JP2013123275A - Variable-speed drive device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a development period and cost by arranging a function for detecting a fault or failure of hardware or the like to necessary minimum devices.SOLUTION: A variable-speed drive device comprises: a normal arithmetic unit 2 for performing arithmetic processing on the basis of a normal parameter; a normal memory 3 for storing the normal parameter; a safety arithmetic unit 4 which performs arithmetic processing on the basis of a safety parameter and can communicate with the normal arithmetic unit 2; a safety memory 5 for storing the safety parameter; a PC loader 7 and an operation panel 6 which are connected to the arithmetic units 2 and 4 and perform setting, change, and display of the normal and safety parameters, respectively; and data error detection means 8 and 9 for checking data validity. A safety standard-compliant safety parameter transmitted from the PC loader 7 is: received through the data error detection means 8 and 9 and displayed, by the operation panel 6; and stored in the safety memory 5 after determining that the safety parameter is valid when the safety parameter displayed on the operation panel 6 corresponds to a safety parameter displayed on the PC loader 7.

Description

  The present invention relates to a variable speed drive apparatus that drives a load such as an electric motor with a power converter at a variable speed, and more particularly to a variable speed drive apparatus having an emergency stop function as a safety function.

FIG. 5 shows a conventional safety device applied to a power converter that drives a motor at a variable speed.
In FIG. 5, reference numeral 100 denotes a power converter, which includes a main circuit 110 that performs AC-DC-AC conversion, a control board 120, and a safety function board 130. Here, the control board 120 and the safety function board 130 are also components of the safety device 150.
The main circuit 110 includes a rectifier circuit 111, an inverter unit 112, and a smoothing capacitor 113. The rectifier circuit 111 is connected to an AC power source via a connector 161, and the inverter unit 112 is connected to an electric motor via a connector 162.

  The control board 120 includes a calculation means 121 such as a microcomputer, a gate circuit 122 that generates a gate signal for the semiconductor switching element of the inverter unit 112, and a type identification circuit 123 that outputs a gate cutoff signal and an operation permission signal. . Various commands such as an operation / stop command for the power converter 100, a speed detection signal, and an external input / output signal are exchanged via the connector 163 between the calculation unit 121 and the outside. The type identification circuit 123 is for identifying the type (safety standard) of the safety function board 130 connected to the control board 120.

The safety function board 130 has, for example, a safe torque-off function (function for emergency stopping the motor) in accordance with the European safety standard ISO13849-1, etc., and the arithmetic means 131 composed of a logic circuit or the like is connected via a connector 164 from outside. A safety torque-off command is input as a safety related command.
The control board 120 and the safety function board 130 are connected by a connector 165, and a type identification signal, a safe torque-off command, and the like are exchanged between the type identification circuit 123 and the calculation means 131 via the connector 165. It has become.
The safety function board 130 is not limited to the one conforming to the safety standard, and a safety function board having various functions can be connected to the control board 120 via the connector 165.

In this prior art, the type identification circuit 123 sends a reference signal to the calculation means 131 of the safety function board 130 connected to the control board 120, and the calculation means 131 sends the type identification signal of the safety function board 130 to the type identification circuit. Reply to 123. Based on the returned type identification signal, the type identification circuit 123 identifies whether the board 130 is a safety function board of a predetermined standard determined in advance. As a result, in the case of a safety function board of a predetermined standard, an operation permission signal is sent to the calculation means 121 to permit the power conversion operation by the main circuit 110, and if not, a gate cutoff signal is sent to the gate circuit 122. The control signal from the calculation means 121 is forcibly interrupted to stop the power conversion operation.
Thereby, the driving | operation of the power converter 100 in the state in which the inappropriate safety function board | substrate was connected can be prevented beforehand.

Further, when a safety torque-off command is input from the outside as a safety-related command to the safety function board 130, the calculation means 131 sends this safety torque-off command to the type identification circuit 123. Similarly to the above, a gate cutoff signal is sent to the gate circuit 122 to forcibly cut off the control signal from the computing means 121.
Thereby, even when the calculation 121 in the control board 120 runs away or breaks down, the operation of the main circuit 110 can be stopped reliably and the motor can be stopped in an emergency.

