JPH0840659A - Control system of ac elevator at service interruption - Google Patents

Abstract

PURPOSE:To provide the operation control means of an AC elevator at service interruption capable of operating the AC elevator with DC power of small capacity at service interruption without necessitating any load detector device. CONSTITUTION:In a device which, when a service power supply RST interrupts, a power is fed from a DC power EB and an inverter device INV to a three phase induction motor IM in a specified operating direction, when it is detected that the current traveling is in a heavy load direction by a value calculated from an output current of the inverter device INV after current supply which is measured by an output current value measuring device CT, an elevator can be operated controllably at service interruption without necessitating a load detector device by switching over the operating direction of an operating direction reverse circuit DRC to the reverse direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an operation control device for an AC elevator during a power failure in which an elevator is rescued by using a separately installed DC power source during a power failure in a regular power supply, and more particularly to a control of a driving direction of the AC elevator during a power failure. Regarding

[0002]

2. Description of the Related Art Conventionally, as disclosed in Japanese Examined Patent Publication (Kokoku) No. 58-13470, when a rescue operation of an elevator is performed by using a separately installed DC power source during a blackout of a regular power source, a light load detected by a load detector is detected. In the load direction, if the elevator does not start in the same direction as the operation command direction for a predetermined time after issuing the operation command, or if the operation speed does not reach the predetermined value or reverses even if it starts, A technique for changing the driving direction is known.

[0003]

In the above-mentioned prior art, since the load detecting device is necessary to determine the driving direction,
There was a problem that the cost would increase accordingly.

An object of the present invention is to provide an AC elevator operation control means at the time of a power failure, which can operate an AC elevator with a small capacity DC power source at the time of a power failure at a low cost without the need for a load detection device. It is in.

[0005]

In order to achieve the above-mentioned object, the present invention firstly provides a common power source, an induction motor for driving an elevator which is fed from the common power source, and a DC power source.
An inverter device, and means for instructing a driving direction of an elevator in a predetermined direction, and when the DC power source and the inverter device supply power to the induction motor in the driving direction during a power failure of the regular power supply, the inverter Means for detecting the output current value of the inverter device after power supply to the induction motor from the device, and means for detecting that the value calculated by the output current value has reached a predetermined value after a lapse of a predetermined time, And means for switching the driving direction to the opposite direction in response to the means.

In order to achieve the above object, the present invention secondly provides a common power source, an induction motor for driving an elevator which is fed from the common power source, a DC power source, an inverter device, and an elevator in a predetermined direction. A means for instructing a driving direction, wherein during the power failure of the regular power supply, in the driving direction, the DC power supply and the inverter device to supply power to the induction motor, the inverter after the power supply to the induction motor Means for detecting an output current value of the inverter device, and means for detecting that a value calculated by the output current value has reached a predetermined value after a predetermined time has passed,
Means for switching the driving direction to the reverse direction in response to the means, and detecting that the value calculated by the output current value reaches a predetermined value after a predetermined time has elapsed in response to the command in the reverse direction. And means for issuing a command to stop the operation of the elevator in response to the means.

[0007]

According to the present invention, firstly, in the case of supplying power to an induction motor from a DC power supply and an inverter device in a predetermined operation direction during a power failure of a regular power supply, the output current of the inverter device after the power is supplied from the inverter device to the induction motor. A means for detecting the value, a means for detecting that the value calculated by the output current value has reached a predetermined value after a lapse of a predetermined time, and a means for responding to the means and switching the operating direction to the opposite direction As a result, it is possible to control the operation of the elevator during a power failure without the need for a load detection device.

Secondly, according to the present invention, in the case of supplying power to the induction motor from the DC power supply and the inverter device in a predetermined operation direction during a power failure of the regular power supply, the output of the inverter device after supplying power from the inverter device to the induction motor. A means for detecting a current value, a means for detecting that the value calculated by the output current value has reached a predetermined value after a lapse of a predetermined time, and a means for responding to the means to switch the operating direction to the opposite direction, A means for detecting that the value calculated by the output current value has reached a predetermined value after a lapse of a predetermined time with respect to the command in the opposite direction, and a means for issuing an elevator stop command in response to the means As a result, it is possible to control the operation of the elevator during a power failure without the need for a load detection device.

[0009]

Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing an example of an elevator main circuit to which the present invention is applied. In the figure, a three-phase induction motor IM directly connected to the traction machine TM
Always receives power from the regular power supply RST via the control device CP. A car F is hung on one side of the traction machine TM via a rope, and a counterweight W is hung on the other side. By the way, when the regular power supply RST fails, the three-phase induction motor IM has an inverter device IN for converting direct current from the direct current power supply EB (battery or the like) into alternating current.
Power is supplied via V. The inverter device INV is composed of six transistors. When the output current from the gate current supply circuit GD is supplied to the gates of the transistors in a predetermined order, the inverter device INV outputs a three-phase AC power supply. It This flows in the primary winding of the three-phase induction motor IM, and by generating a rotating magnetic field, the three-phase induction motor IM rotates in either the forward or reverse direction at the time of a power failure, and raises or lowers the elevator as a load. Further, the predetermined order of the output currents from the gated current supply circuit GD is determined according to the directionality designated by the central processing unit MPU.

