JPS60249882A - Controller for elevator - Google Patents

Abstract

PURPOSE:To effectively turn OFF a thyristor of a regenerative power inverter by adding a power drive regeneration detector and a converter voltage drop instructing unit in a controller. CONSTITUTION:When a regenerative operation is discriminated, a power drive regeneration dectector 20 supplies a voltage drop command signal 22 to a converter voltage drop instructing unit 21, thereby supplying a voltage drop command signal 23 to a converter controller 11. When the controller 11 which receives the signal 23 generates an output signal 17 to control a power inverter 6. Thus, the regenerative current is fed back to a 3-phase AC power source 1 to drop the DC voltage. Accordingly, since the DC power source voltage always decreases lower than the voltage of the 3-phase AC current 1 at the regeneration time, the thyristor of the inverter 6 can be effectively turned OFF.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to an elevator control device for controlling voltage supplied to an elevator driving motor, and particularly to elevator control using a variable voltage converter that controls voltage using a converter device. This relates to improvements in equipment.

[Prior art]

FIG. 1 is a circuit diagram showing an example of a commonly used elevator control device. 3 is a smoothing capacitor inserted between the output terminals of the forward converter 2, and 4 is an inverter device which uses the output of the forward converter 2 as human power, and the output is supplied to an induction motor 5. 6 is an inverse converter, 7 is a speed command signal, which is supplied to a speed calculator 8 and is calculated by K to generate a voltage command signal 9.
and a current command signal 10 is generated. 11 is a converter control device, 12 is a PWM control device, 13 is an induction motor 50
A pulse generator that detects rotational speed, and an actual speed signal 14 generated from this pulse generator 13.
is supplied to the speed calculator 8.

15 is an output signal of the PWM control device 12, which controls the inverter device 4. 16 is an output voltage signal of the forward converter 2, which is fed back to the inverter controller 11. 17
．． 18 is an output signal output from the inverter control device 11 and supplied to the forward converter 2 and the inverse converter 6, and 19 is an autotransformer.

In the device configured in this way, firstly, the power operation will be explained.The output of the three-phase AC power supply 1 is converted to DC in the forward converter 2, and then smoothed in the capacitor 3. This smoothed direct current is then converted into alternating current in the inverter device 4.

On the other hand, a speed command signal 7 is issued from a control device (not shown) and supplied to a speed calculator 8. The speed calculator 8 determines the operating direction of the elevator and also generates a voltage command signal 9 in accordance with the actual speed signal 14 corresponding to the actual speed obtained from the pulse generator 13 that detects the rotational speed of the induction motor 5. Supplied to converter control device 11. The converter control device 11 controls the forward converter 2 in order to obtain a voltage according to the voltage command signal 9. Also-P
The WM control device 12 has a speed command signal 7 and an actual speed signal 1.
4 inverter device 4 is controlled.

Next, during regenerative operation, the kinetic energy of the drive system is regenerated to the DC power supply circuit system via the induction motor 5 and the inverter device 4, contrary to the case of the continuous operation.The output of the inverter device 4 is then 3 to increase the DC voltage, this output voltage signal 16 is fed back to the converter control device 11 and an output signal 17 corresponding to the difference with the voltage command signal 9 is given to the inverter 6. C,
The regenerative current to the three-phase AC power supply 1 is controlled via the autotransformer 19.

However, in a circuit configured in this manner, the autotransformer 19 is indispensable in order to ensure that the thyristor of the inverter 6 is turned off even if the DC power supply voltage exceeds the AC power supply voltage, thereby preventing a short circuit between phases. It has become a thing. Moreover, this autotransformer 19 is bulky and heavy, which makes it difficult to save space in the control panel, requires a great deal of labor to transport during installation, and has the problem of significantly increasing costs. .

[Summary of the invention]

This invention was made to solve the above-mentioned conventional problems, and it is an object of the present invention to provide an elevator control device that can reliably turn off the thyristor of the regenerative inverter without using an autotransformer. .

