JPH01242382A - Elevator control device - Google Patents

Abstract

PURPOSE:To have smooth operation by emitting a speed reference with the acceleration suppressed when the torque reference signal from a speed calculation amplifier exceeds a torque limit value in comparing the speed reference with a speed feedback signal. CONSTITUTION:A speed comparison amplifier 12 compares the speed reference Sr from a speed reference generator 11 with a speed feedback signal Sd given from a pulse generator 24 via an F/V 25 and emits a torque reference signal Tr, and control of a winch 17 is made through a vector control calculator circuit 16, current computing amplifier 22, PWM control circuit 21, and converter/inverter circuits 18-20. When the absolute value of the torque reference signal Tr exceeds the torque limit value Tl set previously on a setting device 13, output of a comparator circuit 15 causes output of reference signal Sr from the speed reference generator 11 with acceleration suppressed. Thus smooth operation of the elevator is obtained, wherein no device with greater capacity is required.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a control device for an elevator having a mode of deceleration.

(Conventional technology) For medium and low-rise buildings such as condominiums and office buildings,
- Geared elevators, which generally have a speed reducer between the electric motor and the drive section, are widely used as medium-low speed elevators. This is because the system can be configured easily and compactly by selecting the rotational speed of the electric motor and the reduction ratio of the reducer to optimal values.

On the other hand, the development of control technology for driving electric motors and the desire to save energy and save equipment have led to the use of inverter control methods instead of the conventionally widely used primary voltage control method.

Generally, in a geared elevator having such a reduction gear, the speed of the elevator and the desired torque and rotation speed of the electric motor are determined by the sheave diameter and reduction ratio of the hoist, and the required If the torque is TI, it is given by the following formula.

TI= Here, Tm: Motor desired torque GD12: Motor GD2 (Moment of inertia 1-) GD
b2 Brake coupling part GD2 GDs2: Straight line part GO2: Coefficient α: Elevator acceleration ηr: Hoisting efficiency Tl: Load torque D: Sheave diameter R: Gear ratio W: Loading weight oB Niover balance.

Therefore, by increasing the rotation speed of the electric motor and increasing the reduction ratio, the output torque of the motor can be reduced and the motor can be made smaller. However, in general, increasing the rotation speed may shorten the life of the bearings in the reducer. The optimum motor rotation speed and reduction ratio are selected in consideration of issues such as noise, vibration, etc.

Now, as is clear from the above equation (1), in a geared elevator, the desired torque of the electric motor depends on the efficiency ηt of the hoist once the reduction ratio is determined.

Therefore, when ηf decreases, the required torque of the electric power #JJm also increases.

An example of a conventional elevator control device is shown in FIG. 5, and the operation of the elevator is controlled according to a command value 3r from an elevator speed reference generation circuit 1.

The speed control calculation circuit 2 compares and calculates the speed reference command value 3r that is the output of the speed reference generation circuit 1 and the detection signal of the speed detector 4 that detects the speed of the hoisting machine 3, and calculates the necessary torque command value. Outputs Tr.

The torque limiter circuit 5 provides a limiter to the torque command value Tr of the speed control calculation circuit 2, and is intended to prevent a large current exceeding an allowable value from flowing into the inverter circuit 6 of the load due to load fluctuations, etc. It is.

The output from this torque limiter circuit 5 is given to a current reference generation circuit 7, which converts the torque signal into a current value flowing through the motor. The output ir of this current reference generation circuit 7 and the current detection signal i detected by the current detector 8
d by the current control calculation circuit 9, and the hoisting machine 3
A control current command value is output to the inverter circuit 6 that controls the.

In this way, in the conventional elevator control device, the rotation of the hoist is automatically controlled in accordance with the speed command value from the speed reference generation circuit 1.

(Problems to be Solved by the Invention) However, in general, in a geared elevator, when the temperature decreases, the viscosity of the oil in the reducer increases, and exhibits a temperature-viscosity characteristic as shown in FIG. Therefore, as the temperature decreases and the oil viscosity increases, the efficiency η of the hoisting machine 3 increases.
[ decreases, and as shown in equation (1) above, the required torque Tm of the electric motor to perform constant acceleration or running increases. In particular, if the oil has been stopped for a long time in the winter when the temperature drops, the oil temperature will drop significantly, resulting in the above-mentioned tendency becoming more pronounced.

In consideration of this large increase in the required torque Tll1, it was necessary to increase the capacity of the system in order to prevent the protection circuit from operating even with a large torque.

This invention was made in view of these conventional problems, and it is not necessary to take a system capacity sufficiently larger than that required for normal operation, and it allows operation with good interlocking ratio. The object of the present invention is to provide an elevator control device that can perform the following steps.

