JP2010013268A - Elevator control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an elevator control device for performing torque control of high accuracy to obtain desired torque and to suppress the occurrence of torque pulsation or the like with no risk of causing the deterioration of comfortableness of elevator users even at the occurrence of magnetic saturation of reactance due to a large current. <P>SOLUTION: The elevator control device includes: a motor having a reactor and driving an elevator; an electric power supply means for supplying electric power for driving the motor; a torque component extracting means for extracting a torque component related to the motor, from the electric power supplied to the motor from the electric power supply means and outputting a torque detection signal; a magnetic saturation detecting means for estimating an inductance value at the occurrence of magnetic saturation of the reactor which the motor has, based on the torque detection signal; and a control means for controlling electric power supplied to the motor from the electric power supply means based on the inductance value estimated by the magnetic saturation detecting means. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an elevator control device.

As an electric motor for driving an elevator, an AC electric motor such as a synchronous motor using a permanent magnet is widely used, and a vector control method is often adopted for torque control. When torque control of an electric motor is performed by this vector control method, electric motor constants determined by the circuit configuration of the electric motor are necessary, and currents are measured using these electric motor constants measured in advance or measured in real time during driving of the electric motor. Control is performed by calculating a command value and the like.
Accordingly, since the accuracy of the values of these computer constants greatly affects the control performance, it is very important how accurately these computer constants are obtained.
Here, as one of the computer constants, there is reactance inductance of the motor, but when the current value flowing through the reactance increases beyond a certain value, magnetic saturation occurs, and the inductance value of this reactance decreases. Is generally known.
In the conventional motor control device related to the magnetic saturation of the reactance, the step-up / step-down booster includes a reactor and a switching element, controls the current flowing through the reactor by switching the switching element, and outputs a step-up / step-down DC voltage. A converter, a buck-boost converter control means for controlling a DC voltage output from the buck-boost converter by controlling a switching operation of the switching element, and a DC power output from the buck-boost converter is converted into an AC power. An inverter that outputs to a three-phase AC motor, converts AC power generated by the three-phase AC motor into DC power, and outputs the DC power to the buck-boost converter, and inverter control means that controls AC power output from the inverter And the change of the current flowing through the reactor with respect to time. Magnetic saturation detection means for detecting magnetic saturation of the reactor by determining that magnetic saturation of the reactor has started when the magnitude of is greater than a predetermined threshold, and in the magnetic saturation period detected by the magnetic saturation detection means, Inverter power adjusting means for adjusting AC power output from the inverter to the three-phase AC motor is known to suppress the occurrence of overcurrent and overvoltage (for example, patent document) 1).

JP 2006-121875 A

In the operation of an elevator, it is necessary to perform acceleration / deceleration for each run, and the acceleration / deceleration torque required for the motor when performing this acceleration / deceleration is required for the motor during constant speed running. Often times greater than several times the torque. In particular, in the case of large capacity hoisting machines (electric motors) used in high-lift elevators installed in high-rise buildings, the difference in torque required during acceleration / deceleration and constant speed is very large. A large current is required during deceleration.
For this reason, at the time of acceleration / deceleration, there is a concern about the occurrence of the above-described reactor magnetic saturation due to a large current. When the magnetic saturation of the reactor occurs, as described above, the inductance value of the reactor decreases, and thus a deviation between the actual inductance value and the inductance value used for calculating the command value in the control system occurs.
In the conventional elevator control device, when the deviation of the inductance value generated by the magnetic saturation of the reactance due to the large current during acceleration / deceleration increases in this manner, the apparent current response value increases. There is a problem that an oscillation phenomenon is likely to occur, and as a result, there is a risk of causing a torque pulsation and a deterioration in ride comfort of an elevator user.

Further, in the conventional motor control apparatus disclosed in Patent Document 1, when the magnetic saturation detection of the reactor is detected by the magnetic saturation detection means, the magnetic saturation is performed so that the inverter power adjustment means does not generate an overcurrent or overvoltage. Therefore, there is a problem that a sufficient current cannot be passed through the electric motor and a necessary torque cannot be obtained during acceleration / deceleration.
In addition, since the magnetic saturation detection means determines that magnetic saturation has started when the magnitude of the time change of the current flowing through the reactor is greater than a predetermined threshold, the controller that performs constant current control detects the occurrence of magnetic saturation. There is also a problem that it cannot be detected and is difficult to apply.

  The present invention has been made to solve the above-described problems. Even when magnetic saturation of reactance due to a large current occurs, highly accurate torque control can be performed and a desired torque can be obtained. An elevator control device that suppresses the occurrence of an oscillation phenomenon and torque pulsation and does not cause a deterioration in the riding comfort of the elevator user is obtained.

