JPH0266084A - Device for controlling elevator - Google Patents

Abstract

PURPOSE:To restrain voltage drop and the extreme lowering of elevator speed by providing an arithmetic processing means for giving a speed limiting command enabling input current limitation to a speed command means in a power running mode. CONSTITUTION:By estimating an operation in which an input current to an elevator device is increased by a power running mode detecting means, an arithmetic processing means 13 gives a speed command control signal 13C as to limit an input current in response to the limiting command 13B of the input current of an elevator device to an elevator operating speed command means 6. Thereby, an input current to an elevator can be restricted at the peak of power consumption in summer time, etc. suppressing the lowering of source voltage, to restrain the extreme lowering of elevator speed.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to an elevator control device.

(Prior Art) As an elevator control device that performs control using an inverter device, the one shown in FIG. 5 is conventionally known.

This conventional elevator control device includes a three-phase AC type 11,
A rectifier circuit 2 that converts this three-phase AC power supply 1 into DC, a smoothing capacitor 3 that smoothes the output from the rectifier circuit 2,
It includes an inverter device 4 that performs variable voltage and variable frequency control on this DC power source, and an induction motor 5 driven by the inverter device 4.

Then, the inverter device 4 is provided with an elevator speed command generation device 6, and a speed control device that controls the inverter device @4 by comparing the speed command from the speed command generation device 6 with the actual speed signal of the motor 5. 7 is provided.

In addition, 8 is a sheave rotationally driven by the induction motor 5, 9 is an elevator car, and 10 is a counterbalance weight with the elevator car 9, which is connected by a loaf 11, and the elevator car is rotated by the rotation of the sheep 8. 9 to move up and down.

In such a conventional elevator control device, an AC power source 1
The rectifier circuit 2 performs three-phase full-wave rectification of the alternating current from the inverter 4, and supplies the rectifier to the inverter device 4 via the smoothing capacitor 3.

In the inverter device 4, the speed control device 7 controls the frequency of the inverter device 4 by comparing the speed command signal from the speed command bag @6 and the actual speed signal of the elevator car 9, and controls the rotational speed of the induction motor 5. and controls the elevator car 9 to a speed that matches the speed command from the speed command device 6.

(Problem to be Solved by the Invention) However, such a conventional inverter control type elevator control device uses a voltage type inverter device that converts an AC N source into a three-phase full-wave rectified DC power source, so the input The fundamental wave power factor of the current is very high at 0.95, and as a result, the input power increases or decreases in proportion to the motor output power, which is determined by the elevator load and speed, and when the power supply voltage decreases, the input current will increase in inverse proportion to that, and if the power supply voltage from the power company drops, especially during peak power usage in the summer, the input current will increase, and control will be performed in a direction that further promotes the voltage drop. There was a problem in that the lifting speed of the elevator corner decreased significantly as the power supply voltage decreased.

This invention was made in view of the above-mentioned conventional problems, and it limits the input current to the elevator during peak power consumption such as summer, and prevents voltage drop, thereby reducing the voltage at any operating speed of the elevator. It is an object of the present invention to provide an elevator control device that can suppress the degree of decrease accompanying the decrease.

[Structure of the Invention] (Means for Solving the Problems) An elevator control device of the present invention includes an inverter device for an elevator driving motor, a command means for commanding an operating speed of the elevator, and a control device for controlling the inverter according to a speed command from the speed command means. A speed control means for controlling the device, a means for detecting the power running mode of the elevator, an input current limit command input means for inputting a limit command for the input current of the elevator device;
In response to the input current limit command from the input current limit command input means, when the power running mode detection means detects the power running mode, a speed limit command is issued to the speed command means to limit the input current. It is equipped with an arithmetic processing means for giving.

(Function) In the elevator control device of the present invention, the power running mode detecting means predicts an operation in which the input current to the elevator apparatus becomes large, and the arithmetic processing means inputs a limit command for the elevator apparatus input current in response to the input current. A speed command limit signal that limits the current is given to the speed command means, and input 1 due to a drop in power supply voltage! - to prevent an extreme drop in power supply voltage.

(Example) Hereinafter, embodiments of the present invention will be explained in detail based on the drawings.

FIG. 1 shows an embodiment of the present invention, with reference numerals 1 to 1.
Reference numeral 1 indicates the parts with the same reference numerals in the elevator control device shown in FIG. 5, which was explained in the conventional example.

In this embodiment, a load detection device 12 is further provided in the car 9, and an arithmetic processing device 13 is connected to the speed command device 6.

The load detection device 12' detects the load of the car 9, and its load signal 12A is input to the arithmetic processing device 13.

