A method, device, medium and equipment for realizing transformer de-inrush blocking

Abstract

The application discloses a transformer de-blocking of inrush current implementation method, device, medium and equipment. The method comprises the following steps: calculating the differential current sampling value mutation of the transformer corresponding to the sampling point in the first predetermined time interval; in the case that the differential current sampling value mutation of the two continuous sampling points meets the starting criterion, the time corresponding to the latter sampling point is determined as the first starting time; after the second predetermined time interval from the first starting time, in the case that the differential current sampling value mutation of the two continuous sampling points meets the starting criterion, the time corresponding to the latter sampling point is determined as the second starting time; after the first starting time, whether to send a blocking signal is determined according to the differential current sampling value mutation and the intermittent angle blocking criterion; whether to send a blocking signal is determined according to the differential current sampling value mutation of the two sampling points of the second starting time and the intermittent angle blocking criterion, and whether the transformer is de-blocked from the excitation inrush current is determined.

Description

Technical Field

[0001] This invention relates to the field of power transformer technology, and more specifically, to a method, apparatus, medium, and equipment for releasing inrush current lockout in a transformer. Background Technology

[0002] As crucial equipment in power plants and substations, the safe operation of power transformers directly impacts the continuous and stable operation of the entire power system. Inrush current, a unique electromagnetic phenomenon of transformers, can reach 4 to 8 times the normal operating current and is a major source of maloperation of transformer differential protection. Therefore, transformer differential protection typically requires inrush current blocking as a criterion for operation.

[0003] When a transformer experiences a progressive fault, the transformer differential protection is easily blocked by the inrush current blocking criterion during the fault development process. This can cause the transformer differential protection to fail to clear the fault in time, thereby affecting the transformer's service life and causing serious damage to the transformer, or even leading to the serious consequence of the transformer burning out. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a method, apparatus, medium, and equipment for releasing inrush current blocking in transformers.

[0005] According to one aspect of the present invention, a method for releasing inrush current blocking in a transformer is provided, comprising:

[0006] The abrupt change in the differential current sampling value of the transformer corresponding to the sampling point at the first predetermined time interval is calculated in real time based on the current sampling values ​​on each side of the transformer.

[0007] If the abrupt change in the differential current sampling value at two consecutive sampling points satisfies the pre-built trigger criterion for the abrupt change in the differential current sampling value of the transformer, the time corresponding to the next sampling point is determined as the first trigger time for the abrupt change in the differential current sampling value.

[0008] After the second predetermined time interval of the first start-up time interval, if the differential current sampling value mutation of two consecutive sampling points meets the differential current sampling value mutation start-up criterion, the time corresponding to the next sampling point is determined as the second start-up time of the differential current sampling value mutation.

[0009] After the first start-up time, based on the sudden change in the differential current sampling value of the transformer sampling point and the pre-set discontinuity angle blocking criterion, it is determined whether to issue a blocking signal.

[0010] Based on the sudden change in the differential current sampling value of the two sampling points that determine the second start-up time and whether a blocking signal is issued according to the discontinuity angle blocking criterion, it is determined whether the transformer has released the inrush current blocking.

[0011] Optionally, the abrupt change in the differential current sampling value of the transformer corresponding to the sampling point at a first predetermined time interval is calculated in real time based on the current sampling values ​​on each side of the transformer, including:

[0012] The differential current sampling value of the transformer corresponding to the sampling point at the first predetermined time interval is calculated in real time based on the current sampling value of each side of the transformer.

[0013] The abrupt change in the differential current sampling value of the transformer at the sampling point corresponding to the first predetermined time interval is calculated in real time based on the differential current sampling value of the transformer.

[0014] The formula for calculating the differential current sampling value of the transformer is as follows:

[0015]

[0016] The formula for calculating the sudden change in differential current sampling value is as follows:

[0017]

[0018] in, Let be the abrupt change in the differential current sample value at time t. This is the sampled value of the transformer differential current. A, B, and C are the three phases of the transformer. The current sample value on the i-th side of the transformer is the result of balance factor conversion and phase correction, and T is the power frequency period.

[0019] Optionally, the trigger criterion for the sudden change in differential current sampling value is:

[0020]

[0021] in, I represents the abrupt change in the differential current sampling value. set The starting setting value for transformer differential protection.

[0022] Optionally, based on the abrupt change in the differential current sampling value at the transformer sampling point and the pre-set discontinuity angle blocking criterion, it is determined whether to issue a blocking signal, including:

[0023] If the abrupt change in the differential current sampling values ​​at four consecutive sampling points satisfies the pre-set discontinuity angle blocking criterion, the discontinuity angle blocking criterion issues a blocking signal; otherwise, the discontinuity angle blocking criterion does not issue a blocking signal.

