Toshiba Mitsubishi-electric Industrial Systems Corporation

Yamatake Corporation

Kabushiki Kaisha Toshiba

Tokin Corporation

Toshiaki Oka

Hiroaki Tsutsui

Akihiko Kuroiwa

Hiromitsu Suzuki

Shunsuke Tobayashi

Masashi Nakamura

Kazuto Kawakami

Ritaka Nakamura

Naoto Niimura

Ryoji Tsuruta

Junji Nishimura

Takuji Shimoura

An inductor comprises a core and a coil. The coil has a first terminal, a second terminal, a first portion, a second portion, a third portion, a first coupling portion, a second coupling portion, a first extending portion and a second extending portion. Each of the first portion and the second portion is positioned apart from a first edge of the core. Each of the first portion and the second portion is parallel to the first edge. Each of the first portion and the second portion is positioned apart from the third portion in a first horizontal direction. The third portion is positioned apart from a second edge of the core. The third portion is parallel to the second edge. The first extending portion couples the first portion and the third portion with each other. The second extending portion couples the second portion and the third portion with each other.

Inductor

A power conversion device includes a transformer, a plurality of converter cells, and a control circuit that controls semiconductor switching elements in each of the converter cells to be turned on and off. The transformer includes: a primary winding group being connected in multiple phases to an AC power supply including multiple phases; and a plurality of secondary winding groups. Each secondary winding group includes, in each of the multiple phases, secondary windings each formed of a single-phase open winding. Each converter cell converts a single-phase AC voltage between AC nodes connected to the respective secondary windings into a DC voltage by control of the semiconductor switching elements to be turned on and off, and outputs the converted DC voltage between a pair of DC nodes. The DC nodes of the plurality of converter cells are connected in series between a first DC terminal and a second DC terminal.

Power conversion device

A power conversion apparatus comprises, a converter that receives a three-phase AC power supply 1 and outputs a DC voltage, an inverter that is connected to the output of the converter and drives the AC motor via the output switch, a power switch for directly driving an AC motor from the AC power supply, a current detector for detecting the output current of the inverter, a voltage detector and a current detector for detecting the voltage and current of the power supply system on the input side of the converter, respectively, and a control unit for controlling the three-phase output voltage of the inverter based on the voltage command of three phases. The control unit includes a vector control unit that performs vector control of the AC motor and a synchronous incorporation controller. The synchronous incorporation controller switches to operate the inverter as a reactive power controller for the power supply system after closing the power switch to synchronize the AC motor with the AC power supply.

Power conversion apparatus

A power conversion apparatus having a converter, an inverter controlled by inverter controller, and an input power source fluctuation detecting and controlling circuit is proposed. The input power source fluctuation detecting and controlling circuit includes an input power source fluctuation detector and a converter failure detector to detect overcurrent and/or overvoltage of the converter. When both of the input power source fluctuation and the converter failure are detected, the converter is gate blocked, and the inverter continues its operation, and when the DC voltage become lower than a threshold voltage during the converter is gate blocking, the input power source fluctuation detecting and controlling circuit outputs an inverter control changeover flag to the inverter controller for switching a contents of inverter control.

An inverter test apparatus includes a DC power supply, a second inverter which is connected to a DC side of the first inverter, an inductor which is connected between an AC side of the first inverter and an AC side of the second inverter, a first controller which controls an AC voltage of the first inverter to be at a constant amplitude and a constant frequency, a current detector which detects a current that flows through the inductor, a phase command value computation module which computes a phase command value of the second inverter so as to control the current detected by the current detector, and a second controller which controls a phase of the second inverter, based on the phase command value computed.

Inverter test apparatus

In a motor driving system, a motor driving system is provided which simplifies the system by ceasing ON/OFF control of a commercial driving command, and by performing commercial synchronous transfer and capture control based on a drive speed reference. A system controller performs synchronization control so as to make a drive output coincident with a phase/amplitude of a commercial AC power source when a rotation speed of a motor exceeds a drive speed reference n, and when a prescribed requirement is satisfied, the commercial AC power source is synchronously transferred, and the motor is driven by the commercial AC power source. In addition, when the drive speed reference is set to n, and a drive output side switch is closed, the drive output is connected to the commercial AC power source, and when a prescribed requirement is satisfied, the motor is started to be driven at a variable speed (t), and thereby the synchronous capture is performed.

Motor driving system

It is composed of a three-phase three-level inverter, three single-phase five-level inverters, each of which is connected in series with an output of each phase of the three-phase three-level inverter, and pulse width modulation control meansprovided for each phase which supplies gate pulses to the three-level inverterand the single-phase five-level inverterof the relevant phase. State transition meanswhich determines an output of a switching leg of the three-level inverter, and outputs of outside and inside switching legs of the single-phase five-level inverter based on transition of a voltage level created by the pulse width modulation control means, makes all of the three outputs of the three-level inverter, and the outside and inside switching legs of the single-phase five-level inverter0 or positive, when the voltage level is positive, makes all of the outputs of these three legs 0 or negative, when the voltage level is negative, and makes all of the outputs of these three legs 0, when the voltage level is 0.