[Structure of the Invention] (Means for Solving Problem A speed operational amplifier that outputs a torque reference signal, a torque limit value setting circuit, a comparison circuit that compares the torque reference signal output of the speed operational amplifier with the torque limit value output of the torque limit value setting circuit, and this comparison circuit. and a speed reference generation circuit which receives the output of the elevator and outputs a speed reference that suppresses the acceleration of the elevator when the torque reference signal exceeds the torque limit value.

(Function) The elevator control m+ device of the present invention compares and calculates an elevator speed reference signal and a speed feedback signal, and outputs a torque reference signal. Then, the absolute value of this torque reference signal is compared with a preset value, and if it exceeds the preset m, the elevator acceleration is limited to suppress the required acceleration torque, and the system To realize stable elevator fblJ control without being subject to torque limitation even when the efficiency of the elevator fblJ decreases.

(Example) Hereinafter, embodiments of the present invention will be explained in detail based on the drawings.

FIG. 1 shows an embodiment of the present invention, which includes a speed reference generator 11 that outputs a speed reference value Sr according to the operation mode of the elevator, a speed command value Sr from the speed reference generator 11, and a speed detection signal Sd. and input the torque reference signal 7.
A speed operational amplifier 12 that calculates r to aliF and outputs the result, a torque limit setting device 13, an absolute value amplifier 14 for the torque reference value Tr, and the torque reference value Tr.
and a torque limit value 1''r.

The comparison pressure of this comparison circuit 15 is input to the speed reference generator 11, and becomes a command signal for lowering the acceleration relative to the speed reference 3r.

The output Tr of the speed operational amplifier 12 is given to the vector control calculation circuit 16, and the vector control calculation circuit 16 receives the excitation current command value, the secondary time constant, the motor rotation angular velocity, as well as the torque reference signal Jr. The current reference signal ir is output by inputting ωr and performing vector calculation.

Furthermore, a converter circuit 18 serves as a power supply circuit for the hoisting machine 17 with a speed reducer, a capacitor 19 smoothes the DC pulsating current of the converter circuit 18, and an inverter that controls the rotation of the hoisting machine 17 using the smoothed DC by the capacitor 19. 20 is provided, and for this inverter 20, a pulse width modulation control circuit 21, a current operational amplifier 22,
A current detector 23 is provided to detect the current flowing to the hoist 17.

Further, the hoisting machine 17 is provided with a pulse generator 24 for detecting its rotational speed.
4 is added to the speed reference value Sr from the speed reference generator 11 via the frequency-voltage converter 25 as the speed feedback signal Sd.

Note that 26 indicates an elevator car, and 27 indicates a counterweight.

The operation of the elevator control device having the above configuration will be described next.

The speed reference generator 11 can be configured using, for example, a microcomputer as shown in FIG. 32, and a D/A converter 33 for outputting the speed reference signal Sr from the input/output device 31 as an analog value.

In this speed reference generator 11, the memory 30
According to the program written in the elevator, a speed standard suitable for the elevator operation mode is calculated according to the elevator operation command, and a speed standard command value is output. This speed reference command value is then converted by the D/A converter 33,
It is output to the speed operational amplifier 12 as the speed reference value Sr.

The rotational speed of the hoisting machine 17 is converted into pulses by a pulse generator 24, converted into a speed feedback signal 3d via a frequency/voltage converter 25, and fed back to the operational amplifier 12.

The operational amplifier 12 calculates a torque reference value Tr from the difference signal between the speed reference Sr and the speed feedback Sd, and provides it to the vector control calculation circuit 16.

In the vector system wJPIi calculation circuit 16, the torque command value T
r, each rotation speed ωr from the pulse generator 24, 2
Next, the time constant and other information are vector-aligned to calculate a current reference signal Jr, which is output to the current operational amplifier 22.

The current operational amplifier 22 compares and calculates the current value for the winding R17 with the current feedback signal 1d obtained by the current detector 23, and provides a voltage reference to the PWM control circuit 21.

The PWM control circuit 21 controls the inverter 20 according to the voltage reference from the current operational amplifier 22, controls the rotation of the hoist v117, and controls the speed of the elevator.

Here, the torque command value Tr from the operational amplifier 12 is given to the vector control arithmetic circuit 16 , the polarity is made the same by the absolute value amplifier 14 , and the torque command value Tr is input to the comparison circuit 15 .

In the comparator circuit 15, the torque command value Tr is compared with the torque limit value Tr set by the torque limit setter 13, and if the torque command value Tr is larger than the torque limit value Tl, its output is fed back to the speed reference generator 11. Ru. That is, in FIG. 2, the torque limit comparison signal is input to the input/output device 31,
If the torque command value exceeds the torque limit value based on the torque limit comparison signal, the arithmetic processing unit 28 performs acceleration limit calculation for performing torque limit.

Now, when the temperature of the oil in the elevator hoist n17 decreases due to a decrease in temperature, the viscosity of the oil increases, and the efficiency ηf of the hoist 17 decreases. Furthermore, the efficiency ηf of the hoisting machine 17 of the elevator will also be reduced if the guide shoe is insufficiently attached.