[0024] The criteria for intermittent angle blocking are as follows:

[0025]

[0026] in, This represents the sudden change in the differential current sampling value. A, B, and C are the three phases of the transformer, I set The starting setting value for transformer differential protection.

[0027] Optionally, based on the sudden change in the differential current sampling values ​​at the two sampling points determining the second start-up time and whether a blocking signal is issued according to the discontinuity angle blocking criterion, it is determined whether the transformer has released the inrush current blocking, including:

[0028] The lockout release criterion setting is determined based on the sudden change in the differential current sampling value of two consecutive sampling points that determine the second start time.

[0029] After the second predetermined time interval of the second start-up, if the lockout release criterion setting satisfies the preset lockout release criterion for inrush current, and the intermittent angle lockout criterion does not issue a lockout signal, the transformer inrush current lockout is released.

[0030] The inrush current blocking criterion is:

[0031]

[0032] in, To release the locking criterion setting, This represents the sudden change in the differential current sampling value. A, B, and C are the three phases of the transformer, and k is the braking coefficient.

[0033] Optionally, the lockout release criterion setting is determined based on the sudden change in the differential current sampling values ​​at two consecutive sampling points that determine the second start-up time, including:

[0034] The smaller value of the differential current sampling value change at two consecutive sampling points that determine the second start-up time is used as the unlocking criterion value, and the formula is as follows:

[0035]

[0036] in, The change in the differential current sample value at time t2 is the amount of change. A, B, and C are the three phases of the transformer. The value of the differential current sample at time t2-δt is the abrupt change in the value, where δt is the first predetermined time period.

[0037] According to another aspect of the present invention, an apparatus for releasing inrush current lockout of a transformer is provided, comprising:

[0038] The calculation module is used to calculate in real time the abrupt change in the differential current sampling value of the transformer corresponding to the sampling point at a first predetermined time interval based on the current sampling values ​​on each side of the transformer.

[0039] The first determining module is used to determine the time corresponding to the next sampling point as the first start time of the differential current sampling value mutation when the mutation amount of the differential current sampling value at two consecutive sampling points meets the pre-built differential current sampling value mutation start criterion of the transformer.

[0040] The second determining module is used to determine the time corresponding to the next sampling point as the second start time of the differential current sampling value mutation after the second predetermined time period of the first start time interval, when the mutation amount of the differential current sampling value at two consecutive sampling points meets the differential current sampling value mutation start criterion.

[0041] The third determining module is used to determine whether to issue a blocking signal after the first start-up time, based on the sudden change in the differential current sampling value of the transformer sampling point and the pre-set discontinuity angle blocking criterion.

[0042] The judgment module is used to determine whether the transformer has released the inrush current lockout based on the sudden change in the differential current sampling value of the two sampling points that determine the second start-up time and whether a lockout signal is issued according to the discontinuity angle lockout criterion.

[0043] According to another aspect of the present invention, a computer-readable storage medium is provided, the storage medium storing a computer program for performing the methods described in any of the above aspects of the present invention.

[0044] According to another aspect of the present invention, an electronic device is provided, the electronic device comprising: a processor; a memory for storing executable instructions of the processor; the processor being configured to read the executable instructions from the memory and execute the instructions to implement the method described in any of the preceding aspects of the present invention.

[0045] Therefore, this application proposes a method for releasing inrush current blocking in a transformer. This method calculates the sudden change in the differential current sampling value of the transformer at sampling points within a first predetermined time interval in real time. Based on the differential current sampling value sudden change criterion, it determines the first and second start-up times. An intermittent angle blocking criterion is added to determine whether a blocking signal should be issued. Finally, based on the sudden change in the differential current sampling value at the two sampling points used to determine the second start-up time and whether a blocking signal is issued according to the intermittent angle blocking criterion, it is determined whether the transformer has released the inrush current blocking. This method quickly clears the short circuit from small-turn to large-turn development after inrush current blocking, thereby accelerating the operation speed of the transformer fault protection, enabling the transformer differential protection to clear faults in a timely manner, and improving the transformer's service life and safety. Attached Figure Description

[0046] Exemplary embodiments of the present invention can be more fully understood by referring to the following figures:

[0047] Figure 1 This is a flowchart illustrating a method for releasing inrush current blocking in a transformer, provided by an exemplary embodiment of the present invention.

[0048] Figure 2 This is another flowchart illustrating a method for releasing inrush current blocking from a transformer, provided in an exemplary embodiment of the present invention.

