JPH0115470B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to elevator operation control, and particularly to an operation frequency control device.

The permissible operating frequency of an elevator is determined by the permissible temperature of the drive motor used.

Therefore, if the elevator is used at a frequency exceeding the set value, the temperature of the electric motor will naturally exceed the allowable value, which will eventually lead to deterioration of the insulation of the electric motor and, eventually, to burnout.

Conventionally, as a method to prevent the above-mentioned problems, a temperature sensor is embedded in the coil of the motor to detect the coil temperature, and when the coil temperature reaches the set value of the temperature sensor (motor permissible temperature), the sensor is activated. The system was designed to stop the elevator from operating.

However, in this method, when the temperature sensor is activated, the operation is immediately stopped. In particular, this temperature sensor operates when it is used frequently, that is, when there are many customers, and it becomes a major hindrance.

For this reason, by counting the frequency of elevator operation within a certain period of time, and detecting when this count exceeds a set value, the door opening time limit is extended to suppress operation and reduce the number of elevator activations per unit time. A possible method is to release the driving suppression when the number of times falls below a set value. However, this method suppresses and cancels operation based on the count of the number of elevator activations within a certain period of time, so even though the number of activations tends to increase,
If the most recent count value in a short period of time just happens to be below the set value, the suppression of operation will be lifted, leading to a rise in temperature of the elevator drive motor.
Furthermore, in a state where the motor temperature is rising, even if the number of operations within a certain period of time is within a set value, there is a risk that the motor burnout prevention temperature switch will be activated and the operation will be stopped. Therefore, it is necessary to set the above-mentioned set value to a small value with a margin, which may unnecessarily suppress driving and degrade service.

On the other hand, the frequency of elevator operation varies depending on the building where the elevator is delivered, and cannot be determined until after the elevator is in operation. Therefore, it is necessary to deliver the motor with sufficient capacity, and depending on the building, a motor that is larger and more expensive than necessary may be used.

SUMMARY OF THE INVENTION An object of the present invention is to provide an elevator operation frequency control device that can efficiently operate an elevator drive motor within an allowable temperature range.

A feature of the present invention is that the number of times the motor is operated is counted per unit time and the operation is suppressed according to the counted value, and the number of times the motor is operated is set to a different number of times.
and by counting every second unit time,
The present invention is configured to detect the frequency of operation of the electric motor in a plurality of time periods, and to reduce the suppression of the operation of the electric motor in accordance with the plurality of times of operation per unit time. For example, by counting the number of driving times in the immediately preceding unit of time and the number of driving times in a second unit of time that includes the previous time period, not only the driving frequency immediately before but also the driving frequency before that can be considered. The system is designed to suppress and release the suppression of driving.

The present invention will be described below with reference to an illustrative embodiment.

FIG. 1 is a block diagram of an elevator control circuit for implementing the present invention, in which an AC elevator is shown.

In the figure, an elevator car 1 and a counterweight 2 are suspended from a sheave 4 via a rope 3 in a hanging shape. The sheave 4 is the reducer 5
The induction motor 6 is connected to an elevator driving three-phase induction motor 6 and an electromagnetic brake 7, and the induction motor 6 is connected to a device that generates pulses proportional to the traveling distance, such as an AC speed generator 8. .

R, T, and S are three-phase AC power supplies, and the main contact circuit 17
The thyristor control device 1 switches between raising, lowering, normal operation, maintenance operation, etc. using a combination of switches.
6. Here, the thyristor control device 16 is configured in combination with a thyristor or a switch, and is controlled by a drive circuit such as the phase shifter 15 and the switch. The phase shifter 15 controls the thyristor 1 in response to a speed command signal 18 etc. from the elevator control digital computer 14.
ignition control of 6. The computer 14 inputs signals from the speed generator 8 and performs speed feedback control. As a result, the car 1 travels at a speed equal to or higher than the speed command 18 commanded by the computer 14.

In addition, a position detector 1 attached to the car 1
0 and 11 are activated when passing through a shield plate 9 provided in the tower, and the position signals at this time are transmitted to the computer 14 via the waveform shaping circuit 12.

Such an elevator control circuit is well known, and a flowchart of a well-known main program built into the elevator control digital computer 14 is shown in FIG.