  In the elevator control apparatus according to the present invention, an electric motor having a reactor and driving the elevator, electric power supply means for supplying electric power for driving the electric motor, and the electric power supply means are supplied to the electric motor. Torque component extracting means for extracting a torque component related to the electric motor from the generated electric power and outputting a torque detection signal, and estimating an inductance value at the time of occurrence of magnetic saturation of the reactor of the electric motor based on the torque detection signal A magnetic saturation detection unit and a control unit that controls electric power supplied from the power supply unit to the electric motor based on an inductance value estimated by the magnetic saturation detection unit.

  The present invention relates to an elevator control apparatus, which includes a reactor, an electric motor that drives the elevator, electric power supply means that supplies electric power for driving the electric motor, and electric power that is supplied from the electric power supply means to the electric motor. Torque component extracting means for extracting a torque component related to the motor from the torque and outputting a torque detection signal; and magnetic saturation for estimating an inductance value at the time of occurrence of magnetic saturation of the reactor of the motor based on the torque detection signal A configuration comprising a detection means and a control means for controlling the electric power supplied from the power supply means to the electric motor based on the inductance value estimated by the magnetic saturation detection means. Desirable to enable accurate torque control even when reactance magnetic saturation occurs due to It can be obtained torque and suppressing the occurrence of oscillation phenomena and torque pulsation, an effect that no risk to lead to deterioration of the riding comfort of the elevator user.

Embodiment 1 FIG.
FIGS. 1 to 3 relate to Embodiment 1 of the present invention. FIG. 1 is a block diagram showing the overall configuration of an elevator control device, FIG. 2 is a block diagram showing the internal configuration of a magnetic saturation detector, and FIG. These are graphs showing the relationship between the torque DC component and the estimated inductance value.
In the figure, reference numeral 1 denotes a car that is disposed in an elevator hoistway (not shown) so as to be lifted and lowered. One end of a main rope 2 is connected to the upper end of the car 1. The main rope 2 is wound around a hoisting sheave 3 and a slewing wheel 4 that are rotatably disposed on the upper part of the hoistway, and the other end of the main rope 2 is placed in the hoistway. It is connected to the upper end of the counterweight 5 arrange | positioned so that raising / lowering is possible.
The hoisting sheave 3 has a reactor and is attached to a rotating shaft of an electric motor 6 that drives the elevator. The main rope 2 is driven via the hoisting sheave 3 by rotating the electric motor 6. The motive power is transmitted to the elevator car, and the car 1 and the counterweight 5 move up and down in the hoistway like a slab.

The electric motor 6 is provided with an encoder 7 that detects the rotational position of the electric motor 6 and generates a position detection signal Ps. The position detection signal Ps output from the encoder 7 is input to the speed detector 8. Is done. The speed detector 8 generates a speed detection signal ωs by obtaining a time derivative of the position detection signal Ps, and outputs the speed detection signal ωs to the first subtractor 9a.
In the first subtractor 9a, a deviation between the speed command signal ωr generated and output by the speed command generator 10 and the speed detection signal ωs output by the speed detector 8 is obtained, and as a result, A speed deviation signal ωe is output.
The speed deviation signal ωe output from the first subtractor 9a is input to the speed controller 11, and the speed controller 11 generates a torque command signal τr based on the speed deviation signal ωe.

Three-phase power supplied to the motor 6 from a power converter 14 to be described later is detected as a power detection signal is by a current transformer, and a torque related to the motor 6 is detected from the power detection signal is by a torque component extractor 12. Components are extracted and a torque detection signal τs is output.
Then, in the second subtractor 9b, a deviation between the torque command signal τr output from the torque controller 13 and the torque detection signal τs output from the torque component extractor 12 is obtained, and as a result, A torque deviation signal τe is output.
The torque deviation signal τe output from the second subtractor 9b is input to the torque controller 13, and the torque controller 13 generates a voltage command signal Vr for the electric motor 6 based on the torque deviation signal τe. Generated. The voltage command signal Vr is converted into three-phase power corresponding to the voltage command signal Vr by the power converter 14 and supplied to the electric motor 6.

The torque detection signal τs output from the torque component extractor 12 is input to a magnetic saturation detector 15, which is used for torque control by the torque controller 13. Various constants related to the inductance of the reactor of the electric motor 6 are estimated and calculated based on the torque detection signal τs.
Specifically, first, the absolute value of the torque detection signal τs output from the torque component extractor 12 is obtained by an absolute value converter 15a included in the magnetic saturation detector 15, and an absolute value torque detection signal. converted to τsa.
The absolute value torque detection signal τsa is applied to a low-pass filter 15b that cuts off a signal having a frequency higher than a predetermined threshold and passes only a low-frequency signal to separate the torque direct current component τsl.

