A 220KV start-up transformer differential protection start-up test method and device

Abstract

The present invention discloses a differential protection startup test method, device, electronic device and storage medium for a 220KV starter transformer. The method involves two groups of starter transformers connected in parallel. The method includes: using an unloaded bus to charge the first group of starter transformers so that the low-voltage side of the first group of starter transformers and the low-voltage side of the second group of starter transformers are operated in parallel; adjusting the voltage difference between the low-voltage side voltage of the first group of starter transformers and the low-voltage side voltage of the second group of starter transformers to a preset difference range, and collecting the power parameters of the low-voltage side of the first group of starter transformers; based on the power parameters, determining whether the first group of starter transformers is wired incorrectly. The present invention does not require the relevant generator set to start to provide a controllable short-circuit current, is not limited by the test mode conditions, and does not require the switching operation mode to carry the operating unit plant power load, so as to avoid the risk of expanding the test range and causing the operating unit to trip, and can also reduce the test difficulty and cost, and improve the test efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of starting standby transformer test, and in particular to a differential protection starting test method, device, electronic equipment and storage medium for a 220KV starting standby transformer. Background Art

[0002] The standby transformer is a backup transformer, which is a power transformer that provides power for the generator, main transformer and other equipment. Since the correctness of the differential protection of the standby transformer will be affected by a slight error in the wiring of the standby transformer, it is necessary to conduct a starting current test on the standby transformer to verify the polarity of the differential protection and the correctness of the protection device.

[0003] At present, the commonly used test method is to adopt a short-circuit current test scheme, that is, to provide a controllable short-circuit current for the starting standby transformer and detect the power parameters of the starting standby transformer output to determine whether the wiring of the starting standby transformer is wrong; or to adopt a starting standby transformer power-on load test scheme, that is, to provide the starting standby transformer with user load and detect the charge value output by the starting standby transformer to determine whether the wiring of the starting standby transformer is wrong.

[0004] However, the commonly used test methods currently have the following technical problems: the short-circuit current test scheme is easily restricted by conditions and the test is complex and difficult to operate; while the start-up standby transformer load test scheme requires switching the operating mode to carry out the factory power load of the operating unit, which requires a wide test range and a large number of operating units, with high test costs, and there is a risk of the operating unit tripping, which will lead to test interruption. Summary of the invention

[0005] The present invention proposes a 220KV starting standby transformer differential protection starting test method, device, electronic equipment and storage medium. The method starts and adjusts the starting standby transformer and another starting standby transformer tap connected to the same system power supply in parallel to form a circulating current on the low-voltage side of the starting standby transformer to check the correctness of the starting standby transformer differential protection, thereby reducing the test difficulty and cost and improving the test efficiency.

[0006] A first aspect of an embodiment of the present invention provides a differential protection startup test method for a 220KV starter transformer, the method involving two groups of starter transformers connected in parallel, the method comprising:

[0007] Using the unloaded busbar to charge the first group of standby transformers, so that the low-voltage side of the first group of standby transformers and the low-voltage side of the second group of standby transformers can be operated in parallel;

[0008] Adjusting the voltage difference between the low-voltage side voltage of the first group of standby transformers and the low-voltage side voltage of the second group of standby transformers to a preset difference range, and collecting power parameters of the low-voltage side of the first group of standby transformers;

[0009] It is determined based on the power parameters whether the first group of standby transformers has a wiring error.

[0010] In a possible implementation manner of the first aspect, determining whether the first group of standby transformers has a wiring error based on the power parameter includes:

[0011] The power parameters include: current amplitude and phase value, differential current value, and braking current value of the low-voltage side of the first group of standby transformers;

[0012] If the current amplitude phase value is different from the preset phase value, the braking current value is not within the preset range value, and the differential current value is greater than the preset current value, it is determined that the wiring of the first group of standby transformers is wrong, wherein the preset range value is an interval range value of the center value of half of the sum of the absolute values ​​of the currents on each side of the first group of standby transformers;

[0013] Otherwise, it is determined that there is no wiring error in the first group of standby transformers.

[0014] In a possible implementation manner of the first aspect, after the step of determining that a wiring error occurs in the first group of standby transformers, the method further includes:

[0015] Correct the phase current polarity connection of the first group of standby transformers until the differential current value is less than a preset current value and the braking current value is within a preset range.

