JP4127027B2 - elevator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an elevator intended to save space in a machine room.
[0002]
[Prior art]
One motor is stored in the machine room of a conventional elevator. However, when the rope winding sheave is positioned at the center of the hoistway, a part of the motor does not fit within the projection surface of the hoistway, and the machine room becomes larger. This becomes more prominent as the motor capacity increases.
[0003]
Further, the following prior art discloses an elevator having a structure in which a rope winding sheave is sandwiched between two motors.
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 51-20351 [Patent Document 2]
Japanese translation of PCT publication No. 2001-508744
[Problems to be solved by the invention]
However, since the prior art described in Japanese Patent Application Laid-Open No. 51-20351 uses an induction motor, the size of the apparatus cannot be avoided. Moreover, the synchronous motor has a permanent magnet, and it is necessary to know the position of this magnet accurately at the time of control. For this reason, it is usually necessary to attach a rotary encoder for detecting the magnetic pole position for each synchronous motor. On the other hand, since the induction motor does not have a permanent magnet and rotates the conductive cylinder, it is superior to the synchronous motor in that the control reference position can be arbitrarily set. However, when comparing an induction motor and a synchronous motor having the same output, the synchronous motor has a much smaller volume and is more efficient. For this reason, this conventional technique cannot achieve a space saving in the machine room.
[0006]
In the prior art described in JP-T-2001-508744, an example using a synchronous motor is described, but there is no description about a rotary encoder attached to the synchronous motor. When the rotary encoders are attached to both synchronous motors, the positions of the respective magnetic poles can be detected and control is facilitated. However, the size of the device increases as the number of rotary encoders increases. Further, even when the rotary encoder is attached to one side of the synchronous motor, the floor area of the machine room is increased depending on the attachment direction.
[0007]
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to save space in an elevator machine room using two synchronous motors and one rotary encoder.
[0008]
[Means for Solving the Problems]
A first synchronous motor, a second synchronous motor, a sheave connected to these synchronous motors and installed between these synchronous motors to drive an elevator, an encoder connected to the first synchronous motor, and the encoder And a control panel for controlling the first synchronous motor and the second synchronous motor based on the signal output from. The control panel includes a first inverter that drives the first synchronous motor and a second inverter that drives the second synchronous motor, and is based on the magnetic pole position of the first synchronous motor detected by the encoder. The first synchronous motor is driven to rotate the second synchronous motor and the output voltage of the second inverter detected when the current output from the second inverter is controlled to be zero, or Based on the command value, that is, based on the speed electromotive force generated in the second synchronous motor according to the rotation, the magnetic pole position of the second synchronous motor is calculated.
[0009]
Since there are two synchronous motors on both sides of the sheave, the capacity of the synchronous motor can be reduced compared to driving an elevator with one, and the installation balance of the synchronous motor and sheave is improved, and the projection of the hoistway is improved. The synchronous motor can easily be accommodated in the plane.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0011]
FIG. 1 shows an elevator according to a first embodiment of the present invention, which includes a synchronous motor 1, a sheave 2, a rotary encoder 3, a connector 4, an inverter 5, a control circuit 6, a microcomputer 7, and an instruction means 70 for a synchronous motor with a rotary encoder. It is composed. In FIG. 1, a sheave (a sheave for winding a rope) 2 is sandwiched between two synchronous motors 1, and the synchronous motor 1, the sheave 2, or a control device (not shown) is installed. The space of the room is saved. Currently, there is a high demand for saving space in the machine room and effectively using the floor area of the building. In particular, there is an increasing demand for a so-called “on-top” elevator system that houses the machine room within the projection surface of the hoistway. ing. In this case, it is necessary to consider securing a working space in the machine room, and it is necessary to optimize the arrangement of the equipment and downsize the equipment itself. FIG. 13 is a layout diagram of the motor 12, sheave 2, and rotary encoder 3 as seen from the projection surface of the hoistway in the conventional elevator. The motor 12 is a DC motor, an induction motor, a synchronous motor, or the like. In a general conventional configuration, one motor 12 is configured for one elevator. For this reason, when the sheave 2 is positioned at the center of the hoistway as shown in FIG. 13, it is difficult to fit the motor 12 and the rotary encoder 3 within the projection surface of the hoistway, particularly when the motor capacity increases. It becomes increasingly difficult.
