JPS60191980A - Controller for alternating current 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 [Technical Field of the Invention] The present invention relates to an improvement in a device for controlling an elevator driven by alternating current of variable voltage and frequency.

[Prior art]

In recent years, the rapid development of semiconductor technology has made it possible to increase the capacity of power converters such as inverters.

As a result, even in the field of elevators, attempts have been made to control the induction motors for windings with variable voltage/variable frequency semiconductor power converters. As an example of induction motor control using a power converter, for example, JP-A-52-14
There is a slip frequency type vector control disclosed in Japanese Patent No. 9314. Torque control of the induction motor using this slip frequency type is performed using the following equation.

ω1=ω+ω81 +ωI12 ...■Here, J
: Imaginary unit 1, : Primary current io of induction motor 2 Same as above Secondary excitation current ■, 2 Same as above Torque current ω: Same as above Rotor angular speed ω 1: Same as above - Secondary current angular frequency 0)・1: Same as above Steady term of slip angular frequency ω,, 2: Transient term of angular frequency as above R2: Secondary resistance L2 as above: Secondary inductance as above T: Same as above Output torque M: Same as above - order secondary mutual inductance In other words, slipping from the required output torque T by equation 0 Stationary term ω at one frequency. 1, the torque current factor 2 from equation 0, the transient term ω, 2 of the slip angular frequency from equation (2), and the primary current angular frequency ω1 from equation (2). From this result, the primary current 11 is calculated using equation (2), and this is supplied to the induction motor.

Here, if a failure occurs in the control device and even one of the above equations is not calculated correctly, the negative current 11 no longer corresponds to the required torque T, and the rotation of the electric motor will become abnormal. As a result, the running speed of the car may become abnormal, endangering passengers.

[Summary of the invention]

This invention is intended to improve the above-mentioned problems, and detects an abnormality when the difference between the frequency of the primary current of the induction motor and the speed command signal is outside a predetermined range, or when the frequency of the negative current exceeds a predetermined value. An object of the present invention is to provide a control device for an AC elevator that ensures the safety of passengers by stopping a lever.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 1 to 10.

In FIG. 1, (1) is a speed command signal ω that commands the running speed of the elevator. (2) is an adder (see Fig. 2 and Figure 3), (3) is a speed control amplifier (Figures 2 and 3) which calculates the above deviation signal and generates the torque command signal T.'(41 is the torque command value')
8T0 is input and an absolute value calculator (
4A) and a slip frequency calculator (4B) that calculates the slip sub-wave number signal (4Ba) (Fig. 4);
(5) A current control amplifier (Fig. 5) which calculates the primary current 11 according to the formula and supplies the three-phase alternating current U - W to the induction motor (9), (6A) to (6C) are the current U - current transformers that detect W and generate current signals, respectively;
(78) to ('7c) are normally open contacts inserted into the current U-W line and pre-made by the main circuit contactor (7) described later;
(8) is the primary current angular frequency ω1 which is obtained by adding the slip angle frequency signal (4Ba) and the speed signal ω to the current control amplifier (5).
The adder (Fig. 4), (9) supplies contacts (7a) to
The hoisting induction motor connected to (7c), OO is the delivery of the hoist driven by the electric motor (9), 0υ is the deflection wheel, a2 is the sheave Q and the deflection wheel 0υ. The main rope, α→, is the rope connected to one end of the main rope 0 seconds, a4)
is the counterweight also connected to the other end, and 0υ is the delivery weight (
An electromagnetic brake that applies a braking force to the motor (9), Q$ij: A speed detector consisting of a rotational encoder and the like that detects the rotational speed of the electric motor (9) and outputs a speed signal ω.

Figures 2 and 3 show the adder (2) and the speed control amplifier (
3), in which A1-A3 are operational amplifiers, R
,~R1□ is a resistor, 01~c4 is a capacitor, (3A)
is an adder, K1-3 is a transfer function, and 3-2S where G, ~G3: Gain T1-T4: Time constant S Nira plus operator (a/a, t) Operational amplifier A1, Resistor R2 ~Rf3 and capacitor C1
, C2, the adder (2) and the transfer function shown in FIG.
The operation of 2 is performed on the transfer function of FIG. 3 in the circuit MY consisting of R9 and capacitor C3, and the operational amplifier A3 and resistor RIn
l The third circuit Z consists of R11 and capacitor C4.
Operation 3 is performed on the adder (3A) and transfer function in the figure,
The output of operational amplifier A3 becomes torque command signal Ji+T0.

Figure 4 shows the circuit of the current command device (4) and adder (8), in which A4 to A8 are operational amplifiers, and M1 to M4 are multipliers (for example, ANALOG DEvICES 429).
, R1° to R30 are resistors, C5 is a capacitor, -V. is a semiconductor negative electrode type.

The torque command signal T, , is generated by the operational amplifier A4 and the resistor R1.
It is amplified in an amplifier circuit consisting of □~RI4.

This is squared in a squaring calculation circuit consisting of a multiplier M1 and becomes rice. On the other hand, the negative power supply - ■. 1 due to the voltage of
The value of ° is determined. Then, the -order current absolute value ffi is calculated by a square calculation circuit including a multiplier M2, a square root calculation circuit including an operational amplifier A5, and resistors R15 to R38. This output is calculated by 1°+- by a square calculation circuit consisting of a multiplier M3, and is sent to a slip frequency calculation unit (4B). The slip frequency calculator (4B) is a differentiating circuit comprising a capacitor C5, an operational amplifier A6, and resistors R19 to R21, and outputs 1, y, and 0d. Multiplier M4, operational amplifier A7 and resistor R2
The absolute value calculator (
By dividing by the output (1o + I2) of 4A), the transient term ω82 of the slip angle frequency is calculated (formula 0)
. Further, the torque command signal T0 becomes a steady term ωsl of the slip angle frequency via the resistor R2. The adder (8) calculates the slip angle frequency ω, 4. The current angular frequency ω1-ω+ω8. +ω, , 2 is calculated and sent to the current control amplifier (5) (formula 0).

Figure 5 shows the circuit of the current control amplifier (5), in which (
5A) changes the input voltage to its corresponding frequency (pulse)
A voltage/frequency converter (hereinafter referred to as a V/F converter; for example, BURR-BROWN, VFC52),
(5B) is a binary counter that counts input pulses (e.g.
T E X A S E N S T FI U M E
N T 8 company, 5N74LS293), (5CU)
~(5CW) is a U phase~W consisting of a read-only memory in which a sine value corresponding to the input value is stored as a digital value.
Phase SIN function converter (for example, INTKL, 2'i'
16, (5DU) to (5DW) convert the digital ray direct signal to an analog value, and also convert the -order current absolute value signal (4
A digital/analog converter (hereinafter referred to as a D/Af converter) whose gain is adjusted by
-BROWN, DAC80), (5EU) ~ (5E
W) is an adder that adds the output of the D/A converters (5DU) to (5DW) and the feedback current signal TII to outputs the deviation signal, and (5FU) to (5FW) are the inputs. This is a power amplifier that amplifies the current UW and supplies the current UW.

The primary current angular frequency ω1 is converted into a digital value and calculated, and the gain is adjusted to \r-hi1 by the D/A converters ('5DU) to (5DW) to become a current command signal.

This corresponds to calculating the primary current i using the equation 0. And electrician Shinobu. ~ ■ Compared with 1, the current U ~ from the power amplifier (5FU) ~ (5FW) to '4 motive (9)
W is supplied.

In FIG. 6, α'7) is the speed command signal ω. In order to keep the polarity constant, its absolute value is detected and the speed command signal ω is set. The absolute value circuit (Fig. 8) that emits 1, 08) is a current signal ■.

A frequency/voltage conversion circuit (hereinafter referred to as F/
It is called a V converter. For example, BIJRR-BROWN,
VFC52), 0 [phase] is the speed command signal 5ω. , and the current signal generator u1 to generate a deviation signal (19a) 'f: Adder that emits, μ) operates when the above deviation (ω.+-Iu+) is outside a predetermined range, and the output (20a) becomes rLJ (Fig. 9), υ is a comparator that operates when the current signal factor u1 exceeds the first predetermined value and outputs rLJ (Fig. 10), and (2) is a current signal factor as well. The comparator (Figure 1O) whose output becomes "L" when u1 becomes equal to or higher than the second predetermined value is operated when the comparator 0υ operates while the door is open, or when the comparator 0υ operates during the floor alignment operation. When the device (A) operates, the output (23
a) is a processing circuit where rLJ becomes rLJ (Fig. 10), (c) is a NAND gate, (c) is an N'OT gate, (c), @
is a diode, (c) is a conductor, (a) is a transistor, and cI is an abnormality detection relay connected to a transistor. is a semiconductor positive electrode power supply.

