JPS59198365A - Trouble detector - Google Patents

Abstract

PURPOSE:To enble an accurate detection of troubles by providing a self-diagnosing function for a A/D converter susceptible to abnormality to prevent misdetection. CONSTITUTION:An analog signal corresponding to the output voltage of an inverter 1 is applied to an A/D converter 14 to be converted into an digital signal and memorized into an RAM16. A CPU18 reads out and compares the memory contents of an ROM15 and the RAM16 to determine whether or not the output voltage of the device 1 is normal. When it is determined to be abnormal, a voltage signal of a battery 19, namely, an analog signal serving as reference is taken in and converted with a converter 14 into a digital signal, which is memorized into the RAM16 and compared with a reference value memorized into the ROM15 to determine whether or not the converter 14 operate normally. When it is determined to be normal, a trouble detection signal is provided to an output circuit 17 and actuates a protective circuit 3 to stop the device 1. On the other hand, when it is determined to be abnormal, a display ''the A/D converter is abnormal'' is given and no stop command is outputted to the device 1.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] This invention converts an analog signal corresponding to the state of a failure detection target into a digital signal, and then determines whether there is an abnormality by comparing it with the contents of a preset register. The present invention relates to a failure detection device.

[Technical Background of the Invention and Problems Therewith] FIG. 1 is a block diagram showing the configuration of a conventional failure detection device used to protect an impark device.

This failure detection device mainly includes converters 11 and 12 that output analog signals corresponding to the voltage and current on the output side of the inverter device 1 that supplies power to the load 2, and a converter 11 and 12 that select and handle these analog signals. an analog type multiplexer ratio to be input, and an A-D converter 1 that converts the analog signal taken in by the multiplexer 13 into a digital signal.
4, a ROM 15 that sets thresholds for voltage and current fluctuation ranges allowed for the inverter device 1, and an RA that stores signals digitized by the A-D converter 14.
M16, an output circuit 17 that inputs a digital signal and outputs a stop command for the inverter device 1, the multiplexer 13, the A-D converter 14, the ROM 15, and the R
, AM16, and also determines whether the inverter device 1 is normal or not and outputs the output circuit 1.
Processor circuit (hereinafter referred to as CPU) that provides an abnormality detection signal to
18).

Note that the output circuit 17 is connected to a protection circuit 3 that stops the operation of the inverter device 1;
A current transformer 10 for current detection is provided between the load 2 and the load 2 .

In FIG. 1, the voltage and current of an inverter device 1 are detected by converters 11 and 12, respectively, and simultaneously converted into an analog signal corresponding to an effective value, for example, and applied to a multiplexer 13.

Here, when the CPU 18 gives a command to the multiplexer 3 to take in the output of the converter 11, the analog signal that is the output of the converter 11 is converted into a digital signal by the AD converter 14. At the same time, CPU18
generates a write signal, this digital signal becomes R,
It is stored in AM16.

Subsequently, the CPU 18 simultaneously reads out the threshold value written in advance in the ROM 15 and the content stored in the AM16 and compares the two. When the content of the RAM 16 exceeds the threshold value in the AM15, the Add failure detection signal.

At this point, the output circuit 17 outputs a signal for operating the protection circuit 3 to stop the inverter device 1, while causing a display (not shown) to display, for example, "output voltage abnormality".

Next, when the CP 018 gives a command to the multiplexer 13 to receive the output signal of the converter 12, the same process as described above is performed, and when the current exceeds the allowable fluctuation range, the inverter device 1 is stopped. At the same time, a display (not shown) is made to display "Output current abnormality".

Therefore, in the event of a failure of the inverter device 1, the failure is maintained and at the same time, the cause of the stoppage is displayed.

Although this example describes a failure detection device that protects the inverter device 1, it is possible to use a detector other than this by using a detector capable of outputting an analog signal corresponding to the state of the failure detection target instead of the converters 11 and 12. It is also possible to detect failures in other devices.

By the way, the above-mentioned A-D converter 14 relatively often malfunctions, and even though the inverter device 1 is outputting a normal voltage, the CPU 18 determines that the output voltage is abnormal, and the impark device 1 was sometimes stopped.

In particular, when the A-D converter 14 malfunctions temporarily and the above-mentioned failure is detected as a result, it is impossible to investigate the cause of the failure.

[Purpose of the invention]

This invention was made in consideration of the above circumstances, and A-D
It is an object of the present invention to provide a failure detection device that has a self-diagnosis function to determine whether a converter is operating normally and can perform reliable failure detection.

