Mitsubishi Electric Corporation

Shuta Ishikawa

Akihiko Iwata

Tatsuki Matsunaga

Yoshiaki Yamamoto

Masanori Kato

Kazufumi Tanaka

Kazutoshi Kurahashi

Teruaki Tanaka

Satoshi Azuma

Keiichi Yamamoto

Shinsaku Kusube

Kenta Yuasa

Akihiro Tsumura

Shinichi Furutani

Ryuichi Takezawa

Shusaku Nakase

Koyo Matsuzaki

Yuki Kawauchi

Keisuke Ishikura

Shotaro Marumoto

Shunichi Nishimura

Yoichi Egashira

An active filter device includes a power module configured to generate a compensating current to suppress a harmonic current generated from a load device and a controller configured to control the power module. The controller includes a current command calculation unit configured to calculate a compensating current command to suppress the harmonic current, a control variable calculation unit configured to calculate a control variable based on a deviation between the compensating current command and an actual compensating current, a duty cycle calculation unit configured to calculate duty cycle of each of three phases based on the control variable, a duty cycle modulation unit configured to perform two-phase modulation on the duty cycle of each of three phases, and a control signal generation unit configured to, after the two-phase modulation, generate, from the duty cycle of each of three phases, a control signal to drive the power module.

Active filter device and air conditioner

A series multiplex inverter includes a power conversion unit, a phase difference selection unit, a drive signal generation unit, and a drive signal output unit. The phase difference selection unit selects, from among a plurality of phase difference candidates, the phase difference between rectangular wave voltages from a plurality of single-phase inverters. The drive signal generation unit generates a plurality of drive signals that causes the different single-phase inverters to output a plurality of rectangular wave voltages sequentially out of phase by the phase difference selected by the phase difference selection unit. The drive signal output unit outputs the plurality of drive signals generated by the drive signal generation unit to the plurality of single-phase inverters.

Series multiplex inverter

The power conversion device includes a multilevel boosting circuit and a smoothing capacitor for smoothing output voltage of the multilevel boosting circuit. The multilevel boosting circuit includes: a leg portion in which four semiconductor elements, i.e., a first diode, a second diode, a first switching element, and a second switching element are connected in series; and an intermediate capacitor connected between a connection point of the first diode and the second diode, and a connection point of the first switching element and the second switching element. When voltage of the smoothing capacitor becomes a reference voltage value or more, the control unit executes a protection mode to fix the first switching element and the second switching element in OFF states.

Power conversion device including a boosting converter for boosting output voltage from a DC power supply

A series multiplex inverter includes a power conversion unit, a drive signal generation unit, and a drive signal output unit. The drive signal generation unit generates n drive signals that cause different single-phase inverters of n single-phase inverters to output n rectangular wave voltages sequentially out of phase, where n is an integer of three or more. The drive signal output unit outputs the n drive signals to the n single-phase inverters in rotation that shifts, by p every m-fold time of half an output voltage period of the power conversion unit, the single-phase inverters corresponding one-to-one to the n drive signals in a combination of the n drive signals with different single-phase inverters of the n single-phase inverters, where m is a natural number and p is a natural number relatively prime to n or one.

The power conversion device includes: a boosting unit for boosting DC voltage, the boosting unit including a second switching element, a third switching element, a second reverse-current blocking element, and a third reverse-current blocking element which are connected in series, the boosting unit including an intermediate capacitor connected between a connection point between the second reverse-current blocking element and the third reverse-current blocking element, and a connection point between the third switching element and the second switching element; a smoothing capacitor which is connected in parallel to the boosting unit and smooths the DC voltage boosted by the boosting unit; and a control unit for turning on the third switching element so that the intermediate capacitor is charged to charge completion voltage of the intermediate capacitor.

Power conversion device with an intermediate capacitor and a smoothing capacitor

A converter supplies an output voltage, generated by stepping down or up an input voltage from a DC power supply, to an inverter for driving an AC motor. In the converter in a boost mode, a buck circuit is stopped, a boost circuit is operated, and a first bypass switch is turned on to form a path from the DC power supply to the boost circuit. In a buck mode, the boost circuit () is stopped, the buck circuit is operated, and a second bypass switch is turned on to form a path from the buck circuit to the inverter.

Power conversion device

A series connection body wherein a first backflow prevention elements, a second backflow prevention element, a first switching element and a second switching element are connected in series in this order; a reactor; a first output capacitor connected between a first end of the series connection body and a second end of the series connection body; and a second output capacitor connected between a connection point between the first switching element and the second switching element and a connection point between the first backflow prevention element and the second backflow prevention element are provided, a DC is inputted between an end of the reactor and the second end section of the series connection body, and power is supplied to a first load connected to both ends of the first output capacitor and a second load connected to both ends of the second output capacitor.

Power converter with different output voltages for plurality of loads

An A/D converter converts an output from a temperature sensor into a digital signal. A service life diagnostic unit diagnoses a service life of a power module based on a signal indicating a temperature outputted from the A/D converter. An output unit generates a signal representing a diagnostic result and outputs the generated signal from an output terminal to outside.

Power module

A power converter includes a transformation circuit configured to transform a rectified voltage, and a converter control unit configured to control a switching element of the transformation circuit. The converter control unit calculates a current command value based on a line voltage or the phase voltage, calculates a current deviation between the current command value and the reactor current, and calculates a switching command value from the current deviation. The converter control unit includes a plurality of integrators for the respective different phase angles of a power supply voltage. The integrator corresponding to a power supply phase angle is caused to accumulate the current deviation, and the integrator corresponding to a phase angle that is advanced by a set delay phase from the power supply phase angle is caused to output the control amount. A switching signal is generated with use of the control amount and the switching command value.

Power converter and air-conditioning apparatus using the same

A power conversion device includes a high-pass filter for extracting an AC component of voltage Vdc of a DC link section, a multiplier for multiplying output VdcAC of the high-pass filter by a first gain K1 and outputting the result, a multiplier for multiplying output of the multiplier by a second gain K2 and outputting the result as a d-axis voltage correction signal vdcmp*, and a multiplier for multiplying output of the multiplier by a third gain K3 and outputting the result as a q-axis voltage correction signal vqcmp*. The gate signal generation section generates gate signals on the basis of a signal vdobtained by adding the d-axis voltage correction signal vdcmp* to a d-axis voltage command value vd* and a signal vqobtained by adding the q-axis voltage correction signal vqcmp* to a q-axis voltage command value vq*.

A power module including: a power conversion unit including N switching-element pairs; and a control circuit. The control circuit receives N command signals, which correspond respectively to the N switching-element pairs, and a shared enable signal. The control circuit is configured to, when the enable signal is negated, execute all-off control of turning off all of the switching elements constituting the power conversion unit, and when the enable signal is asserted, execute normal control, dead-time addition control, and dead-time compensation control for each of the switching-element pairs per period of a corresponding command signal.

A resonance suppression control block includes a high-pass filter for extracting an AC component of DC link voltage, and a gain section for outputting a correction signal obtained by multiplying the AC component by a gain. A control unit controls an inverter based on a signal obtained by adding the correction signal to the voltage instruction. Thus, a power conversion apparatus with a simple configuration can be obtained that can suppress resonance of a DC link section and omit extra work for performing adjustment again in accordance with a power supply frequency.

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Chiyoda-ku, Japan

Shuta Ishikawa