Zinc oxide valve plate analysis device in zinc oxide arrester and data processing method

Abstract

The invention discloses an analysis device for a zinc oxide valve plate in a zinc oxide lightning arrester and a data processing method. The device comprises a device shell and a shell cover which covers and is mounted at a shell opening of the device shell; a fixed electrode plate is fixed at the bottom in the device shell and is connected with a plurality of fixed electrode plate pressing rods; a movable electrode plate insulating layer is arranged above each fixed electrode plate pressing rod in the device shell, a movable electrode plate is fixed at the bottom of the movable electrode plate insulating layer, and the movable electrode plate is connected with a movable electrode plate pressing rod; the device further comprises a high-voltage tester which is electrically connected with the fixed electrode plate and the movable electrode plate. According to the method, voltage and current data are obtained through multiple times of pressurization measurement, then fitting parameters are obtained through least square method processing, the fitting parameters are compared with corresponding parameters of normal and abnormal zinc oxide valve plates, and judgment can be achieved.

Description

Technical Field

[0001] The invention relates to the field of arrester fault analysis devices in power transmission and transformation equipment of power systems, and in particular to a zinc oxide valve plate analysis device in a zinc oxide arrester and a data processing method. Background Art

[0002] Lightning arresters can release lightning or power system operation overvoltage energy to protect electrical equipment from instantaneous overvoltage hazards. Lightning arresters are composed of a body, an insulating base, leads, etc. Zinc oxide valve plates are usually used as the main components inside the arrester. In the actual use of zinc oxide lightning arresters, zinc oxide valve plates occasionally burn or even explode, affecting the safety of equipment operation. When a single-phase zinc oxide lightning arrester fails, the lightning arrester on the phase circuit is generally damaged, and the working state of the remaining phases or other similar zinc oxide lightning arresters is still uncertain. It is necessary to quickly determine whether there are potential fault points through on-site analysis of zinc oxide lightning arresters and predict the working life of the same batch of lightning arresters.

[0003] When a zinc oxide arrester fails in the 10kV and 35kV circuits in a 110kV substation, the zinc oxide arrester and the zinc oxide arresters of the same batch that are still working under the same working conditions can be disassembled, and the zinc oxide valve pieces in the zinc oxide arrester can be taken out for testing. Through the testing and analysis of the zinc oxide valve pieces, it can be determined whether there are potential faults in the zinc oxide arresters of the same batch under the same working conditions. Summary of the invention

[0004] The present invention provides a device for analyzing zinc oxide valve plates in zinc oxide arresters and a data processing method, which are applied to perform on-site fault analysis on zinc oxide arresters in 10kV and 35kV circuits in a 110kV substation, so as to judge the possibility of faults in zinc oxide arresters of the same batch and find zinc oxide arresters that have already failed. After replacing the zinc oxide arresters that have failed or are likely to fail, the operation of the power grid can be made safer and more stable.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] A zinc oxide valve plate analysis device in a zinc oxide lightning arrester comprises a device housing (1) and a housing cover (2) which is installed and covers the top shell opening of the device housing (1); a fixed electrode plate (10) is fixed at the bottom of the device housing (1), and the fixed electrode plate (10) is connected to a plurality of fixed electrode plate pressure rods (9) extending upward; a movable electrode plate insulating layer (5) is also provided above each fixed electrode plate pressure rod (9) in the device housing (1), a movable electrode plate (6) is fixed at the bottom of the movable electrode plate insulating layer (5), and the movable electrode plate (6) is connected to a plurality of movable electrode plate pressure rods (7) extending downward; a zinc oxide valve plate (8) to be tested is placed at the upper end of each fixed electrode plate pressure rod (9), and the housing cover (2) applies force to the movable electrode plate insulating layer (5), thereby causing the lower end of each movable electrode plate pressure rod (7) to be pressed against the zinc oxide valve plate (8) to be tested;

[0007] It also includes a high-voltage tester (13), which is electrically connected to the fixed electrode plate (10) and the movable electrode plate (6) respectively.

