JPS6242070A - Insulation deterioration degree diagnosing device - Google Patents

Abstract

PURPOSE:To easily diagnose an insulation deterioration degree at high accuracy and to prevent a production line from being stopped for a long period by detecting each parameter showing the insulation deterioration degree of a high voltage electronic equipment during driving. CONSTITUTION:A sensor 11 detects a leaked current and a corona discharge in the high voltage electronic equipment in operation, and a signal showing the corona discharge is led to an arithmetic part 25 through a BPF 12, slicers 14-18 and counters 20-24. Then a total power amount being a parameter showing a void deterioration is calculated and given to a designating part 27. Due to the output of a highest level counter 24, an arithmetic part 28 calculates a maximum discharged electric charge amount being a parameter showing the void deterioration and gives it to a designating part 29. On the other hand, the signal showing the leaked current is digitized 31, and given as a leaked current amount being a parameter showing the moisture adsorption deterioration to a designating part 32. The output of the counter 24 is also given to an arithmetic part 33. Then a general deterioration index being a parameter showing the general insulation deterioration regarding the void deterioration is calculated according to the prescribed equation, and given to a designating part 35.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement of an insulation deterioration degree diagnosing device for high-voltage electrical equipment such as high-voltage motors and high-voltage cables.

[Conventional technology]

Generally, if high-voltage electrical equipment related to a production line stops functioning due to a winding failure such as insulation deterioration, the production line will be out of operation for a long period of time, and there is a risk of suffering great damage. Therefore, it is desirable to update high-voltage electrical equipment that has reached the end of its lifespan and whose insulation has deteriorated as soon as possible, but updating requires a huge amount of cost. For this reason, it is required to diagnose the degree of insulation deterioration with high reliability and to take economical measures according to the degree of insulation deterioration, such as one-time varnish treatment, renewal, etc.

Incidentally, insulation deterioration can be roughly divided into two types: hygroscopic deterioration and void deterioration. When hygroscopic deterioration occurs, insulation resistance decreases, and when void deterioration occurs, corona discharge occurs in the voids.

Therefore, conventionally, the DC test method and dielectric loss tangent test method (described later) have been used.
It has been common practice to diagnose the degree of insulation deterioration based on moisture absorption deterioration or void deterioration of high-voltage electrical equipment using four methods: tan δ test method (hereinafter referred to as tan δ test method), alternating current test method, and corona test method.

The DC test method calculates the polarization index PI (PI - [insulation resistance value 10 minutes after the start of DC current]/[1 minute after the start of DC current) from the insulation resistance value measured by a DC high voltage tester. Insulation resistance value]) is determined and only moisture absorption deterioration is diagnosed based on this polarization index PI, and when moisture absorption deterioration occurs, the polarization index PI becomes smaller.

The tan δ test method is based on the applied AC voltage and the dielectric loss tangent ta.
It diagnoses hygroscopic deterioration and void deterioration from the relationship with nδ, and when hygroscopic deterioration occurs, tan
When δ increases and void deterioration occurs, tan δ increases at a predetermined applied voltage.

The AC test method diagnoses insulation from the relationship between the applied AC voltage and the magnitude of the detected current, and when void deterioration occurs, the slope of the current increase curve changes due to corona tIl electricity. rapidly increasing.

The corona test method is based on the applied alternating current voltage and the maximum discharge charge f.
The insulation property is diagnosed from the relationship with fl Q max or dielectric 'vJfaQo, and when void deterioration occurs, the maximum discharge charge m Q max or the amount of dielectric charge QO increases.

[Problem that the invention seeks to solve]

However, all of the above four methods require a large-scale measuring device, take a long time to measure, and are extremely expensive, so they lack simplicity. Further, it has the disadvantage that it is not reliable and can only be carried out when the high-voltage electrical equipment is stopped.