The arithmetic processing unit 13 receives a detection signal 13A of the elevator's ascending and descending operating states in addition to the load signal 12A.
and the external input current limit command signal 13B are input, and the calculation processor 1j performs arithmetic processing to determine whether or not input current limit is necessary, and instructs the speed command device 6 to set the speed in order to limit the input current. It is connected to provide an in-device input current limit command signal 13C for reducing the command.

Note that this arithmetic processing unit i13 can be configured by a relay sequence, but it can also be configured by using a logic IC, or even by a calculation by a microcomputer, and especially when configured by a microcomputer, incorporates the speed command device 6 and the speed control device 7 together with the arithmetic processing bag @13 into one IC,
- Can be processed in batches.

The operation of the elevator control device having the above configuration will be explained next.

As shown in the flowchart of FIG. 2, it is determined whether or not the external input current limit command signal 13B is input (Step S1), and when the external input current limit command signal is given, the load signal 12A from the load detection device 12 is used to detect the load. The load is confirmed (step 82).

Next, the ascending/descending operating direction of the elevator is confirmed using the signal 13A (Step 3), and based on these inputs, arithmetic processing is performed to determine whether or not the device should perform input current limiting operation (Step S4).

If it is determined by the calculation to determine whether or not to perform the input current limited operation (step S5), the input current limited command signal 1 is sent to the speed command device 6.
3C is output (step 86).

Here, the determination of the load state will be explained in more detail.

(1) When determining by comparing the load between the car 9 and the counterweight 10, for example, by providing the car 9 with a micro switch that turns on at a balanced load as the load detection device 12, the car 9 and the counterweight 1
Equilibrium with 0 can be detected. In other words, if the overbalance between the car 9 and the counterweight 10 is 0.45 for a car 9 with a rated load capacity of 1000 ko, and the micro switch is set to turn on when the load m is 450 kG, then When the micro switch is turned off, it can be determined that the balance weight is greater than the basket, and when the micro switch is turned on, it can be determined that the basket is equal to the balance weight.

Furthermore, if the load detection device 12 is a strain gauge that outputs the load signal 12A in a continuous amount, the load is determined by comparing it with a bias amount that gives an overbalance of 0.45. be able to.

(2) When determining that the unbalance between the car 9 and the counterweight 10 is greater than a certain value, use two microswitches similar to those used in (1) above as the load detection device 12. amount is 100
By setting it to turn on at 250ko and 650io for the live load when the overbalance is 0.45 and the overbalance is 0.45, ±2 for the balanced load.
It can be determined from the output of the microswitch that the unbalanced state is greater than or equal to 00Ω. If the number of microswitch settings is further increased, even more detailed judgments can be made, and in this case, the continuous load signal can be used for soft calculation processing.

Next, the criteria for determining the input current limited operation based on the elevator's ascending and descending directions will be explained.

In the case of the judgment described in (1) above, for example, if the microswitch as the load detection device 12 is turned off and the balance weight is in the car state, input current limiting operation is performed only when a descending operation command is issued. If the microswitch is on and the car is equal to or less than the counterbalance weight, it is determined that the input current limiting operation is performed only when the ascending operation command is issued. In other words, input current limiting operation is set only in a mode in which most of the driving is in power running.

For example, during descending operation when the rated load is applied, most of the operation is in the regenerative operation mode, and
This is because in a 1wJ device, the input current from the power supply side to the main circuit device side during regenerative operation is almost O, and even if this input current is limited, it has almost no effect on fluctuations in the power supply voltage.

Further, in the case of the judgment described in (2) above, it becomes possible to make a judgment based on more detailed judgment. In other words, if the microswitch is set at the two points mentioned in (2), there will be three load ranges.

For example, if both the 250 ka and 650 kg microswitches are off, the mode is determined to be input current limited operation for descending operation, and if the microswitch on the 650 kg side is turned on, the input current limited mode is determined for upward operation. Determine mode.

This means that for live loads between 250kg and 650kg,
This is because the input current is controlled within a relatively small range even during power running, and the voltage drop cannot be suppressed even by limiting the input current.

Furthermore, the balance load detection described in (1) above is also added,
Load range below 250ko, 250~450.450k
Judgment can be made in four load ranges from a to 650k (to 1,650!J), and the input current limit can be changed to light and heavy.
This means that judgment can be made by dividing into modes.

Note that the input current limit determination process for these devices is performed in synchronization with the input current limit command from the outside through the signal line 13B. The external input current limit command signal 13B is applied when the current limit decreases significantly, and the device input current limit command processing calculation is executed in such a state.

Furthermore, regarding this external input current limit command signal 13B, there is not only one type of signal of limit command on/off;
Two levels are provided depending on the magnitude of the voltage drop. Level 1 regulates the input current limit operation mode "heavy" by the arithmetic processing unit 13, there is no regulation for the "light" mode, and level 2 restricts the input current limit operation mode. An input power limit command signal 13C is given to the speed command device 6 to make the regulations even stricter for the "heavy" current limit operation mode, and to make the same regulations as level 1 for the "light" mode. It is also possible.

