JP2015024867A - Elevator control device and elevator system - Google Patents

Abstract

An elevator control device and an elevator system using the same can expand a dynamic range of a detected current according to the capacity of an electric motor without increasing the circuit scale. A current detector for detecting a current flowing in an electric motor driving an elevator, a current detection circuit for outputting a signal corresponding to a value of the electric motor current detected by the current detector, and a current detection circuit. Based on the signal output from 111, control circuit sections 114 to 120 that control inverter device 107 that drives electric motor 106, and gain adjustment circuit 112 that arbitrarily changes the gain of current detection circuit 111 according to the gain switching signal. And a gain switching signal creation circuit 113 that creates a gain switching signal based on the capacity of the electric motor 106. [Selection] Figure 1

Description

  The present invention relates to an elevator control device that controls an electric motor of an elevator and an elevator system using the same.

  The inverter device that rotationally drives the elevator motor is controlled based on the current flowing through the motor. As means for detecting a current flowing through an electric motor, a hall current transformer (hereinafter referred to as HCT) is known. The HCT includes a Hall element that detects a magnetic flux generated by a current, and a current detection circuit that amplifies a voltage signal output from the Hall element and outputs an analog signal corresponding to a current value. The analog signal output from the current detection circuit is input to a control circuit unit that creates a control signal for the inverter device. Since the control signal is created by signal processing by the microcomputer, the analog signal output by the HCT is converted into a digital signal by the A / D converter at the input stage of the control circuit unit.

  In an elevator, it is preferable to use HCT of the same specification for several types of electric motors for ease of design and cost merit. For this reason, HCT with a wide dynamic range is required. However, since the gain of the current detection circuit in the HCT is uniquely set according to the specifications of the Hall element and the A / D converter, if the gain of the HCT is set in accordance with the motor having a large capacity, the motor having a small capacity In, the current detection resolution is reduced.

  As general means for improving current detection resolution, A: Use an A / D converter with high resolution, B: Change the number of turns of HCT, C: Gain suitable for each motor capacity Can be specially designed. The means A causes an increase in cost. Since the means B involves human work, there is a concern that yield and reliability may be reduced if the number of turns is changed for each motor capacity. The means C causes an increase in cost and man-hours.

  Further, in the case of an elevator, since the motor capacity is generally selected from the maximum speed and the maximum load capacity, when the elevator is operated at a low speed or a low load capacity, the resolution of current detection is lowered.

  As a conventional technique corresponding to the above problems, there is a technique described in Patent Document 1. In the present technology, a current detection signal detected by a current detector is amplified to create a plurality of signals having different gains. One signal is selected from the plurality of signals in consideration of the accuracy of the current detector. As a result, the dynamic range of current detection is expanded.

Japanese Patent Laid-Open No. 10-17222

  In the prior art described in Patent Document 1, since the current detection signal detected by the current detector is amplified to generate a plurality of signals having different gains, the number of amplifiers and gain adjusting resistors used increases. . For this reason, the size and cost of the control device increase.

  Therefore, the present invention provides an elevator control device and an elevator system using the same that can expand the dynamic range of current detection without increasing the circuit scale.

  In order to solve the above problems, an elevator control apparatus according to the present invention includes a current detector that detects a current flowing through an electric motor that drives an elevator, and an electric signal that is output from the current detector. A current detection circuit that outputs a signal corresponding to the detected current value; and a control circuit unit that controls an inverter device that drives the electric motor based on the signal output by the current detection circuit; Furthermore, a gain changing means for arbitrarily changing the gain of the current detection circuit in accordance with a gain switching signal, and a signal creating means for creating the gain switching signal based on the capacity of the motor.

  The elevator system according to the present invention includes an electric motor, an inverter device that drives the electric motor, a sheave rotated by the electric motor, a rope wound around the sheave, and a lift driven by the rope driven when the sheave rotates. And a control device that controls the inverter device, and the control device is the elevator control device according to the present invention.