Therefore, the present invention is capable of easily and highly accurately diagnosing the degree of insulation deterioration of high-voltage electrical equipment while the equipment is in operation.
The purpose of the present invention is to provide an insulation deterioration degree diagnostic device that can prevent long-term operation stoppages of production lines due to malfunctions of high-voltage electrical equipment, and can economically carry out maintenance according to the degree of insulation deterioration. do.

[Means for solving problems]

The present invention is characterized by taking the following measures in order to solve the above problems and achieve the objects. That is,
A detector detects the leakage current amount and corona discharge amount of the electric device during operation, and predetermined signal processing is performed on the output signal from this detector based on the leakage current amount and corona discharge amount to create a parameter that indicates insulation deterioration. Moisture deterioration degree as
The present invention is characterized in that a degree of void deterioration and a total degree of deterioration are detected, and the degree of insulation deterioration of the electrical equipment is diagnosed according to the degree of deterioration of at least one of the degree of moisture absorption deterioration, the degree of void deterioration, and the total deterioration degree. .

Note that the void deterioration degree is detected based on the total discharge charge amount or the maximum discharge charge amount of the corona discharge ω.

Note that the overall degree of deterioration is calculated by performing predetermined calculation processing on the maximum discharge charge amount during corona discharge.

[Effect]

By taking such measures, various parameters indicating insulation deterioration of the high-voltage electrical equipment during operation can be detected easily and with high accuracy.

〔Example〕

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention. In the figure, 11 is a sensor that detects wet current and corona discharge in high-voltage electrical equipment in operation. Leakage current is detected using a Hark tester, and corona discharge is detected wirelessly using an antenna or the like. To detect. Reference numeral 12 denotes a band-pass filter (
(hereinafter abbreviated as BPF), and in this example, 100
It is designed to extract signals from H2 to 2MH2. The output terminal of this BPF 12 is connected to an amplifier 13, and the output terminal of the amplifier 13 is connected to a plurality of (five in this embodiment) slicers 14 to 18. The slicers 14 to 18 divide the output signal of the amplification 513 into predetermined levels by a level setter 19.
The signals divided by v1 at 4 to 18 are sent to each counter 2o to 2.
Counted by 4. Above, counters 20 to 24
Each output terminal is connected to the dielectric charge calculating section 25. This dielectric charge calculating section 25 calculates each set level v1 to v5 of the slicers 14 to 18 and each count of the counters 20 to 24! The capacitance input section 26 is connected to each product of IN1 to N5.
The total sum is calculated by integrating predetermined capacitances C given by . That is, ΣVn-Nn・C
Perform the calculation. The dielectric charge ff1Qo as a parameter indicating void deterioration, that is, the result of the arithmetic processing in the dielectric charge calculation section 25, is then instructed to the dielectric charge instruction section 27.

Also, a counter 24 counts the output of the slicer 18 set to the maximum level among the slicers 14 to 18.
The output of is also connected to the maximum discharge charge calculating section 28. The maximum discharge charge calculating section 28 is configured to integrate the product of the set level V5 of the slicer 18 and the count value N5 of the counter 24 by a predetermined capacitance C' given from the capacitance input section 26. Then, the calculation processing result in the maximum discharge charge calculating section 28, that is, the maximum discharge charge ji Q n + ax as a parameter indicating void deterioration is as follows:
Instructs two maximum discharge charge instructing sections.

On the other hand, the output signal indicating the leakage current detected by the sensor 11 is outputted to the rectifier circuit 30, converted to a digital value by an analog-digital converter (hereinafter abbreviated as A/D) 31, and then converted to a digital value. The current indicator 32 indicates the leakage current level, which is a parameter indicating moisture absorption deterioration.

Further, the output terminal of the counter 24 is the total insulation deterioration due to void deterioration and moisture absorption deterioration, that is, the total deterioration layer r&IS.
It is also connected to a comprehensive deterioration index calculation unit 33 that performs the performance.

