Solution method based on abnormality of on-load tap changer position

Abstract

The application discloses a solution method based on abnormal tap of on-load tap changer, and relates to the technical field of on-load tap changer of transformer, which comprises S1, inquiring specific information of on-load tap changer; S2, determining position; S3, visual position reference; S4, detecting position; S5, manual adjustment of tap; S6, confirmation of turns; and S7, end of debugging. The solution method based on abnormal tap of on-load tap changer detects voltage ratio by using a variable ratio tester, and uses a visually observable electric mechanism tap indicator as a reference, which is beneficial to detecting whether the tap is abnormal, and after the electric mechanism tap indicator is consistent with the actual position of the switch electric mechanism, the number of turns M of the rotating shaft after the switch from high tap to low tap and from low tap to high tap is observed, and the closer the two numbers of turns M, the more accurate the tap indication, thereby solving the problem that the tap is chaotic and cannot be accurately adjusted.

Description

Technical Field

[0001] This invention relates to the field of on-load tap changer technology for transformers, specifically to a solution for abnormal on-load tap changer positions. Background Technology

[0002] On-load tap changers, as key accessories for adjusting transformer voltage amplitude, have been widely used for nearly a century. The quality of maintenance and testing of on-load tap changers directly affects the stable and reliable operation of transformers. In many applications, on-load tap changers need to be frequently and extensively adjusted to meet the power quality requirements of customers or loads.

[0003] In the current maintenance and testing of on-load tap changers, it is impossible to determine the true tap position when the tap position is already confused. Simply adjusting the bevel gear box and the electric mechanism's tap position indicator is no longer effective. In this situation, the current technology is lacking in solving the problem of inaccurate adjustment due to confused tap positions. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a solution based on abnormal on-load tap changer positions, thus resolving the problems mentioned in the background section.

[0005] To achieve the above objectives, the present invention provides a solution for the abnormal tap position of an on-load tap changer, the solution comprising the following operational steps:

[0006] S1. Query the specific information of the on-load tap changer:

[0007] The electric mechanism can complete one gear shift every fifteen turns of the coil. The number of turns of the switch core is determined to be between 10.5 and 11.5 turns, and the position of the gear indicator of the electric mechanism is determined after the shift.

[0008] S2. Determine the location:

[0009] A voltage ratio tester is used to detect the high-to-medium or high-to-low voltage ratio in order to determine the actual position of the switch electric mechanism.

[0010] S3, Visual Position Reference:

[0011] Using the electric mechanism gear position indicator as a visual position reference, manually adjust the gear position of the switch electric mechanism. When you hear the gear position click, record the number of coil turns N. Continue to adjust the number of turns between 14-N and 15-N. At this time, use a gear ratio tester to detect the actual gear position.

[0012] S4. Detection location:

[0013] If the gear position indicator of the electric mechanism does not match the actual gear position after the electric mechanism is adjusted, disconnect the upper and lower bearings, adjust the electric mechanism to the gear position indicated by the indicator, and then reconnect the bearings.

[0014] S5, manual gear adjustment:

[0015] After the electric mechanism gear position indicator matches the actual gear position under the natural state of the spring, manually adjust it from the high gear to the low gear. After adjustment, use a gear ratio tester to check whether the actual gear position matches the electric mechanism gear position indicator. If they do not match, disconnect the connecting bearing and adjust the electric mechanism gear to the low gear separately. If the adjustment is repeated and the gear position still does not match, there may be an abnormality in the electric mechanism or selector. A detailed inspection and confirmation are required.

[0016] S6. Confirm lap count:

[0017] After two adjustments, once the gear position indicator of the electric mechanism is consistent with the actual gear position under the natural state of the spring, the gear position is manually adjusted clockwise and counterclockwise respectively. Each gear position is tested with a gear ratio tester to confirm that it is consistent with the electric mechanism: when adjusting from a low gear to a high gear, observe the number of rotations M1 of the shaft after starting the engine; when adjusting from a high gear to a low gear, observe the number of rotations M2 of the shaft after starting the engine. The closer the two are, the more accurate the gear position indication is, that is, the weaker the cumulative effect of gear error during the gear adjustment process. The farther the two are, the more likely the cumulative effect of gear error will occur in subsequent gear adjustments, which may cause gear adjustment errors.