JP 2011-8642 A (paragraphs [0022] to [0034], FIG. 1 and the like)

  Now, the above-described safe torque-off command is generated based on various safety parameters required for emergency stop of the electric motor to ensure safety. For example, when an emergency stop command for the motor is input to the control device, the motor starts decelerating, and when the speed reaches a predetermined speed, the predetermined speed when the motor is free-runned is set to “SS1 level”, or There is known a safe operation in which the above-mentioned predetermined time when the electric motor is free-runned after the elapse of a predetermined time after the emergency stop command is input to the control device is the “SS1 timer”. "Is a kind of the safety parameter.

The set values (speed, time, etc.) of these safety parameters are appropriately changed as necessary. However, the safety parameters such as the arithmetic device, the setting display device, the storage device, etc. When a failure occurs, the safety parameter may be set to a value not intended by the user, and as a result, an appropriate safety operation may not be executed.
For this reason, conventionally, it is necessary to provide the above-mentioned various devices and software with a function for detecting the occurrence of a failure or failure, and these have to be developed in accordance with a process for preventing design errors and the like.
In other words, in the past, all devices and software related to the setting and changing of safety parameters have to be equipped with a function to detect hardware and software abnormalities. There was a problem of becoming.

  SUMMARY OF THE INVENTION Accordingly, the problem to be solved by the present invention is to provide a variable speed drive device that allows a minimum necessary device to have a function of detecting a hardware or software failure or failure, thereby shortening the development period and reducing the cost. There is.

In order to solve the above problems, the invention according to claim 1 is a normal arithmetic device that performs arithmetic processing based on normal parameters necessary for basic control for driving a load at a variable speed;
A normal memory for storing the normal parameters;
A safety arithmetic device that performs arithmetic processing based on a safety parameter on a predetermined safety standard necessary for emergency stop of the operation of the load, and that can communicate with the normal arithmetic device;
A safety memory for storing the safety parameters;
A first setting display device connected to the normal arithmetic device for setting, changing, and displaying the normal parameters and safety parameters;
A second setting display device connected to the safety calculation device for setting, changing, and displaying the normal parameter and the safety parameter;
First data error detection means provided between the normal arithmetic unit and the first setting display device for checking the validity of data;
A second data error detection means provided between the safety arithmetic unit and the second setting display device for checking the validity of the data,
The safety parameter in accordance with the safety standard displayed and transmitted by one of the first and second setting display devices is displayed on the other setting via the first and second data error detection means. The safety parameter is received and displayed by the device, and when the safety parameter displayed on the first and second setting display devices matches, the safety parameter is determined to be appropriate and stored in the safety memory.

  According to a second aspect of the present invention, in the variable speed drive device according to the first aspect, the first data error detecting means and the second data error detecting means detect errors by different detection methods.

  According to the present invention, both the setting display means for setting, changing, and displaying the safety parameter and the data error detecting means provided in the path for transmitting the safety parameter to the computing means are made redundant, so that It is not necessary to provide a function for detecting an abnormality of hardware or software in all devices and software related to setting, changing, etc. In addition, it is possible to set and change appropriate safety parameters in accordance with safety standards without developing hardware and software in accordance with a process for preventing design errors, etc. Reduction is possible.

It is a block diagram which shows 1st Embodiment of this invention. It is a block diagram which shows 2nd Embodiment of this invention. It is a block diagram which shows 3rd Embodiment of this invention. It is a block diagram which shows 4th Embodiment of this invention. It is a block diagram which shows a prior art.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
First, FIG. 1 is a block diagram showing a first embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a variable speed drive device such as a power converter for driving a motor (not shown). Note that a main circuit and the like for performing power conversion by an on / off operation of the semiconductor switching element and supplying a predetermined voltage to the electric motor are not shown for convenience.

The variable speed drive device 1 includes a normal calculation device 2, a normal memory 3, a safety calculation device 4, and a safety memory 5.
The normal arithmetic unit 2 controls the operation of the main circuit based on normal parameters and output signals of various sensors (speed sensor, current sensor, voltage sensor, etc.) and performs various calculations for driving the motor at a variable speed. For example, an operation for generating a drive pulse of the semiconductor switching element of the main circuit by PWM control is executed. Here, the normal parameters are a motor control method, an operation command, an acceleration / deceleration time, a torque limit value, and the like, and are parameters necessary for basic control for driving the motor at a variable speed. Is normally stored in the memory 3.