The output terminal of the capacitance input section 26 is also connected to the comprehensive deterioration index calculation section 33. This comprehensive deterioration index calculation unit 3
3 performs calculation processing using a predetermined calculation formula according to the output from the counter 24 regarding void deterioration and the output from the capacitance input section 26 and the various constant input section 34 regarding moisture absorption deterioration. The result, that is, the overall deterioration index rS as a parameter indicating the overall insulation deterioration is:
An instruction is given to the comprehensive deterioration index instruction section 35.

Next, the dielectric charge calculation section i 25. R large discharge charge calculation section 28
．． Evaluation of the calculation processing results in the comprehensive deterioration index calculation section 33 will be explained.

Figures 2 (a) to (C) show high-voltage electrical equipment with uniformly shaped voids (indicated by the solid line in the figure) and high-voltage electrical equipment with voids of various shapes (indicated by the broken line in the figure). ), whereas conventional corona test method (a), tan δ test method (b)
) is a diagram showing data obtained by the alternating current test method (C).

In addition, Figures 3 (a) to (C) show how the conventional high-voltage electricity meter (indicated by the solid line in the figure) in a dry state and the high-voltage electrical equipment (indicated by the broken line in the figure) that has deteriorated due to moisture absorption Corona test method (a), tan δ test method (b), alternating current test method (C)
It is a figure which shows the data calculated|required by.

In addition, corona test (Figure 2 (a) and Figure 3 (a))
For the data, the vertical axis represents the number of corona occurrences CDS, the horizontal axis represents the corona size Q (coulombs), and the data for the tan δ test method (Figures 2 (b) and 3 (b)) are shown on the vertical axis. to
Jan 5, the horizontal axis shows the applied voltage V, and the data of the AC voltage test method (Figure 2 (C) and Figure 3 (C)) shows the current I (mA) on the vertical axis, and the applied voltage V on the horizontal axis. is taking. In addition, in Fig. 2(a), "3" means that the applied voltage is 3KV.
(7) If r4Jt, t4KV17) in, "5"
shows an example of 5KV.

These figures 2(a) to (C) and 3(a) to (C)
) The following ■～■ can be understood from the data results shown in ).

■ From the data results in FIG. 2(a), the characteristics obtained by the corona test change depending on the form of void generation. Therefore, it is necessary to correct this characteristic change when diagnosing void deterioration.

(2) From the data results shown in FIGS. 2(a) to (C), it can be assumed that there is a correlation among the respective test methods, considering the characteristic patterns of the corona test method, AC test method, and tan δ test method.

(2) From the data results shown in FIGS. 3(a) to ('C), the data of the corona test method, tan δ test method, and alternating current test method vary depending on the state of moisture absorption deterioration.

Therefore, it is necessary to correct the degree of void deterioration depending on humidity or temperature.

Therefore, considering the contents of ■ to ■ above, we calculated the correlation between the degree of insulation deterioration and the detected amount of leakage current and the detected amount of corona discharge, and performed calculation processing using multi-variable surface analysis with coefficients assigned according to this correlation. By doing so, highly accurate insulation deterioration diagnosis becomes possible. Therefore, the dielectric charge calculating section 25. By configuring the function of the maximum discharged charge calculation unit 4 28° comprehensive deterioration index indicating unit 33 based on the above, each parameter indicating insulation deterioration is sieved with good viscosity.

Thus, according to this embodiment, leakage current and corona discharge are detected by the sensor 11 for high-voltage electrical equipment in operation, and after predetermined calculation processing is performed, the processing result, that is, the parameter indicating insulation deterioration, is Load instruction section 27. Maximum discharge charge instruction section 29. Since the leakage current indicator 32 and the comprehensive deterioration index indicator 35 are instructed, the degree of insulation deterioration of high-voltage electrical equipment can be easily and accurately diagnosed. Furthermore, since the configuration of this embodiment is as shown in FIG. 1, it is possible to reduce the size and to easily diagnose. As a result, it is possible to easily and accurately grasp the state of insulation deterioration before the high-voltage electric weapon stops functioning due to insulation deterioration, making it possible to prevent long-term shutdowns of the production line, as well as prevent maintenance due to insulation deterioration (varnish treatment 2 volumes). It also has the effect of being able to perform economical changes (replacement, renewal).