[0008] Furthermore, the housing cover (2) is connected to the movable electrode plate insulating layer (5) via a plurality of springs, whereby the housing cover (2) applies force to the movable electrode plate insulating layer (5) via the springs.

[0009] Furthermore, the lower end of the fixed electrode plate pressing rod (9) is threadedly connected to the fixed electrode plate (10), and the upper end of the movable electrode plate pressing rod (7) is threadedly connected to the movable electrode plate (6).

[0010] Furthermore, the upper end of each fixed electrode plate pressure rod (9) is in full contact with the zinc oxide valve plate (8) to be tested, and the lower end of each movable electrode plate pressure rod (7) is in full contact with the zinc oxide valve plate (8) to be tested.

[0011] Furthermore, a conductive paste is provided at the upper end of each fixed electrode plate pressure rod (9) in contact with the zinc oxide valve plate (8) to be tested, and a conductive paste is provided at the lower end of each movable electrode plate pressure rod (7) in contact with the zinc oxide valve plate (8) to be tested.

[0012] A data processing method for the zinc oxide valve plate analysis device in the above zinc oxide lightning arrester comprises the following steps:

[0013] Step 1, the high-voltage tester (13) applies a voltage to the zinc oxide valve plate (8) to be tested between the fixed electrode plate (10) and the movable electrode plate (6), and the measurement starts when the applied voltage is lower than 20% of the value obtained by dividing the overall working voltage of the zinc oxide lightning arrester by the number of valve plates, and the applied voltage makes the working current in the circuit formed by the high-voltage tester (13), the fixed electrode plate (10), the fixed electrode plate pressure rod (9), the zinc oxide valve plate to be tested (8), the movable electrode plate pressure rod (7), and the movable electrode plate (6) within the range of 0.5mA-1.5mA;

[0014] Step 2, allowing the high-voltage tester (13) to collect voltage and current data in the loop for multiple times;

[0015] Step 3, performing least squares fitting on the voltage and current data collected by the high-voltage tester (13) to obtain the intercept and slope of the fitting, and comparing the intercept and slope obtained by fitting with the corresponding data of the normal zinc oxide valve piece and the corresponding data of the abnormal zinc oxide valve piece, respectively, thereby evaluating the performance of the zinc oxide valve piece to be tested.

[0016] Furthermore, in step 1, the voltage is applied in a unidirectional and slow manner.

[0017] Furthermore, the number of collection times in step 2 is no less than 8 times.

[0018] Furthermore, in step 3, a correlation coefficient is obtained by least square fitting. When the correlation coefficient is less than 0.90, the corresponding voltage and current data collected multiple times are invalid.

[0019] The technical solution adopted by the present invention is: to propose a zinc oxide valve plate analysis device and data processing method in a zinc oxide lightning arrester. The device is used to measure the zinc oxide valve plate taken out after the zinc oxide lightning arrester is disassembled on site to obtain original measurement data, and the data processing method is used to perform least squares data processing on the original measurement data.

[0020] The beneficial effect of the present invention is that the failure causes of zinc oxide lightning arresters of the same type and the same batch are extremely similar. Therefore, when a single zinc oxide lightning arrester fails, the zinc oxide valve plate analysis device and data processing method in the zinc oxide lightning arrester proposed by the present invention can perform performance analysis on similar zinc oxide lightning arresters of the same type and the same batch, and confirm whether the remaining zinc oxide lightning arresters have common problems, so as to avoid the recurrence of failures of zinc oxide lightning arresters of the same type and the same batch. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Shown is a schematic diagram of a zinc oxide valve plate analysis device in a zinc oxide lightning arrester.

[0022] Figure 2The figure shows a plan view of the contact surface between a movable electrode plate, a fixed electrode plate and a pressure rod in a zinc oxide valve plate analysis device in a zinc oxide lightning arrester; specifically, the lower surface of the movable electrode plate and the upper surface of the fixed electrode plate.

[0023] Figure 3 The figure shows a schematic diagram of the main wiring structure of a zinc oxide valve plate analysis device in a zinc oxide lightning arrester.