[Summary of the invention]

In order to achieve this object, the failure detection device of the present invention includes a detector that detects the state of a failure detection target and outputs an analog signal, a signal generation means that outputs a reference analog signal, and this signal generation means. and a signal selector that selects and passes the output signal of the detector, an A-D converter that converts the output signal of the signal selector into a digital signal, and an A-D converter and the signal selector. means for controlling, means for determining whether the state of the failure detection target exceeds an allowable fluctuation range based on the output signal of the A-D converter, and a means for converting the signal of the signal generating means into a predetermined digital signal. means for determining whether or not the operation of the A-D converter is normal based on whether or not the A-D converter is operating normally; The present invention is characterized in that it includes means for generating a failure detection signal when a failure occurs.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 2 shows an example of the configuration of a failure detection device according to the present invention, in which the same reference numerals as in FIG. 1 indicate the same elements. Further, in order to add a reference analog signal to the multiplexer 13, a battery 19 is newly added as a signal generating means, and the ROM 15. RAM16.
It differs from Figure 1 in that a new function has been added to CPU1B.

The operation of the failure detection device configured as described above will be explained below with reference to the flowchart of FIG.

First, when the CPU 18 gives a command to the multiplexer 13 to take in the output signal of the converter 11, an analog signal corresponding to the output voltage of the inverter device 1 is applied to the AD converter 14. At this time, the CPU 18
When an operation command is given to the converter 14 and a write command is given to the RAM 16, this analog signal is converted into a digital signal and stored in R and AMlG.

Next, CPU 18 ROM 15: RAM 16
The stored contents are read out and compared, and it is determined whether the output voltage of the inverter device 1 is normal or not (Fig. 3 82).
.

As a result, when the output voltage of the inverter device 1 is determined to be abnormal, the CPU 18 gives a command to the multiplexer 13 to take in the voltage signal of the battery 19, that is, the reference analog signal.

This analog signal is converted into a digital signal by the AD converter 14 and stored in the RAM 16 in the same manner as described above. In this case, a value corresponding to the magnitude of the reference analog signal is written in advance in the field 0M15.

Next, the CPU 18 compares the value corresponding to the reference analog signal stored in the ROM 15 with the digitized value newly stored in the R, AM 16, and
It is determined whether the operation of the D converter 14 is normal (2) 3 (Fig. 83).

Here, if it is determined that the A-D converter 14 is operating normally, the CPU 18 gives a failure detection signal to the output circuit 17, and displays "Output voltage abnormality" on a display (not shown). (Fig. 3, 84).

Subsequently, the m-power circuit 17 outputs a signal that activates the protection circuit 3 to stop the inverter device 1 (FIG. 3, 85).
.

(Fig. 3, 86).

Further, when the CP 018 gives a command to the multiplexer 13 to take in the output signal of the converter 12, the same processing as described above is performed.

Thus, A-1) a failure detection signal is output only when the output of the converter 14 indicates a magnitude corresponding to an abnormality in the inverter device 1 and the operation of the A-D converter 14 is normal; - Even if the output of the D converter 14 shows a magnitude corresponding to an abnormality in the inverter device 1, the A-D converter 1
If the operation of No. 4 is determined to be abnormal, it is simply treated as an apparent abnormality, and of course no stop command is output to the inverter device I.

In the above embodiment, the failure detection and protection of the inverter device l was explained, but the present invention can be applied to any other device as long as it can convert a change in state due to a failure into an analog signal. can do.

〔Effect of the invention〕

As is clear from the above explanation, the failure detection device of the present invention has a self-diagnosis function for the A-ray converter, which is said to be most prone to abnormalities, and is capable of detecting errors caused by abnormalities in the A-ray converter. Detection can be prevented before it happens, and if it becomes possible to detect failures reliably, a great effect can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a conventional failure detection device together with a protection circuit to be detected. FIG. 2 is a block diagram showing the configuration of an embodiment of the failure detection device according to the present invention. The block diagram shown together with FIG. 3 is a flowchart for explaining the operation of the embodiment. DESCRIPTION OF SYMBOLS 1... Inverter device, 2... Load, 3... Protection circuit, 11, 12... Converter, 13... Multiplexer, 14... A-D converter, 15... ROM ,
16...R, AM, 17... Output circuit, 18.
...Processor circuit, 19...Battery. Applicant's agent Seitaku Inomata Figure 1 Figure 3

Claims (1)

[Claims] A detector that detects the state of the failure detection target and outputs an analog signal, a signal generating means that outputs a reference analog signal, and output signals of the signal generating means and the detector are selected and passed. a signal selector, an A-D converter that converts an output signal of the signal selector into a digital signal, a means for controlling the A-D converter and the signal selector, and an output of the A-D converter. means for determining whether the state of the failure detection target exceeds an allowable fluctuation range based on the signal; and operation of the A-D converter depending on whether the signal of the signal generating means is converted into a predetermined digital signal. The device comprises means for determining whether or not it is normal, and means for generating a failure detection signal when the state of the failure detection target exceeds an allowable variation range and the A-D converter is operating normally. A failure detection device characterized by: