Hitachi, Ltd.

Hitachi Engineering Co., Ltd.

Hitachi Elevator Engineering & Service Co., Ltd.

Hitachi Building Systems Engineering and Service Co., Ltd.

Sadao Hokari

Hideaki Takahashi

Koichi Sato

Hiromi Inaba

Seiya Shima

Katsu Komuro

Kiyoshi Nakamura

Yasunori Katayama

Takanobu Hatakeyama

Takeki Ando

Yoshio Sakai

Shigeta Ueda

Atsuya Fujino

Toshiaki Kurosawa

Kenji Yoneda

Satoshi Fukuda

Toshimitsu Tobita

Tetsuya Ooshima

Tomiaki Kurihara

Yasuyuki Maeda

Toshio Meguro

Kazuhiro Sakata

Toshifumi Yoshikawa

Nobuo Mitsui

Takamasa Hori

Seikichi Masuda

Akira Kimura

Toshisuke Mine

Hideki Ayano

Kanji Yoneda

Akinori Watanabe

Tadao Kameyama

Takao Kishikawa

Naoto Ohnuma

Hirokazu Nagura

Masakazu Kume

Noboru Arahori

Toshiroo Narita

Hiromi Inabe

Naoyuki Outi

Toshiro Narita

Takei Ando

Akihiro Nokita

Masahiro Konya

Naoyuki Oouchi

Kan Miyoshi

Yasushi Tsukamoto

A driving system for driving an AC motor, which is capable of promptly switching to an individual inverter operation mode, wherein a control instruction for each of a plurality of power converters is generated by summing outputs of a plurality of current compensation units connected in parallel, and each of the plurality of current compensation units makes compensation to reduce a deviation of a detected output current value of an associated power converter from a current instruction value to be outputted from the power converter to zero.

Driving system for driving AC motor

The number of electrical wires in the car is reduced by radio communications between the operation panel and terminal. Furthermore, reliability and dependability of communications are improved because the operation panel and terminal communicate with each other at a comparatively short distance.

Elevator communications apparatus

An elevator capable of supplying electric power to accessory hall devices such as up/down elevator buttons and position indicators without requiring power supply lines between the cage and each hall. A drive battery which supplies electric power to hall devices provided in each hall and a receptor connected to the battery are provided on the hall. A feeder contactable with the respective receptors, a charging device that charges the battery via the feeder and receptor are provided on the top of the cage. When the charging voltage, for example, used in a hall of the floor drops below a predetermined voltage value, the cage stops automatically at the floor and the charger charges the drive battery in the hall of the floor via the receptors and feeder.

Charger for elevator call devices

An elevator system which is provided with power converters, electric motors supplied with power from the power converters, and a torque distributing section having functions for determining allocation of output power from the power converters on the basis of a required torque, by which an elevator is operated on the basis of functions selected in accordance with the operation mode. The system is able to save power in the elevator operation and also improve control functions and increase system capacity.

Elevator system

A power converter comprising a current-type inverter is disclosed, in which an output of a converter unit is applied as an input to the inverter unit through a DC reactor, and AC power is supplied to a load from the inverter unit. A ripple component of the DC input of the inverter unit is detected, and the switching elements of the inverter unit are controlled by modulation rate if they are to be subjected to PWM control, thus completing a sinusoidal waveform of the output of the inverter unit. Specifically, since the input to the inverter unit is allowed to contain a ripple, the DC reactor is reduced in size. The output of the inverter unit is a sinusoidal AC power containing no high harmonics and therefore the load is free of effects of high harmonics.

Power converter with current-type inverter

Disclosed is an apparatus and method for controlling switching elements (51-56) of a PWM-controlled value type inverter by a software program using a microcomputer (10). The control apparatus of the present invention produces a switching element control signal (an on/off signal) according to the following steps. When a control command value commanding the output of the inverter is determined, a control mode corresponding to the commanded output value is selected from among a plurality of control modes (M1-M6) previously contained in a table to determine the switching elements to which the control signal is applied and the order of controlling the switching elements. Further, on the basis of the control command value, the difference between a modulation signal and a predetermined reference value is computed for each phase to determine the timing of controlling the switching elements. The unit control period of each control mode is divided into halves, and the switching element control timing is determined in each of the halves of the unit control period. The control signal is produced on the basis of the combination of the selected control mode and the determined control timing.