[0012]
2 is a detailed view of the synchronous motor 1, sheave 2 and rotary encoder 3 portion of the first embodiment of FIG. 1, and FIG. 14 is a layout view of FIG. 2 as seen from the projection surface of the hoistway. As shown in FIG. 2, the configuration in which the sheave 2 is sandwiched between the two synchronous motors 1 has an effect of facilitating the “on-top” configuration as apparent from FIG. 14. Moreover, in FIG. 1, a rotary encoder is connected to the synchronous motor of the long side (L2) among each distance (L1, L2) between the non-sheave side surface of each synchronous motor and the machine room wall surface. As a result, it is possible to save work space and save space in the machine room. Each distance (L1, L2) between the non-sheave side surface of each synchronous motor and the machine room wall surface is as shown in FIG.
L1 <L2
However, it usually varies from building to building. For this reason, the shaft end of each synchronous motor has an effect capable of adapting to various building forms by providing a structure to which a rotary encoder can be connected. Further, by making the rotary encoder connecting portions of both the synchronous motors the same structure, there is another effect that the cost can be reduced due to the mass production effect.
[0013]
In FIG. 2, the synchronous motor 1 is used for the motor. In order to control the synchronous motor 1 satisfactorily, it is necessary to accurately grasp the magnetic pole position of the internal magnet. However, the volume can be reduced as compared with an induction motor having the same output, which is suitable for space saving. The synchronous motor is also excellent in efficiency.
[0014]
In the first embodiment shown in FIG. 1, the two synchronous motors 1 are controlled by one rotary encoder. The synchronous motor needs to accurately grasp the magnetic pole position in order to prevent a decrease in efficiency or loss of synchronization. Normally, a rotary encoder 3 is attached to each synchronous motor 1 as shown in FIG. However, in this case, the space for disposing the rotary encoder 3 is not limited, and space saving is hindered. Further, in order to perform detailed position control in an elevator, it is necessary to use a rotary encoder having a high pulse number. For this reason, the increase in rotary encoders leads to an increase in cost and an increase in failure rate.
[0015]
In order to control using only one rotary encoder 3 as in the first embodiment, it is only necessary to know in advance the phase relationship between the magnetic pole positions of the two synchronous motors 1. For example, when the phase difference between the magnetic pole positions of two synchronous motors 1 is A radians, one synchronous motor 1 detects the magnetic pole position with the rotary encoder 3 and the other synchronous motor 1 detects the detected value of the rotary encoder 3. The detected value may be obtained by adding A radians to. However, in the case of an elevator, since the synchronous motor 1 and the sheave 2 are installed locally, it is difficult to accurately grasp the phase relationship between the magnetic pole positions. In addition, since the synchronous motor is detached and attached each time the sheave is adjusted or periodically replaced, there is a high possibility that the magnetic pole position will fluctuate.
[0016]
As a method for solving this problem, as shown in FIG. 4, a holder 11 capable of grasping the magnetic pole position is attached to the shaft of the synchronous motor 1. Further, by providing a key hole in the shaft hole 42 of the connector 4, the relationship between the magnetic pole positions of the two synchronous motors 1 can be grasped. Or even when not using the holder 11 which can grasp | ascertain a magnetic pole position, you may devise the screw hole 41 position of a connection tool, and you may comprise before carrying in so that a magnetic pole position and the screw hole 41 position may correspond. . That is, by providing the magnetic pole position grasping means of the synchronous motor as described above on both sides of the sheave 2, it is possible to grasp the relationship between the magnetic pole positions of the two synchronous motors 1. Synchronous motors used for elevators generally have a large number of poles, so even if the mechanical angle is very small, the electrical angle is greatly shifted by the number of poles. For this reason, sufficient accuracy is required for the attachment of the holder 11 that can grasp the magnetic pole position before delivery. However, there is an effect that it is possible to easily assemble in the case of assembling work on site.
