JPH0336757B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a control device for an AC elevator that uses an induction motor as a hoisting motor for the elevator.

[Technical background of the invention and its problems]

In recent years, with advances in power electronics and microelectronics, induction motors have come to be used in many fields where DC motors were previously used exclusively from the standpoint of control performance.

Also in the field of elevators, AC elevators using induction motors have come into practical use in place of DC elevators using DC motors with separately excited field windings. However, the conventional control means for an AC elevator using an induction motor is a so-called primary voltage control means that simply controls the magnitude of the primary winding voltage of the induction motor using a thyristor or the like. Therefore, there was a natural limit to control performance. Therefore, we improved control performance and
Furthermore, various control devices configured to perform variable voltage/variable frequency control have been proposed as control devices for AC elevators that can achieve power saving and power saving equipment. An example of a control means for realizing the above control device is a sine wave PWM control means using a voltage source inverter that controls the primary winding current of an induction motor in a sine wave shape, or a control means for controlling an induction motor like a DC motor. There are vector control means etc. that make this possible. By applying these control means to an elevator control device, not only excellent control performance can be obtained, but also a comfortable ride center value.

However, the AC elevator control device using the induction motor has the following problems. That is, the control device for an AC elevator is significantly different from the control device for a conventional DC elevator using a separately excited DC motor. For example, in a separately excited DC motor, the magnetic flux component is approximately proportional to the current in the field winding, so the state of the magnetic flux can be determined from the value of the field current, but in an induction motor, the magnetic flux is determined by the primary current. Unless the component and torque component are controlled together, the state of the magnetic flux cannot be known. Therefore, it is necessary to perform appropriate control that matches the operating characteristics of the elevator.

In addition, as an operation control means specific to elevators,
A control means is required to compensate for the unbalanced torque between the car and the counterweight when starting the elevator, but the control means using the induction motor controls the magnetic flux component and torque component together using only the primary current. Even if control is performed using an appropriate unbalanced torque command at the start of control, the secondary magnetic flux of the induction motor will rise due to the secondary time constant determined by the resistance and inductance of the secondary winding, and the generated torque will increase in a transient state. may change in size. For this reason, accurate torque may not be obtained immediately, and there is a risk that proper unbalanced torque control may not be performed even if the brake is released.

[Purpose of the invention]

An object of the present invention is to provide a control device for an AC elevator in which speed control including unbalanced torque control is performed smoothly and with high precision, control performance is improved, and a comfortable ride can be obtained.

[Summary of the invention]

In order to achieve the above object, the present invention is characterized by the following configuration. That is, when a control command is given from the outside, the magnetic flux component current command device commands the magnetic flux component current value of the AC elevator driving induction motor, and excitation control based on this command is started. After the magnetic flux establishment detection device detects that the secondary magnetic flux of the electric motor is established, the addition device is activated to command a torque component current based on the unbalanced torque command signal output from the unbalanced torque command device. A signal is obtained, and torque control is performed using this torque component current command signal, and a brake release command is given to the brake device of the AC elevator, and after the brake is released, the speed command generation device and the speed calculation device are activated to issue a speed control torque command. The present invention is characterized in that a signal is supplied to the adding device.

[Embodiments of the invention]

FIG. 1 is a block diagram showing the configuration of a first embodiment of the present invention. In FIG. 1, numeral 1 is an induction motor used as a hoisting motor for driving an elevator, and numeral 2 is a variable voltage/variable frequency control device that controls the variable voltage and variable frequency of the induction motor 1. Reference numeral 3 denotes a vector control calculation device that calculates command values for the amplitude and frequency of the primary current of the induction motor 1 and outputs a command value signal 3a to the variable voltage/variable frequency control device 2. 4
is the sheave of the elevator hoist, 5 is the elevator car, 6 is the counterweight, and the car 5 is
The main rope 7 is connected to the counterweight 6 via the sheave 4. 8 is a brake for braking the rotation of the sheave 4, and 9 is a brake device for releasing the brake 8. 10 is a speed command generator that generates a speed command signal 10a for the elevator, 11 is a speed detector that detects the speed of the elevator and outputs a speed signal 11a, and 12 is a device that responds to the deviation between the speed command signal 10a and the speed signal 11a. This is a speed control calculation device that outputs a speed control command signal 12a. 13 is a load detector provided in the car 5; 14 is an unbalanced torque command signal 14 in response to a load signal 13a from the load detector 13;
The unbalanced torque command generation device 15 that generates the unbalanced torque command signal 14a is an addition device that adds the unbalanced torque command signal 14a and the speed control command signal 12a and outputs a torque component current command signal 15a. 16 is a magnetic flux component current command generating device that generates a magnetic flux component current command signal 16a for controlling the magnitude of the magnetic flux component of the induction motor 1; 17 is a device that generates a magnetic flux component current command signal 16a for determining the magnitude of the secondary magnetic flux from the magnetic flux component current command signal 16a; This is a magnetic flux establishment detection device that detects and generates a magnetic flux establishment signal 17a. Reference numeral 18 inputs various elevator operation signals 18A, such as elevator call signals, for starting control of the induction motor 1, and sends control start command signals to each of the devices 2, 9, 10, 12, 15, and 16. This is a driving operation command device that outputs signals 18a to 18f. When this driving operation command device 18 receives a control command from the outside, it starts excitation control according to the command from the magnetic flux component current command device, and detects that the secondary magnetic flux of the induction motor has been established by the magnetic flux detection device. After the detection, the addition device is operated to perform torque control based on the torque component current command, and a brake release command is given to the brake device, and after the brake is released, the speed command generation device and the speed control calculation device are operated. It is designed to give driving operation commands so as to cause the vehicle to move.

