Hitachi Industrial Equipment Systems Co., Ltd.

Kiyomi Tashima

Takashi Kobayashi

Tatsuya Kobayashi

Kenichi Saito

Toshifumi Suzuki

Koji Ono

Norinaga Suzuki

Yasuei Yoneoka

Masahiro Sano

Akihiro Takanuki

Tomofumi Okubo

Kei Okafuji

Kazutaka Ichiki

Kunihiko Oikawa

A compressor, a monitoring system and a method of monitoring a compressor that make it possible to monitor the remaining lifetime of a semiconductor element of a motor control system while the processing load is reduced are provided. A compressor () includes: a motor control system () that controls the rotation speed of a motor (); a compressor body () that compresses air by being driven by the motor (); a pressure sensor () that is provided on the discharge side of the compressor body (); and a running controller () that performs switching between load running and no-load running on the basis of the pressure sensed by the pressure sensor (). A motor controller () of the motor control system () calculates a relative temperature of a semiconductor element relative to a reference temperature by using a temperature of the semiconductor element sensed by a temperature sensor () at the time of switching from no-load running to load running, and calculates an amount of change in a remaining lifetime of the semiconductor element corresponding to the relative temperature of the semiconductor element, whereby monitoring the remaining lifetime of the semiconductor element.

Compressor, monitoring system, and method of monitoring compressor

The purpose of the present invention is to improve the reliability of a power conversion system while reducing the size. In addition, the purpose of the present invention is to reduce noise. This power conversion system has a first power converting device that supplies power to a first motor and a second power converting device that supplies power to a motor different from the first motor, wherein the first power converting device and the second power converting device are each provided with a power converter for converting the power to be supplied to the motors, and a control unit for controlling the power converter, and the first power converting device is provided with a transformer unit for supplying power to the control units, and the transformer unit of the first power converting device supplies power to the control unit in the second power converting device.

Power conversion system

A power converting apparatus and method includes a converter for converting AC power from a commercial power supply into DC power, a smoothing unit for smoothing the DC power from the converter, an inverter for converting an output of the smoothing unit into another AC power, a control unit for controlling the inverter, and a current detector for detecting an output current of the inverter and providing a detection signal indicative thereof. A cooling device for cooling at least one of the converter or the inverter. The detection signal of the current detector is inputted into the control unit so that the control unit estimates a temperature of the inverter or the converter based on the detection signal and controls a cooling device for cooling based on the estimated temperature.

Frequency converting apparatus and control method for the apparatus

The difference between internal processes of a power converting apparatus may bring about a heat difference in the apparatus. In the cooling process, it is presumed that the temperature change of the inverter or converter module may be made so great that the power converting apparatus may be less reliable. In order to overcome this shortcoming, the temperature of the internal module is measured and a cooling control of a cooling fan or the like is carried out on the measured result. This cooling control of the cooling fan causes the life of a switching element of the inverter or converter to be longer.

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Funabashi, Japan

Kiyomi Tashima