[0017]
FIG. 5 is a flowchart of another example of a method for solving the above problem. In FIG. 5, the same motor 1 that is directly connected to the rotary encoder 3 in FIG. 1 is the A-system synchronous motor (the magnetic pole position can be detected by the rotary encoder), and the other synchronous motor (the magnetic pole position is unknown) is the B-system synchronous motor. It is said. FIG. 6 is a simplified diagram of the B-system synchronous motor 1 to be detected and the B-system inverter 5 that drives it. First, at 101 in the flowchart of FIG. 5, the A-system synchronous motor is driven. The A-system synchronous motor can be driven normally because the rotary encoder can grasp the magnetic pole position. At this time, the B system synchronous motor is rotated by the A system synchronous motor, and a speed electromotive force Vm corresponding to the rotation speed is generated in the B system synchronous motor. When the rotation speed of the A-system synchronous motor is made constant, the speed electromotive force Vm generated by the B-system synchronous motor changes in a sine wave shape according to the magnetic pole position. The amplitude of the sine wave increases in proportion to the rotational speed. Here, if the current Iinv output from the B-system inverter 5 is controlled to be zero, the voltage Vinv generated by the B-system inverter 5 becomes equal to the speed electromotive force Vm, as is apparent from FIG. That is, if Vinv is observed under these conditions, the magnetic pole position of the B system synchronous motor can be accurately grasped. In the flowchart 102 of FIG. 5, the output voltage Vinv of the B system inverter or the command value Vinv ^* for outputting the output voltage Vinv is detected. In 103 of the flowchart of FIG. 7 is used for calculation. (In FIG. 6, the inverter output command value Vinv ^* is taken into the microcomputer 7, but it goes without saying that it may be calculated inside the microcomputer 7.) This operation is performed when the elevator is started. , You can adjust without inconvenience the customer. The rotational direction of the synchronous motor during this adjustment will be described with reference to FIG. FIG. 7 is a simplified diagram of the elevator car 8 and the weight 9, and it is assumed that there is no person in the car 8, and the weight Mc of the car 8 is lighter than the weight Mw of the weight. In this case, since it is driven in the forward direction with respect to gravity by rotating in the direction of the arrow (the car 8 moves upward and the weight 9 moves downward), it can be operated with light torque. In the means of FIG. 5, since the torque source is only the A-system synchronous motor, the magnetic pole position can be detected satisfactorily by operating in a direction that does not oppose gravity as shown in FIG.
[0018]
Next, the control circuit portion 6 of the first embodiment shown in FIG. 1 will be described. In a normal inverter system, one microcomputer is used for one inverter main circuit. However, when two motors are simultaneously driven at the same speed, it is necessary to perform information communication between the microcomputers, which may hinder high-speed response. In particular, in elevators, high accuracy of landing is required at the time of stopping, and thus high-speed response is required. Therefore, in the example of FIG. 1, the calculation for driving the two inverters 5 is performed by one microcomputer 7. This eliminates the need for information communication between microcomputers, and has the effect of achieving high speed.
[0019]
The control circuit portion 6 has an instruction means 70 for a synchronous motor with a rotary encoder. This is to transmit to the microcomputer 7 information on which of the two synchronous motors in the configuration of FIG. 1 is attached to the rotary encoder 3. For example, when the sheave 2 rotates clockwise as viewed from the left synchronous motor, the right synchronous motor rotates counterclockwise. That is, the rotation directions of the two synchronous motors are opposite to each other. For this reason, it is grasped | ascertained to which synchronous motor the rotary encoder is attached using the instruction | indication means 70 of the synchronous motor with a rotary encoder so that a synchronous motor can be controlled favorably by the microcomputer 7. FIG. For the instruction means 70 of the synchronous motor with a rotary encoder, for example, a manual dip switch is used. When ON, the rotary encoder signal is used as it is, and when OFF, a part of the rotary encoder signal is inverted. Let As a result, even when the rotary encoder is attached to any of the synchronous motors, good driving is possible.