[0018] S7. Debugging complete:

[0019] The electric mechanism gear position indicator is consistent with the actual tap positions. Directly unscrew the two Allen screws near the red dot inside the bevel gear box, manually adjust the gear position indicator disc to the correct position, and manually adjust the gear again clockwise and counterclockwise. Ensure that the positions of the internal selector, the bevel gear box indicator, and the electric mechanism gear position indicator are consistent to indicate that the switch gear adjustment is normal.

[0020] Furthermore, in step S2, the test using the transformer ratio tester must be performed on the premise that the switch selector is not faulty.

[0021] Furthermore, in step S3, when the gear is engaged, considering the difference between the actual operation of the switch and the factory condition, the spring performance will only decrease and not increase, as well as the mechanical error between the gears, so there is no need to strictly adjust 15-N turns. At this point, the upper spring of the core is in a natural state and has not stored energy.

[0022] Furthermore, in step S6, the number of revolutions M1 and M2 are the number of gear shifts between low gear and high gear and the number of gear shifts between high gear and low gear. For example, if the low gear is 1st gear and the high gear is 17th gear, then the number of revolutions M is between 1 and 17.

[0023] This invention provides a solution to an abnormal tap position of an on-load tap changer, which has the following beneficial effects:

[0024] This solution for abnormal on-load tap changer positions utilizes a voltage ratio tester to detect the voltage ratio and a visually observable electric mechanism position indicator as a reference. This facilitates the detection of position abnormalities. After the electric mechanism position indicator aligns with the actual position of the switch's electric mechanism, the number of rotations M2 and M1 of the shaft after switching from a high to a low position and from a low to a high position is observed. The closer the two rotation counts M are, the more accurate the position indication, thus resolving the problem of inconsistent and inaccurate position adjustments. Detailed Implementation

[0025] The embodiments of the present invention will be described in further detail below with reference to examples. These examples are for illustrative purposes only and should not be construed as limiting the scope of the invention.

[0026] This invention provides a technical solution for an abnormal tap position of an on-load tap changer, the solution comprising the following steps:

[0027] S1. Query the specific information of the on-load tap changer:

[0028] The electric mechanism can complete one gear shift every fifteen turns of the coil. The number of turns of the switch core is determined to be between 10.5 and 11.5 turns, and the position of the gear indicator of the electric mechanism is determined after the shift.

[0029] S2. Determine the location:

[0030] A voltage ratio tester is used to detect the high-to-medium or high-to-low voltage ratio in order to determine the actual position of the switch electric mechanism.

[0031] S3, Visual Position Reference:

[0032] Using the electric mechanism gear position indicator as a visual position reference, manually adjust the gear position of the switch electric mechanism. When you hear the gear position click, record the number of coil turns N. Continue to adjust the number of turns between 14-N and 15-N. At this time, use a gear ratio tester to detect the actual gear position.

[0033] S4. Detection location:

[0034] If the gear position indicator of the electric mechanism does not match the actual gear position after the electric mechanism is adjusted, disconnect the upper and lower bearings, adjust the electric mechanism to the gear position indicated by the indicator, and then reconnect the bearings.

[0035] S5, manual gear adjustment:

[0036] After the electric mechanism gear position indicator matches the actual gear position under the natural state of the spring, manually adjust it from the high gear to the low gear. After adjustment, use a gear ratio tester to check whether the actual gear position matches the electric mechanism gear position indicator. If they do not match, disconnect the connecting bearing and adjust the electric mechanism gear to the low gear separately. If the adjustment is repeated and the gear position still does not match, there may be an abnormality in the electric mechanism or selector. A detailed inspection and confirmation are required.

[0037] S6. Confirm lap count:

[0038] After two adjustments, once the gear position indicator of the electric mechanism is consistent with the actual gear position under the natural state of the spring, the gear position is manually adjusted clockwise and counterclockwise respectively. Each gear position is tested with a gear ratio tester to confirm that it is consistent with the electric mechanism: when adjusting from a low gear to a high gear, observe the number of rotations M1 of the shaft after starting the engine; when adjusting from a high gear to a low gear, observe the number of rotations M2 of the shaft after starting the engine. The closer the two are, the more accurate the gear position indication is, that is, the weaker the cumulative effect of gear error during the gear adjustment process. The farther the two are, the more likely the cumulative effect of gear error will occur in subsequent gear adjustments, which may cause gear adjustment errors.