[0049] Figure 3 This is a logic diagram of a transformer developmental fault release inrush current blocking method provided by an exemplary embodiment of the present invention;

[0050] Figure 4 This is a schematic diagram of the action result of a transformer inter-turn progressive fault provided in an exemplary embodiment of the present invention;

[0051] Figure 5 This is a schematic diagram of the excitation inrush current action result during transformer inter-turn empty charging provided by an exemplary embodiment of the present invention;

[0052] Figure 6 This is a schematic diagram of the transformer inter-turn occurrence and inrush current response results provided in an exemplary embodiment of the present invention;

[0053] Figure 7 This is a schematic diagram of the result of a restorative inrush current action between transformer turns provided in an exemplary embodiment of the present invention;

[0054] Figure 8 This is a schematic diagram of the structure of a transformer inrush current release device provided in an exemplary embodiment of the present invention;

[0055] Figure 9 This is the structure of an electronic device provided in an exemplary embodiment of the present invention. Detailed Implementation

[0056] Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. It is obvious that the described embodiments are merely some embodiments of the present invention, and not all embodiments of the present invention, and it should be understood that the present invention is not limited to the exemplary embodiments described herein.

[0057] It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of the invention.

[0058] Those skilled in the art will understand that the terms "first," "second," etc., in the embodiments of the present invention are only used to distinguish different steps, devices, or modules, and do not represent any specific technical meaning, nor do they indicate a necessary logical order between them.

[0059] It should also be understood that in the embodiments of the present invention, "multiple" can refer to two or more, and "at least one" can refer to one, two or more.

[0060] It should also be understood that any component, data or structure mentioned in the embodiments of the present invention can generally be understood as one or more unless explicitly defined or given contrary instructions in the context.

[0061] Furthermore, the term "and / or" in this invention is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this invention generally indicates that the preceding and following related objects have an "or" relationship.

[0062] It should also be understood that the description of the various embodiments in this invention emphasizes the differences between the various embodiments, and the similarities or similarities can be referred to each other. For the sake of brevity, they will not be described in detail.

[0063] At the same time, it should be understood that, for ease of description, the dimensions of the various parts shown in the accompanying drawings are not drawn according to actual scale.

[0064] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the invention or its application or use.

[0065] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, they should be considered part of the specification.

[0066] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0067] The embodiments of this invention can be applied to electronic devices such as terminal devices, computer systems, and servers, and can operate together with a wide range of other general-purpose or special-purpose computing system environments or configurations. Well-known examples of terminal devices, computing systems, environments, and / or configurations suitable for use with electronic devices such as terminal devices, computer systems, and servers include, but are not limited to: personal computer systems, server computer systems, thin clients, thick clients, handheld or laptop devices, microprocessor-based systems, set-top boxes, programmable consumer electronics, network PCs, minicomputer systems, mainframe computer systems, and distributed cloud computing environments including any of the above systems, etc.

[0068] Electronic devices such as terminal devices, computer systems, and servers can be described in the general context of computer system executable instructions (such as program modules) executed by a computer system. Typically, program modules can include routines, programs, object programs, components, logic, data structures, etc., which perform specific tasks or implement specific abstract data types. Computer systems / servers can be implemented in distributed cloud computing environments, where tasks are executed by remote processing devices linked through communication networks. In distributed cloud computing environments, program modules can reside on local or remote computing system storage media, including storage devices.

[0069] Exemplary methods

[0070] Figure 1 This is a flowchart illustrating a method for releasing inrush current blocking in a transformer, provided by an exemplary embodiment of the present invention. This embodiment can be applied to electronic devices, such as... Figure 1 As shown, the method 100 for releasing the inrush current lockout of the transformer includes the following steps:

[0071] Step 101: Calculate the sudden change in the differential current sampling value of the transformer corresponding to the sampling point at the first predetermined time interval based on the current sampling values ​​of each side of the transformer.

[0072] Optionally, the abrupt change in the differential current sampling value of the transformer corresponding to the sampling point at a first predetermined time interval is calculated in real time based on the current sampling values ​​on each side of the transformer, including:

[0073] The differential current sampling value of the transformer corresponding to the sampling point at the first predetermined time interval is calculated in real time based on the current sampling value of each side of the transformer.

[0074] The abrupt change in the differential current sampling value of the transformer at the sampling point corresponding to the first predetermined time interval is calculated in real time based on the differential current sampling value of the transformer.

[0075] The formula for calculating the differential current sampling value of the transformer is as follows:

[0076]

[0077] The formula for calculating the sudden change in differential current sampling value is as follows:

[0078]

[0079] in, Let be the abrupt change in the differential current sample value at time t. This is the sampled value of the transformer differential current. A, B, and C are the three phases of the transformer. The current sample value on the i-th side of the transformer is the result of balance factor conversion and phase correction, and T is the power frequency period.

[0080] Specifically, refer to Figure 2 As shown, the differential current sampling value of the transformer at each sampling point is calculated in real time using the calculation formulas for the differential current sampling value and the differential current sampling value mutation.