Next, the operation of this embodiment configured as described above will be explained. Now, when an excitation control start command is given as an elevator operation signal 18A to the operation command device 18 from the part that calls the elevator, etc.
The driving operation command device 18 includes a variable voltage/variable frequency control device 2 and a magnetic flux component current command generation device 1.
Control start command signal 1 instructs 6 to start excitation control
8a and 18f are output. Therefore, the magnetic flux component current command generator 16 generates an excitation control start command signal 1.
8f, a magnetic flux component current command signal 16a is sent to the vector control calculation device 3 and the magnetic flux establishment detection device 17.
Output. The vector control calculation device 3 performs a predetermined vector control calculation based on the magnetic flux component current command signal 16a, and outputs a command value signal 3a indicating an amplitude command value I1 and a frequency command value ω of the primary current of the induction motor 1. The above vector control calculation is performed as follows.

The amplitude command value I1 is the magnetic flux component current command generator 1.
The magnetic flux component current command value from 6 is added to Id, adding device 15
If the torque component current command value from is Iq, it is expressed as I1=√ ² + ² ...(1). On the other hand, the frequency command value ω is the slip frequency ωs and the rotation frequency of the induction motor 1 ωr.
Then, ω=ωs+ωr...(2) In addition, the above slip frequency ωs is
If the secondary resistance of the induction motor 1 is R2, and the secondary inductance is L2, then ωs=(Iq/Id)(R2/L2)×{1+(L2/R2)S}...(3). Note that in equation (3), S is a differential operator.

Therefore, as is clear from equations (1) to (3) above,
When excitation control is started when the elevator is stopped, that is, Iq=0, ωr=0, I1=Id, ω=
It will be controlled by 0.

Then, by starting the excitation control, the induction motor 1
The secondary magnetic flux φ2 responds to the magnetic flux component current command value Id by the following equation.

φ2=[L2/{1+(L2/R2)S}]Id...(4) On the other hand, the magnetic flux establishment detection device 17 calculates the secondary magnetic flux φ2 based on the above equation (4), and calculates the secondary magnetic flux φ2. After detecting the establishment, a magnetic flux establishment detection signal 17a is output to the driving operation command device 18.

FIG. 2 is a block diagram showing a specific configuration of the magnetic flux establishment detection device 17 for realizing the calculation for detecting the establishment of the secondary magnetic flux φ2. In Figure 2, 21 is an operational amplifier, and 22 is a resistance value of "1/L2".
23 is a resistor with a resistance value of "1", 24
is a capacitor with a capacitance of "L2/R2", 25 is a setting device for secondary magnetic flux φ2, and 26 is the above operational amplifier 2.
This comparator compares the output signal of No. 1 with the set value of the secondary magnetic flux φ2 set by the setter 25, and outputs a magnetic flux establishment detection signal 17a when the output signal reaches the set value. Note that the secondary magnetic flux φ2 rises with a delay of a secondary time constant T2=L2/R2 with respect to the magnetic flux component current command value Id, but this secondary time constant T2 differs depending on the motor. However, the above quadratic time constant
T2 can be roughly determined from the design value or the attenuation of the induced voltage, that is, the attenuation of the motor terminal voltage when the motor is rotated under control and the control is stopped.

The driving operation command device 18 to which the magnetic flux establishment detection signal 17a is input outputs a control start command signal 18a to the adding device 15. Then, the addition device 15 receives the command value Iqw from the unbalanced torque command generator 14 and the command value from the speed control calculation device 12.
Iqo is added to find the torque component current command value Iq,
A torque component current command signal 15a is output to the vector control calculation device 3. However, since speed control has not been started in this state, the torque current component command value Iq becomes equal to the unbalanced torque command value Iqw.

