JP2006213447A - Elevator device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an elevator device provided with an overheat protection function without accompanying a rise of cost. <P>SOLUTION: This elevator device is provided with electrical appliances required for overheat protection such as a hoisting machine motor 5, an inverter device 7, an electromagnetic brake 8 and a door motor 9 and a microcomputer 10 for a control for controlling current to be supplied to each of the electrical appliances. A means for calculating the temperature for each of the electrical appliances required for executing the overheat protection function of each of the electrical appliances by suming up an ambient temperature taken from a temperature detecting device 11 and a temperature rise value selected from a square average value of current carried to each heating equipment per unit time is provided in the microcomputer 10 for the control. When the calculated temperature is an allowable temperature or more, a state is transferred to an operation mode for imparting lowering of the temperatures of the electrical appliances, while suppressing lowering of serviceability. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an elevator operation control system, and more particularly, to an elevator apparatus having an overheat protection function for electrical equipment required for elevator operation.

  Naturally, elevators require a hoisting machine, which has a motor. In addition, there are various types of motors such as an inverter device for driving a hoisting machine motor, an electromagnetic brake, and a motor for opening and closing a car door. In general, electrical equipment is provided, all of which generate heat during operation and the temperature rises.

  By the way, it is usual that the allowable temperature is set as a rated value for these electric appliances, but this allowable temperature depends mainly on the material used, and therefore the electric It is a different value for each device. And if it exceeds this allowable temperature, it will break down and burn out due to overheating, so overheating protection is required.

Therefore, for example, in one conventional technology, a fan or an air conditioner that operates in conjunction with a temperature detector is provided in a machine room of an elevator so that the temperature of the machine room does not exceed a certain value. In technology, an overheat protection target device such as a hoist motor is equipped with a temperature detector, and when the temperature of the device exceeds a certain value, the elevator is stopped or the elevator is effective for suppressing the heat generation of the device. A method of switching to the mode has been proposed (see, for example, Patent Document 1).
JP 2002-60147 A

  The above prior art does not give consideration to the fact that the allowable temperature differs for each electric device to be overheat protected, and has a problem in maintaining the overheat protection function and reducing the cost.

  As described above, an elevator includes various electric devices such as a hoist motor, an electromagnetic brake, a door opening / closing motor, and an inverter device, all of which are subject to overheat protection.

  At this time, in the conventional technology in which a fan linked to the temperature detector is provided in the machine room of the elevator, if the temperature detector or the fan fails, the device will be overheated, so overheat protection cannot be obtained. Problems arise in maintaining the overheat protection function.

  In addition, in the conventional technology in which a temperature detector is provided in the overheat protection target device, since the allowable temperature of the protection target device is different for each device, it is necessary to provide a temperature detector in all the devices. The number of temperature detectors increases and becomes expensive, thus causing a problem in cost control.

  An object of the present invention is to provide an elevator apparatus in which an overheat protection function can be obtained without an increase in cost.

  The above object is to provide an electrical appliance that requires overheat protection, in an elevator apparatus that includes at least a motor for driving a car, based on the mean square value per unit time of the current passed through the electrical equipment. Means are provided for retrieving a temperature rise value from a table, and when the sum of the temperature rise value and the detected ambient temperature exceeds the allowable temperature of the electric device, the operation mode of the elevator is switched to the temperature drop mode. .

  At this time, the temperature lowering mode includes a first operation mode in which the stop time of the car is lengthened, a second operation mode in which the acceleration and deceleration of the car are lowered from the rated values, and the travel of the car. The above object can be achieved even in any of the third operation modes in which the speed is reduced from the rated speed.

  According to the present invention, since it is not necessary to detect the current of the electrical device to be overheat protected, it is possible to further suppress the cost increase of the elevator device in combination with the cost reduction due to the absence of the temperature detector. be able to.

  Hereinafter, the elevator apparatus by this invention is demonstrated in detail by embodiment of illustration.