  According to the present invention, since the gain of the current detection circuit is changed by a gain switching signal generated based on the motor capacity, the dynamic range of current detection can be expanded without increasing the circuit scale. As a result, the speed and torque of the electric motor can be controlled with high accuracy, so that the riding comfort of the elevator is improved.

  Problems, configurations, and effects other than those described above will become apparent from the following description of embodiments.

1 shows an overall configuration of an elevator system according to an embodiment of the present invention. A specific configuration example of the gain adjustment circuit is shown. Another specific configuration example of the gain adjustment circuit will be shown. It is a flowchart which shows the flow of a process of an elevator control apparatus.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows an overall configuration of an elevator system including an elevator control device as one embodiment of the present invention.

  In this figure, 101 is a commercial power source, 102 is a converter device that rectifies the commercial power source 101, 103 is a smoothing capacitor that smoothes the voltage rectified by the converter device 102, 104 is an elevator car that services the floors of the building, Reference numeral 105 denotes a counterweight, 106 denotes an electric motor that moves the car 104 up and down, 107 denotes an inverter device that drives and controls the electric motor 106, 108 denotes a current detector that detects a current flowing through the electric motor 106, and 109 denotes a load on the car 104 A load detector 110 detects the rotation speed of the electric motor 106 and an encoder that detects the position of the car 104. In addition, the circuit unit with 111 to 113 constitutes a current detection device 300 that outputs a detected value of the current flowing through the motor, and the circuit unit and operation unit with 114 to 120 give a control command to the inverter device 107. The control circuit unit to be created is configured.

  The elevator control apparatus in this embodiment includes these current detection unit and control circuit unit. As the current detector 108, the Hall element described above or a general current transformer (CT) can be applied.

  The three-phase AC voltage of the commercial power supply 101 is rectified by the converter device 102 and the voltage pulsating by the smoothing capacitor 103 is smoothed to obtain a constant DC voltage. The inverter device 107 converts this DC voltage into an AC voltage in accordance with a control command created by the elevator control device, and outputs the AC voltage to the electric motor 106. When the electric motor 106 is rotated by the AC voltage supplied from the inverter device 107, the sheave 400 mechanically connected to the electric motor 106 is rotated. When the sheave 400 rotates, the rope 401 wound around the sheave 400 is driven, and the car 104 attached to the rope 401 moves up and down in the hoistway.

  In the present embodiment, the converter device 102 includes a diode rectifier. The inverter device 107 converts a DC voltage into an AC voltage by controlling on / off of a semiconductor switching element such as an IGBT (Insulated Gate Bipolar Transistor).

  Next, a control circuit unit that performs feedback control of the electric motor 106 will be described.

  Based on the speed command value created by the operation control command unit 116 and the speed detection value of the electric motor 106 detected by the encoder 110, the operation control calculation unit 117 rotates the rotation coordinates so that the speed detection value approaches the speed command value. Create a current command value in the system. The current control calculation unit 118 receives a current detection value in the rotating coordinate system calculated by the three-phase two-phase coordinate conversion unit 115 from the detection current value converted into a digital signal by the AD converter 114, and an input from the operation control calculation unit 117. Based on the current command value to be generated, a voltage command in the rotating coordinate system is created so that the detected current value approaches the current command value in the rotating coordinate system. The voltage command in the rotating coordinate system created by the current control calculation unit 118 is converted into a three-phase AC voltage command by the two-phase / three-phase coordinate conversion unit 119. The PWM generator 120 compares a three-phase AC voltage command with a triangular wave to generate a pulse width modulation (hereinafter abbreviated as PWM) signal for on / off control of the semiconductor switching element of the inverter device 107. Output.

  As described above, so-called vector control is employed in the control circuit unit in the present embodiment. Further, the control circuit unit in the present embodiment is configured by an arithmetic processing device such as a microcomputer.

  Next, the current detection device 300 will be described.