In the vector control calculation device 3, when the torque component current command signal 15a is given, the
The amplitude command value I1 and the frequency command value ω of the primary current are determined based on equations (1) to (3). In this case, since the induction motor 1 is in a stopped state, equation (2) becomes ω=ωs. That is, when an unbalanced torque control command is given, the primary current frequency is controlled by the slip frequency.

On the other hand, the generated torque τ, the torque component current I1q flowing in the primary winding of the induction motor 1, and the secondary magnetic flux φ2
There is the following relationship: τ=(M/L2)I1q・φ2...(5) That is, in a state where the secondary magnetic flux φ2 is established, the torque is proportional to the torque component current I1q. Therefore, the torque component current I1q is controlled by the torque component current command value Iq, and torque is generated. Generally, the current control response speed is very slow, so when unbalanced torque control is started, the torque reaches the target value immediately.

FIG. 3 is a diagram showing the characteristics of the unbalanced torque command value Iqw. The unbalanced torque command value Iqw becomes zero when the loading amount is such that the car 5 and the counterweight 6 are exactly balanced, and the unbalanced torque command value Iqw becomes zero depending on the unbalanced state of the car 5 and the counterweight 6. The characteristics are as shown in Figure 3.

After generating an unbalanced torque generation command, the driving operation command device 18 outputs a brake release command to the brake device 9 as a control start signal 18b. Here, when the magnetic flux is established, torque is generated very quickly, so there is no problem in practice even if the brake release command is generated almost simultaneously with the unbalanced torque control command.

After confirming that the brake 8 is released by the brake release command, the driving operation command device 18 outputs a speed control start command to the speed command generation device 10 and the speed control calculation device 12 as signals 18c and 18d. Although not shown, the confirmation means for brake release can be performed by a device that generates a signal when the brake operation time after a brake release command has elapsed, or by the operation of a limit switch that can detect brake release.

The speed command generation device 10 outputs a speed command signal 10a according to the operation mode of the elevator to the speed control calculation device 12 in response to the speed control start command.
Then, in the speed control calculation device 12, a torque command value Iqo for making the speed follow the torque is calculated according to the deviation between the speed command signal 10a and the speed signal 11a from the speed detector 11,
A speed control command signal 12a is output to the adding device 15. As a result, as mentioned above, the adder 1
5, the torque current component command value Iq is obtained, and the vector control calculation device 3 calculates the amplitude command value I1 of the primary current.
After the frequency command value ω is determined, the variable voltage and variable frequency of the induction motor 1 are controlled by the variable voltage and variable frequency control device 2.

The driving operation command device 18 that operates as described above can be easily realized using a sequence circuit such as a relay, a logic sequence circuit, or software using a microcomputer. FIG. 4 is a flowchart showing the flow of the above-mentioned driving operations.

As described above, in this embodiment, when a control start signal is given to the speed control device section of the elevator, excitation current control is first started. Thereafter, when establishment of the secondary magnetic flux is detected by a device that simulates the secondary magnetic flux, unbalanced torque control, which is control unique to elevators, is started, and a brake release command is given. Then, when it is confirmed that the brake is released, speed control is started, and the elevator is operated at a desired speed based on the speed command.

Therefore, torque control is performed after the magnetic flux is established, which not only ensures reliable and accurate control of unbalanced torque, but also speed control starts after the brake is released, resulting in a smooth start and a comfortable ride. You can feel good.

By the way, since the rise of the secondary magnetic flux φ2 is determined by the secondary time constant L2/R2 as shown in equation (4) above, in the first embodiment, when the secondary time constant of the induction motor 1 is large, It takes a considerable amount of time to establish magnetic flux. Therefore, it may take a relatively long time until the elevator starts.

FIG. 5 is a diagram showing a magnetic flux component current command generating device 16' in a second embodiment of the present invention, which is constructed to solve the above problems. In FIG. 5, 51 is a first setting device for setting a rated magnetic flux component current value, 52 is a second setting device for setting a forcing current value higher than the rated value, 53 is an operational amplifier,
54, 55, and 56 are resistors each having a resistance value of "1", and 57 is a capacitor having a capacitance of "C" installed to avoid a sudden change in the magnetic flux command. Further, 58 and 59 are the first and second setting devices 5.
The first switch 58 is a first switch and a second switch for selecting signals output from the first switch 58
is turned on when both the excitation control start command 18a and the magnetic flux establishment signal 17a from the driving operation command device 18 are given, and the rated current value is set as the magnetic flux component current command value. On the other hand, the second switch 59 turns on when the excitation control start command 18a is given and sets the following current value to the magnetic flux component current command value, and turns off when the magnetic flux establishment signal 17a from the magnetic flux establishment detection device 17 is given. do.

