Hitachi, Ltd.

Hitachi Industrial Equipment Systems Co., Ltd.

Hitachi Car Engineering Co., Ltd.

Tokyo Gas Company Limited

Hitachi Home and Life Solutions, Inc.

Nabtesco Corporation

Kiyoshi Sakamoto

Yoshitaka Iwaji

Tsunehiro Endo

Kazuaki Tobari

Shigehisa Aoyagi

Yuhachi Takakura

Daigo Kaneko

Tomofumi Okubo

Takashi Matsunobu

Takuji Yanagibashi

Kenichi Azegami

Hiroshi Fujii

Haruo Miura

Naohiko Takahashi

Yukio Kawabata

Tsutomu Hasegawa

Tsunehiro Endou

Hideki Miyazaki

Daisuke Maeda

Masaya Ichinose

Osamu Koizumi

Toshiyuki Ajima

Kenichi Onda

Takashi Ikimi

Yasuo Notohara

Junnosuke Nakatsugawa

Atsushi Takagi

Hidefumi Shirahama

Tomohiro Fujii

Masahiro Tobise

Masakazu Hase

Wataru Hatsuse

Noriyuki Uchiyama

Yoshiyuki Taguchi

Seishi Watahiki

Takahiro Suzuki

Dongsheng Li

Takao Yanai

Shinji Ueda

Chikara Sato

Shinichi Kurita

Hajime Uematsu

Yasuzi Sakuma

Toshifumi Sakai

Hikaru Meguro

Noriaki Yamada

Yuki Takayama

Yoshiaki Ajima

Tomohiro Sugino

Donsheng Li

Kouji Nakatani

Yutaka Honoki

Takuji Ishida

According to the present invention, a wind turbine generator system is provided which can not only remove the influence of salt damage in case the system is established off-shore, but even if the facility becomes larger, which can also cool equipment and the generator provided in the tower and can reduce the possibility of decreasing power generation efficiency. The wind turbine generator system of the present invention comprising a rotor having a hub and blades; a generator connected with the rotor by way of a main shaft connected with the hub; a nacelle which contains at least the generator and supports the rotor pivotally by way of the main shaft; a tower on a top of which the nacelle is supported, and opposite to the top the tower is fixed to a base, wherein a heat exchanger is provided at the tower close to the base and cooling medium passes through the heat exchanger by way of a pipe arrangement, and thereby the heat of the cooling medium and the heat of air inside the tower are exchanged and the air inside the tower is cooled.

Wind turbine generator system

A wind turbine able to generate power irrespective of a presence of and a state of a power grid is disclosed. Specifically, a wind power generation system is provided with a wind turbine, the wind turbine including a blade that rotates in response to the wind, a generator that rotates with rotation of the blade to generate power, and an auxiliary machine that controls a pitch angle of the blade. The auxiliary machine is driven by the generated power of a downwind type wind turbine to which a permanent magnet type generator is mounted and which generates power in a state in which a blade of the downwind type wind turbine rotating in response to the wind faces downwind.

Wind power generation system, device using wind power generation system, and method for operating same

This invention is intended to provide a wind power generator system or method for controlling a wind power generator system, designed to implement switching-initiated smooth energy changeover without leading to a complex system configuration. The method of controlling a wind power generator system according to an aspect of the invention, wherein the generator system includes a wind turbine that uses wind to generate electric power and a control device that controls the wind turbine, is a control method designed so that when the wind turbine is generating power, the turbine drives the control device by use of the turbine-generated power, irrespective of an electric power system state.

Wind power generator system, and control method for the same

When applying a high frequency voltage which alternates on positive and negative sides to a permanent magnet synchronous motor, a driving system of synchronous motor switches the applied voltage phase by 120 degrees successively and applies resultant voltages to three phases. A pulsating current generated by applying a high frequency voltage is detected at timing of elapse of a predetermined time &#x394;t since an output voltage of at least one phase has changed from a state in which all output voltages of the three phases of a power converter are positive or negative. Current detection is conducted by using a DC resistor or a phase current sensor provided on a DC bus. A magnetic pole estimation unit calculates the rotor magnetic pole position of the permanent magnet synchronous motor on the basis of differences between positive side and negative side change quantities in three-phase currents obtained from detected current values.

Driving system of permanent magnet synchronous motor

The device is provided with an electric power conversion circuit including switching elements for converting a DC electric power to an AC electric power, a load connected to an output side of the electric power conversion circuit, means for detecting a current flowing through a DC side in the electric power conversion circuit, a voltage command value preparing means for controlling the operation of the switching elements in the electric power conversion circuit and a wire breaking detecting means. The wire breaking detection means judges a wire breaking in the load or an abnormality of any of the switching elements in the electric power conversion circuit by making use of a DC current detection value in a period when a current of maximum voltage phase or of voltage minimum phase of the electric power conversion circuit is flowing in a DC current.

