JPS606573A - Speed controller for elevator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an elevator speed control device, and more particularly to an improvement in a circuit for compensating the torque characteristics of an electric motor that drives an elevator car.

FIG. 1 is a block diagram showing the general structure of an elevator and the structure of a conventional speed control device.

In the figure, a rope (
A counterweight (1) is connected to one end of 2), and an elevator car (hereinafter simply referred to as a car) (4) is connected to the other end, and the top floor (5) is raised and lowered by the elevator car (4).
In front of the bottom floor (6) are end point detectors (7A), (7B) that detect the end point, such as limit switches, and in front of the bottom floor (6) are end point detectors (8A), (7B) that also detect the end point.
8B) are arranged in a column, and an end point detection cam (9) for operating these end point detectors is attached to the car (4).

In addition, a three-phase induction motor (hereinafter simply referred to as an electric motor) that drives the car (4) is delivered to the car via a hoist (not shown).
The rotational speed of this electric motor (10) is controlled by a thyristor device k (1η) as a motor control circuit which is connected to the three-phase father-flow power supply α6).

On the other hand, a tachometer generator (1) serving as a speed detector for detecting the speed of the car (4) is directly connected to the electric motor, and a speed detection signal vT of this tachometer generator and an end point detector (7A),
(7B), (8A), (8B) end point detection signal L
is taken into the speed control circuit θB).

This speed control circuit 03) includes a terminal floor deceleration command signal generation circuit (13b) that generates a deceleration command signal V8 for the car at the terminal floor based on the terminal detection signal L, and a speed command signal vP and the above-mentioned speed detection signal, which will be described later. (1) An adder (13c) for calculating the deviation of 1, and a compensator (13a) for compensating the torque characteristics of the electric motor based on the output of the adder (13c).

In addition, in order to obtain a command signal vP at speed, a normal speed command signal generator (14) is provided which generates a normal speed command signal V including a deceleration command for the terminal floor, and this normal speed command signal Vn and terminal floor Floor deceleration command signal generation circuit (1
A comparator (15J) is provided which compares the deceleration command signal V8 of 3b) and outputs the lower value as the speed command signal vP.

The operation of the speed control device configured as described above will be explained, particularly when performing deceleration control.

First, the terminal floor deceleration command signal generation circuit (13b) is designed to safely decelerate and land the car (4) even if the normal speed command signal generation device <141 fails.
When the car (4) approaches the top floor (5) or the bottom floor (6), the end point detector (7A), (7B) or (8A),
When (8B) is activated, the end point detection signal L8 is added, and the deceleration command signal V8 becomes independent from the normal speed command signal V.
Output.

At this time, comparator 05) detects these signals Vn and V
Compare V when v < v, ■.

When s n s n ≧■, V is selected and added to the adder (13c) as the speed command signal 8s. This adder (13c) calculates the deviation between the speed detection signal VT, which is the output of the tachometer generator (b), and the speed command signal (a), and adds it to the compensator (13a).

Further, the compensator (13a) is composed of an analog circuit and performs phase compensation and gain compensation of this speed control system, but normally the transmission interval k G (S) shown by the following equation is expressed as:
K is a gain, TIT2 is a time constant, and S is a Laplace operator.

Thus, when the deviation between the speed detection signal vT and the speed command signal VP is input, gain compensation and phase compensation are performed to improve the riding comfort and landing accuracy of the car (4), and the thyristor device Voltage signal V for controlling the thyristor firing angle of αη. On the other hand, the thyristor device A outputs a voltage signal of V.

If V is positive, this voltage signal V applies torque to the motor state. When is negative, the control torque is generated in the electric motor state by ``-1.'' In this way, the speed detection signal vT is made to follow the speed command signal VP° to control the speed in (4). ing.

By the way, as shown in FIG. 2, the DC braking torque of an induction motor has a significantly nonlinear characteristic with respect to its rotational speed. Furthermore, this characteristic curve■. □.

VOIa is the output voltage of the compensator (13a). A constant value■. □ and ■. 2, the horizontal axis represents the slip S with respect to the synchronous speed of the induction motor, and the vertical axis represents the DC braking torque T.

Here, in order to ensure sufficient landing accuracy by making the speed detection signal ■7 follow the speed command signal vP when decelerating the sword, the transfer function G■ of the compensator (taa) must be It is necessary to set the gain K high.