  FIG. 1 is an example of an elevator apparatus to which an embodiment of the present invention is applied. As shown in the figure, a elevator car 1 and a counterweight 2 are provided, which are connected by a rope 3 and then the rope 3 is made into a sheave 4. By hanging and driving the sheave 4 with a motor 5, the car 1 and the counterweight 2 are moved up and down in a slidable manner, so that the elevator can be operated between a plurality of floors. Yes.

  At this time, the motor 5 constitutes an elevator hoisting machine together with the sheave 4 and is variable-speed controlled by three-phase AC power of variable voltage and variable frequency supplied from the inverter device 7 of the elevator controller 6. For this reason, the inverter device 7 includes a forward conversion unit 7A and an inverse conversion unit 7B, converts the three-phase AC power fed from the commercial power source AC into the three-phase AC power of variable voltage and variable frequency, and supplies it to the motor 5. Is configured to do. At this time, the control of the inverse conversion unit 7B is performed by the PWM method.

  Further, at this time, the rotating shaft of the sheave 4, that is, the rotating shaft of the motor 5 is provided with an electromagnetic brake 8, and when the car 1 is stopped, the sheave 4 is prevented from rotating and the car 1 is moved. It works to keep it stopped. For this reason, the electromagnetic brake 7 is configured by a so-called electromagnetic open type electromagnetic brake in which the brake is applied by a spring force and the brake force is released when the electromagnet coil is energized. Well known.

  On the other hand, the car 1 is provided with a door opening / closing motor, that is, a so-called door motor 9, which can open and close the door necessary for servicing a plurality of floors. It is well known in the art.

  The elevator control unit 6 is provided with a control microcomputer 10, and a predetermined program is stored in the elevator control unit 6 so that general control necessary for operation of the elevator is performed. Then, a temperature detector 11 is further provided.

  Thus, the control microcomputer 10 takes in a signal (temperature data) representing the ambient temperature from the temperature detector 11 and is necessary for the operation of the elevator in parallel with the general control necessary for the operation of the elevator described above. Therefore, the temperature detector 11 is installed in the machine room of the elevator.

  Next, the operation of this embodiment will be described with reference to FIG. Here, FIG. 2 is a flowchart showing the operation when the motor 5 of the hoisting machine is targeted as an example of an electric device that requires overheat protection.

  In this embodiment, calculation processing of the control program is started every control cycle by the control microcomputer 10. When the process is started, first, temperature data is fetched from the temperature detector 11 (201). At this time, as described above, the inverse conversion unit 7B is PWM-controlled. For this reason, the current command value of the inverse conversion unit 7B is calculated by the control microcomputer 10 every control cycle.

  Therefore, the root mean square current is calculated from the current command value calculated by the control microcomputer 10 (202). Specifically, the current average value calculated in the control microcomputer 10 is squared, and a value obtained by multiplying the squared value by the control cycle time is stored in a memory for a predetermined time, thereby calculating a mean square. The current is calculated.

  Next, a data table is searched with the calculated mean square current, and a temperature rise value is selected (203). For this reason, the control microcomputer 10 is preliminarily provided with a temperature rise value as a data table with respect to the mean square current of the electric device, in this case, the motor 5. At this time, the temperature rise value with respect to the mean square current value to be stored in the data table is usually difficult to derive from a mathematical formula. Therefore, an experiment is performed for each electric device in advance, and a table is formed from the actually measured data. It is practical to leave.

  Next, the operation state of the elevator is determined (204). Then, when the elevator is running, the process is terminated here. On the other hand, when the elevator is stopped, the sum of the ambient temperature taken in in process 201 and the temperature rise value obtained in process 203 is compared with the allowable temperature of the electric device, in this case, the allowable temperature of motor 5. (205).

  If the comparison result is below the allowable temperature, the operation mode in general control necessary for the elevator operation being performed in parallel is set to the normal mode (206). Is set to the temperature lowering mode (207).

