JPH0240587B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an improvement in a device for controlling a plurality of AC elevators.

[Prior art]

There is an elevator that converts AC power from a commercial AC power source into DC using a converter, converts this into AC power with variable voltage and variable frequency using an inverter, and supplies this converted AC to an induction motor to operate the car. In this case, it is uneconomical to install converters for the number of cars, considering the operation mode of the elevator. That is, while operating an elevator may consume a large amount of electric power, such as when a heavy load is raised, there may be times when a large amount of electric power is regenerated, such as when a heavy load is lowered. This is because it is rare for each of these to occur at the same time, and the converter does not require a very large capacity when viewed as a whole. Therefore, for example, in Japanese Unexamined Patent Application Publication No. 1983-1997, a system was developed in which DC power was supplied from one converter to multiple motors and inverters.
This is shown in Publication No. 66598. This will be explained with reference to FIGS. 1 and 2.

In Figure 1, 1 is a three-phase AC power supply, 2 is a converter connected to the power supply 1, 5 is a smoothing capacitor connected to the DC side of the converter 2, and 6 is a resistor connected to both ends of the smoothing capacitor 5. voltage signal
Voltage detectors that emit V _b ; 71 to 75 are inverters of units 1 to 5 connected in parallel to each other and connected to smoothing capacitor 5; 81 to 85 are three-phase inverters connected to the AC side of inverters 71 to 75, respectively. Induction motors, 91 to 95 are motors 81 to 95, respectively.
Drive sheave of the hoist driven by 85, 101
~105 are the main ropes wound around the sheaves 91~95, respectively, and 111~115 are the main ropes 101, respectively.
A cage connected to one end of ~105, 121-12
5 is a counterweight also connected to the other end, 13
1 is a speed detector that is directly connected to the electric motor 81 and includes a speedometer generator, an encoder, etc. that outputs a speed signal V _t ; 141 is an adder that outputs a deviation signal between the speed command signal V _p and the speed signal V _t ; 151 is a base drive circuit which inputs the deviation signal and provides a base drive signal to be output later to the inverter 71; 161 is a control circuit for the first machine consisting of a speed detector 131, an adder 141 and a base drive circuit 151; 162 to 16;
Similarly, 4 is a control circuit for the second to fourth machines.

In Fig. 2, 3 is a regenerative converter connected to the AC power supply 1 and a three-phase full-wave rectifier circuit is formed by thyristors 3a to 3f, and 4 is a thyristor 4a connected to the DC side of the AC power supply 1 and the regeneration inverter 3. ~
A power running converter 71 is connected to both ends of the smoothing capacitor 5, and is connected in parallel to three sets of transistors 7A to 7F, each two of which are connected in series. This is a No. 1 inverter that is well-known as a pulse width modulation method that converts DC power into AC power of variable voltage and variable frequency using a base drive signal 151a from a base drive circuit 151, which is configured by diodes 7a to 7f. inverter 72
75 are similarly configured. 20 is the voltage command signal V _c corresponding to the speed and the negative feedback voltage signal
This is a phase control circuit that operates the ignition circuit 21 or 22 according to _Vb , and the ignition signal 21a from the ignition circuit 21 is sent to the gates of the thyristors 3a to 3f, and the ignition signal 22a from the ignition circuit 22 is sent to the gates of the thyristors 3a to 3f. are sent to the thyristors 4a to 4f, respectively.

That is, during power running of the electric motor 81, there is a relationship of potential command signal V _c ≧ voltage signal V _b , the phase control circuit 20 operates the ignition circuit 22, and the thyristors 4a to 4f of the power running converter 4 perform phase control. The AC power from the AC power supply 1 is converted into DC by the converter 4 and supplied to the inverter 71. On the other hand, the speed command signal V _p and the speed signal V _t are sent to the adder 1.
41, the deviation signal is calculated in the base drive circuit 151, the base drive signal 151a is output, the inverter 71 operates, and the motor 81 is supplied with variable voltage/variable frequency AC power. The electric motor 81 is now driven, and the car 111
runs.