Now, if the regular power supply RST fails for some reason during elevator operation, the elevator will suddenly stop, the non-voltage detection relay SA will detect it and turn off, and the emergency operation relay SB in a circuit not shown. (Not shown) turns on. Therefore, the central processing unit MPU is turned on by a circuit (not shown), and after ascertaining the safety of the existing elevator, a command for ascending operation is issued. The gate current supply circuit GD, which has received the rising operation command, moves the three-phase induction motor I in the rising direction.
A gate current is supplied to each transistor of the inverter INV so as to obtain an inverter output current that rotates M. After a lapse of a certain time, a circuit (not shown) turns on the inverter INV driving relay 10T (not shown) and closes the contact 10T1, so that the inverter INV is supplied with DC power. Then, in response to the output current of the inverter device INV, the three-phase induction motor IM starts rotating in the direction of raising the car F.

By the way, if the loading amount of the car F is small, the ascending operation is performed without any problem. However, if the loading amount is large, an operation command is issued in the heavy load direction, and the driving torque output from the three-phase induction motor IM. The direction of the load torque becomes larger than that. Therefore, there is a problem in that the elevator locks or reverses.

In such a case, the central processing unit MPU executes the following processing. Immediately after driving the inverter device INV, the output current value of the inverter device INV is measured by the current value measuring device CT. This value is I1. next,
After the elapse of the predetermined time T1, the inverter device output current is measured again. This value is I2. And immediately after I2 measurement,
Compare I1 and I2. If the traveling direction is a light load direction, the output current value of the inverter INV changes as shown in FIG. 2 and the ratio of I1 and I2 is large. It is determined that the running direction is the light load direction, and the inverter device INV is continuously driven. However, if the traveling direction is the heavy load direction, the output current value of the inverter INV is
Since the ratio of I1 and I2 is small, the driving direction determination circuit DRC of the central processing unit MPU determines that the traveling direction is the heavy load direction, and the driving circuit DV
A direction reversal command is issued to C. As a result, the driving direction of the elevator is switched, and the elevator comes to start normally.

Furthermore, after the elapse of a predetermined time T1 after switching the operating direction of the elevator, the inverter device output current is measured again. This value is I3. Immediately after the measurement of I3, I2 and I3 are compared. If the elevator is normally started, the ratio of I2 and I3 is the same as the ratio of I1 and I2 in FIG. 2, so the central processing unit MPU determines that the elevator is normally started, and the inverter device IN
Continue to drive V. However, if the elevator was not started normally, the ratio of I2 and I3 would be I1 in FIG.
Since the ratio is the same as that of I2, the operation stop circuit STC of the central processing unit MPU determines that the elevator is not normally started and issues a stop command to the operation circuit DVC to stop the operation of the elevator. .

In the present embodiment, the method using the output current value of the inverter device is used as the condition for directional reversal. However, other than this method, the torque of the three-phase induction motor is calculated from the inverter output current value, There is also a method of using it.

[0016]

According to the present invention, it is possible to control the operation of an AC elevator during a power failure without the need for a load detection device.

[Brief description of drawings]

FIG. 1 is a block diagram showing an example of a main circuit configuration of an elevator to which the present invention has been applied.

FIG. 2 is an inverter output current waveform diagram during operation in the light load direction.

FIG. 3 is a waveform diagram of an inverter output current when operating in a heavy load direction.

[Explanation of symbols]

RST ... Regular power supply, EB ... DC power supply, INV ... Inverter device, GD ... Gate current supply circuit, MPU ... Central processing unit, DVC ... Driving circuit, DRC ... Driving direction reversing circuit,
STC: Shutdown circuit, CT: Inverter output current value measuring device, IM: Three-phase induction motor, TM ... Traction machine, F ... Car, W ... Counterweight, SA ...
Non-voltage detection relay, 10T ... Inverter drive relay.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takao Hata 1070 Ige, Katsuta-shi, Ibaraki Hitachi, Ltd. Mito Plant (72) Inventor Katsuhiro Inoue 1-6, Kandanishiki-cho, Chiyoda-ku, Tokyo Hitachi Co., Ltd. In the building system service

Claims (2)

[Claims] 1. A utility power supply comprising: a service power supply; an induction motor for driving an elevator, which is fed from the service power supply; a direct current power supply; an inverter device; and means for instructing an elevator running direction in a predetermined direction. When a power failure occurs, in the operating direction, in the power supply to the induction motor from the DC power supply and the inverter device, a means for detecting the output current value of the inverter device after feeding the induction motor from the inverter device, It is provided with means for detecting that the value calculated by the output current value has reached a predetermined value after a lapse of a predetermined time, and means for responding to the means and switching the operating direction to the opposite direction. Control system for AC elevator during blackout. 2. A utility power supply, an elevator drive induction motor fed from the utility power supply, a direct current power supply, an inverter device, and means for instructing a running direction of the elevator in a predetermined direction. In the case of a power failure, in the one that supplies the induction motor from the DC power supply and the inverter device in the operating direction, a means for detecting an output current value of the inverter device after the inverter device supplies power to the induction motor, and a predetermined value. After a lapse of time, means for detecting that the value calculated by the output current value has reached a predetermined value, means for responding to the means to switch the operating direction to the reverse direction, and a command for the reverse direction. On the other hand, after a lapse of a predetermined time, means for detecting that the value calculated by the output current value has reached a predetermined value, and operation stop of the elevator in response to the means. Control Method of AC elevator during a power failure, characterized in that a means for emitting decree.