The safety calculation device 4 performs various calculations for performing processing related to the emergency stop of the motor based on the safety parameters and the output signals of the various sensors. An operation for setting the run state is executed. Here, the safety parameters include the aforementioned “SS1 level” and “SS1 timer” based on a predetermined safety standard, and these safety parameters are stored in the safety memory 5.
The normal arithmetic device 2 and the safety arithmetic device 4 can communicate with each other.

Further, the normal arithmetic device 2 and the safety arithmetic device 4 are provided with connecting means 10 and 11 such as connectors for connecting an operation panel 6 described later.
The connection means 10 is for connecting the operation panel 6 to the normal arithmetic device 2, but when the operation panel 6 is exclusively connected to the safety arithmetic device 4, the connection means 10 on the normal arithmetic device 2 side is not necessary. Therefore, the connection means 10 can be omitted as in the second embodiment shown in FIG.

  A PC loader 7 serving as a first setting display device is connected to the normal arithmetic device 2 via the first data error detection means 8, and the safety arithmetic device 4 is connected to the connection means 11 and the second data error detection. An operation panel 6 as a second setting display device is connected via the means 9.

Here, the PC loader 7 is for setting, changing, and displaying normal parameters and safety parameters from the outside of the variable speed driving device 1, and is a general-purpose personal computer provided with a loader function. For example, a USB connection terminal is used for connection between the PC loader 7 and the variable speed drive device 1.
The operation panel 6 is also used to set, change, and display normal parameters and safety parameters from the outside of the variable speed drive device 1. In this embodiment, for example, a programmable operation display (POD) is assumed. However, a PC loader other than the PC loader 7 may be used instead of the operation panel 6.
It is desirable that the operation panel 6 and the PC loader 7 have a password lock function.

  The data error detection means 8 and 9 are means for realizing an error detection method such as CRC (Cyclic Redundancy Check) and check SUM, for example. In this case, the detection methods of the two detection means 8 and 9 may be the same. For example, the first data error detection means 8 performs error detection by CRC, and the second data error detection means 9 checks SUM. The detection methods of the two detection means 8 and 9 may be made different so as to perform error detection.

Next, the operation of the first and second embodiments will be described.
The feature of these embodiments is that the setting display means is made redundant so that the PC loader 7 and the operation panel 6 can set, change and display safety parameters, etc. Further, the redundant data error detecting means 8 and 9 The data transmission error can be detected.

Here, for example, the safety parameter changing means defined in the European safety standard ISO13849-1 is the following two points.
(1) Means for controlling hardware and software failures and faults (2) Appropriate means other than communication data error detection means for confirming the integrity of safety parameters Among the above (1), hardware faults As for the control means for the failure, the setting display means made redundant by the PC loader 7 and the operation panel 6 makes it possible to maintain a sound one even if one of the setting display means loses its function due to a failure or failure. The safety parameter can be reliably set, changed, and displayed by the setting display means.
Among the above (1), regarding the means for controlling software failures and faults, one of the detection means can detect an error due to a fault or fault by the redundant data error detection means 8 and 9. Even if not, the error can be reliably detected by the other healthy detection means.

  As an appropriate measure regarding the above (2), as a means for confirming the integrity of the safety parameter transmitted from one setting display means (PC loader 7 or operation panel 6), the other setting display means (operation panel 6 or PC). By displaying the safety parameter on the loader 7), the user can confirm that the safety parameter is an inappropriate safety parameter that is not intended due to a failure or failure.

The specific operation of the first and second embodiments is as follows.
First, a safety parameter based on a safety standard suitable for the variable speed drive device 1 is transmitted from the PC loader 7 to the normal arithmetic device 2, and the data error detection means 8 checks the validity of the safety parameter at that time. The normal calculation device 2 transmits the safety parameter received from the PC loader 7 and checked for validity to the safety calculation device 4.
Next, the safety arithmetic unit 4 transmits the safety parameter to the operation panel 6 via the connection unit 11, and the data error detection unit 8 checks the validity of the safety parameter at that time.