In Figure 1, P and N are DC power supply busbars, (7) is the main circuit contactor, (7d) is its normally open contact, (15A) is the brake coil that releases the electromagnetic brake α in Figure 1, (31a
) is the normally closed contact of the abnormality detection relay 01) in Figure 6, 02 is the travel command relay contact that closes when a travel command is issued, (g)
is a brake release relay contact that closes when a command to release the brake 0υ is issued.

FIG. 8 shows the absolute value detection circuit a'I), in which All
Al2 is an operational amplifier, D, , D, , are diodes,
R41 to R4□ are resistors.

Speed command signal ω. has positive and negative values as it rises and falls, but one of them passes through a half-wave rectifier circuit consisting of operational amplifier AI2, diodes D, , D2, and resistors R41 to R43, and the output of operational amplifier A12 has a predetermined value. It becomes a half-wave power with gain. This and the original waveform are the operational amplifier A1
1 and resistors R44 to R47,
In addition, since the polarity is inverted, the speed command signal (θ., which is the output of the operational amplifier A11) becomes the absolute value of the speed command signal ω.

Figure 9 shows the circuit of the comparator (E), in which (2OA)
are operational amplifier A13, reference voltage E1, and diode D.
3 and a comparison circuit consisting of resistors R48 to R50, 1oB)
is a comparison circuit consisting of an operational amplifier AI4, a reference voltage E2, a diode D4, and resistors R51 to R53, and (20C) is a NOR gate.

When the deviation signal -jt (19a) exceeds the first predetermined value determined by the reference voltage E, the output of the comparator circuit (2OA) becomes "
II”. Also, the deviation signal (19a) is the reference voltage E
2, the comparator circuit (2
The output of oB) becomes [J. Therefore, the comparison circuit (2
OA).

Whichever output of (20E) becomes rHJ is NOR
The output (20a) of (20C) is "LJ VC, comparison circuit (2OA).

When both the outputs of (20B) are k to rLJ, the output (20a
) becomes rHJ.

FIG. 10 shows a comparator (21), (A) and a processing circuit. (a) is operational amplifier A16, reference voltage E4, diode D6
and a comparator consisting of resistors R5□ to R59, (a) is a semiconductor positive electrode power supply V. , door open detection relay contact (g) that closes when the door opens, floor alignment operation relay contact (to) that closes while car θ → is floor alignment, NAND gate (b) ~) and NO
This is a processing circuit consisting of a T gate (6).

When the current signal power, . . . 1 exceeds a third predetermined value determined by the reference voltage E3, the output of the comparator I2υ becomes rHJ.

Also, current signal ■. , is determined by the reference voltage E4.
When the value exceeds a predetermined value, the output of the comparator (a) becomes rHJ. When the door opens, the door closed detection relay contact 2 closes, but at this time, when the output of the comparator ■υ becomes 1lij, kJAN
The output of the D gate (b) is rLJ, which is N A N D
The output of C'll becomes [J, and the output (23a) of NOT gate) becomes "L". Also, when the car u-purifier is in floor matching operation, the floor matching operation relay contact () is closed, but at this time, if the output of the comparator (a) becomes "H", the NA
The output of the ND gate So becomes rLJ, and in the same way, NOT
The output (23a) of gate (2) becomes "L".

Next, the operation of this embodiment will be explained.

Now, when a travel command is issued, the travel command relay contact 0 closes. Normally, the abnormality detection relay t3) is de-energized and the contact (31a) is closed, so p-(31a)
-82(7)' circuit, the main circuit contactor (7) is energized, contacts (1a) to (7c) are closed, and the motor (9
) is connected to the current control amplifier (5). Next, when the brake release relay contact - is closed, since the contact (7d) is closed, P -(31a) -e33- (Ma
) -(15A)-N circuit, brake coil (15
A) is energized and the electromagnetic brake tm is released.

Next, a speed command signal ω is sent from the speed command device (1). is generated, this speed command signal ω. is added to the speed signal ω generated from the speed detector Qf9 by the adder (2), and the deviation signal thereof is amplified by the speed control amplifier (3) and output as the torque command signal T0. This torque command signal T. is supplied to the current command device (4), and the absolute value calculator (4A) calculates the -order current absolute value ω8□) is calculated. Primary current calculated in this way 1. Based on the absolute value of and the angular frequency, in the current control amplifier (5),
By executing the calculation of Equation 0, the -order current 11 is collected and supplied to the electric motor (9). Now the electric motor (9) is -
Next, rotation is started by the current 11, and the heel O→ is run via the sheave O0.