Therefore, when the efficiency ηr of the hoisting machine 17 of the elevator decreases, the electric motor torque required for a set acceleration increases. As a result, in the system of this embodiment in which the speed feedback signal Sd is fed back to the speed reference signal Sr to perform minor loop control, the torque reference signal @Tr, which is the output of the speed operational amplifier 12, increases, and the hoisting Trying to adjust the torque of machine 17 to the standard.

Here, the torque reference signal Tr from the speed operational amplifier 12
becomes too excessive, the comparison circuit 15 compares the torque reference signal Tr from the absolute value amplifier 14 with the torque limit value TfL from the torque limit setter 13, and the torque reference value 1 exceeds the torque limit value TfL. ``When r is large, the signal will be input to the speed reference generator 11.

The operation of the comparator circuit 15 causes the microcomputer of the speed reference generator 11 to execute control based on the flowchart shown in FIG.

Referring to FIG. 3, when the processing unit 28 enters the acceleration calculation routine for the unit speed command, it calculates the preset acceleration α.
0, the speed change interval α×Δ[ determined by the acceleration α] is added for each unit time, and the speed reference 3r is output (step 8
1-84).

Here, if the detection signal of the torque limit comparison circuit 15 described above is not operating, the required torque has not increased and the acceleration is calculated using the set value of α=α0, but the efficiency is reduced. When the comparison circuit 15 operates, the acceleration α is calculated by subtracting a preset constant suspension A from the initial setting value α0,
Set α=α−A as a new acceleration, and calculate the speed standard Sr based on this acceleration (step S5.83.84)
.

This acceleration suppression calculation is repeated until the comparison circuit 15 is turned off, that is, until the torque reference signal Tr becomes equal to or less than the torque limit value T (step 86).

The change characteristics of the elevator speed at this time are shown in the graph of FIG.
The elevator speed is increased while changing from α1 → α2 → α3.

In this way, even if the efficiency of the elevator hoisting machine 17 decreases, it is possible to perform control within the control range without applying the torque limiter, and it is possible to perform smooth elevator operation. .

On the other hand, when the oil temperature rises and the efficiency of the hoisting machine 17 increases, the torque reference signal Tr decreases, and the comparison circuit 1
5 is now turned off, so that the acceleration can be controlled again under the initial setting conditions without unnecessarily lowering the acceleration and prolonging the driving time.

[Effects of the Invention] As described above, according to the present invention, fluctuations in load torque are detected based on increases and decreases in the torque reference signal, which is the output of the speed operational amplifier, and a torque greater than the torque limit value is now required. In some cases, the output torque is automatically limited by suppressing the acceleration in the speed reference generation circuit. Even if the required torque increases and is applied to the torque limiter, the torque standard is also lowered by suppressing the acceleration by comparison with the torque limit value, and the elevator The elevator can be operated while avoiding being applied to the torque limiter by increasing the speed, and the elevator can be operated smoothly within the control range without preparing a large capacity device. As the oil temperature rises and the efficiency of the hoisting machine increases, the required torque also decreases, allowing the acceleration to return to its original state naturally, which may lead to a decrease in operating efficiency during normal operation. do not have.

[Brief explanation of the drawing]

FIG. 1 is a circuit block diagram of one embodiment of the present invention, FIG. 2 is a block diagram showing the detailed configuration of the speed reference generator in the above embodiment, and FIG. 3 is a decreasing speed in the speed reference generator of the above embodiment. A flowchart showing the calculation operation, FIG. 4 is a graph showing the elevator speed increasing operation in the above embodiment, FIG. 5 is a circuit block diagram of the conventional example, and FIG. 6 is a temperature-viscosity characteristic curve of general oil. . 11...Speed reference generator 12...Speed calculation JJ!
JrA unit 13...Torque limit setter 14...Absolute value amplifier 15...Comparison circuit 16.
...Vector control calculation circuit 17...Hoisting machine 18...Converter circuit 19...Capacitor 20...Inverter 21
...PWM control circuit 22...Current operational amplifier 23
...Current detector 24...Pulse generator 25...F/V converter 26...Cage 27...
Counter weight 28... Arithmetic processing unit 29... Memory (RAM
>30...Memory (ROM) 31...I/O device

Claims (1)

[Claims] An elevator control device that performs feedback control according to a speed reference signal includes a speed operational amplifier that compares and calculates a speed reference signal and a speed feedback signal and outputs a torque reference signal, a torque limit value setting circuit, and a torque limit value setting circuit for the speed operational amplifier. A comparison circuit that compares the reference signal output with the torque limit value output of this torque limit value setting circuit, and the output of this comparison circuit is input, and when the torque reference signal exceeds the torque limit value, the acceleration of the elevator is suppressed. An elevator control device comprising a speed reference generation circuit that outputs a speed reference.