However, as the torque characteristic during deceleration is shown in FIG. 2, the torque at the start of deceleration, that is, near point A, is small, and the gain of the entire control system is small. Therefore, although the damping performance of the control system is good, the coordination is poor, and as a result, the ability to follow the speed command signal (2) is poor.

On the other hand, at low points, that is, near point B, the torque T becomes excessive and the gain of the entire control system becomes too weak. Therefore, although the coordination of the control system is good, the damping performance is poor.

As a result, the riding comfort becomes poor, and disturbances caused by the shaking of the car (4), the vibration of the rope (2), etc. are superimposed on the speed detector No. 16 V, and this is further applied to the compensator (13a). Vibration is likely to occur due to feedback.

This is true not only for AC elevators, but also for elevators that are generally equipped with 4 speed control circuits made up of analog circuits. , < l1iJ.

However, conventional elevator speed control devices cannot sufficiently compensate for the nonlinearity and saturation characteristics of the electric motor, resulting in poor ride comfort from the start of deceleration of the car to the landing of the car. However, there was a drawback that good landing accuracy could not be ensured.

The present invention has been made to eliminate the above-mentioned drawbacks.
Able to achieve good riding comfort and cylinder-accurate landing control,
The purpose of this invention is to provide an elevator speed control device.

Hereinafter, one embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 3 is a block diagram showing the configuration of the main parts of the elevator speed control device according to the present invention. A control circuit (13A) is used.

Here, the speed control circuit (13A) includes an adder (130) that calculates a deviation between the speed command signal VP and the speed detection signal VT.
), an analog compensator (131) having substantially the same input/output characteristics as the compensator (13a) shown in FIG. 1, and a speed detection signal VT'f! : An A-to-digital converter (135) that converts into a digital signal, and an output signal of the A-to-digital converter (135) and end point detectors (7A), (7B), (8A)
A digital processing device (132) using a microprocessor receives the end point detection signal Ls of (8B), calculates the amount of gain compensation that is insufficient by the analog compensator (131) alone, and generates a terminal floor deceleration command signal. ), an analog gain compensator (133) which is connected in series with the analog compensator (131) and whose gain can be switched in accordance with the gain compensation amount of the digital processing device (132), and a digital processing device 9i ( I/ created by 132)
A: D-A converts the end floor deceleration command signal into an analog signal
a converter (136).

FIG. 4 is a circuit diagram showing the detailed configuration of the gain compensator (133), and the inverting input terminal (-) of the operational amplifier OP is connected to an analog circuit! The resistor 1 (□) which inputs the output signal Ds of 1j (131) is connected to the non-inverting input terminal (+), one end of which is grounded, and the other end of the resistor R2, which is connected to the inverting input terminal (+). It has a phase compensation capacitor C and multiple contacts between the output terminal and the digital processing equipment.
A resistor Rf□""Rfn for gain compensation is connected through each contact of the selection switch sw which can close a desired contact in response to the signal D8 of (132).

The operation of the elevator speed control device according to the present invention constructed as described above will be explained below.

First, the adder (130) of the speed control circuit (13A) and the speed controller (131) receive a voltage signal V that has undergone gain compensation and phase compensation, similar to the compensator (13a) shown in FIG.

is added to the gain compensator (133).

On the other hand, when the speed detection signal 7 is applied to the digital processing device & (132) by the A-D converter (135),
This digital processing device (132) operates immediately after the start of deceleration, that is, in order to compensate for the torque characteristics shown in FIG.
Near point A, the gain compensation amount that is necessary to increase the coordination of the control system is calculated, and the selection switch SW of the gain compensator (133) is switched so that the corresponding gain is obtained.

Furthermore, each time the car speed gradually decreases, that is, as it moves toward point B, the amount of gain compensation must be increased to increase the damping properties of the control system. Therefore, the selection switch SW of the gain compensator (133) is switched so that the gain is suppressed to the corresponding gain.
1) compensates for the glandular portion of the torque characteristic of the electric motor during deceleration control, and the gain compensator (133) compensates for the nonlinear portion of this torque characteristic.

As is clear from this, the ride comfort of the elevator can be improved and floor landing errors can be reduced.