Electric power conversion device, compressor motor with the device, and air conditioner with the motor

In a motor control apparatus, apparatus all switching devices of all phases of an inverter are kept fixed at OFF in accordance with a value of an all-OFF control pulse signal Poff outputted by a pulse generator. The pulse generator generates at least twice a pulse causing an induced voltage detection signal Pdet to change to an H level. A terminal voltage of a motor is inputted in accordance with the value of the induced voltage detection signal Pdet. Data of the sampling round in which amplitude of the induced voltage signal is great and the signal is not in saturation is selected from the data so inputted and a rotor position is estimated.

Motor control apparatus and motor system

It is attained by being provided with a motor constant calculation unit for calculating electric constants of a motor, and by correcting setting values of electric constants defined on one of the axes of two orthogonal axes, by a functional expression using a state variable defined on the same axis, and by correcting them by a functional expression using a state variable defined on the other axis.

Control apparatus for AC motor

A semiconductor power converter includes a power converter for converting direct current to three-phase alternating current or vice versa; a means for detecting a current in an alternating current side of the power converter; a means for providing a current reference in the alternating current side of the power converter; a current controller for calculating a voltage reference in the alternating current side of the power converter to match the current reference and a value of the detected current; and a pulse width modulation means for controlling the power converter through pulse width modulation based on the voltage reference, wherein the current reference is used in place of the value of the detected current for at least one phase current among three phase currents in the alternating current side.

Semiconductor power converter

In a system in which current is detected in an inexpensive manner or in a system in which a position detector is omitted, the present invention provides a high-efficiency vector controller for a permanent magnet motor that can minimize current at the same torque even when there is setting error (R&#x2212;R*) in resistance. Even when a current value commanded for the d-axis is set to zero, a virtual inductance value calculated from a detected q-axis current value is used for output voltage value calculation and phase error estimation calculation; so even if there is setting error (R&#x2212;R*) in resistance, current can be minimized at the same torque and thereby the present invention can provide a high-efficiency vector controller for a permanent magnet motor.

Vector controller for a permanent magnet motor and inverter module

In a driving system for an inverter that uses a diode rectifying circuit to convert a single-phase or three-phase AC voltage to a desired DC voltage and drives a permanent magnet motor, a DC-voltage pulsating frequency is estimated from a pulsating frequency setting calculated from the power supply frequency of an AC voltage and the detected current values of the inverter, and the resulting estimated pulsating frequency value and detected current values are used to correct the output voltage of the inverter.

Beat-less controller for permanent magnet motor

A vector control system for a permanent magnet synchronous motor, using a current control equivalent output value, a frequency instruction value, a current detection value, an inference phase error value, and a motor constant, identifies a motor resistance equivalent or a resistance setting error equivalent. Next, the vector control unit, using the identified value, corrects a set value R* equivalent of a voltage instruction calculation unit and a n inference phase error calculation unit. Thereby, a vector control system for a permanent magnet synchronous motor can realize a robust control characteristic for changing of a resistance constant of a motor in a low rotation speed area under position sensor-less control. Further, a vector control system for a permanent magnet synchronous motor can be applied in common in a system performing inexpensive current detection.

Control system for permanent magnet synchronous motor and module

A driving apparatus of a synchronous motor fixes all the switching devices of an inverter at OFF in accordance with a value of an all-OFF control pulse signal outputted by a pulse generator. A motor current keeps flowing through free wheel diodes for a predetermined period even after all the switching devices shift to the OFF state. Therefore, pulse generator changes an induced voltage detection signal to an H (high) level after the passage of the time in which a motor current drops down to zero. A terminal voltage of the motor is taken in to acquire an induced voltage and a rotor position is estimated.

System and method for driving synchronous motor

A rotary sensor that outputs two analog signals, such as one sine wave and one cosine wave and has multiple periods within one period of the electrical angle of a motor is employed. The motor is energized at each position for a specified length of time upon its startup by using multiple electrical angles corresponding to the multiple candidate absolute angles obtained from the rotary sensor signal as the initial position of the motor, and the electrical angle at which the motor acceleration becomes maximum is determined as the absolute angle. While the motor drive is in operation, on the other hand, the phase difference &#x394;&#x3b8; between the phase of the motor at the counter electromotive voltage and the control phase is directly computed from the parameters of the motor, sensed current, voltage command and angle speed so as to correct the shifted position.

Synchronous motor drive unit and a driving method thereof

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

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Hitachinaka, Japan

Kiyoshi Sakamoto