[0024] Figure 4 Shown is a graph of original measurement data of a zinc oxide valve plate analysis device in a zinc oxide lightning arrester.

[0025] Figure 5 Shown is the data fitting diagram of zinc oxide valve plate after least squares data processing. DETAILED DESCRIPTION

[0026] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0027] like Figure 1 , Figure 2 , Figure 3 The figure shows a schematic diagram of a zinc oxide valve plate analysis device in a zinc oxide lightning arrester according to the present embodiment. The device is used to analyze zinc oxide valve plates in zinc oxide lightning arresters. The device includes a high-voltage tester 13, a device housing 1, and a housing cover 2 that is installed and covered at the top shell opening of the device housing 1. A fixed electrode plate 10 is fixed to the bottom of the device housing 1, and a plurality of conductive fixed electrode plate pressure rods 9 extending vertically upward are connected to the top of the fixed electrode plate 10. A movable electrode plate insulating layer 5 is also provided above each fixed electrode plate pressure rod 9 in the device housing 1, and a movable electrode plate 6 is fixed to the bottom of the movable electrode plate insulating layer 5, and a plurality of conductive movable electrode plate pressure rods 7 extending vertically downward are connected to the bottom of the movable electrode plate 6. A plurality of cylindrical grooves are provided on the top of the movable electrode plate insulating layer 5, and a spring 4 is placed in each cylindrical groove. The lower end of the spring 4 contacts the bottom of the cylindrical groove but is not fixed. The upper end of the spring 4 passes through the notch of the cylindrical groove and contacts the bottom of the outer shell cover 2 but is not fixed. In this way, the spring 4 is assembled between the movable electrode plate insulating layer 5 and the outer shell cover 2, and the spring 4 can be removed and replaced.

[0028] A fixed insulating layer 3 is also provided in the device housing 1 and surrounds the fixed electrode plate 10 , the fixed electrode plate pressure rod 9 , the movable electrode plate pressure rod 7 , the movable electrode plate 6 , and the movable electrode plate insulating layer 5 .

[0029] The zinc oxide valve sheet 8 to be tested is placed on the upper end of each fixed electrode plate pressure rod 9, and is supported on the bottom surface of the zinc oxide valve sheet 8 to be tested by each fixed electrode plate pressure rod 9, and the zinc oxide valve sheet 8 to be tested is pressed by the lower end of each movable electrode plate pressure rod 7, and the outer shell cover 2 applies force to the movable electrode plate insulating layer 5 through each spring 4, so that the lower end of each movable electrode plate pressure rod 7 is pressed tightly against the top surface of the zinc oxide valve sheet 8 to be tested.

[0030] The housing cover 2 is connected to the movable electrode plate insulating layer 5 via a plurality of springs, whereby the housing cover 2 applies force to the movable electrode plate insulating layer 5 via the springs.

[0031] A high-voltage anode terminal 11 is installed through the middle of the movable electrode plate insulating layer 5, the lower end of the high-voltage anode terminal 11 is connected to the movable electrode plate 6, and the upper end of the high-voltage anode terminal 11 passes through the housing cover 2. A high-voltage cathode terminal 12 is connected to the side of the fixed electrode plate 10, and the high-voltage cathode terminal 12 passes through the corresponding side of the device housing 1. The high-voltage tester 13 is connected to the passing ends of the high-voltage anode terminal 11 and the high-voltage cathode terminal 12 respectively, thereby realizing the electrical connection between the high-voltage tester 13 and the fixed electrode plate 10 and the movable electrode plate 6.

[0032] In this embodiment, the zinc oxide valve plate 8 to be tested comes from a disassembled zinc oxide lightning arrester.

[0033] In this embodiment, the bottom surface of the movable electrode plate 6 and the top surface of the fixed electrode plate 10 are as follows: Figure 2 As shown, a plurality of threaded holes are respectively provided on the bottom surface of the movable electrode plate 6 and the top surface of the fixed electrode plate 10, the upper end of the movable electrode plate pressing rod 7 is fixedly connected to the bottom surface of the movable electrode plate 6 by a threaded connection, and the lower end of the fixed electrode plate pressing rod 9 is fixedly connected to the top surface of the fixed electrode plate 10 by a threaded connection.

