Mitsubishi Denki Kabushiki Kaisha

Westinghouse Electric Corporation

Masami Nomura

Hiroyuki Ikejima

Masayuki Yoshida

William R Caputo

Hideo Uchino

Masumi Kanbe

Takaaki Aoi

A ropeless linear motor elevator system includes linear motor coils disposed along a guide rail for guiding an elevator car. A linear motor propulsion unit (14) including an operating bar movable relative to the car is mounted on the car for generating a car propulsion force in cooperation with the linear motor coils. The elevator car has mounted thereon a brake unit including a brake shoe engageable with the rail to stop the car and biasing member for urging the brake shoe toward the rail. The operating bar of the propulsion unit is movable between a first position in which the brake shoe engages the rail against the action of the biasing member and a second position in which the brake shoe is released from the rail by the action of the biasing member in response to a propulsion force acting on the propulsion unit.

Ropeless linear motor elevator system

An electromagnetic brake for arresting the rotation of a driving shaft of an elevator includes a pair of brake shoes and a pair of plungers operated by separate solenoidal coils. Each plunger is in communication with a corresponding break shoe. A brake coil exciting circuit is provided for exciting the brake coils and differentiating the timing at which the excitations of the brake coils are attenuated, so that the brake shoes can be applied to the driving shaft intermittently.

Two stage electromagnetic braking device for an elevator

In a control apparatus for A.C. elevator, this invention consists in comprising a current control circuit which compares a current command of a brake coil current generated by a current command generator and an actual current thereof detected by a current detector, so as to control the brake coil current, whereby a riding quality of a cage is improved. This invention further comprises a velocity control circuit which adds a bias corresponding to a load in the cage, to a reference velocity command for the cage generated by a velocity command generator, whereby the riding quality of the cage is improved still further.

Control apparatus for A.C. elevator

An elevator control apparatus includes a brake having a brake coil which is energized in response to a start signal to release the braking force exerted by the brake. A current sensor detects the current flowing through the brake coil and generates an actuating signal when the brake coil current changes due to the brake being released. The actuating signal causes a drive circuit to supply current to a motor for driving an elevator cage. As a result, the elevator cage can be smoothly started.

Elevator control apparatus

An elevator cage control apparatus includes a brake coil energized and deenergized by start and stop command signals to move and restrain the cage, respectively. A current detector detects current flowing through the brake coil. A counter counts a time interval beginning at generation of the stop command signal and ending when current in the brake control gradually decreasing increases instantaneously and a time interval beginning at generation of the start command signal and ending when current in the brake coil gradually increasing decreases instantaneously. A memory stores the counted time intervals. A drive command issuer commands a motor driving circuit to stop and start the cage, after the counted time intervals stored in the memory have lapsed, respectively.

Three pairs of reversed polarity thyristors 20a,21a; 24a,25a; 28c,29c are connected directly between the three phases R, S, T of an AC power source and the corresponding phases of an elevator drive motor 5. The two pairs connected to the R and S phases implement upward driving, and the third pair connected to the T phase is used for both upward and downward driving but is held non-conductive during regenerative braking/deceleration when the motor operates in a two phase mode. Two additional thyristor pairs 22b,23b; 26b,27b which are used for downward driving are cross-connected between the R and S power source phases and two of the motor phases, to thus reverse the direction of motor rotation. Different individual thyristors in the pairs coupled to the R and S phases are selected in upward and downward deceleration modes. The overall circuit arrangement and firing selection/control scheme is designed to implement load sharing between the various thyristors and thus minimize duty cycle differences.

Control system for an AC elevator

In a case where a braking torque is required as in the slowdown mode of the cage of an elevator, regenerative power within a range within which the generation of heat by a motor is permissible is consumed in the motor, and excess regenerative power is consumed by a regeneration resistor, so that a control apparatus can be made smaller in size. A braking torque is controlled in such a way that when a braking torque command is not greater than a predetermined value, only the magnitude of current is controlled with a slip fixed, and that when the braking torque command has exceeded the predetermined value, the slip is decreased without increasing the magnitude of the current. Regenerative power is partly fed back to a D-C side. Since, however, the current is suppressed within a predetermined value, so that the current capacity of an inverter can be restrained and that the resistor for consuming the regenerative power on the D-C side does not increase considerably. Moreover, since the power to be consumed in the motor decreases, the heat generation of the motor can be suppressed. Thus, a system with a thermal balance considered as a whole can be constructed.

Control apparatus for A-C elevator

A control apparatus for an A.C. elevator wherein regenerative power produced from an induction motor is consumed within the motor. In case of causing the induction motor to generate a braking torque, current to be supplied to the induction motor is controlled in accordance with a current command value having a frequency which does not generate regenerative power and an amplitude which is based on a torque command. Thus, the regenerative power is prevented from arising in the slowdown mode and unloaded operation of the elevator, and a good controllability is attained without spoiling a comfortable ride.