[0020]
FIG. 12 shows an example in which a system controlled by a single microcomputer is used for another purpose. The rectifier converter 10 and the inverter 5 are driven by a single microcomputer 7 mounted on the control circuit 6. Here, by synchronizing the carrier frequency of the converter 10 for rectification and the carrier frequency of the inverter 5 and driving them in the same phase, there is an effect that the voltage ripple generated by the system can be reduced. When the inverter 5 and the rectifying converter 10 have separate microcomputers, it is necessary to perform extremely complicated processing in order to synchronize the carrier frequency. However, in the example of FIG. 12, since computation is performed by a single microcomputer, it is not necessary to perform information communication or the like, and a configuration for synchronizing carrier frequencies with a very simple configuration can be realized.
[0021]
FIG. 8 shows an example in which synchronous motors having different capacities are used in the first embodiment of FIG. Since the torque required for winding the rope is determined by the sum of the output torques of the two synchronous motors, synchronous motors having different capacities as shown in FIG. 8 may be used. In this case, a drive command output from a control circuit (not shown) needs to be calculated by a microcomputer or the like so as to be a command corresponding to the capacity ratio. Further, by synthesizing the capacity of the synchronous motors and changing the capacity of the entire system depending on the combination, even if the number of single synchronous motors is small, many kinds of capacity can be realized depending on the combination. In particular, in the case of an elevator, high-accuracy driving is required under conditions of low speed and high torque, and therefore, a special synchronous motor having a larger number of poles than a general industrial synchronous motor is used. For this reason, the series is effective in reducing costs. Alternatively, one synchronous motor may be used as a main motor, and the other synchronous motor may be used as a “torque assist” means for driving only when torque is insufficient. In this case, since the inverter main circuit for torque assist performs switching only when necessary, there is an effect that loss is reduced and efficiency is improved. FIG. 8 shows an example in which the axial capacity of the synchronous motor 1 is changed to change the capacity of the motor. However, as shown in FIG. 9, the synchronous motor 1 is changed in the radial direction to change the capacity. Needless to say.
[0022]
Next, a description will be given of the operation when one of the two synchronous motor drive systems is abnormal. In the first embodiment, in the normal operation state, the synchronous motors of both systems are driven, and the sum of the output torques of the respective synchronous motors becomes the output torque of the system. At this time, if it is detected that an abnormality has occurred in one of the systems, it is necessary to drive only with the remaining system. In this case, since the output torque is lower than usual, it is necessary to change the speed pattern such as suppressing the maximum speed and reducing the acceleration / deceleration rate. FIG. 10 is a flowchart of operation when the one-side system is abnormal in the first embodiment of FIG. 1, and an example in which one system (A system) fails and only one system (B system) is driven. It is. The process of the flowchart of FIG. 10 is performed inside the microcomputer on the control circuit. First, when an abnormality of the A system is detected in the conditional branch 111 of the flowchart of FIG. 10, the A system inverter is stopped according to the flowchart 112 of FIG. (Voltage may be applied, but at least switching is not performed.) Next, in the flowchart 113 of FIG. 10, the operation constant in the microcomputer is rewritten so that it can be driven only by the B system. Further, in the flowchart 114 of FIG. 10, the operation pattern is rewritten in consideration of the maximum speed and acceleration / deceleration rate that can be output only by the B system. Then, according to this operation pattern, control calculation and command value output are performed according to flowcharts 115 and 116 in FIG. In particular, elevators need to drive to at least the nearest floor so that passengers are not locked in the car. In the configuration of the first embodiment, there is an effect that even if one motor fails, there is no feeling of anxiety to the user.
[0023]
Next, a method for suppressing torque pulsation that occurs when the elevator is driven in the first embodiment of FIG. 1 will be described. FIG. 11 is a flowchart of torque pulsation reduction control, and this processing is performed inside the microcomputer on the control circuit. Torque pulsation occurs when the weight of a car or rope and the resonance point of the mechanical system determined by the synthesis of the rope and the harmonic of the rotational frequency of the motor (mainly the sixth harmonic component) match. For this reason, when accelerating / decelerating, car vibration occurs when the rotational frequency or its harmonic becomes a frequency near the resonance point. The sixth harmonic is the phase difference between the magnetic pole positions of the two synchronous motors.
