Daikin Industries, Ltd.

Nobuo Hayashi

Takurou Ogawa

Morimitsu Sekimoto

Tomoisa Taniguchi

Takayuki Miyajima

Daisuke Ueki

Eiji Tooyama

Yuki Handa

Takuro Ogawa

Tomoki Nakata

An air conditioner includes an indoor unit, outdoor unit, indoor unit power line, and outdoor unit power line. The power lines branch from a common power line. Each of the indoor and outdoor units includes a converter circuit, an inverter circuit, and a capacitor. A total of effective values of integer-order components from second to 40th orders in a total current, which is obtained by adding up an indoor-unit input current and an outdoor-unit input current and which flows through the common power line, is less than a sum of a total of effective values of integer-order components from the second to 40th orders included in the indoor-unit input current that flows through the indoor-unit power line and a total of effective values of integer-order components from the second to 40th orders included in the outdoor-unit input current that flows through the outdoor-unit power line.

Air conditioner

Power conversion apparatus, air conditioner and refrigeration apparatus

A motor control apparatus configured to convert an input power supplied from a power supply to an output alternating-current power having a predetermined voltage and a predetermined frequency is provided. The motor control apparatus includes an inverter circuit configured to supply the output alternating-current power to a motor, and is configured to perform a control to suppress an amplitude of a first harmonic component that occurs synchronously with a rotation rate of the motor in a power input into the motor to be lower than or equal to a predetermined value and to suppress an amplitude of a second harmonic component that occurs in an electromagnetic exciting force of the motor at a same frequency as the first harmonic component to be lower than the amplitude of the second harmonic component in a case of the amplitude of the first harmonic component being suppressed to a minimum.

Motor control apparatus, motor, compressor, refrigeration apparatus and vehicle

A direct power conversion device includes a control unit. tb=1/|fdc&#x2212;n&#xd7;fL|. fdc is a frequency twice as high as a frequency of an AC power supply, fL is a frequency of periodic load fluctuations, and n is a positive integer that maximizes tb. In a half period of power supply during a period of tb, the half period including a timing at which peaks of a fundamental wave of load torque and an absolute value of a power supply voltage substantially coincide with each other, the control unit being configured to control the switching elements so that two or more local maximum points appear in the half period of power supply, in a waveform obtained by combining a second harmonic, a fourth harmonic, and a sixth harmonic of a power supply frequency contained in a waveform of an absolute value of a motor current vector.

Direct power conversion device

In order to suppress vibration with a motor a load torque of which periodically fluctuates, an output torque of the motor is controlled to be periodically changed. In this case, in order to increase a vibration suppressing component by a direct power conversion apparatus, at least one of first control and second control is performed. In the first control, an output torque having a waveform including a fundamental frequency component of the load torque a fundamental frequency of which is a frequency in accordance with a fluctuation period of the load torque and at least one of a fourth harmonic and a sixth harmonic of a power source frequency of an AC power source is generated. In the second control, the output torque having a waveform including at least one of a second harmonic and a third harmonic of the fundamental frequency of the load torque and a second harmonic of the power source frequency of the AC power source is generated.

Power conversion apparatus

A power converter includes a plurality of switching elements, a converter circuit that rectifies an AC voltage of an AC power source, a DC link that receives output of the converter circuit and generates a DC voltage, an inverter circuit that converts the DC voltage into an AC voltage of a predetermined frequency through a switching operation, and a control unit that controls the switching operation. A capacitance value of a capacitor is set so that a maximum value of the DC voltage becomes twice or more of a minimum value. The control unit controls the switching elements such that two or more extrema appear in a power source half cycle in a waveform synthesized from second, fourth, and sixth harmonics that have a power source frequency as a fundamental frequency and are extracted from a waveform of an absolute value of a motor current vector.

Power conversion device

Disclosed herein is a power conversion device including a storage and a power conversion controller. The storage stores multiple values, each correlated to a disturbance that causes distortion in a current to a power converter, in association with a phase angle of a voltage of an AC power supply. The power conversion controller controls ON/OFF operations by using the values stored in the storage to compensate for a manipulated variable of control performed by the power converter in association with the phase angle of the voltage of the AC power supply.

Growing community of inventors

Osaka, Japan

Nobuo Hayashi