When the electric motor 81 rotates at a rotational speed equal to or higher than the synchronous speed, such as when a heavy load is lowered, the electric motor 81 operates as a generator, and the electric power is returned to increase the voltage on the DC side of the inverter 71. When the voltage command signal V _c <voltage signal V _b is established, the phase control circuit 20 operates the ignition circuit 21, the thyristors 3a to 3f of the regenerative converter 3 are phase-controlled, and the regenerative power is transferred to the regenerative converter 3. It is returned to the AC power supply 1 via 3. The same applies to machines No. 2 to No. 5.

In this way, the speed command signal V _p and the speed signal
Each inverter 71 to 75 is controlled by V _t ,
Cars 111 to 115 of cars No. 1 to No. 5 are operated.

However, since one converter 2 supplies power to the inverters 71 to 75 of all the elevators, if the converter 2 breaks down, the running elevator will suddenly stop and the passengers will be trapped in the car. Furthermore, all elevators may stop, resulting in a so-called system down. This is fatal for elevators. Therefore, the capacity of the converter 2 must be selected so that sufficient power can be supplied no matter what condition the converter 2 is operating under, for example, even when all the machines are accelerating under heavy load operation.

However, an actual elevator can go up, down,
From no load to heavy load, various conditions such as acceleration, deceleration, constant speed, and stop are mixed, and on average, about 30 to 50% of the power is required when all units are operating at capacity. It's nothing more than that. Therefore, as described above, it is extremely uneconomical to install a large capacity converter 2.

[Summary of the invention]

This invention improves the above-mentioned problems. By detecting the current flowing through the converter and managing the operation of the car accordingly, reliable operation can be achieved even when using a small-capacity and inexpensive converter. It is an object of the present invention to provide a control device for an AC elevator that can perform the following functions.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 3 to 6.

FIG. 3 is an overall configuration diagram of one embodiment, which is constructed as described below. That is, 23 is a current detector that detects the current flowing through converter 2, and 24 is a current detector that detects the current flowing through converter 2.
1 to 245 are cars 111 to 11 of machines 1 to 5.
The car load detector detects the load of No. 5, and these outputs are input to the management device 25. Management device 25
The output corresponding to the output of the current detector 23 is output from the first unit to
It is sent to the speed command generation circuits 261 to 265 of the No. 5 cars, and depending on the operating state of the cars 111 to 115, it is made impossible to start, the acceleration is stopped, or all the cars are stopped.

In FIG. 4, 23 is the above-mentioned current detector, 27A~
27D is a comparator that is connected to the current detector 23 and operates when the inputs reach i ₁ to i ₄ respectively, and when the inputs i ₁ <
Input i ₂ < input i ₃ < input i ₄ is set. 28
A to 28D are current detection relays energized by the outputs of comparators 27A to 28D, respectively. Other than the above, the configuration is the same as in FIG. 1.

In Fig. 5, 25 is a management device composed of a microcomputer, which includes a central processing unit (hereinafter referred to as CPU) 30A, a read-only memory (hereinafter referred to as ROM) 30B in which programs and fixed value data are stored, and calculation results. A read/write memory (hereinafter referred to as RAM) 30 that temporarily stores data such as
C, and a contact receiver 3 that is connected to the normally open contacts 28Aa to 28Da provided in the current detectors 28A to 28D in FIG. 4 and converts the input signal level.
It has 0D. Also, CPU1~CPU5,3
1A~35A, ROM31B~35B, RAM3
1C to 35C, each car load detector 241 to
Input devices 31D to 35D connected to 245 and converting input levels and speed command generation circuits 2
It has output devices 31E to 35E connected to terminals 61 to 265 and converting output levels.

Next, the operation of this embodiment will be explained using the flowchart of the operation of the program (stored in ROM 30B, 31B to 35B) shown in FIG.

AC power from an AC power source 1 is converted to variable voltage/variable frequency AC power via a converter 2 and inverters 71 to 75, and this is converted into a speed command signal.
The electric motors 81 to 85 are controlled by the deviation signal between V _p and the speed signal V _t , and the cars 111 to 115 are
As mentioned above, the train will be operated.

