JP2016222420A - Diagnostic system for elevator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate necessity for additional equipment for detecting breakage of a wire rope of an elevator.SOLUTION: When a motor for elevating a cage of an elevator is controlled by an inverter having a cage position control function, an abnormality detection part is provided on a control device for the inverter. When torque ripple occurs due to partial kink of a wire rope and a torque current detection value is increased, the abnormality detection part calculates an absolute value of current deviation from a difference between a current command for the inverter and the torque current detection value. When the absolute value of current deviation exceeds a preset threshold specified times, it is judged that abnormality of an elevator structure occurs, and an abnormality detection signal is outputted.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an elevator diagnosis apparatus, and more particularly to an elevator rope diagnosis apparatus for an inverter control apparatus having a car position control function.

  In a general elevator system, a car and a counterweight connected to a wire rope are moved up and down by a motor drive. The wire rope may be stretched or broken due to secular change, and the wire rope may be kinked or entangled due to vibration at the time of emergency stop due to an earthquake or failure.

  In order to grasp the state of such a wire rope, Patent Document 1 discloses that a strand break of an elevator rope is detected instead of a periodic inspection by a human eye and the like, and the elevator is controlled based on the break detection result. It is publicly known. Further, Patent Document 2 is publicly known as a rope swing detection sensor attached to a rope slip prevention guide instead of an expensive long period vibration sensor.

JP-A-8-301543 JP 2010-215410 A

  Patent Documents 1 and 2 both add additional equipment such as a wire rope sway detection sensor, and are expensive because they require initial investment and inspection costs.

  When an elevator car lifting / lowering motor is operated using an inverter control device, some inverter control devices have a car position control function such as position information and door sensor information. The position information is a pulse signal detected by a speed detector such as an encoder installed in the car lifting motor, and the door sensor information is a door sensor on each floor installed in the car hoistway. The inverter control device takes in such information and performs predetermined operation control.

  An object of the present invention is to provide an abnormality diagnosis device for an elevator structure such as an elevator rope or rail having a car position control function in an inverter control device.

The present invention generates a current command based on the difference between the speed command and the detected speed value, generates a torque command based on the difference between the current command and the detected torque current value, and then generates an elevator car via an inverter based on the torque command. Inverter control device for controlling the lifting motor of the inverter having a car position control function in the inverter control device,
The absolute value of the current deviation is calculated from the difference between the current command and the torque current detection value, and when the absolute value of the current deviation exceeds a preset threshold value a predetermined number of times, it is determined that the elevator structure is abnormal and an abnormality detection signal Is provided with an abnormality detecting unit for outputting the.

The abnormality detection unit of the present invention, means for storing the position of the basket when the difference between the current command and the torque current detection value exceeds a threshold;
A means for judging whether or not the position of the car when the threshold value is exceeded is the same position, and for outputting an abnormality occurrence signal of the elevator structure when the preset threshold value is exceeded in the case of the same position; It is characterized by that.

  The abnormality detection unit of the present invention is characterized in that a plurality of values for determining abnormality in stages are provided as threshold values when the difference between the current command and the detected torque current value is determined as an abnormal value. is there.

  In addition, the abnormality detection unit of the present invention is characterized by measuring the duration of occurrence of the difference between the current command and the detected torque current value to determine that an abnormality has occurred.

  As described above, according to the present invention, it is possible to diagnose abnormality of an elevator structure such as a wire rope or a rail at all times while operating the elevator. In addition, when an abnormality occurs, it is possible to take safety measures such as immediately stopping the elevator operation. In addition, even at the time of abnormality diagnosis, it is possible to realize abnormality diagnosis simply by adding a function based on a simple program to an inverter control device having a conventional car position control function without adding a new member. Is.

The block diagram of the inverter apparatus which shows embodiment of this invention. Time chart of current, speed, acceleration and detected current during elevator operation. Time chart of current, speed, acceleration, and detected current during elevator operation when an abnormality occurs. The function flowchart of an abnormality detection part. Time chart at the time of abnormality judgment.

  FIG. 1 is a configuration diagram of an elevator lifting / lowering operation apparatus according to the present embodiment. Reference numeral 1 denotes a command unit that outputs a speed command that changes based on load information, acceleration information, speed information, position information, and the like necessary for elevator control to the speed control unit 2. The speed control unit 2 obtains a difference between the input speed command and the motor speed detected by the speed detector 9 and generates a current command by calculation such as PID control based on the difference.

  A difference between the generated current command and a current detection value obtained by the current transformer 6 and the current detector 7 is obtained by the adding unit 10, and this difference is input to the current control unit 3 as a torque command Tref. The current control unit 3 outputs a control command with a signal corresponding to the torque command Tref, and controls the car lifting / lowering motor 5 via the inverter 4. An encoder 8 is attached to the motor 5, and the speed detector 9 takes in the pulse signal of the encoder 8 to make a motor speed signal, and inputs this speed signal to the speed control unit 2. The motor current is detected by the current transformer 6, and the detection signal is output to the adder 10 as a current detection value (torque current detection value) via the current detector 7.

  The present invention is such that an abnormality detection unit 11 is provided in such a control device for elevator elevator operation.

  The position information in the elevator is acquired by adding simple hardware such as contact input and serial communication in a general elevator inverter. Then, before operating the elevator, for example, by raising or lowering the cage from the state where the cage is previously positioned on the lowest floor or the highest floor of the building, and by information such as the number of pulses of the encoder until the door sensor on each floor is turned on Learning driving to grasp the position of each floor. During the operation, the comparison between the position of each floor and information such as the number of pulses of the encoder is stored, and the deceleration start position and the like are calculated and stored in advance. The elevator is operated up and down by controlling the inverter based on the stored information.

  FIG. 2 shows a time chart during elevator operation. When an on command is issued to the inverter 4 at time t1, a torque current corresponding to a load required from a load sensor or the like installed in an elevator control device is shown. An Iload command (inverter output current command) is output from the command unit 1 as a command value. Further, from time t2, a torque current Iacc command corresponding to the speed command and acceleration is output from the command unit 1, and the current detection value by the current detector 7 from the starting floor to the stop floor of the car has a waveform like Il. . This current detection value Il is a waveform diagram when there is no abnormality in the wire rope, rail, or the like.

  FIG. 3 is a waveform diagram when an abnormality occurs, such as when a part of the wire rope is kinked or entangled, or an abnormality occurs in a portion of the rail. When an abnormality occurs, the running resistance increases at that portion of the car and torque ripple occurs, and this torque ripple is superimposed on the detected current value Il. The current transformer 6 detects this superimposed load current, and as a result, the absolute value of the torque command Tref calculated by the adder 10 becomes a value different from that in the normal state. The abnormality detection unit 11 captures this phenomenon and performs abnormality diagnosis.

  FIG. 4 is a flowchart of abnormality diagnosis based on the function of the abnormality detection unit 11. In S1, the torque command Tref calculated by the adder 10 is input, and the absolute value of the deviation between the torque signal generated by the speed controller 2 and the detected torque current value is calculated. In S2, it is determined whether or not the absolute value of the deviation exceeds a preset abnormality determination value. If it is within the normal determination value (False), the process proceeds to S4, but if the abnormality determination value is exceeded ( True) stores the current car position in S3, and if it exceeds the same time, the number of times is accumulated.

  In S4, it is determined whether or not the position where the abnormality has occurred is the same position as before, and if it is the same position, whether or not the number of times that the abnormality determination value has been exceeded has exceeded a preset abnormality determination value. Determine whether. If the abnormality judgment value is exceeded, it is judged that there is an abnormality in the elevator structure and the inverter operation is stopped, or an alarm is issued from the inverter controller to the elevator controller to stop at the nearest floor. Executes means such as transmission and failure processing, and safely stops at a predetermined floor even during elevator operation. If the abnormality determination value is not exceeded in S4, the process returns to S1.