As shown in FIG. 2, this main program 100 is
First, in step 110, initialization processing is executed. Next, step 120 is executed to sequentially execute various elevator processes at predetermined time intervals. If the timer flag is set in this step 120, an input processing step 130 is executed and data necessary for elevator control is loaded into the computer 14. Next, in step 140, car position calculation processing is performed based on the pulses proportional to the travel distance from the AC speed generator 8. At step 150, elevator operation is managed based on input data such as calls and the car position data calculated at step 140, and operation frequency control, which is a feature of the present invention, is executed as described later. In step 160, elevator speed control processing is executed. In step 170,
The control data calculated as described above is output, and based on this output control data, the relay drive circuit 19
and controls the elevator via the phase shifter 15.

In this embodiment, the elevator management processing steps are
At 150, the processing shown in FIG. 3 is performed. That is, in addition to the normal operation management processing step 200, a driving frequency measurement processing step 300 and a driving frequency suppression processing step 400 are executed.

FIG. 4 is a detailed flowchart of the driving frequency measurement processing step 300, and FIG. 5 shows a memory map of the data used here.

Here, the number of operations is measured by counting the start signals set in operation management processing step 200, but in addition, signals generated in proportion to the number of operations, such as deceleration commands, are also counted. The same can be achieved by doing the following.

In the figure, in step 310, it is determined whether or not there is a start signal, and if the start signal is present, step 320 is executed and the register for counting the number of starts is set to "1".
Count up. Therefore, the number of times the elevator has been started is set in this start-up count register.

Next, in step 330, it is determined whether the value of the timer t has exceeded the unit time ΔT. This unit time ΔT is a value corresponding to the first unit time. When the value of timer t exceeds ΔT, the step
340 is executed, and if the following is true, this subroutine ends.

In step 340, addresses AD1 to AD1 in FIG.
Address the counting data stored in AD9
Shift from AD2 to AD10. Therefore, data _n10 at address AD10 is deleted.

In step 350, the count value of the activation count register is stored at address AD1, and in step 360, this count value is reset to "0". Therefore, the latest count value _n1 is always stored in address AD1, and the previous count values _n2 to _n10 are stored in addresses AD2 to AD10, respectively.

Then, in step 370, addresses AD1~
The total sum n _t of the count values of AD10 is calculated and the value nT is stored at address AD11. That is, the second count value per unit time is stored at address AD11.

After completing such processing, in step 380, the timer t is reset. Therefore, thereafter, the number of activations is counted in step 320 during unit time t.

In this way, the count value per unit time of the first
n ₁ and a second count value n _t per unit time are measured.

FIG. 6 is a detailed flowchart of the driving frequency suppression process 400. Although it is shown here that the main program is executed every time the main program is processed, it may be executed every time t following step 370.

In the figure, in step 410, it is determined whether the first number of operations per unit time _n1 exceeds the set value _N1 , and if it is less than the set value _N1 , the process on the right is executed to perform normal operation. . If the set value N ₁ is exceeded,
Next, step 420 is executed to compare the number of operations n _t per second unit time, which is a long time interval, with the set value N _t . At this time, the number of operations nt
If the value exceeds the set value _Nt , the door close button is disabled at step 450. Therefore, even if the passenger operates the door close button, the door will not close until the non-interference time period has elapsed, and driving will be suppressed. Furthermore, in step 460, the door opening time limit extension time Δd _t
is extended by Δt ₁ hour. Therefore, each time this step 460 is executed, the door open time is extended by _Δt1 . Finally, at step 470,
Determine whether the door opening time limit extension time Δd _t exceeds the set value DT. This set value DT is preset as the maximum door opening time limit extension time, and if this set value DT is exceeded, it is determined that there is an abnormality and the elevator is stopped at step 480.

If it is determined in step 420 that the second count value n _t per unit time does not exceed the set value N _t , step 430 is executed and the count value m is set to "1".
Count up. This is to count the number of times that the first count value per unit time n ₁ exceeds the set value N ₁ and the second count value per unit time n _t does not exceed the set value N _t . If the numerical value m exceeds the predetermined number of times M, steps 450 and 460 are also executed to suppress the operation of the elevator.