[Embodiments of the invention]

FIG. 2 is a circuit diagram showing an embodiment of the elevator control system according to the present invention, and the same parts as in FIG. 1 are indicated using the same symbols. In the figure, reference numeral 21 denotes a converter voltage reduction command device, 22 a control signal generated from the power regeneration detection device to control the converter voltage reduction command device 21, and 23 is a pressure reduction command signal generated from converter voltage reduction command device 21 and controlling converter control device 11 . And the first
The difference from the figure is that the autotransformer 19 is removed by providing the power regeneration detection device I and the converter voltage reduction command device 21.

In the device configured in this way, the power regeneration detection device side detects the speed of the induction motor 5 based on the speed command signal 7 and the actual speed signal 14 generated from the pulse generator 13, and detects the speed of the induction motor 5. Distinguish between power and regeneration based on the size.

If the first regeneration operation is determined here, a pressure reduction command signal is supplied from the negative regeneration detection device to the converter voltage reduction command device 21, and accordingly, a pressure reduction command signal is supplied to the converter control device 11. The converter control device 11 that receives this pressure reduction command signal generates an output signal 17 and controls the inverter 6, so that the regenerative current is fed back to the three-phase AC power supply 1 and the DC voltage is reduced. do. Therefore, during the first regenerative operation, the DC power supply voltage is always lower than the voltage of the three-phase AC power i1, so even if the autotransformer 19 is omitted and connected directly, the thyristor of the inverter 6 can be turned off reliably. Accordingly, short circuits between phases can be reliably prevented.

〔Effect of the invention〕

As explained above, the elevator control device according to the present invention can quickly increase the DC power supply voltage during regenerative operation by adding a power regeneration detection device and a converter voltage reduction command device to a conventional control device. The thyristor of the inverter is reliably turned off to prevent phase-to-phase short circuits. As a result, the autotransformer can be omitted and the control panel can be made space-saving and lightweight, resulting in a significant increase in cost, and other excellent effects.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a conventional elevator control device.
FIG. 2 is a block diagram showing an embodiment of an elevator control device according to the present invention. DESCRIPTION OF SYMBOLS 1... Three-phase AC power supply, 2... Forward converter, 3... Capacitor, 4... Inverter device, 5... Induction motor, 6... Inverse converter, 8... Speed Arithmetic unit, 11...
・Conn 7 controller, 12... PWM controller,
19... Regenerative feedback transformer (auto transformer), application... power running regeneration detection device, 21... converter voltage reduction command device. Note that the same reference numerals in each figure indicate the same or corresponding parts. Agent Masuo Oiwa (2 others)? 1511 La 2. Amendment band (voluntary) Commissioner of the Japan Patent Office 3. To Hitoshi Katayama, representative of the person making the amendment. 5. Subject of amendment (1) Claims column of the specification (2) Invention of the specification Detailed explanation column (3) Brief explanation of drawings column 6 of the specification, Contents of amendment (1) The claims of the specification are amended as shown in the attached sheet. (2) In the second line of page 5 of the specification section, amend the phrase ``and without'' to ``without and''. (2) On page 7, line 5, the phrase ``cost increase'' is corrected to ``cost reduction.'' (3) Page 7, line 14, “19 Regenerative feedback transformer (
Auto transformer), J is amended to read "19 Regenerative power feedback) Lance (auto transformer), -1. 7. Attached documents (11 Document containing the full text of the amended scope of claims) Amend one copy Later Claim 2, Claims In an elevator control device having a converter that variably controls the voltage supplied to the electric motor that drives the elevator,
Engineering 1.・A power regeneration detection device that distinguishes between the power running state and the regeneration state of the beta, and a conover voltage reduction command device that supplies a pressure reduction command to the converter during regeneration are installed, and a DC power supply is provided by the conover voltage reduction device during regenerative operation of the elevator. An elevator control device that lowers the voltage.

Claims (1)

[Claims] In an elevator control device having a converter for variable control of voltage supplied to an electric motor that drives an elevator, a power regeneration detection device for determining a power running state and a regeneration state of the elevator, and a converter for supplying a pressure reduction command to the converter during the first regeneration. An elevator control device that is equipped with a voltage reduction command device and lowers the DC power supply voltage using a converter voltage reduction detection device during regenerative operation of the elevator.