JPH0311916A - Digital protective relay device - Google Patents

Abstract

PURPOSE:To allow this device to make preventive repairs by determinating whether a defective phenomenon is a single-shot one, or it is a forerunner of defect or it is already defective from the generation frequency of the defective phenomenon or from the difference between the amplitude value and the reference value of AC input quantity. CONSTITUTION:This device is composed of a defect detection means 11 to detect a defective phenomenon of a device, a frequency measurement means 12 to measure the generation frequency of the detected defective phenomenon, a defect determination means 13 whether or not the defective phenomenon is caused in a single-shot one from the defect generation frequency and an output means 14 to alarm for display and to output externally respectively that it detected the forerunning phenomenon of defect in device or the defect in device as a result of determination by the defect determination means 13. That is to say, the device determines whether it is a single-shot defect or a forerunner of defect or it is already a defect from the generation frequency or the difference of AC quantity. The defect in device can thereby be detected in advance, so that a preventive repair of the applicable defective region can well be made accordingly.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a digital protective relay device for protecting a power system.

(Prior Art) In digital protective relay devices, device failures are detected by an automatic monitoring function. At this time, confirmation is performed using a predetermined method to avoid excessively detecting defects due to isolated defects, and an alarm is displayed or an external output is performed only when it is determined that the device is in a completely defective state.

(Problem to be Solved by the Invention) Once a device defect occurs, the device is put out of use and the defective part is repaired before use is started. However, from the time the defect occurs until the repair is completed, Utilization efficiency decreases due to inability to operate.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a digital protective relay device that enables preventive repair by detecting signs of device failure and improves the utilization efficiency of the device. The purpose is

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention uses system voltage and current values that are sampled at predetermined time intervals and converted into digital quantities to generate electric power. A digital protective relay device for protecting a power system includes a first means for detecting a defective phenomenon in the device, and a second means for measuring the frequency of occurrence of the defective phenomenon or the difference between the amplitude value of the AC input amount and a reference value. a third means for determining from the occurrence frequency or difference whether the defective phenomenon is a one-off event, a precursor to a device defect, or a device defect; and fourth means for performing external output according to the determination result.

(Function) First, when a device failure occurs, the frequency of occurrence or the difference between the amplitude value of the AC input amount and the reference value is determined.

Then, it is determined from the frequency of occurrence or the difference in the amount of alternating current whether it is a one-off defect, a sign of a defect, or a defect, and an external output is performed according to the determination result.

(Example) The present invention will be described in detail below with reference to the drawings.

FIG. 1 shows a first example of a digital protective relay device according to the present invention.
FIG. 2 is a functional block diagram of an embodiment of the present invention. In FIG. 1, a digital protective relay device 10 includes a defect detection means 11 for detecting a defective phenomenon in the device, a frequency measuring means 12 for measuring the frequency of occurrence of the detected defective phenomenon, and a frequency measuring means 12 for measuring the occurrence frequency of the detected defective phenomenon. a failure determination means 13 for determining whether the phenomenon is a one-off event, a precursor phenomenon of a device failure, or a device failure; and detecting a precursor phenomenon of a device failure according to the determination result of the determination means 13; or output means 14 for displaying an alarm and outputting to the outside that a device failure has been detected.
It consists of

FIG. 2 shows a flowchart showing the details of the process for detecting a precursor phenomenon of device failure. The content shown in FIG. 2 is an example in which each of the means 11, 12, 13, and 14 shown in FIG. 1 is configured by software.

In FIG. 2, in step 821, the program ROM
Calculate the sum of data within. In step S22, the total sum determined in step 321 is compared with the previously determined total sum, and if they do not match, a checksum determination is performed in which it is determined that the data in the ROM has changed. In step S23, it is measured how many times a failure occurs within a predetermined period of time. In step 324, it is determined whether or not it is a one-off calculation error based on the number of failure occurrences. If it is determined that it is a one-time failure, the process is terminated, and if it is determined that it is not a one-time failure, the process proceeds to step 325. In step S25, the number of failure occurrences is determined. Determine whether the data in the ROM is changing from time to time as a precursor to a defect, or if the ROM has become completely defective.
If it is determined that the phenomenon is a precursor to a ROM defect, the process proceeds to step S28, and if it is determined that the ROM is defective, the process proceeds to step S26. In step 326, an alarm is displayed to indicate that a device failure has been detected. Step S27
In this case, an external output indicating that a device defect has been detected is performed.