The torque direct current component τsl generated by the low-pass filter 15b is input to the inductance estimator 15c, and the inductance estimator 15c estimates and derives the estimated inductance value Lr.
The inductance estimation value Lr is derived by the inductance estimator 15c by substituting the torque direct current component τsl, that is, τ = τsl, into an inductance estimation function L (τ) given by an inductance learning unit 15g described later.
For example, the following linear approximation function is used as the inductance estimation function. Here, k is a slope and L0 is an intercept, both of which are constants.

  L (τ) = k · τ + L0

  Therefore, the estimated inductance value Lr can be obtained as follows by substituting τ = τsl into this equation.

  Lr = k · τsl + L0

An upper limit limiter Lrlim is provided as an upper limit value that can be taken by Lr. When the inductance estimated value Lr based on the inductance estimation function L (τ) exceeds the upper limit limiter Lrlim, the inductance estimation is performed. The value Lr is an upper limit limiter Lrlim. This Lrlim is set using, for example, the inductance design value of the reactor of the electric motor 6 as a guide (FIG. 3).
Then, the inductance estimated value Lr estimated by the inductance estimator 15c is output to the control constant calculator 15d, and the control constant calculator 15d that receives the inductance estimated value Lr is based on the inductance estimated value Lr. The various constants related to the inductance of the reactor is calculated, and these constants are output to the torque controller 13.

The absolute value torque detection signal τsa is applied to a high-pass filter 15e that cuts off a signal having a frequency lower than a predetermined threshold and passes only a high-frequency signal, thereby separating the torque pulsation component τsh.
The torque pulsation component τsh generated by the high-pass filter 15e is input to the torque pulsation detector 15f, and the torque pulsation detector 15f has a case where the amplitude of the torque pulsation component τsh exceeds a predetermined threshold value. The generation of torque pulsation is detected and a pulsation generation signal e0 is output.

The pulsation signal e0 output from the torque pulsation detector 15f is input to an inductance learning device 15g. When the inductance learning device 15g receives the input of the pulsation signal e0, that is, when occurrence of torque pulsation is detected. The torque direct current component τsl and the estimated inductance value Lr are stored.
Then, Lr2 is calculated by multiplying the stored estimated inductance value Lr by a predetermined coefficient k2 that is larger than 0 and smaller than 1.

  Lr2 = k2 · Lr (0 <k2 <1)

In this way, when it is determined that torque pulsation has occurred, magnetic saturation has occurred in the reactor of the electric motor 6, and it is highly possible that the inductance value of the reactor has been reduced. By multiplying the value Lr by a predetermined coefficient k2 (0 <k2 <1), Lr2 is obtained as the reduced inductance value.
Then, for the relationship between the torque DC component τsl and the Lr2 stored at the time of the stored torque pulsation, a linear regression equation is obtained using, for example, the least square method, and this is used as a new inductance estimation function L (τ). Thus, the inductance estimation function is updated, and the inductance estimation value in the inductance estimator 15c is derived using the inductance function L (τ) updated in the inductance learning device 15g (FIG. 3). .

In the elevator control apparatus configured as described above, first, the speed command generator 10 outputs the speed command signal ωr based on a control command from an elevator control panel (not shown).
Then, the rotational speed of the electric motor 6 is fed back as the speed detection signal ωs by the speed detector 8 through the encoder 7 attached to the electric motor 6, and the speed command signal ωr and the speed detection signal ωs are fed back. The speed controller 11 generates and outputs the torque command signal τr based on the speed deviation signal ωe indicating the deviation from the speed controller 11.
The torque controller 13 performs torque control based on the torque command signal τr. At this time, the torque component extractor 12 is detected by detecting three-phase power supplied from the power converter 14 to the motor 6. The voltage command signal Vr is generated based on the torque deviation signal τe indicating the difference between the torque command signal τr and the torque detection signal τs. .

Here, the generation of the voltage command signal Vr in the torque controller 13 is performed using a preset motor constant, and the constants relating to the inductance of the reactor included in the motor 6 are the torque detection signal. What is calculated by the magnetic saturation detector 15 based on τs is used.
As shown in FIG. 3, the estimated inductance value Lr derived by the magnetic saturation detector 15 is equal to the upper limit limiter Lrlim in the low torque range where the torque direct current component τsl is small, that is, the reactor 6 The value is set with the inductance design value as a guideline, but is derived as a value smaller than the upper limit limiter Lrlim in the high torque region where the torque direct current component τsl is large in consideration of the occurrence of magnetic saturation of the reactor.