[0081] Step 102, refer to Figure 2 As shown, if the abrupt change in the differential current sampling value at two consecutive sampling points satisfies the pre-built trigger criterion for the abrupt change in the differential current sampling value of the transformer, the time corresponding to the next sampling point is determined as the first trigger time for the abrupt change in the differential current sampling value.

[0082] Optionally, the trigger criterion for the sudden change in differential current sampling value is:

[0083]

[0084] in, I represents the abrupt change in the differential current sampling value. set The starting setting value for transformer differential protection.

[0085] Specifically, the differential current sampling value mutation start criterion is met for two consecutive sampling points (with an interval of, but not limited to, 0.83ms). The time when the condition is met is recorded as the first start time, and the time corresponding to the next sampling point is recorded as the first start time.

[0086] Step 103, refer to Figure 2 As shown, after the second predetermined time interval of the first start-up time interval, if the differential current sampling value mutation of two consecutive sampling points meets the differential current sampling value mutation start-up criterion, the time corresponding to the next sampling point is determined as the second start-up time of the differential current sampling value mutation.

[0087] Specifically, after the second predetermined time period (which may be but is not limited to 5ms) at the first start time, it is determined again whether the differential current sampling value mutation start criterion is met. When the differential current sampling value mutation start criterion is met for two consecutive sampling points, the time when the condition is met is recorded as the second start time t2, i.e., t2>t1+5ms.

[0088] Step 104, refer to Figure 2 As shown, after the first startup time, the decision on whether to issue a blocking signal is based on the sudden change in the differential current sampling value of the transformer sampling point and the pre-set discontinuity angle blocking criterion.

[0089] Optionally, refer to Figure 2As shown, based on the sudden change in the differential current sampling value at the transformer sampling point and the pre-set discontinuity angle blocking criterion, it is determined whether to issue a blocking signal, including:

[0090] If the abrupt change in the differential current sampling values ​​at four consecutive sampling points satisfies the pre-set discontinuity angle blocking criterion, the discontinuity angle blocking criterion issues a blocking signal; otherwise, the discontinuity angle blocking criterion does not issue a blocking signal.

[0091] The criteria for intermittent angle blocking are as follows:

[0092]

[0093] in, This represents the sudden change in the differential current sampling value. A, B, and C are the three phases of the transformer, I set The starting setting value for transformer differential protection.

[0094] Specifically, the discontinuity angle locking criterion is a discontinuity point. After the first start, if there are 4 consecutive discontinuities, the discontinuity angle locking criterion will send a locking signal to lock the protection. The locking signal extension can be, but is not limited to, 4 seconds.

[0095] Step 105, refer to Figure 2 As shown, based on the sudden change in the differential current sampling value of the two sampling points that determine the second start-up time and whether a blocking signal is issued according to the discontinuity angle blocking criterion, it is determined whether the transformer has released the inrush current blocking.

[0096] Optionally, refer to Figure 2 As shown, based on the sudden change in the differential current sampling values ​​of the two sampling points determining the second start-up time and whether a blocking signal is issued according to the discontinuity angle blocking criterion, it is determined whether the transformer has released the inrush current blocking, including:

[0097] The lockout release criterion setting is determined based on the sudden change in the differential current sampling value of two consecutive sampling points that determine the second start time.

[0098] After the second predetermined time interval of the second start-up, if the lockout release criterion setting satisfies the preset lockout release criterion for inrush current, and the intermittent angle lockout criterion does not issue a lockout signal, the transformer inrush current lockout is released.

[0099] The inrush current blocking criterion is:

[0100]

[0101] Among them, i set.UL To release the locking criterion setting, This represents the sudden change in the differential current sampling value. A, B, and C are the three phases of the transformer, and k is the braking coefficient. Preferably, k = 2.

[0102] Optionally, refer to Figure 2 As shown, the lockout release criterion setting is determined based on the sudden change in the differential current sampling values ​​at two consecutive sampling points that determine the second start-up time, including:

[0103] The smaller value of the differential current sampling value change at two consecutive sampling points that determine the second start-up time is used as the unlocking criterion value, and the formula is as follows:

[0104]

[0105] in, The change in the differential current sample value at time t2 is the amount of change. A, B, and C are the three phases of the transformer. The value of the differential current sample at time t2-δt is the abrupt change in the value, where δt is the first predetermined time period.

[0106] Specifically, the smaller absolute value of the differential current sampling value mutation at the second start time is used as the set value for the unlocking criterion.

[0107] After the second predetermined time period (which may be but is not limited to 5ms) at the second startup time, the transformer excitation inrush current blocking criterion is determined.

[0108] like Figure 3 As shown, when the transformer inrush current blocking criterion is met and the discontinuity angle blocking criterion does not issue a blocking signal, the transformer inrush current blocking is released.

[0109] In addition, refer to Figure 4 The example shown is an application to the developmental faults of a transformer.