[0034] The specific number of movable electrode plate pressure rods 7 and fixed electrode plate pressure rods 9 needs to be determined according to the diameter of the zinc oxide valve plate 8 to be tested. Specifically, take out the zinc oxide valve plate 8 to be tested and measure its diameter, and judge the number of movable electrode plate pressure rods 7 and fixed electrode plate pressure rods 9 according to the diameter, and ensure that all lower ends of the movable electrode plate pressure rods 7 and upper ends of the fixed electrode plate pressure rods 9 are all pressed onto the corresponding surface of the zinc oxide valve plate 8 to be tested, that is, the lower end of each movable electrode plate pressure rod 7 is in full contact with the upper surface of the zinc oxide valve plate 8 to be tested, and the upper end of each fixed electrode plate pressure rod 9 is in full contact with the lower surface of the zinc oxide valve plate 8 to be tested. If the edge of a movable electrode plate pressure rod 7 or a fixed electrode plate pressure rod 9 exceeds the surface of the zinc oxide valve plate, the excess pressure rod must be rotated and removed.

[0035] In this embodiment, there are at least three groups of springs 4 in the zinc oxide valve plate analysis device in a set of zinc oxide lightning arresters to ensure that the movable electrode pressure rods 7 can all be pressed onto the zinc oxide valve plate 8 to be tested. Different types of springs 4 can be selected corresponding to the zinc oxide valve plates 8 to be tested with different thicknesses. Before the measurement begins, the corresponding types of springs 4 need to be selected to be suitable for the zinc oxide valve plates 8 to be tested with different thicknesses.

[0036] When measuring in this embodiment, the upper and lower surfaces of the zinc oxide valve plate 8 to be measured are all coated with conductive paste, and it is placed stably on the upper end of each fixed electrode plate pressure rod 9. Then the movable electrode plate pressure rod 7 is pressed onto the upper surface of the zinc oxide valve plate 8 to be measured. Then the selected spring 4 is placed into the hole of the movable electrode plate insulating layer 5, and the housing cover 2 is covered on the device housing 1 and tightened.

[0037] In this embodiment, the positive and negative electrodes of the high-voltage tester 13 are respectively connected to the high-voltage anode terminal 11 and the high-voltage cathode terminal 12. The high-voltage tester 13 has the ability to measure, display and record voltage and current. All personnel and items that may cause discharge around the zinc oxide valve plate analysis device in the zinc oxide lightning arrester are removed to prepare for pressure measurement. During measurement, the voltage causes the high-voltage tester 13, the high-voltage anode terminal 11, the movable electrode plate 6, the movable electrode plate pressure rod 7, the zinc oxide valve plate to be tested 8, the fixed electrode plate pressure rod 9, the fixed electrode plate 10, and the high-voltage cathode terminal 12 to form a loop.

[0038] This embodiment also discloses a data processing method based on a zinc oxide valve plate analysis device in a zinc oxide lightning arrester, comprising the following steps:

[0039] Step 1, using a unidirectional slow voltage application method, the high-voltage tester 13 applies voltage to the zinc oxide valve plate 8 to be tested between the fixed electrode plate 10 and the movable electrode plate 6, and the measurement starts when the applied voltage is lower than 20% of the value obtained by dividing the overall working voltage of the zinc oxide lightning arrester by the number of valve plates, and the applied voltage makes the working current in the circuit formed by the high-voltage tester 13, the fixed electrode plate 10, the fixed electrode plate pressure rod 9, the zinc oxide valve plate 8 to be tested, the movable electrode plate pressure rod 7, and the movable electrode plate 6 within the range of 0.5mA-1.5mA.

[0040] Step 2: Instruct the high voltage tester 13 to collect voltage and current data in the circuit for multiple times, with the number of collection times being no less than 8 times.