Even if the operation of the above-mentioned gen compensation amount is performed, there is still sufficient margin in terms of processing capacity, so here, the end point detectors (7A), (7B), (8A), and (8B) are It receives the end point detection signal L8 and generates a terminal floor deceleration command signal similar to the terminal floor deceleration command generation circuit (13b) shown in FIG. It is converted into a signal and added to the comparator θ5). Therefore, the terminal floor deceleration command generation circuit (13b) shown in FIG.
becomes unnecessary.

Note that since this speed control circuit (13A) uses an 8-bit microprocessor, it would originally be possible to digitize the entire speed control circuit. However, when the entire speed control circuit (13A) is digitized, the calculation xM becomes large and the processing time becomes long. This increases the wasted time from input input to output output, which tends to degrade control performance.

To solve this problem, an expensive microprocessor must be used.

Therefore, in the present invention, an analog circuit is used to compensate for a linear component that requires a quick response in torque characteristic compensation, and a digital processing circuit is used to compensate for a nonlinear component that is sufficient even for a slow response.

Next, FIG. 5 is a block diagram showing the configuration of the main parts of another embodiment of the elevator speed control device according to the present invention, in which the same reference numerals as in FIG. 4 indicate the same elements. There is. Here, an AD converter (137) is added to convert the voltage signal (1) of the analog compensator (131) into a digital signal, which is then input into a digital processing device (132).

This was achieved by simultaneously performing nonlinear compensation between the input voltage of the sirinutator device (11 J) and the motor torque of the electric motor, which was virtually impossible just by taking in the speed control signal vT. As a result, the controllability can be further improved. In the above embodiment, a speed control device applied to a father-flow elevator has been described, but the present invention can be applied to a DC elevator in the same manner. can be applied.

As is clear from the above explanation, according to the elevator speed control device of the present invention, an analog compensator is used to compensate for the linear component of the torque characteristic during deceleration control, and the analog compensator is insufficient for non-linear For partial compensation,
A separate digital processing device is provided to calculate the amount of compensation, and another gain compensator is used that can switch the gain characteristics or phase characteristics. This makes it possible to maintain good riding comfort and control the landing position with cylinder accuracy. , 4' 5 simple tables of drawings (Figure 1 is a block diagram showing the general configuration of an elevator and the configuration of a conventional speed control device, Figure 2 is a block diagram showing the configuration of the electric motor that drives the elevator and DC braking) FIG. 3 is a block diagram showing the configuration of the main part of an embodiment of the elevator speed control device according to the present invention, and FIG. 4 is a block diagram showing the main elements constituting the embodiment. FIG. 5 is a circuit diagram showing the detailed structure of the other embodiment. FIG.

(4) Fist/Elevator (5) Top floor (6) Bottom floor (7A), (7B), (8A), (8B) End point detector αq... Three-phase induction motor (11 ) φ gentle iris device (12J...tachometer generator (fox (13A), (13B)...speed control circuit 04)
...For the regular speed command signal generator)...Comparator (16)...Three-phase AC power supply (130)
... Adder (131) ... Analog compensator (132) ... Digital processing device (133) ... Gain compensator (135), (137) ... A-D converter (136)
Fist/D-A converter (OP)... operational amplifier (R,), (ij2), (R,,)-(R,, n)
... Resistance (C) ... Capacitor (s'w) ... Selection switch agent Masuo Oiwa Figure 1 Figure 2 Figure 113 Figure 114 Figure 5

Claims (1)

[Claims] A motor control circuit that controls the rotational speed of an electric motor that drives an elevator car, a normal speed command signal generator that generates a normal speed command signal of the corner, a speed detector that detects the speed of the corner, and a speed detector that detects the speed of the corner. an adder that calculates the deviation between the speed signal of the detector and the normal speed command signal; and a first analog that compensates for the gain characteristics and phase characteristics of the linear component of the torque characteristics of the electric motor based on the output of the adder. a type compensator, an A-D converter that converts the speed detection signal into a digital signal, and an input of the output of the A-D converter to calculate the amount of compensation for the non-r-mode part of the torque characteristic of the electric motor. a second analog signal processing circuit connected in series to the first analog compensator and capable of changing at least the gain characteristic according to a command from the digital decoding processing circuit;
an analog compensator, wherein the deviation between the speed signal and the normal speed command signal is compensated by the first and second analog compensators and applied to the motor control circuit. Speed control device.