit acquires and outputs a safety data packet by determining one of one or more communication data packets having the same contents which it has received properly as an effective packet, and the safety data processing unit analyzes a state concerning the safety of a system on the basis of the data about safety acquired from the safety data packet.

Signal transmission device for elevator

An airflow deflector apparatus for a vehicle that protrudes downward from a vehicle body in front of a wheel housing that houses a wheel includes a flap portion having a front surface portion extending substantially in a lateral direction of a vehicle and a vertical direction, and a protrusion portion that protrudes toward a front of the vehicle from the front surface portion of the flap portion and is formed so as to have a shape that tapers toward a protrusion end portion side, in which the front surface portion of the flap portion, when the vehicle is running, changes a moving direction of airflow that flows along a surface of the protrusion portion into a direction away from components that are disposed rearward.

Airflow deflector apparatus for vehicle

A transmission characteristics analyzing device includes a transmission characteristics calculating unit for determining a direction in which a signal flows in each component of a communication network on the basis of a transmitting point and a receiving point of the signal, which are specified in the communication network, and for calculating the transmission characteristics of the communication network in consideration of the direction of the signal.

Transmission characteristics analyzing device and program

An electric power demand adjusting system restrains fluctuation in an incentive for adjusting the demand for electric power or fluctuation in an electric power demand adjustment amount caused by an incentive. The system includes a central apparatus, lower units, and computing machine systems of consumers, which are connected through a communication network. The computing machine system of the central apparatus has a device for predicting a demand, a device for determining the electric power demand adjustment amounts to be sent to the lower units on the basis of the predicted demand and information that includes historical data regarding the electric power demand adjustments of the lower units, and a device for transmitting the determined electric power demand adjustment amounts to the lower units. The arrangement restrains the fluctuation in incentives required for adjusting the demand for electric power.

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Tokyo, Japan

Masashi Kitayama