[0016] In a possible implementation manner of the first aspect, adjusting the voltage difference between the low-voltage side voltage of the first group of standby transformers and the low-voltage side voltage of the second group of standby transformers to a preset difference range includes:

[0017] Adjusting the on-load voltage regulating switches of the first group of standby transformers so that the voltage difference between the low-voltage side voltage of the first group of standby transformers and the low-voltage side voltage of the second group of standby transformers is adjusted to a preset difference range;

[0018] The difference range is 1%.

[0019] A second aspect of an embodiment of the present invention provides a 220KV starter standby transformer differential protection start-up test device, the device involves two groups of starter standby transformers connected in parallel, and the device includes:

[0020] A charging module, used for charging the first group of standby transformers by using an unloaded bus, so that the low-voltage side of the first group of standby transformers and the low-voltage side of the second group of standby transformers can be operated in parallel;

[0021] An adjustment and acquisition module, used to adjust the voltage difference between the low-voltage side voltage of the first group of standby transformers and the low-voltage side voltage of the second group of standby transformers to a preset difference range, and to acquire power parameters of the low-voltage side of the first group of standby transformers;

[0022] A determination module is used to determine whether the first group of standby transformers has a wiring error based on the power parameters.

[0023] In a possible implementation manner of the second aspect, the determining module is further configured to:

[0024] The power parameters include: current amplitude and phase value, differential current value, and braking current value of the low-voltage side of the first group of standby transformers;

[0025] If the current amplitude phase value is different from the preset phase value, the braking current value is not within the preset range value, and the differential current value is greater than the preset current value, it is determined that the wiring of the first group of standby transformers is wrong, wherein the preset range value is an interval range value of the center value of half of the sum of the absolute values ​​of the currents on each side of the first group of standby transformers;

[0026] Otherwise, it is determined that there is no wiring error in the first group of standby transformers.

[0027] In a possible implementation manner of the second aspect, the apparatus further includes:

[0028] The correction module is used to correct the phase current polarity connection of the first group of start-up standby transformers until the differential current value is less than a preset current value and the braking current value is within a preset range.

[0029] In a possible implementation manner of the second aspect, the adjustment and acquisition module is further used to:

[0030] Adjusting the on-load voltage regulating switches of the first group of standby transformers so that the voltage difference between the low-voltage side voltage of the first group of standby transformers and the low-voltage side voltage of the second group of standby transformers is adjusted to a preset difference range;

[0031] The difference range is 1%.

[0032] Compared with the prior art, the differential protection starting test method and device for a 220KV starting standby transformer provided in an embodiment of the present invention have the beneficial effects that: the present invention can charge the starting standby transformer only by unloading a group of 220kV busbars, and its low-voltage side is operated in parallel with the low-voltage side of another starting standby transformer put into operation in the same system power supply, and the tap-type on-load tap-changing switch of the starting standby transformer to be tested is adjusted to test the correctness of the differential protection, thereby eliminating the need for related generator sets to start and provide controllable short-circuit current, and is not restricted by test mode conditions; there is no need to switch the operating mode to carry the plant power load of the operating unit to avoid the risk of expanding the test scope and causing the operating unit to trip, and it can also reduce the difficulty and cost of the test and improve the test efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1It is a flow chart of a differential protection start-up test method of a 220KV start-up standby transformer provided by one embodiment of the present invention;

[0034] Figure 2 is a flow chart of the connection structure of the startup standby transformer provided by an embodiment of the present invention;

[0035] Figure 3 It is a structural schematic diagram of a differential protection starting test device for a 220KV starter standby transformer provided by one embodiment of the present invention. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] The commonly used test methods currently have the following technical problems: the short-circuit current test scheme is easily restricted by conditions and the test is complex and difficult to operate; while the start-up standby transformer load test scheme requires switching the operating mode to carry out the factory power load of the operating unit, which requires a wide test range and a large number of operating units, high test costs, and there is a risk of the operating unit tripping, which will lead to test interruption.

[0038] In order to solve the above problems, a differential protection starting test method for a 220KV starting standby transformer provided in an embodiment of the present application will be introduced and explained in detail through the following specific embodiments.

[0039] Reference Figure 1 , showing a flow chart of a differential protection starting test method for a 220KV starting standby transformer provided by an embodiment of the present invention.