  The current detection circuit 111 performs signal processing such as amplification on the electric signal output from the current detector 108 according to the magnitude of the current flowing through the electric motor 106, and a voltage signal having a magnitude corresponding to the value of the detected current. Is output. The gain adjustment circuit 112 outputs a voltage signal obtained by adjusting the amplitude of the voltage signal input from the current detection circuit 111 with a gain corresponding to the gain switching signal created by the gain switching signal creation circuit 113.

  Here, the gain switching signal generation circuit 113 is in accordance with the capacity value of the electric motor 106 stored in advance in a storage device (not shown), or this value and the load load value of the car 104 detected by the load detector 109. The gain signal is adjusted so that the voltage signal output from the gain adjustment circuit 112 takes a maximum value within the input voltage range of the A / D converter 114 with respect to the maximum current flowing through the motor 106 according to Create a switching signal. This improves the current resolution.

  As described above, the voltage signal output from the gain adjustment circuit 112, that is, the analog signal indicating the detected current value flowing through the motor 106, is converted into a digital signal by the AD converter 114, and is transmitted to the control circuit unit in the elevator control device. Used for current control.

  FIG. 2 shows a specific configuration example of the gain adjustment circuit 112. Reference numerals 201 and 202 denote resistors for adjusting the gain, 203 denotes a gain switching signal, and 204 denotes an operational amplifier.

  The gain is set by the ratio (R2 / R1) between the resistance value R1 of the fixed resistor 201 and the resistance value R2 of the variable resistor 202. Here, it is assumed that the HCT corresponding to the current detector 108 and the current detection circuit 111 in FIG. 1 is used and its specification (input current / output voltage), that is, sensitivity is 100 A / 4V. If R2 / R1 = 1, the gain of the operational amplifier 204 is set to 1, so that the operational amplifier 204 has a voltage of the same magnitude as the voltage output by the HCT, that is, a voltage of up to 4 V for a current of up to 100 A. Output. Therefore, the sensitivity of the current detection device 300 (FIG. 1) including the gain adjustment circuit 112 is the same as that of the HCT. Further, if R2 / R1 = 2, the gain of the operational amplifier 204 is set to 2, so that the operational amplifier 204 has a voltage twice as large as the voltage output by the HCT, that is, up to 8V for a current up to 100A. Is output. Therefore, the sensitivity of the current detection device 300 is twice that of HCT. That is, as shown in FIG. 2, the value of R1 is fixed using the fixed resistor 201, and the value of R2 is changed using the variable resistor 202, thereby changing the current detection sensitivity even when the same HCT is used. be able to.

  In this embodiment, as shown in FIG. 2, the resistance value of the variable resistor 202 is changed by a control signal such as a digital potentiometer, and gain switching generated by the gain switching signal generation circuit 113 (FIG. 1). The gain corresponding to the gain switching signal 203 is set by changing the resistance value R2 of the variable resistor 202 using the signal 203 as a control signal.

  As described above, the gain switching signal 203 is created by the gain switching signal creation circuit 113. At this time, the gain switching signal generation circuit 113 stores in advance information related to the specifications of the electric motor 106, that is, power capacity, rated speed, load capacity (load load), etc., in a storage device such as a semiconductor memory, and supplies power to the elevator system. When a trigger such as turning on occurs, the maximum current flowing through the motor is obtained from these pieces of information. Further, the gain switching signal generation circuit 113 is configured such that the output voltage of the operational amplifier 204, that is, the gain adjustment circuit 112 is close to the upper limit of the allowable input voltage of the A / D converter 114 with respect to the output voltage of the current detection circuit 111 with respect to the maximum current. A resistance value R2 that provides such a gain is obtained. Furthermore, the gain switching signal creation circuit 113 creates a gain switching signal that is a control signal for setting the resistance value of the variable resistor 202 to the obtained R2, and the gain switching circuit 112 of the variable resistor 202 Send to control terminal.