[0041] Step 3, perform least squares fitting on the voltage and current data collected by the high-voltage tester 13 to obtain the fitted intercept a, slope b, and correlation coefficient r. When the correlation coefficient r is less than 0.90, the corresponding multiple collected voltage and current data are invalid. When the correlation coefficient r is greater than or equal to 0.90, the intercept a and slope b obtained by fitting are compared with the corresponding data of the normal zinc oxide valve sheet (i.e., intercept and slope) and the corresponding data of the abnormal zinc oxide valve sheet (i.e., intercept and slope), respectively, to evaluate the performance of the zinc oxide valve sheet to be tested.

[0042] In the method of this embodiment, the pressure test is carried out by slowly applying voltage in one direction, and the applied voltage makes the working current in the circuit within the range of 0.5mA-1.5mA. In order to reduce the measurement error, the voltage of a single zinc oxide valve plate 8 to be tested can only be increased before the whole measurement is completed, and the voltage cannot be increased and decreased repeatedly. Since the measurement error is inevitable, multi-point measurement is adopted.

[0043] Figure 4 This is a graph of the original measurement data of a zinc oxide valve plate analysis device in a zinc oxide lightning arrester. In fact, due to measurement deviations, the current single set of 1mA data used to evaluate the performance of zinc oxide lightning arresters and zinc oxide valve plates is not objective. It is necessary to quantify a certain amount of data near 1mA to reduce measurement errors. This will make the performance evaluation of zinc oxide valve plates more objective. For the full working voltage of the zinc oxide lightning arrester, the current-voltage relationship is not linear. This is the basis for the working of the zinc oxide lightning arrester. However, in a small range, such as when the current is within 0.5mA-1.5mA, the voltage-current relationship is approximately linear, which can be used as a method for processing raw data. Therefore, this embodiment is for Figure 4 The least squares method is used to fit the original data, and the calculation formula is as follows:

[0044]

[0045] Where: x i To measure the current, y i is the measured voltage, n is the number of data samples (n is not less than 8), r is the correlation coefficient, a is the intercept, and b is the slope.

[0046] Figure 5This is the fitting diagram of the zinc oxide valve piece data after least squares data processing. The data evaluation standard consists of slope b, intercept a, and correlation coefficient r. The evaluation of the zinc oxide valve piece is carried out according to these three data. If the conventional requirements of the least squares correlation coefficient are followed, the actual needs of the actual detection of the performance of the zinc oxide valve piece cannot be met. According to actual work experience, the sampling data points must not be less than 8, and the correlation coefficient r must not be lower than 0.90, otherwise the group of data is invalid. The fitting data a and b are used to evaluate the performance of the zinc oxide valve piece to be tested. In fact, at the work site, there must be a faulty zinc oxide valve piece among the zinc oxide valve pieces disassembled and taken out of the faulty zinc oxide arrester, and there must be a normal zinc oxide valve piece among the zinc oxide valve pieces disassembled and taken out of the normal zinc oxide arrester, so the data after the least squares fitting can be used to directly compare with the corresponding data of the normal zinc oxide valve piece and the abnormal zinc oxide valve piece, and directly evaluate the performance of the zinc oxide valve piece. Then the overall performance of the zinc oxide arrester is evaluated according to the performance of the zinc oxide valve piece.

[0047] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. The embodiments described in the present invention are merely descriptions of the preferred embodiments of the present invention, and do not limit the concept and scope of the present invention. The various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction, and such combinations should also be regarded as the contents disclosed in the present disclosure as long as they do not violate the concept of the present invention. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0048] The present invention is not limited to the specific details of the above-mentioned embodiments. Within the technical concept of the present invention and without departing from the design concept of the present invention, various modifications and improvements made to the technical solution of the present invention by technical personnel in this field should fall within the protection scope of the present invention. The technical contents for which protection is sought in the present invention have been fully recorded in the claims.