[0040] In one embodiment, the method is applicable to two groups of start-up and standby transformers connected in parallel.

[0041] Reference Figure 2 , shows a flow chart of the connection structure of the start-up and standby transformers provided by an embodiment of the present invention. Two groups of start-up and standby transformers are connected in parallel through a 220kv busbar.

[0042] Each group of starting and standby transformers has a tapped on-load voltage regulator, which can be used to adjust the voltage of the starting and standby transformers.

[0043] Wherein, as an example, the differential protection startup test method of the 220KV standby transformer may include:

[0044] S11. Using an unloaded busbar to charge the first group of standby transformers, so that the low-voltage side of the first group of standby transformers and the low-voltage side of the second group of standby transformers are connected in parallel for operation.

[0045] In one embodiment, referring to Figure 2 Each set of starting and standby transformers has two sets of busbar connections. One set of 220kV busbars can be unloaded to charge the first set of starting and standby transformers, so that the low-voltage side of the first set of starting and standby transformers can operate in parallel with the low-voltage side of the second set of starting and standby transformers put into operation in the same system power supply.

[0046] In an optional embodiment ongoing, the parallel operation condition of the two groups of start-up and standby transformers can also meet the transformer parallel operation condition. Specifically, the two start-up and standby transformers running in parallel only have power switches running and do not have any electrical equipment - equivalent to no-load parallel operation.

[0047] S12: adjusting the voltage difference between the low-voltage side voltage of the first group of standby transformers and the low-voltage side voltage of the second group of standby transformers to a preset difference range, and collecting power parameters of the low-voltage side of the first group of standby transformers.

[0048] Specifically, the low-voltage side voltage of the first group of standby transformers and the low-voltage side voltage of the second group of standby transformers are adjusted so that the voltage difference between the low-voltage side voltages of the two groups of standby transformers reaches a preset difference range, and then the power parameters of the low-voltage side of the first group of standby transformers are collected, so that it can be determined whether the wiring of the first group of standby transformers is wrong through the power parameters.

[0049] In an optional embodiment, step S12 may include the following sub-steps:

[0050] Sub-step S121, adjusting the on-load voltage regulating switches of the first group of standby transformers so that the voltage difference between the low-voltage side voltage of the first group of standby transformers and the low-voltage side voltage of the second group of standby transformers is adjusted to a preset difference range.

[0051] The difference range is 1%.

[0052] Preferably, the difference range may be smaller than the tolerance of 0.5%.

[0053] S13: Determine whether the first group of standby transformers has a wiring error based on the power parameters.

[0054] In one of the embodiments, the power parameters include: current amplitude and phase values, differential current values, and braking current values ​​of the low-voltage side of the first group of standby transformers.

[0055] As an example, step S13 may include the following sub-steps:

[0056] Sub-step S131: If the current amplitude phase value is different from the preset phase value, the braking current value is not within the preset range value and the differential current value is greater than the preset current value, it is determined that the wiring of the first group of standby transformers is wrong, wherein the preset range value is an interval range value with the center value of half of the sum of the absolute values ​​of the currents on each side of the first group of standby transformers.

[0057] Sub-step S132: Otherwise, it is determined that there is no wiring error in the first group of standby transformers.

[0058] Specifically, by slightly adjusting the tap-on-load voltage regulator of the first set of standby transformers, the low-voltage side voltages of the two sets of standby transformers running in parallel are slightly inconsistent, so that a circulating current can be generated on the high and low voltage sides of the first set of standby transformers. Then, read and collect the power parameters such as the current amplitude phase, differential current, and braking current data on the high and low voltage sides of the first set of standby transformers. It should be noted that the recorded power parameters are greater than the sampling display threshold value.

[0059] After the above three power parameters are collected, the three power parameters can be compared with their corresponding preset values, and whether the wiring is wrong can be determined based on the three comparison results.

[0060] In one embodiment, if the current amplitude phase value is different from the preset phase value, the braking current value is not within the preset range and the differential current value is greater than the preset current value, it is determined that the first set of standby transformer wiring is faulty; otherwise, it is determined that the first set of standby transformer wiring is not faulty.