  In this way, the magnetic saturation detector 15 derives the estimated inductance value while taking into account the occurrence of magnetic saturation in the high torque range based on the torque detection signal τs. In addition, the magnetic saturation detector 15 monitors the generation of torque pulsation by monitoring the torque pulsation component τsh of the torque detection signal τs, and when the torque pulsation occurs, the torque DC at this time is monitored. Based on the relationship between the component τsl and the value of Lr2 calculated from the estimated inductance value Lr, regression analysis is performed, and the inductance estimation function L (τ) is updated.

  The torque controller 13 outputs the voltage command signal Vr by using various constants related to the inductance of the reactor of the electric motor 6 and other electric motor constants calculated by the magnetic saturation detector 15 in this way. The voltage command signal Vr is converted into three-phase power by the power converter 14 and supplied to the motor 6, whereby torque control of the motor 6 is performed.

  In the elevator control apparatus configured as described above, based on the torque detection signal obtained by extracting the torque component related to the motor from the electric power supplied to the motor, the torque DC component separated from the torque detection signal is inducted. By substituting in the estimation function, an inductance value at the time of occurrence of magnetic saturation of the reactor of the electric motor is estimated. And, since torque control of the electric motor is performed based on the estimated inductance value, even when magnetic saturation of reactance due to a large current occurs, it is possible to obtain a desired torque by enabling highly accurate torque control, It is possible to suppress the occurrence of torque pulsation and to reduce the risk of causing a deterioration in the riding comfort of the elevator user.

Further, in addition to deriving the estimated inductance value in consideration of the occurrence of magnetic saturation in the high torque range based on the torque detection signal, the torque pulsation component of the torque detection signal is monitored by monitoring the torque pulsation component of the torque detection signal. It is possible to improve the accuracy of inductance estimation by monitoring the occurrence and performing regression analysis based on the relationship between the torque DC component and the estimated inductance value at the time of occurrence of torque pulsation and updating the inductance estimation function. Thus, more accurate torque control is possible, and the occurrence of torque pulsation can be further suppressed.
Furthermore, along with high-accuracy torque control and suppression of torque pulsation, it is possible to extend the service life by suppressing the deterioration of related parts.

It is a block diagram which shows the whole structure of the control apparatus of the elevator in Embodiment 1 of this invention. It is a block diagram which shows the internal structure of the magnetic saturation detector in Embodiment 1 of this invention. It is a graph which shows the relationship between the torque direct current component and inductance estimated value in Embodiment 1 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Passenger car 2 Main rope 3 Hoisting sheave 4 Solase wheel 5 Balance weight 6 Electric motor 7 Encoder 8 Speed detector 9a 1st subtractor 9b 2nd subtractor 10 Speed command generator 11 Speed controller 12 Torque component extractor 13 torque controller 14 power converter 15 magnetic saturation detector 15a absolute value converter 15b low-pass filter 15c inductance estimator 15d control constant calculator 15e high-pass filter 15f torque pulsation detector 15g inductance learner

Claims (3)

An electric motor having a reactor and driving the elevator;
Power supply means for supplying power for driving the electric motor;
Torque component extraction means for extracting a torque component related to the motor from the power supplied from the power supply means to the motor, and outputting a torque detection signal;
Magnetic saturation detection means for estimating an inductance value at the time of occurrence of magnetic saturation of the reactor of the electric motor based on the torque detection signal;
An elevator control apparatus comprising: control means for controlling electric power supplied from the power supply means to the electric motor based on an inductance value estimated by the magnetic saturation detection means. The magnetic saturation detection means is
A low-pass filter for separating a torque DC component from the torque detection signal;
The inductance estimation means for estimating an inductance value at the time of occurrence of magnetic saturation of the reactor of the electric motor by substituting the direct current torque component into an inductance estimation function. Elevator control device. The magnetic saturation detection means is
A high-pass filter that separates torque pulsation components from the torque detection signal;
Torque pulsation detecting means for detecting occurrence of torque pulsation of the electric motor based on the torque pulsation component;
When the torque pulsation detecting means detects the occurrence of torque pulsation of the motor, the inductance estimation function is updated based on the torque DC component and the inductance value of the reactor of the motor estimated by the inductance estimating means. The elevator control device according to claim 2, further comprising an inductance learning unit.

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