The user visually compares the safety parameter displayed on the PC loader 7 with the safety parameter displayed on the operation panel 6 and confirms that they match, and then the safety parameter is stored in the safety memory 5. A write operation for writing to the PC loader 7 is performed.
Through a series of these operations, it is possible to prevent a safety parameter unintended by the user from being written to the safety memory 5 due to a failure or failure.

  The above operation is the same when a safety parameter is transmitted from the operation panel 6 to the safety computation device 4 and is transmitted from the safety computation device 4 to the PC loader 7 via the normal computation device 2. After confirming that the safety parameter displayed on the screen matches the safety parameter displayed on the PC loader 7, a write operation for writing the safety parameter to the safety memory 5 is performed on the operation panel 6 or the PC loader 7. You can do it from

  When the safety parameter is transmitted from the PC loader 7 to the normal arithmetic unit 2, even if the safety parameter is changed to an unintended value due to noise failure, for example, the abnormality can be detected by the data error detecting means 8. it can. Even if one of the data error detecting means 8 cannot detect an abnormality, the other data error detecting means 9 can detect the abnormality, or the safety parameter displayed on the PC loader 7 and the operation panel 6 can be detected. Abnormalities can be detected from inconsistencies with the displayed safety parameters.

As described above, according to the present embodiment, since the setting display means for setting, changing, and displaying the safety parameter is made redundant by the PC loader 7 and the operation panel 6, one hardware has failed or failed. Even in this case, an appropriate safety parameter can be stored in the safety memory 5 by the processing by the other healthy hardware, and the safe operation can be performed according to the safety parameter.
In addition, these abnormalities can be detected by the redundant data error detection means 8 and 9 for software failures and faults and safety parameter failures resulting from the failure.

Next, FIG. 3 is a block diagram showing a third embodiment of the present invention.
This embodiment is different from the first embodiment of FIG. 1 in that the connection points of the PC loader 7 and the operation panel 6 are exchanged, and the PC loader 7 is connected to the safety arithmetic device 4 via the connection means 11. The operation panel 6 is connected to the normal arithmetic device 2.
The PC loader 7 and the operation panel 6 have substantially the same function as the setting display means in the present invention, and the operation of the third embodiment can be easily inferred from the first embodiment described above, and thus the description thereof is omitted. To do.
Note that when the PC loader 7 is connected exclusively to the safety arithmetic device 4 via the connecting means 11, the connecting means 10 on the normal arithmetic device 2 side is not necessary, and as in the fourth embodiment shown in FIG. The connecting means 10 may be omitted.

1: Variable speed drive device 2: Normal operation device 3: Normal memory 4: Safety operation device 5: Safety memory 6: Operation panel 7: PC loader 8, 9: Data error detection means 10, 11: Connection means

Claims (2)

A normal arithmetic device that performs arithmetic processing based on normal parameters required for basic control for driving the load at a variable speed; and
A normal memory for storing the normal parameters;
A safety arithmetic device that performs arithmetic processing based on a safety parameter on a predetermined safety standard necessary for emergency stop of the operation of the load, and that can communicate with the normal arithmetic device;
A safety memory for storing the safety parameters;
A first setting display device connected to the normal arithmetic device for setting, changing, and displaying the normal parameters and safety parameters;
A second setting display device connected to the safety calculation device for setting, changing, and displaying the normal parameter and the safety parameter;
First data error detection means provided between the normal arithmetic unit and the first setting display device for checking the validity of data;
Second data error detection means provided between the safety arithmetic unit and the second setting display device for checking the validity of data;
With
The safety parameter in accordance with the safety standard displayed and transmitted by one of the first and second setting display devices is displayed on the other setting via the first and second data error detection means. When the safety parameters received and displayed by the device match the safety parameters displayed on the first and second setting display devices, the safety parameters are judged to be appropriate and stored in the safety memory. Variable speed drive. In the variable speed drive device according to claim 1,
A variable speed drive device, wherein the first data error detection means and the second data error detection means detect errors by different detection methods.

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