When the electric motor (9) rotates, a speed signal ω is generated from the speed detector Qej, and this is fed back to correct the torque command signal 83'T0 to an optimum value.

In addition, the speed signal ω is input to the adder (8) by the slip angle frequency &(ω, 1+
By adding ω82), the process of equation (2) is executed to generate an angular frequency ω1 for the primary current 11, which is supplied to the current control amplifier (5).

As a result, when the car @ is operated and reaches the floor where it is scheduled to stop, the travel command relay contact (31a) is opened.
The main circuit contactor (7) is deenergized and the contacts ('7a) to (7c
) is open. The motor (9) is now disconnected from the current control amplifier (5). At the same time, the contact (7d) is also opened, so the brake coil (15A) is deenergized, the electromagnetic brake Q is applied, and the electric motor (9) is restrained.

The above is normal operation.

Next, the operation when a failure occurs in the control device will be explained.

As long as the control device is operating normally, the rotation of the electric motor (9) is based on the speed command signal ω. Since the speed signal ω is controlled to follow the speed command signal ω. approximately equal to. However, if the two do not match due to a failure, the primary current angular frequency range ω1 shown by equation 0 becomes abnormal. As a result, the frequency of the current signal 1u becomes abnormal, and the current signal u1, which is the output of the F/V converter α barrel, becomes abnormal. This is the same result even if the adder (8) or the current control amplifier (5) fails. When (ω.1-Iu,) exceeds the first predetermined value, the output of the comparator circuit (2OA) becomes rHJ, and when it becomes below the second predetermined value, the output of the comparator circuit (20B) becomes rHJ. rHJ, and in both cases it is a NOR game) (
The output (2)a) of 20C) becomes rLJ. That is,
When (ω.1-■.□) is outside the specified range, the output (2, O
a) becomes "L". Now, the output of NAND (c) becomes "■]" and is blocked by the diode, so the power supply V. is connected to the transistor (
to), the transistor <1 becomes conductive, the abnormality detection relay Ql) is energized, and the contact (31a) is opened. Now, the main circuit contactor (7) and the brake coil (15A) are deenergized, so the motor (9) is disconnected from the current control amplifier (5) and the electromagnetic brake 0υ is applied. Note that the output of the NAND gate (c) is rl(
When it reaches J, the output of the NOT gate (c) becomes rLJ and is fed back to the input, so the operation by the output (2Oa) is maintained and the abnormality detection relay GD continues to be energized. This prevents the car θ frame from suddenly stopping and reaching abnormal speeds, thereby ensuring the safety of passengers.

next,! If the primary current angular frequency (・1.) becomes larger than the predetermined value due to a failure of the Itll K wholesale device, as can be seen from the formula (■), this means that the angular velocity ω is large, that is,
This is extremely dangerous as it means that the cage θ 葎 will run out of control. In particular, in order to improve transportation efficiency, elevator doors are generally opened just before the elevator stops at the planned floor.
If this failure occurs while the door is open, there is a risk of serious harm to passengers. In this case, the comparison circuit (2
OA) or the comparator circuit (20B) may operate, but in order to detect a major failure as soon as possible, a circuit consisting of a comparator Qυ and a processing circuit is provided. That is, when the current signal ■u1 exceeds the third predetermined value, the output of the comparator Qυ becomes rHJ. At this time, the door closed detection relay contact Z is closed, so the processing circuit (C)
The output (23a) becomes rLJ, and the abnormality detection relay e41) is energized in the same manner as described above, and the main circuit contactor (7)
is deenergized and electromagnetic brake αQ is activated. As a result, the car a3 comes to a sudden stop, ensuring the safety of the passengers.

In addition, when the car 03 is stopped, a floor alignment operation is performed to minimize the landing error, but in this case, a comparator (input ) and a processing circuit iw are provided. The comparator (a) is normally set to operate at a fourth predetermined value that is lower than the third predetermined value set in the comparator CI). That is, when the number of current signals exceeds the fourth predetermined number, the output of the comparator (A) becomes [J]. At this time, since the floor alignment operation relay contact (7) is closed, the 1b force (23a) of the processing circuit (a) becomes rLJ, and the abnormality detection relay 01) is energized as described above, and the car a The train will make a sudden stop to ensure the safety of passengers.