Apparatus and method for controlling switching elements in a

In a three phase inverter which is composed of transistors turned on or off in accordance with the PWM control, the pulse widths of PWM gate signals for the transistors are determined in accordance with the magnitudes of two of the three phases of the current to be output by the inverter. The load of a processor for generating the gate signals can be reduced to the great extent, and in addition thereto, the waveform of the output current of the inverter is much improved.

Apparatus for controlling power transducers of the pulse width

A current-type converter including a DC power source, a current-type converter, a load and a converter control unit, the converter control unit controlling so as to cause as least two states among a powering conduction state for supplying power from said DC power source to said load within predetermined control periods of both a powering control mode and a regenerative control mode, a regenerative conduction state for regenerating power supplied from the load toward the DC power source, and a reflux conduction state for short-circuiting the output of the current-type converter and returning the circuit current of the load, and the converter control unit varying the period length of respective states.

Current-type converter apparatus

A first apparatus for determining instantaneous reactive currents to determine instantaneous reactive currents in every phase of a three-phase load. Three phase current signals corresponding, respectively, to phase currents of the three-phase load supplied from a three-phase power-supply source are multiplied with sinusoidal wave signals of three phases, each of which has a phase difference of 90.degree. relative to the corresponding phase voltage of the three-phase power supply source to obtain the products for three phase, respectively, which products are added together to produce a sum signal. The instantaneous reactive currents mentioned above are determined on the basis of the sum signal and the three phase sinusoidal wave signals. A second apparatus for compensating the reactive power of the three-phase load by means of a converter load circuit including a current-source type three phase converter connected in parallel with the three-phase load by making use of the instantaneous reactive currents of the three-phase load determined by the first mentioned apparatus.

Apparatus for compensating reactive power by current-source type

Controller for AC elevator

An elevator controller which uses an acceleration command signal that has as its initial value a start shock compensation torque which will offset the unbalance torque caused at the time of starting. From the completion of elevator car acceleration to the start of deceleration, the acceleration command is gradually increased or decreased to control the motor so as to provide a smoother motion of the car. After the inception of the car deceleration a velocity command is issued which decreases with the reducing distance between the car and the destination floor.

Controller for elevator

A pulse generator is coupled to a car drive motor directly coupled to a sheave, over which a rope suspending an elevator car is passed, and the position of the car is calculated through the counting of pulses produced from the pulse generator. First and second car position detectors for detecting respective first and second car positions are provided within a hatchway, and the number of pulses produced during a period from the actuation of the first car position detector till the actuation of the second car position detector is detected. A count value for calculating the car position is corrected according to the difference between the detected pulse number and a reference pulse number corresponding to the distance between the first and second car position detectors, thereby effecting the compensation for the wear of the sheave and rope to improve the precision of the car position detection.

Method and apparatus for detecting elevator car position

An abnormal speed detector for an elevator system having an elevator car for servicing a plurality of floors, means for driving the elevator car in response to a speed command and a speed detector for detecting a running speed of the elevator car is disclosed. The abnormal speed detector comprises means for storing a set of speed data indicating a predetermined abnormal speed checking pattern as a function of running time or running distance of the elevator car, means for reading out of the storage means one of the set of speed data corresponding to an instant value of the running time or running position of the elevator car after the start of run, and means for comparing an actual speed of the elevator car with the readout speed data to determine if the speed of the elevator car is normal or not.

Abnormal elevator speed detector

A control system for an AC elevator system in which an actual speed of an elevator car is compared with a speed command and control is made so that deviation between the actual speed and the commanded speed becomes zero. The speed command is so composed that deceleration of the elevator car is gradually decreased as the car approaches to a target landing position in the stopping operation of the elevator. A motoring torque or a braking torque is additionally generated in dependence on a load on the car in a region close to the target landing position.

AC Elevator control system

In a three phase load controlling system two bilateral switching circuits control the current in the first and the third phases; the first phase is later than the third. The second phase is uncontrolled. The gating signals applied to the bilateral switching arrangement connected in the first phase are advanced by a constant degree with respect to the voltage of the first phase. The gating signals applied to the bilateral switching arrangement connected in the third phase are synchronized with the voltage of the third phase.

Three phase controlling system

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Katsuta, Japan

Sadao Hokari