[0061] Among them, the preset phase value can be to satisfy the positive phase sequence of the current on the high and low voltage sides of the transformer, specifically, the three-phase currents of ABC on the high and low voltage sides of the transformer differ by 120 degrees, phase A leads phase B by 120 degrees, and phase B leads phase C by 120 degrees for the positive phase sequence. The preset current value can be a current value close to zero. The preset range value can be an interval range value with the center value of half of the sum of the absolute values ​​of the currents on each side of the first group of standby transformers.

[0062] Specifically, if the current amplitude and phase value are the positive phase sequence of the high and low voltage side currents of the transformer, the differential current is close to zero, and the braking current value range is about half of the sum of the absolute values ​​of the currents on each side, then there is no error in the wiring of the first set of starting and standby transformers, otherwise there is an error in the wiring of the starting and standby transformer differential protection circuit.

[0063] After a wiring error has been made, it needs to be corrected to avoid continued errors.

[0064] Wherein, as an example, the method may further include:

[0065] S14, correcting the phase current polarity connection of the first group of standby transformers until the differential current value is less than a preset current value and the braking current value is within a preset range.

[0066] Specifically, the phase current polarity connections related to the first group of start-up transformers are corrected until the differential current is close to zero and the braking current is relatively large.

[0067] In this embodiment, the embodiment of the present invention provides a differential protection starting test method for a 220KV starting standby transformer, and its beneficial effects are: the present invention can charge the starting standby transformer only by unloading a group of 220kV busbars, and its low-voltage side is operated in parallel with the low-voltage side of another starting standby transformer put into operation in the same system power supply, and the tap-type on-load tap-changing switch of the starting standby transformer to be tested is adjusted to test the correctness of the differential protection, thereby eliminating the need for related generator sets to start to provide controllable short-circuit current, and is not restricted by test mode conditions; there is no need to switch the operating mode to carry the plant power load of the operating unit to avoid the risk of expanding the test scope and causing the operating unit to trip, and it can also reduce the difficulty and cost of the test and improve the test efficiency.

[0068] The embodiment of the present invention also provides a 220KV start-up standby transformer differential protection start-up test device, see Figure 3 , showing a structural schematic diagram of a differential protection starting test device for a 220KV starting standby transformer provided by an embodiment of the present invention.

[0069] The device involves two sets of starter and standby transformers connected in parallel.

[0070] Wherein, as an example, the differential protection starting test device of the 220KV starter transformer may include:

[0071] The charging module 301 is used to charge the first group of standby transformers by using the unloaded bus, so that the low-voltage side of the first group of standby transformers and the low-voltage side of the second group of standby transformers can be operated in parallel;

[0072] The adjustment and acquisition module 302 is used to adjust the voltage difference between the low-voltage side voltage of the first group of standby transformers and the low-voltage side voltage of the second group of standby transformers to a preset difference range, and to acquire the power parameters of the low-voltage side of the first group of standby transformers;

[0073] The determination module 303 is used to determine whether the first group of standby transformers has a wiring error based on the power parameters.

[0074] Optionally, the determining module is further used for:

[0075] The power parameters include: current amplitude and phase value, differential current value, and braking current value of the low-voltage side of the first group of standby transformers;

[0076] If the current amplitude phase value is different from the preset phase value, the braking current value is not within the preset range value, and the differential current value is greater than the preset current value, it is determined that the wiring of the first group of standby transformers is wrong, wherein the preset range value is an interval range value of the center value of half of the sum of the absolute values ​​of the currents on each side of the first group of standby transformers;

[0077] Otherwise, it is determined that there is no wiring error in the first group of standby transformers.

[0078] Optionally, the device further comprises:

[0079] The correction module is used to correct the phase current polarity connection of the first group of start-up standby transformers until the differential current value is less than a preset current value and the braking current value is within a preset range.

[0080] Optionally, the adjustment and acquisition module is further used for:

[0081] Adjusting the on-load voltage regulating switches of the first group of standby transformers so that the voltage difference between the low-voltage side voltage of the first group of standby transformers and the low-voltage side voltage of the second group of standby transformers is adjusted to a preset difference range;

[0082] The difference range is 1%.

[0083] Furthermore, an embodiment of the present application also provides an electronic device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the differential protection starting test method for the 220KV starting standby transformer is implemented as described in the above embodiment.