[0110] The transformer inter-turn progressive fault scenario is that the transformer develops from a small inter-turn fault to a severe inter-turn fault. The faulty phase is phase B. The first start time is 5.00ms and the second start time is 12.5ms. The criterion for releasing the blockade is twice the smaller absolute value of the differential current sampling value at the second start time. The transformer release inrush current blockade criterion is met at 17.5ms, and the blockade signal is 0. Therefore, the transformer inrush current blockade is released at 17.5ms.

[0111] In addition, refer to Figure 5 The example shown illustrates the application of inrush current during transformer no-load charging.

[0112] When the transformer is charged under no-load conditions, an inrush current occurs. Taking phase C, where the inrush current is most severe, as an example, the first start time is 3.33ms and the second start time is 9.17ms. The criterion for releasing the inrush current is set at twice the smaller absolute value of the differential current sampling value at the second start time. The criterion for releasing the inrush current is never met, and a blocking signal is issued at 20ms. The transformer is in the state of inrush current blocking differential protection and no false tripping occurs.

[0113] In addition, refer to Figure 6 The example shown illustrates the application of current generation and inrush current to transformers.

[0114] When an adjacent transformer is charged under no-load conditions, an inrush current will occur. Taking phase B, where the inrush current is most severe, as an example, the first start-up time during the inrush current period is 59.52ms, and the second start-up time is 79.03ms. The smaller absolute value of the differential current sampling value change at the second start-up time is taken as the unlocking criterion value. The transformer unlocking criterion is met at 98.71ms, but the lockout signal has already been issued at 63.63ms. The transformer is in the state of inrush current locked differential protection and no false tripping occurs.

[0115] In addition, refer to Figure 7 The example shown illustrates an application to a transformer experiencing restorative inrush current.

[0116] When a transformer on the same bus fails, during the process of restoring the bus voltage after the fault is cleared, the unloaded transformer will experience restorative inrush current. Taking phase B, which has the most severe inrush current, as an example, the first start time is 3.79ms and the second start time is 10.32ms. The criterion for releasing the inrush current is set at twice the smaller absolute value of the differential current sampling value at the second start time. The transformer releases the inrush current blocking criterion at 23.71ms, but the blocking signal is issued at 13.15ms. The transformer is in the state of inrush current blocking differential protection and no false tripping occurs.

[0117] Therefore, the method for releasing inrush current blocking proposed in this application can quickly cut off the short circuit between small turns of the transformer that has developed into a short circuit between large turns after being blocked by inrush current, thereby accelerating the action speed of transformer fault protection.

[0118] Exemplary device

[0119] Figure 8 This is a schematic diagram of the structure of a transformer inrush current release device provided in an exemplary embodiment of the present invention. Figure 8 As shown, the device 800 includes:

[0120] The calculation module 810 is used to calculate in real time the abrupt change in the differential current sampling value of the transformer corresponding to the sampling point at a first predetermined time interval based on the current sampling values ​​of each side of the transformer.

[0121] The first determining module 820 is used to determine the time corresponding to the next sampling point as the first start time of the differential current sampling value mutation when the mutation amount of the differential current sampling value at two consecutive sampling points meets the pre-built differential current sampling value mutation start criterion of the transformer.

[0122] The second determining module 830 is used to determine the time corresponding to the next sampling point as the second start time of the differential current sampling value mutation after the second predetermined time period of the first start time interval, when the mutation amount of the differential current sampling value at two consecutive sampling points meets the differential current sampling value mutation start criterion.

[0123] The third determining module 840 is used to determine whether to issue a blocking signal after the first start-up time, based on the sudden change in the differential current sampling value of the transformer sampling point and the pre-set discontinuity angle blocking criterion.

[0124] The judgment module 850 is used to determine whether the transformer has released the inrush current lockout based on the sudden change in the differential current sampling value of the two sampling points that determine the second start-up time and whether a lockout signal is issued according to the discontinuity angle lockout criterion.

[0125] Optionally, the computing module 810 includes:

[0126] The first calculation submodule is used to calculate the transformer differential current sampling value corresponding to the sampling point at a first predetermined time interval based on the current sampling value of each side of the transformer in real time.

[0127] The second calculation submodule is used to calculate in real time the abrupt change in the differential current sampling value of the transformer corresponding to the sampling point at a first predetermined time interval, based on the differential current sampling value of the transformer.

[0128] The formula for calculating the differential current sampling value of the transformer is as follows:

[0129]

[0130] The formula for calculating the sudden change in differential current sampling value is as follows:

[0131]

[0132] in, Let be the abrupt change in the differential current sample value at time t. For transformer Phase differential current sampling value, A, B, and C are the three phases of the transformer. The current sample value on the i-th side of the transformer is the result of balance factor conversion and phase correction, and T is the power frequency period.