  Here, first, the normal mode in the processing 206 simply means that the operation mode in the general control necessary for the operation of the elevator being executed in parallel is not changed and is left as it is. Yes, so no processing for overheat protection is performed in this case. This is because, at this time, the comparison result in the process 205 is YES, and overheat protection is unnecessary. The detailed reason will be described later.

  On the other hand, the temperature decrease mode in the process 207 is an operation mode in which the temperature decrease of the motor 5 is brought about in the general control necessary for the operation of the elevator being executed in parallel. The first method of extending the stop time of the car 1, the second method of lowering the acceleration and deceleration of the car 1 from the rated values, and lowering the traveling speed of the car 1 from the rated speed There is a third method.

  Here, first, in the case of the first method, since the current does not flow to the motor 5 while the car 1 is stopped, the current is reduced as an average value, and the amount of heat generation is reduced accordingly, so the temperature is reduced. The rise can be suppressed and thus overheat protection is obtained.

  Next, in the case of the second method, the torque required for the motor 5 can be reduced by reducing the acceleration and deceleration, and the current value can be reduced. Therefore, overheating protection is also obtained in this case.

  Further, in the case of the third method, since the torque of the motor 5 can be reduced, the current value can be lowered. As a result, the heat generation amount can also be lowered, and the temperature rise can be suppressed. Protection will be obtained.

  Since the heat generation amount of the motor 5 at this time is proportional to the square of the current, any of the above-described methods can suppress the heat generation amount necessary for overheat protection without stopping the rotation of the motor 5. Therefore, according to this embodiment, an undesirable situation in which the operation of the elevator is stopped after the overheating protection of the motor 5 is ensured with only a slight decrease in convenience that the service time is somewhat longer. Occurrence can be suppressed, and the reliability of the elevator can be improved by maintaining the service.

  By the way, if the switching of the operation mode described above is executed during traveling of the elevator, for example, if the rated speed is lowered during traveling, the control of the elevator may not be normally obtained. Therefore, in the above embodiment, the process 204 is executed before the operation mode switching determination is made in the process 205, and the operation mode is not changed when the elevator (the car 1) is traveling. It is.

  Next, in this embodiment, as shown in processes 202 and 203 in FIG. 2, the temperature rise value of the motor 5 calculates the mean square current from the current supplied to the motor 5, and this calculation The data table is selected based on the value. Therefore, the reason why the temperature rise value of the motor 5 can be estimated by this will be described below.

  First, the heat generation of the electrical equipment is almost proportional to the square of the energization current. The temperature of the electrical equipment rises while the heat dissipation due to the temperature difference from the ambient temperature is larger than the heat generation due to the energized current, and the rise stops when the heat dissipation and heat dissipation match, and the temperature is constant. However, the time from the start of energization to the constant temperature at this time depends on the size and thermal resistance of the electrical equipment, and thus varies depending on the electrical equipment, but the temperature after a certain time with respect to the energization current of each electrical equipment. The increase value is determined uniquely.

  Here, in the case of an elevator hoist motor, the energizing current is not constant depending on the frequency of starting and stopping and the load in the car, but as described above, the amount of heat generation is almost proportional to the square of the energizing current. Therefore, if the root mean square current is used, it can be handled almost equivalently to a constant current. Therefore, as in this embodiment, the temperature of the electrical device can be estimated from the ambient temperature and the mean square current of each electrical device. It is.

  Further, in this embodiment, when the electrical device that is the target of overheat protection is the motor 5 of the hoisting machine that is PWM-controlled by the inverter device 7, as described above, the control microcomputer 10 calculates by itself. Since the root mean square current can be calculated from the current command value, there is no need to separately detect the current.

  Specifically, as described above, the current command value is squared, and a value obtained by multiplying the squared value by the control cycle time is stored in a predetermined memory for a predetermined time, thereby squaring. The average current can be calculated. Therefore, according to this embodiment, since it is not necessary to detect the current of the motor 5, a current detector can be made unnecessary, and as a result, the cost can be further reduced.

