Daikin Industries, Ltd.

Reiji Kawashima

Masahiro Yamamoto

Masaki Kono

Takayuki Fujita

Masaki Kouno

Kenichi Sakakibara

Toshiyuki Maeda

Morimitsu Sekimoto

Masahide Fujiwara

Keisuke Ohta

Abdallah Mechi

Yoshitsugu Koyama

Hitoshi Haga

Hiroshi Hibino

Sumio Kagimura

Hirotaka Doi

Nobuyasu Hiraoka

Keito Kotera

Hirotaka Saruwatari

Kazushi Hisayama

Sumikazu Matsuno

Ryou Matsuyama

Yueqiang Zhou

Masakazu Iida

Isao Tanatsugu

Taku Itou

Jun Takahashi

Koudai Okuzono

Yuu Yoshikawa

Hiroki Kojima

Kodai Okuzono

Akihiko Oguri

A noise reduction circuit includes: noise canceler circuitry configured to inject a compensation current into a power line and ground to reduce a common mode noise current that flows through the power line and the ground into a commercial power supply from a power converter with a switching element connected to the commercial power supply; and overcurrent inhibitor circuitry provided on a compensation current path through which the compensation current flows, the overcurrent inhibitor circuitry being configured to inhibit application of an overcurrent to the noise canceler circuitry.

Noise reduction circuit, power conversion device, and refrigeration apparatus

A power conversion system includes an inverter circuit, a harmonic reducer, and a synchronizer. The inverter circuit is operable with electric power supplied from an alternating-current power source. The harmonic reducer is connected to the alternating-current power source. The inverter circuit includes a circuit main portion and a conversion control unit configured to control the circuit main portion. The harmonic reducer includes a current control unit configured to perform control to reduce a harmonic current flowing to the alternating-current power source. The synchronizer is configured to synchronize a state of the harmonic reducer with a state of the inverter circuit.

Power conversion system

An air conditioner is connected to an AC power source. The air conditioner includes an adjustment unit and a control unit. The adjustment unit adjusts apparent power at a power source input terminal of the air conditioner. The control unit controls the adjustment unit, based on information according to a target value of apparent power to be supplied to the AC power source from the air conditioner.

Air conditioner

A power converter includes a power conversion unit for a three-phase alternating current output from an alternating-current power source, and a current compensation unit that supplies a compensating current to the alternating-current power source. The current compensation unit includes a current compensation unit inverter including switching elements, a current compensation unit capacitor, a current compensation unit reactor, a compensation controller that obtains an output voltage command value, and a drive signal generator that generates a drive signal usable to drive the switching elements by a three-phase modulation method. The current compensation unit inverter supplies the compensating current to the alternating-current power source via the current compensation unit reactor. Td≤(34.00/fsw−0.145)(1.55−0.055*Pmax), where fsw represents a carrier frequency employed for generation of the drive signal, Pmax represents a maximum input power of the power conversion unit, and Td represents a dead time for the drive signal.

Power converter and heat pump system provided therewith

[Problem to be solved] To achieve adjustment of an electric line based on indexes set separately for harmonic components having different orders in a current in the electric line. [Solution] A power control system causes a device to adjust apparent power in an electric line, and the power control system includes a setting unit that sets an index regarding each adjustment for a harmonic component of a first order group in a current in the electric line, a harmonic component of a second order group higher in order than the first order group in the current in the electric line, and a fundamental component in the current in the electric line, and a control unit that controls each adjustment by the device based on the index set by the setting unit.

Power control system and device

A technology that can reduce the influence of variations in the reference potential of each current output device on the operation of multiple current output devices, when using the multiple current output devices to reduce the distortion of the load current, is provided. A plurality of active filterstoare configured to reduce distortion of a load current supplied from the AC power supplyto the load device, based on a detection signal output from the load current sensor, the detection signal relating to the distortion of the load current; and the signal transmitting unitconfigured to cause the plurality of active filterstoto acquire a signal relating to the distortion of the load current, to reduce influence due to variation of a standard potential of the plurality of active filtersto, based on the detection signal output from the load current sensor

Current distortion reduction apparatus

A power conversion device () is supplied with an electric power from an alternating current power source (). An active filter device (), which is a power source quality improvement unit, improves a quality of the alternating current power source (). A controller () limits an operation of the power conversion device () so that any one of a power-source electric power, a power-source current, and a power-source harmonic obtained when a failure detection unit () detects a failure of the active filter device () becomes less than or equal to a maximum value of a corresponding one of the power-source electric power, the power-source current, and the power-source harmonic, the maximum value being obtained when no failure has occurred in the active filter device ().