  According to the present embodiment, as described above, the sensitivity of the current detection device 300 is automatically adjusted based on the specifications or performance information including the capacity of the motor stored in advance in the elevator control device. It can be changed according to the full scale of the input voltage. Thus, it is not necessary to provide a plurality of current detection circuits having different gains in order to cope with a plurality of types of motor capacities, and the resolution of current can be improved by adding a simple circuit. Therefore, the dynamic range of current detection can be increased without increasing the circuit scale. In addition, it is possible to detect current with high accuracy for a plurality of types of current capacities, and it is possible to control operation of any capacity of motor with high accuracy. Further, since the current detection resolution is improved, the pulsation of the motor current can be detected with high accuracy during the normal operation of the elevator. As a result, the speed and torque of the electric motor can be controlled with high accuracy, so that the riding comfort of the elevator is improved.

  Further, according to the present embodiment, for a plurality of types of motor capacities, a plurality of current detectors and current detection circuits are provided, replaced or changed one by one, or human work is required for these. There is no. Therefore, the reliability of the elevator control device including the current detection device is improved.

  FIG. 3 shows another specific configuration example of the gain adjustment circuit. In this configuration example, the variable resistor includes a plurality of fixed resistors 202A to 202C and a plurality of semiconductor switches 205A to 205B. In this configuration example, three fixed resistors 202A to 202C are connected to each other in series. Semiconductor switches 205A and 205B are connected in parallel to fixed resistors 202A and 202B, respectively. The gain switching signal creation circuit 113 is an arithmetic processing unit such as a microcomputer and outputs a gain switching signal as a control signal for the semiconductor switches 205A and 205B.

  The semiconductor switches 205A and 205B are turned on / off according to the gain switching signal, and when turned on, the fixed resistors connected in parallel are short-circuited. Therefore, for example, if the resistance values of the fixed resistors 202A to 202C are each R1, the resistance value R2 of the variable resistor is any one of R1, R2, R3. Therefore, the gain (= R2 / R1) of the operational amplifier 204 can be set to one of 1, 2, and 3. Therefore, also in this configuration example, the sensitivity of the current detection device can be changed according to the gain switching signal. Other operations and the operations and effects provided thereby are the same as those of the gain adjustment circuit shown in FIG.

  In the present embodiment, the sensitivity of the current detection device can be changed based on information stored in advance regarding the specification or performance of the electric motor, and in addition to this, based on the loading capacity in the car at the time of elevator service. The process which the elevator control apparatus in this embodiment performs including this point is demonstrated below.

  FIG. 4 is a flowchart showing a flow of processing of the elevator control device in the present embodiment.

  When the elevator power is turned on (step S100), the elevator control device extracts information on the specifications or performance of the motor stored in the storage device in advance during the initial processing (step S200), and sends it to the arithmetic processing unit. Transfer (step S300). Next, it is determined whether there is a hall call from an arbitrary floor (step S400). If it is determined that there is no hall call (step S400, NO), the process of step S400 is repeatedly executed. If it is determined that the passenger has pressed the hall call button and registered the hall call (step S400, YES), the car is dispatched to the floor where the passenger waits.

  When the car arrives and the passenger gets into the car (step S500), the load in the car changes, so the load detector 109 (FIG. 1) detects the load in the car (step S600). ), The detected value is transferred to the storage device and taken in (step S700). In step S700, the gain switching signal generation circuit 113 (FIG. 1) uses the detection value of the load loaded in the storage device in this step and information on the specifications or performance of the motor stored in advance. Then, the maximum value of the current flowing through the electric motor is obtained with respect to the detected value of the loaded load, and a gain switching signal is created according to the maximum value. Then, the sensitivity of the current detection device is changed by changing the resistance value of the variable resistor 202 by the gain adjustment circuit 112 according to the created gain switching signal. For example, when the loading load detected with respect to the maximum loading capacity is small, the sensitivity of the current detection device is increased and the current resolution is increased.

  In the present embodiment, since the gain is adjusted from when the loaded load in the car is detected until the elevator operation is started, that is, when the elevator car is stopped, the gain switching is performed in the elevator. Does not affect driving conditions.

  Next, it is determined whether or not the car door and the landing door have been closed (S800). When it is determined that the door closing has not been completed (step S800, NO), the processes after step S600 are repeatedly executed. If it is determined that the door closing has been completed (step S800, YES), the motor is driven and controlled with the changed current detection sensitivity, and the operation of the elevator is started (step S900). When the car lands on the destination floor of the passenger, that is, the destination floor (S1000), the elevator control device repeatedly executes the processes after step S400.

  As described above, according to the present embodiment, specifications or performance (power capacity, rated speed, load capacity (load load), etc.) are registered in advance in the storage device of the elevator controller for each motor having different capacities. Based on this, since the optimum current detection sensitivity can be set for each electric motor, the dynamic range of the detection current can be expanded without changing the specifications of the current detector and the A / D converter. Further, when the loading state in the car is detected and the motor current is smaller than the rated value, the sensitivity of the current detection device can be increased and the current resolution can be increased. As a result, it is possible to drive and control the electric motor with high accuracy, so that a good riding comfort can be obtained.

  In addition, this invention is not limited to embodiment mentioned above, Various modifications are included. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Further, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

  For example, in step S300 of FIG. 4, after a gain switching signal is generated based on the motor specifications and the gain is adjusted, the gain may be adjusted again based on the detected load value in S700. Further, the converter device 102 in FIG. 1 may use a semiconductor switching element such as an IGBT.

101 ... Commercial power supply, 102 ... Converter device, 103 ... Smoothing capacitor,
104 ... car, 105 ... balance weight, 106 ... electric motor, 107 ... inverter device,
108: current detector 109: load detector 110: encoder
111 ... Current detection circuit, 112 ... Gain adjustment circuit, 113 ... Gain switching signal generation circuit,
114 ... A / D converter, 115 ... three-phase two-phase coordinate conversion unit, 116 ... operation control command unit,
117: Operation control calculation unit, 118: Current control calculation unit, 119 ... Two-phase / three-phase coordinate conversion unit,
120 ... PWM generator, 201 ... fixed resistor, 202 ... variable resistor,
202A, 202B, 202C ... fixed resistor, 203 ... gain switching signal,
204: operational amplifier, 205A, 205B ... semiconductor switch, 300 ... current detection device,
400 ... Sheave, 401 ... Rope

Claims (6)

A current detector for detecting the current flowing in the electric motor that drives the elevator;
A current detection circuit that outputs a signal corresponding to the value of the current detected by the current detector based on the electrical signal output by the current detector;
Based on the signal output from the current detection circuit, a control circuit unit that controls an inverter device that drives the electric motor;
In an elevator control device comprising:
Gain changing means for arbitrarily changing the gain of the current detection circuit according to a gain switching signal;
Signal generating means for generating the gain switching signal based on the capacity of the motor;
An elevator control device comprising: In the elevator control device according to claim 1,
In addition, it has a load detector that detects the load in the car,
The elevator control device characterized in that the signal generating means generates the gain switching signal based on the capacity of the electric motor and the load load detected by the load detector. In the elevator control device according to claim 1 or 2,
The elevator control device characterized in that the signal generating means generates the gain switching signal while the elevator is stopped. An electric motor, an inverter device for driving the electric motor, a sheave rotated by the electric motor, a rope wound around the sheave, a car driven up and down by the rope driven when the sheave rotates, the inverter device An elevator system comprising:
The controller is
A current detector for detecting a current flowing through the electric motor;
A current detection circuit that outputs a signal corresponding to the value of the current detected by the current detector based on the electrical signal output by the current detector;
A control circuit unit for controlling the inverter device based on the signal output from the current detection circuit;
Gain changing means for arbitrarily changing the gain of the current detection circuit according to a gain switching signal;
Signal creating means for creating the gain switching signal based on the capacity of the motor;
An elevator system comprising: The elevator system according to claim 4,
The control device further includes a load detector for detecting the load in the car,
The elevator system according to claim 1, wherein the signal creating means creates the gain switching signal based on the capacity of the electric motor and the loaded load detected by the load detector. In the elevator system according to claim 4 or 5,
The elevator system according to claim 1, wherein the signal creating means creates the gain switching signal while the elevator is stopped.

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