Claims

1. A zinc oxide valve plate analysis device in a zinc oxide arrester, characterized in that: The device comprises a device housing (1) and a housing cover (2) which is mounted on the top shell opening of the device housing (1); a fixed electrode plate (10) is fixed at the bottom of the device housing (1), and the fixed electrode plate (10) is connected to a plurality of fixed electrode plate pressure rods (9) extending upward; a movable electrode plate insulating layer (5) is also provided above each fixed electrode plate pressure rod (9) in the device housing (1), a movable electrode plate (6) is fixed at the bottom of the movable electrode plate insulating layer (5), and the movable electrode plate (6) is connected to a plurality of movable electrode plate pressure rods (7) extending downward; a zinc oxide valve plate (8) to be tested is placed on the upper end of each fixed electrode plate pressure rod (9), and the housing cover (2) applies force to the movable electrode plate insulating layer (5), thereby causing the lower end of each movable electrode plate pressure rod (7) to be pressed against the zinc oxide valve plate (8) to be tested; It also includes a high-voltage tester (13), wherein the high-voltage tester (13) is electrically connected to the fixed electrode plate (10) and the movable electrode plate (6), respectively.

2. The zinc oxide valve plate analysis device in a zinc oxide lightning arrester according to claim 1, characterized in that: The housing cover (2) is connected to the movable electrode plate insulating layer (5) via a plurality of springs, whereby the housing cover (2) applies force to the movable electrode plate insulating layer (5) via the springs.

3. The zinc oxide valve plate analysis device in a zinc oxide lightning arrester according to claim 1, characterized in that: The lower end of the fixed electrode plate pressing rod (9) is threadedly connected to the fixed electrode plate (10), and the upper end of the movable electrode plate pressing rod (7) is threadedly connected to the movable electrode plate (6).

4. The zinc oxide valve plate analysis device in a zinc oxide lightning arrester according to claim 1, characterized in that: The upper end of each fixed electrode plate pressing rod (9) is in full contact with the zinc oxide valve plate (8) to be tested, and the lower end of each movable electrode plate pressing rod (7) is in full contact with the zinc oxide valve plate (8) to be tested.

5. The zinc oxide valve plate analysis device in a zinc oxide lightning arrester according to claim 1, characterized in that: Conductive paste is provided at the upper end of each fixed electrode plate pressure rod (9) in contact with the zinc oxide valve plate (8) to be tested, and conductive paste is provided at the lower end of each movable electrode plate pressure rod (7) in contact with the zinc oxide valve plate (8) to be tested.

6. A data processing method based on the zinc oxide valve plate analysis device in the zinc oxide arrester according to any one of claims 1 to 5, characterized in that: The following steps are involved: Step 1, the high-voltage tester (13) applies a voltage to the zinc oxide valve plate (8) to be tested between the fixed electrode plate (10) and the movable electrode plate (6), and the measurement starts when the applied voltage is lower than 20% of the value obtained by dividing the overall working voltage of the zinc oxide lightning arrester by the number of valve plates, and the applied voltage makes the working current in the circuit formed by the high-voltage tester (13), the fixed electrode plate (10), the fixed electrode plate pressure rod (9), the zinc oxide valve plate to be tested (8), the movable electrode plate pressure rod (7), and the movable electrode plate (6) within the range of 0.5 mA-1.5 mA; Step 2, instructing the high voltage tester (13) to collect voltage and current data in the circuit multiple times; Step 3: Perform a least squares fitting on the voltage and current data collected by the high-voltage tester (13) to obtain a fitted intercept and slope, and compare the fitted intercept and slope with the corresponding data of the normal zinc oxide valve piece and the corresponding data of the abnormal zinc oxide valve piece, respectively, so as to evaluate the performance of the zinc oxide valve piece to be tested.

7. The data processing method of the zinc oxide valve plate analysis device in the zinc oxide arrester according to claim 6 is characterized in that: When applying voltage in step 1, a unidirectional slow voltage application method is adopted.

8. The data processing method of the zinc oxide valve plate analysis device in the zinc oxide arrester according to claim 6, characterized in that: The number of collections in step 2 is no less than 8 times.

9. The data processing method of the zinc oxide valve plate analysis device in the zinc oxide arrester according to claim 6, characterized in that: In step 3, the correlation coefficient is also obtained by least square fitting. When the correlation coefficient is less than 0.90, the corresponding multiple collected voltage and current data are invalid.

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