[0084] Furthermore, an embodiment of the present application also provides a computer-readable storage medium, which stores computer-executable instructions, and the computer-executable instructions are used to enable a computer to execute the differential protection starting test method of the 220KV starting standby transformer as described in the above embodiment.

[0085] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A 220KV start-up transformer differential protection start-up test method, characterized in that: The method involves two sets of start-up and standby transformers connected in parallel, and the method comprises: Using the unloaded busbar to charge the first group of standby transformers, so that the low-voltage side of the first group of standby transformers and the low-voltage side of the second group of standby transformers can be operated in parallel; Adjusting the voltage difference between the low-voltage side voltage of the first group of standby transformers and the low-voltage side voltage of the second group of standby transformers to a preset difference range, and collecting power parameters of the low-voltage side of the first group of standby transformers; Determining whether the first group of standby transformers has a wiring error based on the power parameters; The determining whether the first group of standby transformers has a wiring error based on the power parameter includes: The power parameters include: current amplitude and phase value, differential current value, and braking current value of the low-voltage side of the first group of standby transformers; If the current amplitude phase value is different from the preset phase value, the braking current value is not within the preset range value, and the differential current value is greater than the preset current value, it is determined that the wiring of the first group of standby transformers is wrong, wherein the preset range value is an interval range value of the center value of half of the sum of the absolute values ​​of the currents on each side of the first group of standby transformers; Otherwise, it is determined that there is no wiring error in the first group of standby transformers.

2. The differential protection starting test method of the 220KV starter transformer according to claim 1 is characterized in that: After the step of determining that the wiring of the first group of standby transformers is wrong, the method further includes: Correct the phase current polarity connection of the first group of standby transformers until the differential current value is less than a preset current value and the braking current value is within a preset range.

3. The differential protection starting test method of the 220KV standby transformer according to claim 1 is characterized in that: The step of adjusting the voltage difference between the low-voltage side voltage of the first group of standby transformers and the low-voltage side voltage of the second group of standby transformers to a preset difference range includes: Adjusting the on-load voltage regulating switches of the first group of standby transformers so that the voltage difference between the low-voltage side voltage of the first group of standby transformers and the low-voltage side voltage of the second group of standby transformers is adjusted to a preset difference range; The difference range is 1%.

4. A 220KV starter transformer differential protection start-up test device, characterized in that: The device involves two sets of start-up and standby transformers connected in parallel, and the device comprises: A charging module, used for charging the first group of standby transformers by using an unloaded bus, so that the low-voltage side of the first group of standby transformers and the low-voltage side of the second group of standby transformers can be operated in parallel; An adjustment and acquisition module, used to adjust the voltage difference between the low-voltage side voltage of the first group of standby transformers and the low-voltage side voltage of the second group of standby transformers to a preset difference range, and to acquire power parameters of the low-voltage side of the first group of standby transformers; A determination module, configured to determine whether the first group of standby transformers has a wiring error based on the power parameters; The determining module is also used for: The power parameters include: current amplitude and phase value, differential current value, and braking current value of the low-voltage side of the first group of standby transformers; If the current amplitude phase value is different from the preset phase value, the braking current value is not within the preset range value, and the differential current value is greater than the preset current value, it is determined that the wiring of the first group of standby transformers is wrong, wherein the preset range value is an interval range value of the center value of half of the sum of the absolute values ​​of the currents on each side of the first group of standby transformers; Otherwise, it is determined that there is no wiring error in the first group of standby transformers.

5. The differential protection starting test device of the 220KV starter transformer according to claim 4 is characterized in that: The device also includes: The correction module is used to correct the phase current polarity connection of the first group of start-up standby transformers until the differential current value is less than a preset current value and the braking current value is within a preset range.

6. The differential protection starting test device of the 220KV starter transformer according to claim 4 is characterized in that: The adjustment and acquisition module is also used for: Adjusting the on-load voltage regulating switches of the first group of standby transformers so that the voltage difference between the low-voltage side voltage of the first group of standby transformers and the low-voltage side voltage of the second group of standby transformers is adjusted to a preset difference range; The difference range is 1%.

7. An electronic device comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the differential protection starting test method for the 220KV starting standby transformer as described in any one of claims 1 to 3 is implemented.

8. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer-executable instructions, and the computer-executable instructions are used to enable a computer to execute the differential protection starting test method for the 220KV starting standby transformer as described in any one of claims 1-3.

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