  The abnormality determination in the abnormality detection unit 11 is arbitrary depending on the difference between the current command generated by the speed control unit 2 and the current detection value by the current detector 7, how many times the event occurs at the same position, etc. Set to For example, if there are several stages of abnormality determination values based on the difference between the generated current command and the current detection value, and the difference is large, stepwise determination is made even if the number of occurrences at the same position is small. Is also possible.

  Further, as a stepwise determination, when an abnormality occurs at the same car position and the absolute value of the difference is 5%, the abnormality is determined 5 times, and when the absolute value of the difference is 10%, the abnormality is determined twice. In addition to the information on the difference between the generated current command and the detected current value, the time determination effect may be added to the abnormality determination in which it is determined that the abnormality has occurred when the difference has elapsed for more than a few seconds.

  FIG. 5 is a time chart of the internal count value at the time of abnormality determination in the abnormality detection unit 11. FIG. 5A shows a state of a current detection value in which an arc-shaped torque ripple (line A) is superimposed on the load current with respect to the current command (line A), and a current detection value other than the superimposed torque ripple. Almost agrees with the current command. Th1 in FIG. 5 (b) is a threshold value of the absolute value of deviation between the current command and the detected current value. When a deviation occurs from time t11 and reaches the threshold value th1 at time t12, an abnormality occurs as shown in FIG. 5 (c). When the internal counter of the detection unit 11 starts counting and the count value becomes the threshold value th2 of the number of occurrences at time t13, it is determined as abnormal. FIG. 5 shows a method of reducing the count value at a constant change rate when the amount of absolute value of current deviation changes below a threshold value.

  As described above, according to the present invention, abnormality diagnosis of an elevator structure such as a wire rope or a rail can be performed constantly while operating the elevator. In addition, when an abnormality occurs, it is possible to take safety measures such as immediately stopping the elevator operation. In addition, even when an abnormality is diagnosed, an abnormality diagnosis can be realized by adding a function based on a simple program to a conventional inverter control device having a cage position control function without adding a new member. Is.

DESCRIPTION OF SYMBOLS 1 ... Command part 2 ... Speed calculation part 3 ... Current control part 4 ... Inverter 5 ... Motor 7 ... Current detector 9 ... Speed detector 11 ... Abnormality detection part

Claims (4)

A current command is generated based on the difference between the speed command and the detected speed value, a torque command is generated based on the difference between the current command and the detected torque current value, and the elevator car is lifted and lowered via the inverter based on the torque command. Inverter control device for controlling the inverter control device having a car position control function,
The absolute value of the current deviation is calculated from the difference between the current command and the torque current detection value, and when the absolute value of the current deviation exceeds a preset threshold value a predetermined number of times, it is determined that the elevator structure is abnormal and an abnormality detection signal An elevator diagnosis apparatus characterized in that an abnormality detection unit for outputting is provided. The abnormality detection unit stores the position of the basket when the difference between the current command and the detected torque current value exceeds a threshold value;
It is determined whether or not the position of the cage when the threshold value is exceeded is the same position, and in the case of the same position, an abnormality occurrence signal for the elevator structure is output when the threshold value for the number of occurrences set in advance is exceeded. Means,
The elevator diagnostic apparatus according to claim 1, further comprising: The abnormality detection unit is provided with a plurality of values for determining abnormality in a stepwise manner as a threshold when the difference between the current command and the torque current detection value is determined as an abnormal value. The elevator diagnostic apparatus according to 2. The elevator according to any one of claims 1 to 3, wherein the abnormality detection unit determines that an abnormality has occurred by measuring a duration of occurrence of a difference between the current command and a torque current detection value. Diagnostic device.

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