An AC elevator control system has a converter for converting a three-phase AC power to a direct current, an inverter for inverting the direct current to a three-phase AC power with a variable voltage at a variable frequency, and a three-phase induction motor for receiving the last-mentioned AC power to operate an elevator car connected to a counterweight through a traction rope trained over a sheave. A battery connected across the DC side of the inverter is enabled upon the occurrence of a power failure or a fault. A command emergency frequency generator responds to the occurrence of an emergency such as a power failure to deliver to the inverter a low frequency emergency frequency as determined by the relationship between a difference in weight between the elevator car and the counterweight and various losses of a motor driving system so as to cause the induction motor not to generate regenerative power.

AC elevator control system

An apparatus for controlling an A-C powered elevator in which A-C electric power is converted into D-C electric power through a rectifier, the D-C electric power thus converted is converted into a A-C electric power of a variable frequency via an inverter, an A-C electric motor is driven by the thus converted A-C electric power, the A-C motor being controlled by a controller which is connected to a D-C control source, a cage is driven by the thus controlled electric motor, said motor producing regenerated electric power depending upon the operation condition of said cage, wherein provision is made of a regenerated electric power controlling device which is connected between the D-C side of the inverter and the controller in order to supply the regenerated electric power to the controller. When the voltage on the D-C side of the inverter becomes greater than a predetermined reference value, a switching element is rendered conductive, and the regenerated electric power is supplied to the controller. Therefore, a power regenerating inverter need not be independently provided, and the apparatus can be cheaply constructed. Further, since the electric power is not wastefully consumed, energy can be saved.

Apparatus for controlling an A-C power elevator

An apparatus for controlling an AC powered elevator and for improving the safety of the operation of the elevator includes: a three-phase AC power source; a drive device connected to the three-phase AC power source for converting an AC signal into an AC power having a variable frequency, thereby enabling the controlling of an induction motor; a winding induction motor connected to and controlled by the drive device for driving the cage of the elevator; a door induction motor connected to and controlled by the drive device for opening or closing the cage door provided at the cage of the elevator; and a motor control command device having an operation command generator which generates a command for starting or stopping the cage of the elevator so as to control the drive device and a door command generator which generates a command for opening or closing the cage door so as to control the drive device for independently controlling the winding induction motor and the door induction motor.

Apparatus for controlling an AC power elevator

The disclosed AC elevator control system comprises a converter for converting a three-phase AC power applied to it through an electromagnetic switch closed for the start of an associated elevator car, to a direct current, and an inverter for inverting the direct current smoothed by a smoothing capacitor to a three-phase AC power with a variable voltage at a variable frequency which is supplied to a three-phase induction motor for controllably traveling the elevator car. A rectifier is connected across the smoothing capacitor through an impedance element to continuously apply a rectified voltage from the firstmentioned AC power to the capacitor and a voltage sensor relay connected across the capacitor senses the voltage on the latter and prevents the electromagnetic switch from being closed when the sensed voltage is low.

Described is an emergency drive device for an A.C. elevator which comprises; and alternating current motor for driving a car, an inverter for converting a direct current into an alternating current of variable frequency and supplying the resulting alternating current to said alternating current motor, and an emergency power source connected across input terminals of the inverter with the same polarity as said input terminals and designed to supply direct current power to the drive device.

Emergency drive device for an A.C. elevator

Disclosed is an AC elevator control apparatus, in which AC power supplied from an AC source is rectified by a converter and a smoothing capacitor into DC power, the DC power being in turn converted by an inverter into variable-frequency AC power by which an AC electric motor is driven to operate an elevator cage. The apparatus includes a rectifying circuit connected to the AC source, a resistor connected between the rectifying circuit and the smoothing capacitor, a charging time measuring circuit for measuring the time from turn-on of the AC source until the completion of charging the smoothing capacitor, and a control circuit for producing an abnormality detection signal when it is detected that the output of the charging time measuring circuit is shorter than a predetermined value, whereby the reduction in capacitance of the capacitor, and hence the expiration of the lifetime of the same, can be evaluated in advance.

AC elevator control apparatus

Described is a control device for an a.c. elevator wherein the a.c. voltage from the commercial a.c. source is rectified by a rectifier device, the thus rectified voltage is converted by an inverter into an a.c. power of variable frequency and variable phase order, and an a.c. motor is driven by this a.c. power for driving the elevator car, characterized in that electrical contacts are inserted between said a.c. source and said rectifier so as to be closed and opened at the time of start and stop of the elevator car, respectively.

Growing community of inventors

Nagoya, Japan

Masami Nomura