Furthermore, the speed command procedure based on the determination result of input current limited operation will be described below.

The simplest way to limit the input current of the elevator main circuit is to lower the elevator rated speed.For devices where the input current fundamental wave power factor is close to 1.0, the magnitude of the input current is lower than the motor 5. Since it is approximately proportional to the operating capacity of the rated speed, if the rated speed is lowered, the input current can also be reduced approximately in proportion to the rated speed. Therefore, when a 10% current reduction command is given, the speed command device 6 only needs to output a command to reduce the speed by about 10%.

However, in a device with a poor power factor of the input current, such as a cytaritar Leonard type, the magnitude of the input current does not change much even if the speed is reduced.

Therefore, in such a case, by lowering the acceleration to the elevator, the maximum current peak value during acceleration can be reduced, and the input current value can be limited. Note that this method can be similarly applied to devices with a high power factor, and by limiting the input power peak value, it is possible to widely achieve input current limitation.

In this way, the input current is limited only to the power running operation mode depending on the elevator's load conditions and operating direction, and it is possible to prevent an extreme drop in the power supply voltage during peak power consumption in the summer. .

In the case of this embodiment, the input current limit operation of the device is performed in synchronization with the input current limit command signal from the outside, so if the input current limit command from the outside is not input, that is, the power supply voltage decreases. If not, the input current limited operation is not performed, so the speed does not decrease under normal conditions, and service deterioration can be minimized.

FIG. 3 shows another embodiment of the present invention, and the inverter device 4 shown in FIG. 1 is an embodiment of a voltage type inverter that does not perform power regeneration. In the example shown, an inverter device @14.1 that performs power regeneration and can control the power factor of the input current to approximately 1.0 is used.
5, especially the inverter equipment @14 shown in Figure 3.
is a voltage type, and the inverter device @15 shown in FIG. 4 is a current type.

16 in Fig. 3 is an AC reactor, 1 shown in Fig. 4
7 indicates a DC reactor, and 18 indicates a three-phase capacitor.

Also in the embodiments shown in FIGS. 3 and 4, the load signal 12A1 from the load detection device 12 for the car 9, the elevator operation direction signal 13A1, the input current limit command signal 13B from the outside, is sent to the arithmetic processing device 13. The arithmetic processing unit 13 is configured to determine the necessity of input current limitation for the device based on these input signals, and to provide the determination result to the speed command device 6.

In these embodiments as well, the power running mode of the elevator is determined based on the combination of the load signal and the elevator operating direction signal, as in the embodiment shown in FIG. By taking the input current limit command signal 13G as a device, it operates to give the speed command device 16 an input current limit command signal 13G.

In other words, in the elevator control devices shown in Figures 3 and 4, the power factor is approximately 1.0, and most of the current during regenerative operation is active current, and this current has no effect on power supply voltage drop. On the contrary, it has the function of supplying power to building equipment and other loads, and can be used to improve voltage drops overall.

[Effects of the Invention] As described above, according to the present invention, when an input current limiting command is given from the outside in the power running mode, the speed command means is operated so as to limit the input current as a device. For example, when the power supply voltage drops during peak power consumption in the summer, the input current to the inverter increases in inverse proportion to the drop in power supply voltage, and this increase in input current exacerbates the voltage drop. There is no need to perform direction control, and voltage drops can be suppressed to prevent extreme drops in elevator speed.

[Brief explanation of the drawing]

FIG. 1 is a circuit block diagram of an embodiment of the present invention, FIG. 2 is a flow chart showing the operation of the above embodiment, FIG. 3 is a block diagram of another embodiment of the invention, and FIG. 4 is a block diagram of another embodiment of the invention. FIG. 5 is a block diagram of still another embodiment, and FIG. 5 is a block diagram of a conventional example. 1... AC power supply 2... Rectifier circuit 3...
Smoothing capacitor 4... Inverter device 5... Induction motor 6... Speed command device 7... Speed control device [8... Sheave 9... Car 10... Counterweight 12
...Load detection device 13...Arithmetic processing device Fig. 1 Fig. 2 Fig. 3 Fig. 4

Claims (1)

[Claims] an inverter device for an elevator drive motor, a means for commanding the operating speed of the elevator, a speed control means for controlling the inverter device according to a speed command from the speed command means, a means for detecting a power running mode of the elevator;
Input current limit command input means for inputting a limit command for elevator apparatus input current, and in response to an input current control command from the input current limit command input means, a power running mode is detected by the power running mode detection means. An elevator control device comprising: arithmetic processing means for sometimes giving a speed limit command to the speed command means so as to limit the input current.