30 ° + 60 ° × N (N = 1, 2, 3,...) (Electrical angle) (1)
Therefore, it can be suppressed by setting in advance. However, as described above, since the elevator is installed locally and the synchronous motor is attached and detached, it is difficult to set the angle of the expression (1) accurately. Therefore, first, the speed or position at which resonance occurs is learned in advance using the flowchart 121 of FIG. This learning is sequentially learned during the elevator operation in the flowchart 122 of FIG. 11 and stored in the storage means provided in the control circuit. During the elevator operation, in the normal state, the normal operation is performed as shown in the flowchart 123 of FIG. 11. A voltage command is output so that the phase difference becomes equal to the angle of equation (1). In this case, since the actual magnetic pole position is different from the magnetic pole position of the input command, the efficiency is slightly reduced. However, since it is a short time with respect to the operation time of an elevator, it is hardly a problem. When the resonance point is passed, normal operation is performed again as shown in the flowchart 123 of FIG. By such control, it is possible to reduce the sixth harmonic and to suppress the car vibration.
[0024]
Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and it goes without saying that various modifications can be made without departing from the scope of the present invention.
[0025]
【The invention's effect】
According to the present invention, the synchronous motor can easily be accommodated in the projection surface of the hoistway, and the space of the machine room can be saved.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a first embodiment of the present invention.
FIG. 2 is a detailed view of the synchronous motor and sheave portion of the present invention.
FIG. 3 is an example in which two rotary encoders are used.
FIG. 4 is a detailed view of the connector part of the present invention.
FIG. 5 is a flowchart of magnetic pole position detection.
FIG. 6 is an explanatory diagram of magnetic pole position detection.
FIG. 7 is an explanatory diagram of magnetic pole position detection.
FIG. 8 is Example 1 in the case of using synchronous motors having different capacities.
FIG. 9 is an example 2 in the case of using synchronous motors having different capacities.
FIG. 10 is a flowchart of operation when a one-side system is abnormal.
FIG. 11 is a flowchart of torque pulsation reduction control.
FIG. 12 is a block diagram showing a second embodiment of the present invention.
FIG. 13 is a layout view in the first embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Synchronous motor, 2 ... Sheave, 3 ... Rotary encoder, 4 ... Connection tool, 5 ... Inverter, 6 ... Control circuit, 7 ... Microcomputer, 8 ... Elevator car, 9 ... Weight, 10 ... Converter, 11 ... Magnetic pole position Holding device that can be grasped, 12... Motor, 41... Screw hole of connection tool, 42... Shaft hole of connection tool, 70.

Claims (4)

A first synchronous motor, a second synchronous motor, a sheave connected to these synchronous motors and installed between these synchronous motors to drive an elevator, an encoder connected to the first synchronous motor, and A control panel for controlling the first synchronous motor and the second synchronous motor based on a signal output from an encoder;
The control panel includes a first inverter that drives the first synchronous motor and a second inverter that drives the second synchronous motor, and the magnetic pole of the first synchronous motor detected by the encoder. The first synchronous motor is driven based on the position to rotate the second synchronous motor, and the first detected is detected when the current output from the second inverter is controlled to be zero. An elevator which calculates a magnetic pole position of the second synchronous motor based on an output voltage of the inverter of 2 or a command value thereof .   The first synchronous motor, the second synchronous motor, and a machine room for storing the sheave are provided, and the first synchronous motor has a distance to the wall surface of the machine room on the non-sheave side. The elevator is larger than two synchronous motors, and the encoder is connected only to the first synchronous motor. According to claim 1 or claim 2, wherein the control panel includes a first inverter for driving the first synchronous motor, and said second of said second inverter for driving a synchronous motor, an output from the encoder An elevator comprising a control device that collectively controls these inverters with a single control circuit based on the received signal.   In any one of Claims 1 thru | or 3, when it determines with the detection means which detects abnormality of the said 1st and 2nd synchronous motor, and abnormality having generate | occur | produced in one synchronous motor by this detection means, An elevator comprising means for setting a speed pattern of speed, acceleration rate or deceleration rate to a speed pattern different from that before the abnormality.

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