[0133] Optionally, the trigger criterion for the sudden change in differential current sampling value is:

[0134]

[0135] in, I represents the abrupt change in the differential current sampling value. set The starting setting value for transformer differential protection.

[0136] Optionally, the third determining module 840 includes:

[0137] The first judgment submodule is used to issue a blocking signal based on the discontinuity angle blocking criterion when the sudden change in the differential current sampling values ​​of four consecutive sampling points meets the preset discontinuity angle blocking criterion; otherwise, the discontinuity angle blocking criterion does not issue a blocking signal.

[0138] The criteria for intermittent angle blocking are as follows:

[0139]

[0140] in, This represents the sudden change in the differential current sampling value. A, B, and C are the three phases of the transformer, I set The starting setting value for transformer differential protection.

[0141] Optionally, the judgment module 850 includes:

[0142] The determination submodule is used to determine the unlocking criterion setting value based on the sudden change in the differential current sampling value of two consecutive sampling points that determine the second start time;

[0143] The release submodule is used to release the transformer inrush current lockout when, after the second predetermined time interval between the second startup, the lockout criterion setting value meets the preset release inrush current lockout criterion, and the discontinuity angle lockout criterion does not issue a lockout signal.

[0144] The inrush current blocking criterion is:

[0145]

[0146] Among them, i set.UL To release the locking criterion setting, This represents the sudden change in the differential current sampling value. A, B, and C are the three phases of the transformer, and k is the braking coefficient.

[0147] Optionally, submodules are defined, including:

[0148] As a unit, the smaller value of the sudden change in the differential current sampling value between two consecutive sampling points that determine the second start-up time is used as the set value for the unlocking criterion, and its formula is as follows:

[0149]

[0150] in, The change in the differential current sample value at time t2 is the amount of change. A, B, and C are the three phases of the transformer. The value of the differential current sample at time t2-δt is the abrupt change in the value, where δt is the first predetermined time period.

[0151] Exemplary electronic devices

[0152] Figure 9 This is the structure of an electronic device provided in an exemplary embodiment of the present invention. For example... Figure 9 As shown, the electronic device 90 includes one or more processors 91 and memory 92.

[0153] The processor 91 may be a central processing unit (CPU) or other form of processing unit with data processing and / or instruction execution capabilities, and may control other components in the electronic device to perform desired functions.

[0154] The memory 92 may include one or more computer program products, which may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may include, for example, random access memory (RAM) and / or cache memory. The non-volatile memory may include, for example, read-only memory (ROM), hard disk, flash memory, etc. One or more computer program instructions may be stored on the computer-readable storage medium, and the processor 91 may execute the program instructions to implement the methods of the software programs of the various embodiments of the present invention described above, and / or other desired functions. In one example, the electronic device may also include an input device 93 and an output device 94, these components being interconnected via a bus system and / or other forms of connection mechanisms (not shown).

[0155] In addition, the input device 93 may also include, for example, a keyboard, a mouse, etc.

[0156] The output device 94 can output various information to the outside. The output device 94 may include, for example, a display, a speaker, a printer, and a communication network and its connected remote output devices, etc.

[0157] Of course, for the sake of simplicity, Figure 9Only some of the components of this electronic device relevant to the present invention are shown, omitting components such as buses, input / output interfaces, etc. In addition, the electronic device may include any other suitable components depending on the specific application.

[0158] Exemplary computer program products and computer-readable storage media

[0159] In addition to the methods and apparatus described above, embodiments of the present invention may also be computer program products, which include computer program instructions that, when executed by a processor, cause the processor to perform the steps in the methods according to various embodiments of the present invention described in the "Exemplary Methods" section above.

[0160] The computer program product can be written in any combination of one or more programming languages ​​to perform the operations of the embodiments of the present invention. The programming languages ​​include object-oriented programming languages ​​such as Java and C++, as well as conventional procedural programming languages ​​such as C or similar languages. The program code can be executed entirely on the user's computing device, partially on the user's computing device, as a standalone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server.

[0161] Furthermore, embodiments of the present invention may also be computer-readable storage media storing computer program instructions thereon, which, when executed by a processor, cause the processor to perform the steps of the methods according to various embodiments of the present invention described in the "Exemplary Methods" section above.

[0162] The computer-readable storage medium may be any combination of one or more readable media. A readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may be, for example, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, or any combination thereof. More specific examples (a non-exhaustive list) of readable storage media include: an electrical connection having one or more wires, a portable disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof.

[0163] The basic principles of the present invention have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in the present invention are merely examples and not limitations, and should not be considered as essential features of each embodiment of the present invention. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the present invention to the necessity of employing the aforementioned specific details.

[0164] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For system embodiments, since they largely correspond to method embodiments, the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments.

