JPH0244755B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an elevator control device having an inverter driven by a battery.

In recent years, with the development of semiconductor devices, especially transistors, it has become possible to use transistors to control the speed of elevator induction motors with variable voltage and variable frequency.
So-called VVVF inverter devices have come into practical use. As is well known, in this method, alternating current is once converted to direct current, and this direct current is controlled by pulse width modulation (PWM) using semiconductor elements such as transistors.

Since the elevator has an AC-DC converter as described above, a method has been proposed in which a secondary battery is connected to the converter and the power of the battery covers the shortage of power supply during elevator operation.

FIG. 1 shows a conventional elevator control system of this kind, in which 1 is a sheave, 2 is a rope wrapped around the sheave 1, 3 is a car connected to one end of the rope 2,
4 is a counterweight connected to the other end of the rope 2;
Reference numeral 5 denotes an induction motor that rotationally drives the sheave 1, and this induction motor 5 is supplied with alternating current power obtained by pulse width modulation control of direct current from a variable frequency inverter 6 constituting a VVVF inverter device. The variable frequency inverter 6 is composed of transistors and diodes.
Reference numeral 7 denotes a single-phase AC power supply, and a variable voltage converter for single-phase half-wave rectification, that is, a thyristor 9, is connected to this AC power supply 1 via a control resistor 8, and the voltage half-wave rectified by this thyristor 9 is connected to the AC power supply 1 through a control resistor 8. is supplied to the inverter 6, and a secondary battery 1 is installed on the output side of the thyristor 9 to cover the shortage of AC power during elevator operation.
0 is connected.

In the elevator control device configured as described above, the speed control of the elevator induction motor 5 is performed by controlling the power frequency and voltage using the inverter 6 and the thyristor 9 according to the load characteristics of the elevator. Power running and regeneration operations are performed in response to the rise and fall of the car. In addition, actual power consumption during elevator operation is during power running and regeneration, but since passengers who ascend in an elevator within a building generally use the elevator when descending, the power consumption includes both mechanical and electrical systems. Only the loss amount is included, and its value is surprisingly small.
Therefore, the capacity of the secondary battery 10 is such that, for example, during about an hour of rush time in the morning, only power is used, and in the evening, regeneration is the opposite, so the amount of power required for elevator operation during this time is limited. It is fine as long as it can be supplied.

In addition, the consumption of the secondary battery 10 due to power running and regeneration can be replenished by charging the battery 10 throughout the day in the circuit consisting of the power supply 7 - resistor 8 - thyristor 9 - battery 10 - power supply 7, and the charging current is very low. It is small and requires only a single phase power supply. In this case, it goes without saying that the variable voltage converter may be constituted by a full-wave rectifying thyristor bridge.

However, in the method described above in which the elevator is driven using the power of the secondary battery, the capacity and deterioration of the secondary battery become a problem. That is, if for some reason the capacity of the secondary battery 10 decreases to a state where it cannot compensate for the shortage of single-phase power due to an increase in the car load of the elevator, the power of the single-phase AC power supply 7 cannot drive the elevator. Unable to do so, the elevator function would be lost. Therefore, some kind of measure is required before the power supply from the secondary battery 10 becomes impossible.

This invention has been made in view of the above points, and includes means for detecting the capacity of the secondary battery, and when the capacity of the secondary battery becomes less than a predetermined value, the control mode of the elevator is changed from normal, and the elevator is operated. An object of the present invention is to provide an elevator control device that prevents loss of function.

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

FIG. 2 shows an example of an elevator control device according to the present invention, in which the same reference numerals as in FIG. This is a control circuit that controls the thyristor 9, and the terminal voltage of the secondary battery 10 detected by the voltage detection circuit 11 is input to this control circuit 12. The control circuit 12 is composed of a logical operation circuit using a microcomputer, and has a processing function of detecting the terminal voltage of the secondary battery 10 at the same time as the inverter 6 is cut off when the elevator is stopped. It has a function of determining whether or not the voltage is at an appropriate value, and further has a function of generating an alarm and changing the control form of the elevator when the capacity of the secondary battery 10 falls below the appropriate value.

The operation of this embodiment configured as described above is explained in the third section.
The explanation will be based on the flowchart shown in the figure.

When it is detected in step 20 of FIG. 3 that the elevator has stopped, the capacity detection program of the control circuit 12 moves to step 21, executes processing to cut off the inverter 6, and then moves to the next step 22. do. In this step 22, processing is performed to cut off the secondary battery charging circuit, that is, the thyristor 9 for an extremely short period of time, and the process proceeds to the next step 23, where an operation command is given to the voltage detection circuit 11 to determine the terminal voltage of the secondary battery 10. is normal, that is, within a predetermined value. If the judgment result is "YES", proceed to step 24,
The inverter 6 and the thyristor 9 are controlled by the control circuit 12 so that the elevator operates normally. Then, the process returns to step 20 and processes from step 20 are executed again.

If the determination result in step 23 is "NO", the process moves to step 25 to memorize that the battery capacity is below a predetermined value, and in step 26 it is determined that the capacity of the secondary battery 10 is below a predetermined value. At the same time as giving a warning, the maximum speed of the elevator is lowered or the elevator is operated less frequently to prevent battery 10 from being exhausted. Steps 27 and 28 execute each of these processes. step 27
When the processes in steps 2 and 28 are completed, the process returns to step 20 and the processes in step 21 and subsequent steps are executed.

As means for lowering the frequency of operation, there are methods such as lengthening the non-interference time of doors, and reducing the number of times hall calls are assigned when there are many elevators. In this way, the duty is lowered to continue the operation of the elevator, and then the processing procedure returns to step 20 and is repeated until the capacity of the secondary battery 10 is charged to a predetermined value. Note that when the elevator is operated with the duty lowered, the operation of the elevator can be sufficiently controlled using the power from the single-phase AC power supply 7, and at the same time, the secondary battery 10 is also charged by the charging circuit including the thyristor 9. . In addition, the program shown in FIG.
This is easily achieved.

As described above, according to the present invention, the capacity of the secondary battery used to drive the elevator is monitored using a voltage detection circuit, and when the capacity falls below a predetermined value, the non-interference period of the car door is set. Since the elevator is operated by increasing the time period or by reducing the number of times that hall calls are assigned, there is no over-discharge of the secondary battery and there is no risk of the elevator losing its function. .

[Brief explanation of drawings]

Figure 1 is a circuit diagram of a conventional elevator control device.
FIG. 2 is a circuit diagram showing an example of an elevator control device according to the present invention, and FIG. 3 is a flowchart for explaining the operation of the present invention. 1...sheave, 2...rope, 3...basket, 4...
... Balance weight, 5 ... Induction motor, 6 ... Inverter, 7 ... Single-phase AC power supply, 8 ... Limiting resistor, 9 ... Thyristor (converter), 10 ...
Secondary battery, 11... voltage detection circuit, 12... control circuit. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] 1. In a converter that converts an alternating current power supply to direct current, and a device that controls an induction motor that drives a car by converting the power of a secondary battery charged with a portion of the direct current output of this converter to alternating current using a variable frequency inverter, the above-mentioned A voltage detection circuit is provided to detect the capacity of the secondary battery, and when the car is stopped, the converter and inverter are cut off, and when the voltage detection circuit detects that the capacity of the secondary battery is less than a predetermined value. , an elevator control characterized by comprising a control circuit that lengthens the non-interference time of the car door or reduces the number of times a hall call is assigned to the car if a plurality of cars are installed. Device.