In step 828, an alarm is displayed to indicate that a sign of device failure has been detected, and in step 829, an external output is provided to indicate that a sign of device failure has been detected.

FIG. 3 shows the second embodiment of the digital protective relay device according to the present invention.
FIG. 2 is a functional block diagram of an embodiment of the present invention. In FIG. 3, the digital protective relay 23o includes an amplitude value measuring means 31 for measuring the amplitude value of the AC input amount, a difference measuring means 32 for measuring the difference between the amplitude value and a reference value, and a difference measuring means 32 for measuring the difference between the amplitude value and a reference value. a failure determination means 33 for determining whether the phenomenon is a one-off phenomenon, a precursor phenomenon of a device failure, or a device failure, and detecting a precursor phenomenon of a device failure according to the determination result of the determination means 33; or an output means 34 for displaying an alarm and outputting to the outside that a device failure has been detected.

FIG. 4 shows a flowchart showing the contents of the process for detecting a precursor phenomenon of device failure.The contents shown in FIG. be.

In step S41, a predetermined test input is applied to the AC input circuit, and the amplitude value of the test input is calculated.

In step 842, the difference between the calculated value of the amplitude value and a reference value determined in advance is calculated. In step 343, it is determined whether the difference obtained in step S42 is within an allowable error, and if it is determined that it is within the error, the process is terminated, and if it is determined that it is not within the error, the process proceeds to step S44. In step 844, it is determined based on the magnitude of the difference whether the difference obtained in step S42 is a value that indicates a sign of a defect in the AC input circuit or a value that has occurred due to a defect in the AC input circuit, and If it is determined that the phenomenon is a precursor to a circuit failure, the process proceeds to step 347, and if it is determined that the AC input circuit is defective, the process proceeds to step S45. In step 845, an alarm is displayed to indicate that a device defect has been detected, and in step 846, an external output is provided to indicate that a device defect has been detected. Step 347
Then, an alarm is displayed to indicate that a sign of equipment failure has been detected. In step 348, an external output is provided indicating that a sign of device failure has been detected.

In the first embodiment described above, an example of detecting a program ROM failure using a checksum was explained as an example of device failure detection. It can also be applied to general self-monitoring functions such as detection of data errors.

In addition, in the second embodiment, an example of detecting a defect in an AC input circuit using test input was explained as an example of detecting a device defect.
It can also be applied to general AC input circuit monitoring functions such as monitoring the three-phase balanced state of voltage and current taken in from the actual system, or monitoring zero-sequence voltage and zero-sequence current.

All of the above is an example configured by software processing, but similar functions can also be configured by hardware.

[Effects of the Invention] As explained above, according to the present invention, since a device is configured to distinguish between a device failure and a sign of a device failure, a device failure can be detected beforehand, and preventive repair of the defective part can be performed. Therefore, it is possible to provide a highly efficient digital protective relay device that can minimize the period of outage due to device failure.

[Brief explanation of the drawing]

FIG. 1 shows a first example of a digital protective relay device according to the present invention.
FIG. 2 is a flowchart showing the processing contents of the first embodiment, FIG. 3 is a block diagram of the second embodiment of the digital protective relay device according to the present invention, and FIG.
The figure is a flowchart showing the processing contents of the second embodiment. 10, 30... Digital protective relay device 11...
Defect detection means 12... Frequency measurement means 13, 33
...Defect determination means 14.34...Output means 31.
... Amplitude value measuring means 32... Difference measuring means. , Digitaire Shapeho 1 bulb genus i=+1 Fig. 3 Fig. 2-78 Fig. 4

Claims (2)

[Claims] (1) In a digital protective relay device that protects a power system using system voltage and current values that are sampled at predetermined time intervals and converted into digital quantities, the first step is to detect a defective phenomenon in the device. a second means for measuring the frequency of occurrence of the defective phenomenon; and a second means for measuring the frequency of occurrence of the defective phenomenon; and a second means for measuring the frequency of occurrence of the defective phenomenon; A digital protective relay device comprising: third means for determining based on the frequency of occurrence; and fourth means for outputting to the outside according to the determination result of the third means. (2) In a digital protective relay device that protects a power system using system voltage and current values that are sampled at predetermined time intervals and converted into digital quantities, a first means for measuring an amplitude value; a second means for measuring a difference between the measured value and a reference value; and whether the difference is an allowable error or a precursor to a device failure. Or, it is characterized by comprising a third means for determining whether the difference is caused by a device defect based on the magnitude of the difference, and a fourth means for performing an external output according to the determination result of the third means. Digital protective relay device.