JPH09227037A - Ac elevator controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve ride comfortableness in an AC elevator controller which conducts elevator speed control with a general-purpose inverter by inserting a filter at the subsequent stage of a speed command generating means, and setting time constant of the filter automatically with operated result of a motor constant operating means. SOLUTION: When an elevator operating start command is inputted in an inverter controller 11, a speed command 12a is outputted from a speed command generating part 12 and converted to a frequency command 13a through a frequency command converter 13. The frequency command 13a passes through the filter 14 whose time constant is preset to an appropriate value. When the motor constant operating mode is selected, current flows through an induction motor 6, and based on the detecting signal of a current detector 5 at that time, a motor constant operation is conducted at a motor constant operation part 16. Based on the operation result, an appropriate time constant is determined by a filter time constant setting part 17, thus it is possible to obtain a smooth speed pattern in the induction motor 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a control device for an AC elevator that drives an induction motor with a general-purpose inverter to control the speed of the elevator.

[0002]

2. Description of the Related Art At present, inverter devices are widely used for variable speed control of AC motors such as induction motors and synchronous motors. Recently, among these inverter devices, the one generally called "general-purpose inverter"
The range of application is expanding due to the higher performance and higher functionality that accompany recent improvements in the performance of switching elements and microprocessors.

As a control method for this general-purpose inverter, V / f control has been widely adopted from the past. The V / f control is an open loop control method, and it is not necessary to detect the rotation speed of the electric motor. Therefore, even in the case of an existing AC motor, it is not necessary to attach a speed detector to the motor, and variable speed operation can be performed simply by connecting a general-purpose inverter between the AC power source and the motor. Therefore, when speed control is performed using this general-purpose inverter without speed sensor,
It can be applied to the speed control of the elevator because it can save the labor of mounting the speed detector, can realize a simple control configuration, and has a large cost advantage.

In this general-purpose inverter, a speed pattern is generated by preset acceleration / deceleration in the inverter, and in addition, in order to obtain a smoother speed pattern, the speed is changed by a trapezoidal wave acceleration / deceleration pattern. The function to change the is generally provided.

Further, in a general-purpose inverter without a speed sensor, speed fluctuations occur due to load fluctuations. Therefore, it is becoming possible to estimate the load by current detection or the like and to have a function of compensating for the speed fluctuations. In order to perform load estimation calculation using this function, it is necessary to set a motor constant. So, in this general-purpose inverter,
The motor constant calculation mode is built in beforehand, and when the motor constant calculation mode is selected from the outside with the inverter and the motor connected, a current is automatically supplied to the motor,
It also has the function of calculating the motor constant based on the detection signal.

[0006]

When the elevator speed is controlled by using a general-purpose inverter that changes the speed according to the acceleration / deceleration pattern of the trapezoidal wave, the change of the torque at the portion corresponding to the corner of the trapezoidal wave is generated by the cage. And deteriorates the riding comfort. Therefore, when this general-purpose inverter is applied to an elevator, it is not enough to use the speed command as a trapezoidal wave acceleration / deceleration speed pattern, and it is necessary to further smooth the speed command.

The present invention has been made to solve the above problems, and utilizes a motor constant calculation function to
The purpose is to make the acceleration / deceleration pattern of a general-purpose inverter even smoother and to improve the riding comfort when applied to an elevator.

[0008]

SUMMARY OF THE INVENTION The present invention uses a general-purpose inverter internally provided with a speed command generating means for outputting a speed pattern of trapezoidal wave acceleration / deceleration as a speed command, and a motor constant calculating means. In a control device for an AC elevator that performs control, a filter is inserted in the latter stage of the speed command generating means, and a time constant of the filter is automatically set using the calculation result of the motor constant calculating means. It is equipped with means.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, a filter as a first-order lag element is inserted in the subsequent stage of a speed command generating section so that the speed command becomes smoother, and a trapezoidal wave of a trapezoidal wave acceleration / deceleration speed pattern is generated. Improves riding comfort at the corners. Furthermore, the time constant of this filter is automatically set to an appropriate value by the filter time constant setting unit by using the calculation result of the motor constant calculation function provided inside beforehand.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an overall configuration diagram showing an embodiment of the first invention of the present application.

In FIG. 1, 1 is a three-phase AC power supply, 2 is a converter for converting the AC power supply into DC, 3 is a smoothing capacitor for smoothing the output of this converter, and 4 is a converter 2.
For converting the output of AC into an AC of variable voltage and variable frequency, 5 is a current detector for detecting the output current of each phase of the inverter 4, 6 is an induction motor which is fed by the inverter 4 and drives an elevator, 7 is an induction motor 6 A sheave of a hoisting machine driven by, 8 is a main rope wound around the sheave 7,
Reference numeral 9 is a car coupled to the main ropes 8, 10 is also a counterweight, 11 is an inverter control device composed of a microcomputer, 12 is a speed command generator for generating a predetermined speed command signal 12a, and 13 is a speed command signal. 12a is a frequency command conversion unit that converts the inverter output frequency command 13a, 14 is a filter as a first-order lag element, and 15 is a slip frequency that outputs a compensation amount according to the motor load from the output current of the inverter as a slip frequency command 15a. Arithmetic unit,
When a motor constant calculation mode is selected from the outside, 16 is a motor constant calculation unit that automatically supplies a current to the motor and calculates the motor constant based on the detection signal at that time.
Is a filter time constant setting unit for calculating and setting the optimum time constant of the filter from the motor constant calculated by this motor constant calculating unit, and 18 is input by adding the frequency command 13a and the slip frequency command 15a through the filter. Then, the required inverter operating frequency and voltage are calculated, and the corresponding PWM
A voltage / frequency calculator that generates a signal, 19 is the PWM
It is a base drive circuit that controls a switching element such as a transistor that constitutes an inverter according to a signal.

The operation of the present invention having the above configuration will be described. When an elevator operation start command (not shown) is input to the inverter control device 11, the speed command generation unit 12 outputs the speed command 12a, and the frequency command conversion unit 13 converts the speed command into a frequency command 13a. By passing this frequency command through the filter 14, the corner portion of the trapezoidal wave of acceleration / deceleration is also smoothed. Waveforms of the frequency command waveform before and after passing through the filter are shown in FIG.

In FIG. 2, (a) shows the frequency command before passing through the filter and the waveform of the acceleration / deceleration pattern at that time.
(B) shows the frequency command after passing through the filter and the waveform of the acceleration / deceleration pattern at that time.

The time constant of the filter must be set to an appropriate value in advance, but this setting is performed as follows.

First, when the motor constant calculation mode is selected from the outside by a switch or the like (not shown), a current automatically flows through the induction motor 6, and the motor constant is calculated based on the detection signal of the current detector 5 at that time. The calculation unit 16 calculates a motor constant. Using this calculation result, the filter time constant setting unit 17 calculates an appropriate filter time constant from the balance between the time required for acceleration / deceleration of the elevator and the riding comfort, and stores the value.

By passing through the filter set in this way, it is possible to obtain a velocity pattern in which the corner portion of the trapezoidal wave acceleration / deceleration is also smoothed without unnecessarily increasing the time required for acceleration / deceleration.

[0017]

According to the present invention, even if the speed command in the general-purpose inverter is used, the riding comfort can be improved without unnecessarily increasing the time required for acceleration / deceleration. Moreover, since the time constant of the filter used for that purpose was set using the motor constant calculation function built in the general-purpose inverter in advance, the comfort of the elevator can be easily adjusted at each site without any trouble. Can be improved.

[Brief description of drawings]

FIG. 1 is a diagram showing an overall configuration of the present invention.

FIG. 2 is a diagram showing waveforms of a frequency command and an acceleration / deceleration pattern before and after passing through a filter in the present invention, respectively.

[Explanation of symbols]

 1 Three-phase AC power supply 2 Converter 3 Smoothing capacitor 4 Inverter 5 Current detector 6 Induction motor 9 Cage 11 Inverter control device. 12 Speed Command Generation Section 13 Frequency Command Conversion Section 14 Filter 15 Sliding Frequency Calculation Section 16 Motor Constant Calculation Section 17 Filter Time Constant Setting Section 18 Voltage / Frequency Calculation Section

Claims (1)

[Claims] 1. An AC elevator control device for controlling the speed of an elevator using a general-purpose inverter internally provided with a speed command generation means for outputting a speed pattern of trapezoidal wave acceleration / deceleration as a speed command and a motor constant calculation means. At
And a filter time constant setting means for automatically setting a time constant of the filter by using a calculation result of the motor constant calculating means, while inserting a filter after the speed command generating means. AC elevator control device.