[0039] S7. Debugging complete:

[0040] The electric mechanism gear position indicator is consistent with the actual tap positions. Directly unscrew the two Allen screws near the red dot inside the bevel gear box, manually adjust the gear position indicator disc to the correct position, and manually adjust the gear again clockwise and counterclockwise. Ensure that the positions of the internal selector, the bevel gear box indicator, and the electric mechanism gear position indicator are consistent to indicate that the switch gear adjustment is normal.

[0041] In step S2, the switch selector must be intact before testing with a ratio tester.

[0042] In step S3, when the gear is engaged, considering the difference between the actual operation of the switch and the factory condition, the spring performance will only decrease and not increase, as well as the mechanical error between the gears, so there is no need to strictly adjust 15-N turns. At this point, the upper spring of the core is in a natural state and has not stored energy.

[0043] In step S6, the number of revolutions M1 and M2 are the number of gears between low gear and high gear and the number of gears between high gear and low gear. For example, if the low gear is 1st gear and the high gear is 17th gear, then the number of revolutions M is between 1 and 17.

[0044] In summary, the solution to the problem of abnormal on-load tap changer position is described in Example 1:

[0045] After consulting materials and conducting analysis, the key issues with the tap changer settings of the ABB-manufactured BUL model are as follows: First, the position indicator on the bevel gear box must be aligned with the red dot; second, due to previous misalignment of the settings, the true tap changer position cannot be determined, and simply adjusting the bevel gear box and the electric mechanism's position indicators is no longer effective. The solution to this BUL on-load tap changer setting problem is as follows:

[0046] (1) Check the specific information of the on-load tap changer: The switch is a BUL model manufactured by ABB. It completes one gear every 15 turns. The number of turns of the switch core is between 10.5 and 11.5 turns. Determine the position of the gear indicator of the electric mechanism after switching.

[0047] (2) Provided that the selector is not damaged, use a transformer ratio tester to test the high-to-medium or high-to-low transformer ratio to determine the actual position of the switch electric mechanism. Here, the switch is positioned at position 4.

[0048] (3) Either the bevel gear box gear position indicator or the electric mechanism gear position indicator can be selected. It is strictly forbidden to refer to both position indicators at the same time. For the convenience of on-site work, the electric mechanism gear position indicator is selected as the visual position reference.

[0049] (4) Manually adjust from 4th gear to 5th gear. When you hear the gear turn, record the number of turns N. Continue to adjust the number of turns between 14-N and 15-N. (Considering the difference between the actual operation of the switch and the factory condition, the spring performance will only decrease and not increase, as well as the mechanical error between the gears, there is no need to strictly adjust 15-N turns.) At this point, the upper spring of the core is in a natural state and has not stored energy.

[0050] (5) Use a gear ratio tester to check the actual gear position at this time;

[0051] (6) If the gear position indicator of the electric mechanism is inconsistent with the gear position determined in (5), disconnect the upper and lower bearings, adjust the electric mechanism to gear 5, and then reconnect the bearings.

[0052] (7) After the gear indicator of the electric mechanism is consistent with the actual gear in the natural state of the spring, manually adjust from gear 5 to gear 4. After the adjustment is completed, use a gear ratio tester to check whether the actual gear is consistent with the gear indicated by the electric mechanism. If they are inconsistent, disconnect the connecting bearing and adjust the gear of the electric mechanism to gear 4 separately. If they are still inconsistent after repeated adjustments, there may be an abnormality in the electric mechanism or the selector. A detailed inspection and confirmation should be carried out.

[0053] (8) After the gear position indicator of the electric mechanism is consistent with the actual gear position under the natural state of the spring, manually adjust the gear position clockwise and counterclockwise respectively. Each gear position is tested with a gear ratio tester to confirm that it is consistent with the electric mechanism: when adjusting from 1 to 17, observe the number of rotations of the shaft after starting the engine, M1 (1→17); when adjusting from 17 to 1, observe the number of rotations of the shaft after starting the engine, M2 (17→1). The closer the two are, the more accurate the gear position indication is, that is, the weaker the cumulative effect of gear error during the gear adjustment process. The farther the two are, the more likely the cumulative effect of gear error will occur in the subsequent gear adjustment process, which may cause gear adjustment error.