Seven-level inverter apparatus

On the basis of rainfall amount data () representing a timeseries change in the amount of rainfall in a district as an estimation target and unascertained water amount data () representing a time-series change in the amount of unascertained water at a base point located downstream of each district, an unascertained water occurrence distribution estimating unit () of a control unit () calculates a correlation value between the rainfall amount data () in each district and the unascertained water amount data (), and outputs each correlation value as an unascertained water occurrence distribution in each district.

Device and method for estimating occurrence distribution of unascertained water and recording medium

A multi-level power converter is disclosed. The converter includes a DC power source having N (N is an Integer more than two)-level voltage potentials, and a plurality of switching legs connected in parallel to the DC power source. The switching leg has switching elements in series connection, and clamp diodes connected between intermediate DC potential terminals to middle points of the switching legs. The converter is provided with a control means for supplying gate pulses to the switching elements, and a supervising means for supervising every switching element to output a failure signal. The converter further includes a logic operating means for detecting an over-current failure of main circuit elements to output a device fault signal using the failure signals An operation of the logic operating means at least includes AND condition of at least two failure signals to output the device fault signal.

Multi-level power converter

A case base () is generated from historical data containing inflow data () that indicates a sewage inflow measured at a sewage treatment plant () and meteorological data () corresponding to the inflow data (). A similar case search section () and output estimation section () predict a sewage inflow corresponding to an input prediction condition () after a predetermined prediction time in real time using the case base () and output inflow prediction data ().

Sewage inflow amount predicting device and method, and server device

In a power inverter system, an inverter unit includes first to third single-phase inverters. In the power inverter system, a reference-frequency calculating unit calculates a reference frequency of each of the first to third single-phase inverters. A reference-voltage-calculating unit calculates a reference voltage of each of the single-phase inverters. In the power inverter system, a voltage-correcting unit adds a correction voltage to the reference voltage calculated by the reference voltage-calculating unit. The correction voltage has a frequency three times as high as the reference frequency.

Power inverter system and method of correcting supply voltage of the same

A power conversion device is constituted by: a power converter that receives AC power and uses this to drive an AC motor; a control section for controlling an inverter section of the power converter; a voltage detection section that detects the voltage of the AC power source; a current detection section that detects the input current of the AC motor; and a speed detection section that detects the rotational speed of the AC motor. The control section has a vector control section that converts the current detected by the current detection section into a torque current component and an exciting current component orthogonal thereto and respectively independently controls these, and, when an electrical quantity found from the voltage detected by the voltage detection section has dropped below a first prescribed value, reduces the instruction value of the torque current component in a prescribed ratio in response to the lowered electrical quantity and, when the electrical quantity has dropped below a second prescribed value smaller than the first prescribed value, reduces the instruction value of the torque current component to zero.

Many actual data , each consisting of a set of an actual water distribution amount obtained in advance from a water management system and a variable needed for prediction, are loaded and retained as history data , an input space of a case base is quantized according to a desired output allowance error, each history data is set in the quantized input space, and a case representing at least one history data is prepared to generate a case base . Then a similar case corresponding to a newly input prediction condition is retrieved from the case base , and a water distribution amount corresponding to the prediction condition is estimated from the retrieved similar case.

Water distribution amount predicting system

In a power conversion device comprising an AC filter for harmonic current suppression having a combination of at least some of a reactor, capacitor and resistance and a power conversion circuit that converts AC power into DC power or DC power into AC power and is connected to an AC power source through AC filter by providing: voltage reference calculation means (unit) that calculates and outputs a voltage reference corresponding to the voltage that is to be output by the power conversion device main unit; current detection means (unit) that detects and outputs current flowing through a prescribed location between AC power source and power conversion circuit and voltage reference correction means (unit) that uses the output from current detection means (unit) as a voltage reference correction signal to correct the voltage reference that is output from voltage reference calculation means (unit) resonance of the AC filter for harmonic current suppression is suppressed without employing a damping resistance for resonance suppression.

Provided is an inverter apparatus comprising a three-phase inverter section having a three-phase bridge rectifier for converting three-phase AC power into DC power and a three-phase bridge inverter for converting the DC power converted by the three-phase bridge rectifier into three-phase AC power, 3n (n is a natural number) single-phase inverters, of which n (n is a natural number) single-phase inverters are connected in series with phase outputs of the three-phase inverter section to convert the three-phase AC power into DC power, convert the converted DC power into single-phase AC power, and output the power, and a transformer for supplying insulated AC powers to the three-phase inverter and the 3n single-phase inverters, respectively.

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Tokyo, Japan

Toshiaki Oka