The current flowing through converter 4 increases, and comparator 2
7A operates and current detection relay 28A is energized, contact 28Aa is closed. Similarly, comparators 27B to 27D operate as the current increases,
Current detection relays 28B-28D are energized and contacts 28Ba-28Da are closed.

Determine whether contact 28Aa is closed in step 41,
The procedure will not proceed unless it is closed. When it is determined that the contact 28Aa is closed, the contact 28Aa is closed in step 42.
Determine whether Ba is closed, and if it is not closed,
In steps 431 to 435, car 11 for units 1 to 5
1 to 115 are stopped, and if there is a stopped car, the output is sent to the corresponding speed command generation circuit 261 to 265 in steps 441 to 445, and the speed command signal V of the stopped car is sent. _p is held at zero to prevent restart and eliminate the current increase in converter 2. If all the cars 111-115 are running, the procedure does not proceed.

If it is determined in step 42 that the contact 28Ba is closed, it is determined in step 45 whether the contact 28Ca is closed, and if not, steps 461 to 465 are performed.
Check whether Dekago 111-115 is accelerating,
In steps 471 to 475, the speed command signal V _p of the car that is being accelerated is maintained at the current value, the acceleration is stopped, the car is run at a constant speed, and the increase in current in the converter 2 is removed. The procedure does not proceed unless all cars 111-115 are accelerating.

If it is determined in step 45 that the contact 28Ca is closed, it is determined in step 48 whether the contact 28Da is closed, and if not, steps 491 to 495 are performed.
Based on the outputs of the big load detectors 241 to 245,
It is checked whether the cars 111 to 115 are unloaded, and in steps 501 to 505, a speed command signal V _p for climbing is selected for the unloaded car, and the car is operated in an ascending operation. The electric motor of that car is now in regenerative operation, and the regenerated power is returned to prevent an increase in the current of the converter 2. The procedure does not proceed unless all of the cars 111-115 are unloaded.

When it is determined in step 48 that the contact point 28Da is closed, in step 51 the speed command signal V _p of all cars is set to zero, and all cars 111 to 115 are stopped. Then, in step 52, the speed command signal V _p for stopping at the nearest floor is selected for each car, and the speed command signal V p for stopping at the nearest floor is selected for each car.
Have the 115s drive one by one to the nearest floor.

In the above embodiment, the current flowing through the converter 2 is detected, but the temperature of the converter 2 may be detected in several stages and the operation of the cars 111 to 115 may be managed according to the temperature.

〔Effect of the invention〕

As described above, in this invention, the current flowing through the converter that supplies DC power to the inverter connected to the drive motor of the elevator, or the amount corresponding to this, is detected at multiple stages, and the elevator car Since the operation of the elevators is controlled, an increase in the current flowing through the converters is prevented, and even if a small-capacity, inexpensive converter is used, a greater number of elevators than the number of converters can be operated with high reliability.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a conventional AC elevator control device, FIG. 2 is a main circuit diagram of FIG. 1, and FIG. 3 is an overall block diagram showing an embodiment of an AC elevator control device according to the present invention. , Fig. 4 is a block diagram of the same, Fig. 5 is a block diagram of the management device, and Fig. 6 is a block diagram of the management device.
The figure is a flowchart of the operation of the management device of FIG. 5. In the diagram, 2 is the converter, and 71 to 75 are the first units
Inverter of Unit 5, 111 to 115 are the same left cages, 23 is the current detector, 25 is the management device, 261
~265 is the speed command generation circuit of No. 1 to No. 5 machines,
28A to 28D are current detection relays (abnormality detectors)
It is. Note that the same reference numerals in the figures indicate the same parts.

Claims (1)

[Claims] 1 Convert AC power to DC using a converter,
This is converted into alternating current by a number of inverters greater than the number of converters, and the converted alternating current is used to drive an induction motor to operate the car. control of an AC elevator, characterized in that it is equipped with an abnormality detector that detects quantities corresponding to the above in multiple stages, and a management device that manages the operation of the above-mentioned car according to the output of the above-mentioned respective stages of the abnormality detector. Device.