[0165] The block diagrams of devices, systems, devices, and systems involved in this invention are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, systems, devices, and systems can be connected, arranged, and configured in any manner. Words such as “comprising,” “including,” “having,” etc., are open-ended terms meaning “including but not limited to,” and are used interchangeably with them. The terms “or” and “and” as used herein refer to the terms “and / or,” and are used interchangeably with them unless the context clearly indicates otherwise. The term “such as” as used herein refers to the phrase “such as but not limited to,” and is used interchangeably with it.

[0166] The methods and systems of the present invention may be implemented in many ways. For example, they may be implemented by software, hardware, firmware, or any combination of software, hardware, and firmware. The above-described order of steps for the methods is for illustrative purposes only, and the steps of the methods of the present invention are not limited to the order specifically described above unless otherwise specifically stated. Furthermore, in some embodiments, the present invention may also be implemented as a program recorded on a recording medium, the program comprising machine-readable instructions for implementing the methods according to the present invention. Thus, the present invention also covers recording media storing programs for performing the methods according to the present invention.

[0167] It should also be noted that in the systems, apparatus, and methods of the present invention, the components or steps can be disassembled and / or recombined. These disassemblies and / or recombinations should be considered equivalents of the present invention. The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the invention. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of the invention. Therefore, the invention is not intended to be limited to the aspects shown herein, but rather to be carried out within the widest scope consistent with the principles and novel features disclosed herein.

[0168] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of the invention to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations therein.

Claims

1. A method for releasing inrush current blocking in a transformer, characterized in that, include: The abrupt change in the differential current sampling value of the transformer corresponding to the sampling point at a first predetermined time interval is calculated in real time based on the current sampling values ​​on each side of the transformer. If the abrupt change in the differential current sample value at two consecutive sampling points satisfies the pre-built trigger criterion for the abrupt change in the differential current sample value of the transformer, the time corresponding to the next sampling point is determined as the first trigger time for the abrupt change in the differential current sample value. After the first start-up time interval, if the differential current sampling value mutation amount of two consecutive sampling points meets the differential current sampling value mutation amount start-up criterion, the time corresponding to the next sampling point is determined as the second start-up time of the differential current sampling value mutation amount. After the first start-up time, based on the sudden change in the differential current sampling value of the transformer's sampling point and the pre-set discontinuity angle blocking criterion, it is determined whether to issue a blocking signal. Based on the sudden change in the differential current sampling value of the two sampling points used to determine the second start-up time and whether the intermittent angle blocking criterion issues a blocking signal, it is determined whether the transformer has released the inrush current blocking. Based on the abrupt change in the differential current sampling values ​​at the two sampling points determining the second start-up time and whether the intermittent angle blocking criterion issues a blocking signal, it is determined whether the transformer has released the inrush current blocking, including: The lockout release criterion setting is determined based on the sudden change in the differential current sampling value at two consecutive sampling points that determine the second start time. After the second predetermined time interval of the second start-up time interval, if the unlocking criterion setting satisfies the preset unlocking criterion for inrush current blocking, and the intermittent angle blocking criterion does not issue the blocking signal, the inrush current blocking is released, wherein... The inrush current blocking criterion is: in, To release the locking criterion setting, This represents the sudden change in the differential current sampling value. A, B, and C are the three phases of the transformer. k This is the braking coefficient; Based on the abrupt change in the differential current sampling value at two consecutive sampling points determining the second start-up time, the unlocking criterion setting is determined, including: The smaller value of the sudden change in the differential current sample value at two consecutive sampling points that determine the second start time is used as the unlocking criterion value, and the formula is as follows: in, for The sudden change in the differential current sample value at time t. A, B, and C are the three phases of the transformer. for The sudden change in the differential current sample value at time t. This is the first scheduled time period.

2. The method according to claim 1, characterized in that, The abrupt change in the differential current sampling value of the transformer corresponding to the sampling point at a first predetermined time interval is calculated in real time based on the current sampling values ​​on each side of the transformer, including: The differential current sampling value of the transformer corresponding to the sampling point at the first predetermined time interval is calculated in real time based on the current sampling value of each side of the transformer. The abrupt change in the differential current sampling value of the transformer corresponding to the sampling point at a first predetermined time interval is calculated in real time based on the differential current sampling value of the transformer. The formula for calculating the differential current sampling value of the transformer is as follows: The formula for calculating the abrupt change in the differential current sample value is as follows: in, for t The sudden change in the differential current sample value at time t. This is the sampled value of the transformer differential current. A, B, and C are the three phases of the transformer. For transformer number i The current sampling value after balance factor conversion and phase correction. T It is the power frequency cycle.

3. The method according to claim 1, characterized in that, The trigger criterion for the sudden change in the differential current sample value is as follows: in, This represents the sudden change in the differential current sampling value. The starting setting value for transformer differential protection.