The above operation is the operation frequency suppression processing step.
This is performed every time step 400 is executed, and the extension time Δd _t of the door opening time limit gradually increases each time step 460 is executed.

On the other hand, as a result of extending the door opening time limit and reducing the driving frequency, the first count value per unit time _n1 gradually decreases, and when it falls below the set value _N1 , the step
Run 440. In step 440, the second count value n _t per unit time and the set value N t are compared, and the count value n _t is compared with the set value N t.
If n _t is not less than the set value N _t , this program is terminated. . When the count value n _t becomes less than the set value N _t , in step 445, the number of times m and the door opening extension time Δd _t are reset to "0".

Here, the first unit time t may be set to about 5 minutes for a normal electric motor, and the set value _N1 at that time is the allowable operating frequency per unit time t determined by the allowable temperature rise value of the motor. You can set it to .
Therefore, the second unit time in the above embodiment is t×
10, and the set value _Nt at that time may be set to the allowable operating frequency per time t×10.

In this way, in this embodiment, the driving frequency is suppressed and controlled in accordance with the number of times of driving per unit time of the previous long second unit time, in addition to the short first unit time just before that, so that both counts are equal to each other. Unless the frequency is below the set value, the driving frequency suppression control is not set in the direction of reduction. Therefore, it is possible to avoid a situation where the elevator stops due to an increase in the number of times the elevator is started, and furthermore, even if the number of times the elevator has been operated is large, the operation is not unnecessarily curtailed depending on the previous operation state. In addition, it is possible to prevent damage caused by a sudden rise in the temperature of the motor, which would otherwise occur due to the immediate return to normal operation since the number of previous operations has been reduced.

In the embodiments described above, two types of unit times are used, but it is also possible to set three or more types of unit times and to suppress operation according to the number of times of operation per unit time.

Further, since the temperature of the electric motor is most affected by the number of times of operation, in the above embodiment, only the number of times of operation is measured. However, it goes without saying that by adding the load condition of the elevator to the control elements in addition to the number of operations, even more precise operation suppression control becomes possible. FIG. 7 shows an example of such a case. This FIG. 7 replaces steps 310 and 320 in FIG. In this embodiment, it is determined in step 720 whether the elevator is under heavy load or not, and if the elevator is under heavy load, the start count register is incremented by "2" in step 730. In other words, taking into consideration that the motor temperature rise rate is higher in the case of heavy loads than in light loads, the starting frequency is converted to two times. In this case, it goes without saying that the set values N ₁ and N _t should also be set to appropriate values.

As described above, according to the present invention, unless both the latest driving frequency count value for a short time and the latest driving frequency count value for a longer period of time are below the set value, the operation is continued. Since the frequency suppression control is not reduced, even if the immediately preceding short-time count value happens to be small, if the immediately preceding long-term count value is large, the number of activations will increase depending on the size of the latter count value. Since the system detects that the elevator is in the operating range and continues to perform operation frequency control, it is possible to avoid situations where the elevator stops operating due to a rise in the temperature of the electric motor, and it is possible to provide efficient elevator service within the allowable temperature of the electric motor. can.

[Brief explanation of drawings]

Fig. 1 is a block diagram of an embodiment of an elevator control device to which the present invention is applied, Fig. 2 is a flowchart for explaining the main program of an elevator control computer, and Figs. 3 to 6 are an embodiment of an elevator control device according to the present invention. Yes, Fig. 3 is a flowchart for explaining the elevator management processing program, Fig. 4 is a flowchart for explaining the operation frequency measurement processing program, Fig. 5 is a memory map, and Fig. 6 is a flowchart for explaining the operation frequency suppression processing program. FIG. 7 is a flowchart for explaining a driving frequency measurement processing program according to another embodiment of the present invention.

Claims (1)

[Claims] 1. In an elevator operation frequency control device that suppresses operation according to the operation frequency of an elevator driving electric motor, a first counting means counts the latest number of operations per unit time as a count value _n1 ;
a second counting means for counting the latest number of operations per second unit time set to _a longer time than the first unit time as a count value n _{t ;} An elevator operation frequency control device comprising means for reducing the operation restriction under the conditions that the count value n _t is equal to or less than a predetermined value N _t .