[0054] (9) After the electric mechanism gear position indicator is consistent with the actual 17 tap positions and the error is within the allowable range, then directly unscrew the two internal hex screws near the red dot inside the bevel gear box, manually adjust the gear position indicator disc to the correct gear and align it with the red dot.

[0055] (10) Following (8), manually adjust the gears clockwise and counterclockwise again to ensure that the positions of the internal selector, the bevel gear box indicator, and the electric mechanism gear indicator are consistent, indicating that the switch is operating normally.

[0056] The embodiments of the present invention are given for illustrative and descriptive purposes only, and are not intended to be exhaustive or to limit the invention to the forms disclosed. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described in order to better illustrate the principles and practical application of the invention, and to enable those skilled in the art to understand the invention and to design various embodiments with various modifications suitable for a particular purpose.

Claims

1. A solution to the problem of abnormal tap position of on-load tap changer, characterized by: The solution includes the following steps: S1. Query the specific information of the on-load tap changer: The electric mechanism can complete one gear shift every fifteen turns of the coil. The number of turns of the switch core is determined to be between 10.5 and 11.5 turns, and the position of the gear indicator of the electric mechanism is determined after the shift. S2. Determine the location: A voltage ratio tester is used to detect the high-to-medium or high-to-low voltage ratio in order to determine the actual position of the switch electric mechanism. S3, Visual Position Reference: Using the electric mechanism gear position indicator as a visual position reference, manually adjust the gear position of the switch electric mechanism. When you hear the gear position click, record the number of coil turns N. Continue to adjust the number of turns between 14-N and 15-N. At this time, use a gear ratio tester to detect the actual gear position. S4. Detection location: If the gear position indicator of the electric mechanism does not match the actual gear position after the electric mechanism is adjusted, disconnect the upper and lower bearings, adjust the electric mechanism to the gear position indicated by the indicator, and then reconnect the bearings. S5, manual gear adjustment: After the electric mechanism gear position indicator matches the actual gear position under the natural state of the spring, manually adjust it from the high gear to the low gear. After adjustment, use a gear ratio tester to check whether the actual gear position matches the electric mechanism gear position indicator. If they do not match, disconnect the connecting bearing and adjust the electric mechanism gear to the low gear separately. If the adjustment is repeated and the gear position still does not match, there may be an abnormality in the electric mechanism or selector. A detailed inspection and confirmation are required. S6. Confirm lap count: After two adjustments, once the gear position indicator of the electric mechanism is consistent with the actual gear position under the natural state of the spring, the gear position is manually adjusted clockwise and counterclockwise respectively. Each gear position is tested with a gear ratio tester to confirm that it is consistent with the electric mechanism: when adjusting from a low gear to a high gear, observe the number of rotations M1 of the shaft after starting the engine; when adjusting from a high gear to a low gear, observe the number of rotations M2 of the shaft after starting the engine. The closer the two are, the more accurate the gear position indication is, that is, the weaker the cumulative effect of gear error during the gear adjustment process. The farther the two are, the more likely the cumulative effect of gear error will occur in subsequent gear adjustments, which may cause gear adjustment errors. S7. Debugging complete: The electric mechanism gear position indicator is consistent with the actual tap positions. Directly unscrew the two Allen screws near the red dot inside the bevel gear box, manually adjust the gear position indicator disc to the correct position, and manually adjust the gear again clockwise and counterclockwise. Ensure that the positions of the internal selector, the bevel gear box indicator, and the electric mechanism gear position indicator are consistent to indicate that the switch gear adjustment is normal.

2. The solution to the problem of abnormal on-load tap changer position as described in claim 1, characterized in that: In step S2, the test must be performed on the premise that the switch selector is not damaged before using the ratio tester.

3. The solution to the problem of abnormal on-load tap changer position as described in claim 1, characterized in that: In step S3, when the gear is engaged, considering the difference between the actual operation of the switch and the factory condition, the spring performance will only decrease and not increase, as well as the mechanical error between the gears, the number of turns is adjusted to between 14-N and 15-N. At this point, the upper spring of the core is in a natural state and has not stored energy.

4. The solution to the problem of abnormal on-load tap changer position as described in claim 1, characterized in that: In step S6, the number of revolutions M1 and M2 are the number of gear shifts between low gear and high gear and the number of gear shifts between high gear and low gear.