Fig. 6 is a diagram showing the rise of the magnetic flux component current command Id and the secondary magnetic flux φ2 when no focusing is performed, which is the first embodiment, and Fig. 7 is a diagram showing the rise of the magnetic flux component current command Id and the secondary magnetic flux φ2 when focusing is not performed, which is the second embodiment. FIG. 3 is a diagram showing the rise of the magnetic flux component current command Id and the secondary magnetic flux φ2 in the case of FIG. As is clear from the comparison between FIG. 6 and FIG. 7, according to the second embodiment, the magnetic flux establishment time T _N
is shortened to T _F. Therefore, the elevator can be started quickly.

Note that the present invention is not limited to the above embodiments. For example, in the embodiment described above, the secondary magnetic flux φ2 was determined by simulation as shown in FIG. 2, but the magnetic flux may be directly detected by installing a magnetic flux detecting element in the motor body. Furthermore, since the secondary resistance R2 of the induction motor 1 changes depending on the temperature, the rise of the magnetic flux can be detected by detecting the temperature of the stator of the induction motor 1 and correcting the secondary time constant T2=L2/R2. The accuracy may be increased, and the stability during speed control may be improved by using the correction value as the secondary resistance value of the vector control calculation device.

〔Effect of the invention〕

According to the present invention, when a control command is given from the outside, a magnetic flux component current value of an induction motor for driving an AC elevator is commanded from a magnetic flux component current command device,
Excitation control based on this command is started. After the magnetic flux establishment detection device detects that the secondary magnetic flux of the electric motor is established, the addition device is activated to command a torque component current based on the unbalanced torque command signal output from the unbalanced torque command device. A signal is obtained, and torque control is performed using this torque component current command signal, and a brake release command is given to the brake device of the AC elevator, and after the brake is released, the speed command generation device and the speed calculation device are activated to issue a speed control torque command. To provide a control device for an AC elevator in which a signal is given to the adding device, so that speed control including unbalanced torque control is performed smoothly and with high precision, improving control performance and providing a comfortable ride. can.

[Brief explanation of the drawing]

1 to 4 are diagrams showing a first embodiment of the present invention, in which FIG. 1 is a block diagram showing the configuration, and FIG. 2 is a block diagram showing the specific configuration of the magnetic flux detection device.
Figure 3 is a characteristic diagram showing the output characteristics of the unbalanced torque command generator, Figure 4 is a flowchart for explaining the operation, and Figure 5 is a characteristic diagram showing the output characteristics of the unbalanced torque command generator.
7 to 7 are diagrams showing a second embodiment of the present invention,
FIG. 5 is a block diagram showing the specific configuration of the magnetic flux component current command generating device, and FIGS. 6 and 7 are waveform diagrams for explaining the effects. 1...Induction motor, 2...Variable voltage variable frequency control device, 3...Vector control calculation device, 5...
Elevator car, 8...brake, 9...brake device, 10...speed command generator, 11...
...Speed detector, 12...Speed control calculation device, 13
... Load detector, 14 ... Unbalanced torque command generation device, 15 ... Addition device, 16 ... Magnetic flux component current command generation device, 17 ... Magnetic flux posting device, 18 ...
Driving operation command device.

Claims (1)

[Claims] 1. A magnetic flux component current command device that commands the magnetic flux component current value of an induction motor that drives an AC elevator, and a magnetic flux establishment device that detects the establishment of secondary magnetic flux of the induction motor based on the command signal from this magnetic flux component current command device. a detection device, a speed command generation device that generates a speed command for the AC elevator, a speed detector that detects the speed of the AC elevator, a detected value of the speed detector, and a speed command value of the speed command generator. a speed control calculation device that outputs a speed control torque command signal according to the deviation of the elevator car, a load detector that detects the load of the car of the elevator, and an unbalanced torque command signal that outputs the unbalanced torque command signal according to the detected value of the load detector. A torque component current command is generated by adding the unbalanced torque command signal outputted from the unbalanced torque command generation device and the speed control torque command signal outputted from the speed control calculation device. an addition device that outputs a signal; and a primary induction motor based on a torque component current command signal from the addition device, a magnetic flux component current command signal from the magnetic flux component current command device, and a detected value from the speed detector. a vector control calculation device that commands the amplitude and frequency of the current; a variable voltage/variable frequency control device that controls the variable voltage and variable frequency of the induction motor based on commands from the vector control calculation device; and the AC elevator. a brake device that controls a brake of the induction motor; and when a control command is given from the outside, excitation control is started according to a command from the magnetic flux component current command device, and a secondary magnetic flux of the induction motor is established by the magnetic flux detection device. is detected, the addition device is operated to perform torque control based on the torque component current command, and a brake release command is given to the brake device, and after the brake is released, the speed command generation device and the speed control calculation device are activated. 1. A control device for an AC elevator, comprising: a driving operation command device that gives driving operation commands to cause the elevator to operate.