Power source quality management system and air conditioning apparatus

To achieve high density integration of components while securing an insulation distance between a bootstrap capacitor and an intelligent power module. In a printed wiring board, a region where a capacitor is mounted is located in a region where an intelligent power module is mounted. Therefore, the capacitor mounted on the printed wiring board is placed between the printed wiring board and the intelligent power module.

Inverter device including a bootstrap circuit

A plurality of active filter devices () that each have an output connected to a harmonic-generating load device () and are capable of generating a compensating current for performing at least one of reduction of a harmonic current of the harmonic-generating load device () and improvement of the power factor of the fundamental wave are provided. The plurality of active filter devices () provide two or more types of capacities, and the number and combination of operating active filter devices among the active filter devices () change in accordance with the magnitude of the compensating current.

Active filter system and air conditioning device

A controller performs a first control for controlling the power source power factor or a power source harmonic of the harmonic current such that an input power factor of at least one of a plurality of connection devices changes in a direction preceding the power source power factor in a case where the power source power factor changes in a lagging direction, and performs a second control for controlling the power source power factor or the power source harmonic such that the input power factor of at least one of the connection devices changes in a direction lagging behind the power source power factor in a case where the power source power factor changes in a leading direction.

Power source quality management system and air conditioner

A load apparatus is connected to an AC power source and is supplied with power from the AC power source. An operation state control unit controls, based on a target value about a power-source quality including either a power-source power factor of the AC power source or a power-source harmonic of the AC power source and on a present power-source quality, an operation state of the load apparatus.

Power-source power factor control system, phase modifying apparatus, and active filter apparatus

A power conversion device includes a power conversion unit that converts power into AC power having a predetermined frequency and voltage through a switching operation of a plurality of switching elements, a DC unit including a capacitor and a reactor, and a controller that controls the switching operation. The capacitor smooths a ripple caused by the switching operation in the power conversion unit. The controller monitors an indicator value correlated with a disturbance that distorts an input current supplied to the power conversion unit, and compensates a manipulated variable of control of the switching operation in the power conversion unit in accordance with at least a frequency component closest to a resonant frequency of the DC unit among a plurality of frequency components. The frequency components are included in variations in the indicator value and correspond to integral multiples of a power source frequency of an AC power source.

Power conversion device

A current source capable of generating a current of a first compensation portion for either or both reducing a harmonic current in an air conditioner or improving a fundamental power factor in the air conditioner is provided. If an excess of the current source is larger than a second compensation portion for either or both reducing a harmonic current in a power receiving path of a distribution board or improving a fundamental power factor in the power receiving path of the distribution board, a current obtained through superimposition of a current of a second compensation component and a current of the first compensation component is generated in the current source.

Active filter device, air conditioning device, and air conditioning system

In a device with a built-in active filter, the device incorporating an active filter therein and being connected to an AC power source, the active filter operates based on a value detected by a load information detection unit detecting load information on an AC power source outside the device with a built-in active filter.

Device with built-in active filter

Disclosed is a control device controlling an operation of an active filter which is connected in parallel with a load at an installation point (P) with respect to an AC power source and which supplies a compensation current (Ic) to the installation point (P) so as to compensate for a harmonic component of a load current (Io) flowing through the load. The control device includes: a dq converter converting the load current (Io) into a component of a d-axis current and a component of a q-axis current; a high-pass filter extracting a harmonic component from at least the component of the q-axis current output from the dq converter; a multiplier outputting a result obtained by multiplying a component of a d-axis current output from the high-pass filter by a compensation rate (Kd) as a current command value (id*); and a multiplier outputting a result obtained by multiplying the component of the q-axis current output from the dq converter or a component of a q-axis current output from the high-pass filter by a compensation rate (Kq) as a current command value (iq*). The compensation rate (Kq) of the q-axis current in the multipliers is adjustable.

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Osaka, Japan

Reiji Kawashima