Mitsubishi Electric Corporation

Hitachi Industrial Equipment Systems Co., Ltd.

Yuki Taniyama

Kenji Takahashi

Takeshi Tsuchiya

Yasuhiko Wada

Kotaro Chiba

Toshiyuki Kaitani

Kohei Sakai

Yuichi Shimizu

Toshiaki Yabe

Akane Hongyo

Tomoyuki Kado

Norikazu Saitou

Hiroyuki Kamiko

Sho Nikaido

Shotaro Sano

A suction flow path of a screw compressor includes a male-side flow path that opens in an axial direction with respect to working chambers in a suction process on the male rotor side and extends from a starting end positioned on one side of a virtual plane to a first termination end positioned on the other side; and a female-side flow path on the female rotor side that extends from the starting end to a second termination end positioned on the other side of the virtual plane. The male-side or the female-side first flow path wall is configured such that at least a partial area in a range from the starting end to the first or the second termination end is closer to a male-side or female-side rotor lobe section from the starting end side toward the first or second termination end side.

Screw compressor with improved suction flow

A drive device includes a power converter, a first magnetic pole position identification unit, a second magnetic pole position identification unit, a subtractor, and a current control unit. The power converter supplies power to a main-side synchronous motor and a sub-side synchronous motor connected in parallel. The subtractor obtains an angular difference using the magnetic pole position of the rotor of the main-side synchronous motor identified by the first magnetic pole position identification unit and the magnetic pole position of the rotor of the sub-side synchronous motor identified by the second magnetic pole position identification unit. A magnetic flux current command compensation unit adjusts the absolute value of a magnetic flux current command based on the angular difference. The current control unit controls the power converter using a torque current command and the magnetic flux current command with the absolute value adjusted by the magnetic flux current command compensation unit.

Drive device, fluid utilization device, and air conditioner

A power conversion device includes: a switching signal generator configured to generate a switching signal to output, from an inverter circuit, an AC voltage corresponding to a designated phase; a speed estimator configured to estimate an estimated phase of a rotor of a motor based on a current flowing through the motor; and a beat suppression controller configured to output an adjusted phase to the switching signal generator so as to suppress a beat component superimposed on the current flowing through the motor, the adjusted phase being obtained by adjusting the estimated phase.

Power conversion device

A drive device for an AC motor includes: an adaptive observation unit that adaptively estimates an angular velocity of a rotor of an AC motor; a speed control unit that determines a first torque command with which an angular velocity command matches an average value of an estimated angular velocity; a phase lead amount calculation unit that calculates, based on a disturbance frequency, a phase lead amount of a transfer function from a true angular velocity to a model deviation; a vibration suppression control unit that determines, based on a frequency of load torque pulsations, the model deviation, and the phase lead amount, a second torque command with which speed pulsations in the AC motor are suppressed; and a torque control unit that controls a torque of the AC motor based on the first torque command and the second torque command.

Drive device for AC motor, compressor drive device, and refrigeration cycle device

A fluid machine that performs efficient cooling of a control system, such as a control device. The fluid machine is provided with: a fluid machine body; a drive source; a control device; a housing in which the fluid machine body, the drive source, and the control device are housed; and a cooling fan. The housing has a plurality of intake openings for introducing cooling air into the interior thereof and one exhaust opening, and includes a partition wall which partitions the interior of the housing into a first compartment and a second compartment and which has a communication portion providing communication between the first compartment and a part of the second compartment. A first intake opening among the plurality of intake openings is disposed in a housing wall of the first compartment in which at least the control device is disposed, and a second intake opening is disposed in a housing wall of the second compartment in which at least the drive source is disposed. The exhaust opening discharges the cooling air that has flowed from the first intake opening into the second compartment via the communication portion and that has cooled one of the fluid machine body and the drive source, and the cooling air that has been taken in via the second intake opening. A part of the control device is disposed facing an area of the first compartment downstream of the first intake opening and upstream of the communication portion.

Fluid machine

Growing community of inventors

Tokyo, Japan

Yuki Taniyama