Note that if the current transformer (6A) itself breaks down and the current signal u1 becomes small, there is a possibility that the comparator υ and the comparator (a) may not operate. In this case, (ω.I”-Iul) becomes excessive and the comparator (4) operates.
Since the failure of A) can be discovered in advance, there is no problem with safety. In the embodiment, the U-phase current signal u is used as the detection signal, but the phase 7 or W-phase current signal 7. may also be used. Also, all current signal engineers, ~ ■.

If the above-mentioned detection is performed, the detection becomes even more reliable.

〔Effect of the invention〕

As described above, in this invention, an induction motor for an elevator is driven by a variable voltage/variable frequency AC power source, and if the difference between the frequency of the motor's primary current and the speed command signal is outside a predetermined range, or the motor is When the frequency of the primary current exceeds a predetermined value under predetermined conditions, an abnormality is detected and the car is stopped, thereby preventing the car from running out of control and ensuring passenger safety. Moreover, the above can be achieved without providing a dedicated speed detector for the safety circuit.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of an AC elevator control device according to the present invention, FIG. 2 is a circuit diagram of the adder and speed control amplifier of FIG. 1, and FIG. 3 is for explaining the operation of FIG. 2. The block diagram, Figure 4 is the circuit diagram of the current command device in Figure 1, and Figure 5 is the circuit diagram of the current command device in Figure 1.
The figure is a block circuit diagram of the current control amplifier in Figure 1, Figure 6 is a block circuit diagram of the abnormality detection circuit, Figure 7 is a circuit diagram of the main circuit contactor and brake coil, and Figure 8 is the absolute diagram of Figure 6. Detailed circuit diagram of the value circuit, Figure 9 is a circuit diagram of the comparator in Figure 6, Figure 10 is the comparator Cυ, @ and processing circuit in Figure 6.
FIG. In the figure, (1) is a speed command device, (5) is a current control amplifier, (6A) to (6C) are current transformers, (7) is a main circuit contactor, (9) is a hoisting induction motor, (1, 1 is the cage, θ valley is the electromagnetic brake, (15A) is the brake controller, Oe is the speed detector, α frame is the F/V converter, α1 is the adder, (E) is the comparator (No. 1 comparator), G21), (a) is a comparator (second comparator), (e) is a processing circuit,
A N D gate and GfJ are abnormality detection relays. Note that the same reference numerals in the figures indicate the same parts. Agent Masuo Oiwa Figure 2 Figure 3 Figure 4 Figure 4 i-A Figure β Figure 3 - Figure 7 Figure 8 Yu Figure 9 and Figure 10 Procedural amendment (voluntary) 1. Indication of the case Patent Application No. 69-46787-2, Title of the Invention AC Elevator Control Device 3, Relationship to the Amendment Case Patent Applicant Address 2-2-3 Marunouchi, Chiyoda-ku, Tokyo Name Name
(601,) Mitsubishi Electric Corporation Representative Hitoshi Katayama 4, Agent ・',...ku\,,7. , 212,, r: s-1 5 Figures 4 and 9 of the drawings to be amended 6 Contents of the amendment Figures 4 and 9 of the drawings have been revised as attached. 7 Drawings showing Figures 4 and 9 after the revised list of attached documents 1] Above 6 Figure 4 L L ノ

Claims (3)

[Claims] (1) An induction motor is driven by a variable voltage/variable frequency AC power supply, and the speed is controlled by controlling the primary current of the motor based on a speed command signal to operate the car. , a converter that inputs the primary current of the motor and outputs an output corresponding to the frequency thereof; a first comparator that operates when the difference between the speed command signal and the output of the converter is outside a predetermined range; and the converter. a second comparator that operates when the output of the is equal to or greater than a predetermined value under predetermined conditions;
A control device for an AC elevator, comprising: an abnormality detection circuit that is activated when the first or second comparator is activated; and a stop circuit that stops the above-mentioned device when the abnormality detection circuit is activated. (2) The AC elevator control device according to claim 1, wherein the predetermined condition is that the door is open. (3) The control device for an AC elevator according to claim 1, wherein the predetermined condition is that the car is in floor matching operation.