Hitachi Industrial Equipment Systems Co., Ltd.

Hitachi, Ltd.

Hitachi Home and Life Solutions, Inc.

Tomofumi Okubo

Tsunehiro Endo

Yoshitaka Iwaji

Kiyoshi Sakamoto

Norinaga Suzuki

Daigo Kaneko

Yoshiyuki Taguchi

Kazuaki Tobari

Hideharu Tanaka

Hidefumi Shirahama

Masakazu Hase

Hajime Uematsu

Kiyomi Tashima

Toshio Tomita

Akihiro Takanuki

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 provide an electric motor system such that loss of synchronism of an inverter-driven synchronous motor with no magnetic pole position sensor can be easily detected. In order to achieve the purpose, the present invention pertains to an electric motor equipped with a synchronous motor, an inverter having a power conversion device for driving the synchronous motor, and a load connected to the synchronous motor, and is configured such that loss of synchronism of the synchronous motor is determined on the basis of a direct-current voltage in the power conversion device.

Electric motor system

Disclosed is a motor control apparatus for controlling a synchronous motor, which includes a receiver section for receiving the value detected by a temperature sensor installed inside the synchronous motor. The synchronous motor is started up with the current fed into it, whose magnitude is changed in accordance with the temperature received by the receiver section at the time of starting up the synchronous motor. In this way, the stable startup of the synchronous motor can be guaranteed and the useful life of the semiconductor elements can also be prolonged.

Motor controller, air compressor, air conditioner, controller of passenger conveyor and controller of conveyor

A synchronous motor driving apparatus having a power converter which applies AC variable voltages having variable frequency to a synchronous motor includes a pulsating current application unit for applying pulsating current to the synchronous motor and a magnetic pole position presumption unit. The magnetic pole position presumption unit detects two current values &#x394;Idcpand &#x394;Idcpon the positive side and two current values &#x394;Idcnand &#x394;Idcnon the negative side of the pulsating current and presumes the magnetic pole position of the synchronous motor on the basis of difference between change rates of &#x394;Idcp&#x2192;&#x394;Idcpand &#x394;Idcp&#x2192;&#x394;Idcp

Synchronous motor driving apparatus

A motor drive system without any portion for directly detecting the rotor position, rotation speed and motor phase currents, capable of realizing a high-performance variable speed drive even at high carrier frequencies. When detecting a current from a DC power supply of an inverter for driving a motor, applied voltages and frequencies to the motor are controlled based on sampled values by sampling a current flowing as intermittent pulses in the vicinity of each power conduction time period.

Motor drive system for AC motors

An AC motor control apparatus that is applicable to commonly used PM motors and capable of detecting the magnetic pole position with simple algorithm. The AC motor control apparatus comprises an inverter for applying arbitrary AC power to an AC motor and a controller for sending a control signal to the inverter. The controller comprises a ripple current generator for supplying a ripple current to the AC motor and a magnetic pole position estimator. The magnetic pole position estimator observes at least two current values of the ripple current for both positive and negative sides of the ripple current to estimate the magnetic pole position of the AC motor.

Driving systems of AC motor

The object of the invention is to inhibit the axial displacement caused by the insufficiency of a control response angular frequency of a frequency arithmetic unit of a synchronous motor and realize high-precision torque control also in acceleration/deceleration. To achieve the object, the axial displacement of the synchronous motor caused by the insufficiency of the control response angular frequency of the frequency arithmetic unit is estimated in consideration of the control response angular frequency and input &#x394;&#x3b8;c(=&#x394;&#x3b8;c+&#x394;&#x3b8;c) including an estimated value &#x394;&#x3b8;cin addition to an axial displacement operated value &#x394;&#x3b8;cto the frequency arithmetic unit is acquired. Hereby, even if the frequency arithmetic unit has an insufficient control response angular frequency, the quantity of axial displacement which will be caused by the insufficiency is estimated as a second axial displacement signal &#x394;&#x3b8;c, is added and input. Therefore, actual axial displacement &#x394;&#x3b8;cof the synchronous motor is stable at a value substantially close to zero.

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Narashino, Japan

Tomofumi Okubo