Note that the present invention is not limited to the above embodiments.

For example, in the embodiment described above, there are two methods for diagnosing void deterioration: specifying the dielectric charge country and specifying the maximum discharge charge, but only one of them may be used. Further, as a means for diagnosing the above-mentioned void deterioration, as shown in FIG. Void deterioration may be diagnosed by giving an instruction. Alternatively, the output of the sensor 11 or the output of the BPF 12 may be subjected to predetermined waveform processing in the waveform processing section 43 and then diagnosed using the oscilloscope 44. It goes without saying that various other modifications can be made without exceeding the essential scope of the present invention.

〔Effect of the invention〕

As described in detail above, the present invention detects the amount of leakage current and the amount of corona discharge of electrical equipment during operation using a detector, and outputs a predetermined signal from the detector based on the amount of leakage current and corona discharge. The degree of moisture absorption deterioration, the degree of void deterioration, and the overall degree of deterioration are detected as parameters indicating insulation deterioration through processing, and the degree of moisture absorption deterioration, the degree of void deterioration, and!
The degree of insulation deterioration of the electrical equipment is diagnosed according to the degree of deterioration of at least one of the deterioration degrees of 8 cases.

Therefore, according to the present invention, each parameter indicating the degree of insulation deterioration of the high-voltage electric R unit during operation can be detected easily and with high accuracy. This is an insulation deterioration degree diagnostic device that can prevent long-term operation stoppages of production lines due to malfunction of electrical equipment, and can economically carry out maintenance according to the degree of insulation deterioration. can be provided.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, and FIGS. 4 are block diagrams showing a modification of the present invention. 11...Sensor, 12...Band pass filter (B
PF), 13...Amplifier, 14-18...Slicer, 19...Level setter, 20-24...Counter, 25...Dielectric charge calculation section, 26...Capacitance input Section, 27... Dielectric charge instruction section, 28... Maximum discharge charge calculation section, 29... Maximum discharge charge instruction section, 30... Rectifier circuit, 31... Analog-digital converter (A
/D), 32...Wetting current instruction section, 33...Comprehensive deterioration index instruction section, 34...Constant input section, 35...Comprehensive deterioration index instruction section, 41...Envelope peak value Detection unit,
42... Envelope beak rti instruction section, 43... Waveform processing section, 44... Oscilloscope. Applicant's agent Patent attorney Takehiko Suzue (a) (b)
(c) Figure 2 (a) (b) (c) Figure 3

Claims (4)

[Claims] (1) A detector that detects leakage current and corona discharge of electrical equipment during operation, and a parameter that indicates insulation deterioration by performing predetermined signal processing on the output signal from this detector based on the leakage current amount and corona discharge amount. Moisture deterioration degree as
insulation deterioration parameter detection means for detecting the void deterioration degree and the total deterioration degree; An insulation deterioration degree diagnosing device comprising an insulation deterioration degree diagnosing means for diagnosing the degree of insulation deterioration of equipment. (2) The insulation deterioration parameter detection means for detecting the degree of void deterioration detects the degree of void deterioration based on the total discharge charge amount of the corona discharge amount.
) Insulation deterioration diagnosis device described in section 2. (3) The insulation deterioration parameter detection means for detecting the degree of void deterioration detects the degree of void deterioration based on the maximum discharge charge amount of the corona discharge amount.
1) The insulation deterioration diagnosis device described in item 1). (4) The insulation deterioration parameter detection means for detecting the overall degree of deterioration calculates the total deterioration by performing predetermined calculation processing on the maximum discharge charge amount of the corona discharge amount. ) Insulation deterioration diagnosis device described in section 2.