  Next, as another embodiment of the present invention, the case where an electrical device that requires overheat protection is a switching element that constitutes the inverse conversion unit 7B of the inverter device 7 of FIG. 1 will be described as a second embodiment.

  In the case of this inverse conversion unit, not only one switching element but also six switching elements are generally used, and the amount of heat generated is substantially the same during operation. Therefore, these six switching elements are usually attached to a common heat dissipating fin and are usually kept at the same temperature during operation. The temperature is the average temperature of the six switching elements.

  In the case of the second embodiment, the process is substantially the same as in the case of the embodiment for the motor 5 described above, and only the process 203 in the flowchart of FIG. 2 is different. In short, in the case of the second embodiment, the data table in the process 203 in the flowchart of FIG. 2 gives the temperature rise value with respect to the mean square current of the switching elements constituting the inverse conversion unit 7B. Just replace it with a data table.

  This is because the current flowing through the switching element of the reverse conversion unit 7B and the motor 5 is equal, and therefore, only the data table of the process 203 needs to be changed. Note that the data table at this time is practically the same as a table formed from actually measured data obtained by conducting experiments on switching elements in advance.

  At this time, the energization current of the switching elements constituting the reverse conversion unit 7B varies depending on the frequency of starting and stopping and the load in the car as described above. Since it is almost proportional to the square, it can be handled almost equivalently to a constant current if the mean square current is used.

  As a result, also in the case of the second embodiment, the temperature of the switching element can be estimated from the ambient temperature and the mean square current of the switching element, which is necessary for overheat protection without stopping the operation of the inverter device 7. The amount of heat generated by the switching element can be suppressed, and the occurrence of an undesirable situation in which the operation of the elevator is stopped can be suppressed only by a slight decrease in convenience that the service time is also increased.

  Therefore, according to the second embodiment, the overheating protection of the inverter device 7 can be reliably obtained and the operation of the elevator is stopped only by a slight decrease in convenience that the service time is somewhat longer. The occurrence of an undesirable situation can be suppressed, and the reliability of the elevator can be improved by maintaining the service.

  Next, as an embodiment of the present invention, the case where the electrical device requiring overheat protection is the electromagnetic brake 8 of FIG. 1 will be described as a third embodiment. Strictly speaking, it is the coil of the electromagnetic brake 8 that requires overheat protection at this time, and only the different points in the flowchart of FIG. 2 will be described here.

  First, regarding the calculation of the mean square current in the process 202 in the flowchart of FIG. 2, in the case of the motor 5 or the switching element described above, the value of the energization current differs depending on the load in the car 1, the driving direction, etc. As in the third embodiment, in the case of the electromagnetic brake 8, the current supplied to the electromagnetic brake 8 is almost constant regardless of the number of passengers and the driving direction, and is simply known only on the assumption that the rated voltage is applied. The current value can be taken into the control microcomputer 10.

  Therefore, in the case of the coil of the electromagnetic brake 8 as in the third embodiment, the average current is the product of the rated current value of the coil and the energization ratio (duty ratio). It is the ratio of elevator stop time and travel time.

  Therefore, in the process 202, the energization ratio is calculated from the elevator stop time and travel time in a certain period, and the mean square current is calculated from the calculated energization ratio and the rated current value of the coil given as a known value. It is only necessary to select a temperature increase value at 203. As for the data table used for the processing at this time, it is still practical to perform an experiment on the electromagnetic brake 8 in advance and make a table from the actually measured data.

  By the way, in the case of the third embodiment, the method 2 and the method 3 in the above embodiment cannot be applied to the root mean square current reduction mode in the processing 207. If these methods 2 and 3 are applied, the traveling time of the car 1 becomes longer, and the above-described energization ratio becomes larger. Therefore, in the case of this third embodiment, in the process 207, By applying the above-described first method, the operation mode in which the stop time of the car 1 is extended is set.

  At this time, if the stop time of the car 1 is simply lengthened, the passenger will feel uncomfortable. Therefore, in this case, for example, if the method of slowing the opening and closing operation of the door and applying the opening / closing operation slowly is applied, the stopping time of the car 1 can be naturally extended without feeling uncomfortable even if the stopping time of the car 1 becomes long. it can.

  Therefore, according to the third embodiment, it is desirable that the overheating protection of the electromagnetic brake 8 can be reliably obtained and the operation of the elevator is stopped with only a slight decrease in convenience that the service time is somewhat longer. It is possible to reduce the occurrence of unforeseen events, maintain elevator service, and contribute to improving reliability.

  Next, as an embodiment of the present invention, the case where the electric device requiring overheat protection is the door motor 9 in FIG. 1 will be described as a fourth embodiment. In this case, the electric device that requires overheat protection is the door motor 9, and therefore the heat generation characteristics thereof are the same as those of the electromagnetic brake 8 in the third embodiment described above.

  As described above, in the case of the electromagnetic brake 8, the current supplied to the electromagnetic brake 8 is substantially constant regardless of the number of passengers and the driving direction. Also in the embodiment, the control microcomputer 10 can simply capture the current value from the door motor 9 as a known current value only on the assumption that the rated voltage is applied.

  In the case of the door motor 9, the average current is the same as that of the electromagnetic brake 8 in the case of the third embodiment described above, and is the product of the rated current value and the energization ratio (duty ratio). The energization ratio at this time is also the ratio of the elevator stop time and travel time within a certain period.

  Therefore, also in the fourth embodiment, in the process 202 in the flowchart of FIG. 2, the energization ratio is calculated from the elevator stop time and travel time in a certain period, and the calculated energization ratio and the door motor 9 given as a known value are calculated. The mean square current is calculated from the rated current value of, and the temperature increase value is selected in the process 203. The data table used for the process at this time is practically the same as a table formed from actually measured data by conducting an experiment on the door motor 9 in advance.

  Therefore, the fourth embodiment is the same as the third embodiment described above, and the overheat protection of the door motor 9 can be reliably obtained with only a slight decrease in convenience that the service time is somewhat longer. In addition, it is possible to suppress the occurrence of an undesirable situation in which the operation of the elevator is stopped, maintain the service of the elevator, and contribute to the improvement of reliability.

  By the way, although the above demonstrated the embodiment in case of one electrical device requiring overheat protection, the present invention can be applied to the case of two or more electrical devices requiring overheat protection. Needless to say, in this case, it is only necessary to calculate the mean square current corresponding to each electric device and set an operation pattern corresponding to each.

It is a block block diagram which shows one Embodiment of the elevator apparatus by this invention. It is a flowchart for demonstrating operation | movement of one Embodiment of the elevator apparatus by this invention.

Explanation of symbols

1: Car 2: Balance weight 3: Rope 4: Sheave 5: Motor (winding machine motor)
6: Elevator control unit 7: Inverter device 8: Electromagnetic brake 9: Door motor 10: Microcomputer for control 11: Temperature detector

Claims (2)

As an electrical device that requires overheat protection, at least in an elevator apparatus equipped with a motor for driving a car,
A means for retrieving a temperature rise value of the electric device from a table based on a mean square value per unit time of the current passed through the electric device;
An elevator apparatus characterized in that when the sum of the temperature increase value and the ambient temperature detection value exceeds an allowable temperature of the electric device, the elevator operation mode is switched to a temperature decrease mode. In the elevator control device according to claim 1,
The temperature drop mode is rated for the first operation mode in which the stop time of the car is lengthened, the second operation mode in which the acceleration and deceleration of the car are lowered from the rated values, and the traveling speed of the car. An elevator apparatus characterized by being in one of the third operation modes in which the speed is lowered.

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