4. The method according to claim 1, characterized in that, Based on the abrupt change in the differential current sampling value at the transformer sampling point and the pre-set discontinuity angle blocking criterion, determine whether to issue a blocking signal, including: If the abrupt change in the differential current sampling values ​​at four consecutive sampling points satisfies a pre-set discontinuity angle blocking criterion, the discontinuity angle blocking criterion issues a blocking signal; otherwise, the discontinuity angle blocking criterion does not issue the blocking signal. The intermittent angle locking criterion is as follows: in, This represents the sudden change in the differential current sampling value. A, B, and C are the three phases of the transformer. The starting setting value for transformer differential protection.

5. A device for releasing inrush current lockout in a transformer, characterized in that, include: The calculation module is used to calculate in real time the abrupt change in the differential current sampling value of the transformer corresponding to the sampling point at a first predetermined time interval based on the current sampling values ​​of each side of the transformer. The first determining module is used to determine the time corresponding to the next sampling point as the first start time of the differential current sampling value mutation when the mutation amount of the differential current sampling value at two consecutive sampling points meets the pre-constructed differential current sampling value mutation start criterion of the transformer. The second determining module is used to determine the time corresponding to the next sampling point as the second start time of the differential current sampling value mutation after the second predetermined time period of the first start time interval, when the mutation amount of the differential current sampling value at two consecutive sampling points meets the start criterion of the differential current sampling value mutation amount. The third determining module is used to determine whether to issue a blocking signal after the first start-up time, based on the sudden change in the differential current sampling value of the transformer sampling point and the pre-set discontinuity angle blocking criterion. The judgment module is used to determine whether the transformer has released the inrush current lockout based on the sudden change in the differential current sampling value of the two sampling points that determine the second start time and whether the intermittent angle lockout criterion has issued a lockout signal. The judgment module includes: The lockout release criterion setting is determined based on the sudden change in the differential current sampling value at two consecutive sampling points that determine the second start time. After the second predetermined time interval of the second start-up time interval, if the unlocking criterion setting satisfies the preset unlocking criterion for inrush current blocking, and the intermittent angle blocking criterion does not issue the blocking signal, the inrush current blocking is released, wherein... The inrush current blocking criterion is: in, To release the locking criterion setting, This represents the sudden change in the differential current sampling value. A, B, and C are the three phases of the transformer. k This is the braking coefficient; Based on the abrupt change in the differential current sampling value at two consecutive sampling points determining the second start-up time, the unlocking criterion setting is determined, including: The smaller value of the sudden change in the differential current sample value at two consecutive sampling points that determine the second start time is used as the unlocking criterion value, and the formula is as follows: in, for The sudden change in the differential current sample value at time t. A, B, and C are the three phases of the transformer. for The sudden change in the differential current sample value at time t. This is the first scheduled time period.

6. The apparatus according to claim 5, characterized in that, The calculation module includes: The first calculation submodule is used to calculate the transformer differential current sampling value corresponding to the sampling point at a first predetermined time interval based on the current sampling value of each side of the transformer in real time. The second calculation submodule is used to calculate in real time the sudden change in the differential current sampling value of the transformer corresponding to the sampling point at a first predetermined time interval, based on the differential current sampling value of the transformer. The formula for calculating the differential current sampling value of the transformer is as follows: The formula for calculating the abrupt change in the differential current sample value is as follows: in, for t The sudden change in the differential current sample value at time t. This is the sampled value of the transformer differential current. A, B, and C are the three phases of the transformer. For transformer number i The current sampling value after balance factor conversion and phase correction. T It is the power frequency cycle.

7. The apparatus according to claim 5, characterized in that, The trigger criterion for the sudden change in the differential current sample value is as follows: in, This represents the sudden change in the differential current sampling value. The starting setting value for transformer differential protection.

8. The apparatus according to claim 5, characterized in that, Based on the abrupt change in the differential current sampling value at the transformer sampling point and the pre-set discontinuity angle blocking criterion, determine whether to issue a blocking signal, including: If the abrupt change in the differential current sampling values ​​at four consecutive sampling points satisfies a pre-set discontinuity angle blocking criterion, the discontinuity angle blocking criterion issues a blocking signal; otherwise, the discontinuity angle blocking criterion does not issue the blocking signal. The intermittent angle locking criterion is as follows: in, This represents the sudden change in the differential current sampling value. A, B, and C are the three phases of the transformer. The starting setting value for transformer differential protection.

9. A computer-readable storage medium, characterized in that, The storage medium stores a computer program for performing the method described in any one of claims 1-4.

10. An electronic device, characterized in that, The electronic device includes: processor; Memory used to store the processor's executable instructions; The processor is configured to read the executable instructions from the memory and execute the instructions to implement the method described in any one of claims 1-4.

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