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

Abstract

The application discloses a transformer inrush current unlocking implementation method, device, medium and equipment. The method comprises the following steps: real-time calculation of the differential current sampling value of the transformer corresponding to the sampling point in the interval of the first predetermined time period according to the current sampling value of each side of the transformer; in the case that the differential current sampling value meets the pre-set starting criterion, the starting moment of the starting criterion is determined; according to the starting moment and the differential current sampling value at the moment, the generated unlocking current interval and the generated floating threshold interval of each current calculation moment in the power frequency cycle are determined; according to the differential current sampling value of the generated unlocking current interval and the generated floating threshold interval, the unlocking current and the floating threshold current of each current calculation moment are determined; in the case that the unlocking current and the floating threshold current of any current calculation moment meet the pre-set inrush current unlocking criterion, the transformer inrush current unlocking 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 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.

[0007] If the differential current sampling value meets the preset start criterion, determine the start time of the start criterion;

[0008] Based on the start-up time and the differential current sampling value at that time, determine the generation unlocking current range and the generation floating threshold range for each current calculation time within the power frequency cycle;

[0009] Based on the differential current sampling values ​​of the generated unlocking current range and the generated floating threshold range, determine the unlocking current and floating threshold current at each current calculation moment;

[0010] If the unlocking current and floating threshold current at any given calculation time satisfy the pre-set criteria for releasing the inrush current lockout, the transformer is determined to be released from the inrush current lockout.

[0011] Optionally, the activation criterion is as follows:

[0012]

[0013] The formula for calculating the differential current sample value is as follows:

[0014]

[0015] in, For transformer Phase differential current sampling value, A, B, and C are the three phases of the transformer. I represents the sampled current value on the i-th side of the transformer after balance factor conversion and phase correction. e This is the rated current of the transformer.

[0016] Optionally, based on the startup time and the differential current sampling value at that time, the generation unlocking current range and the generation floating threshold range for each current calculation time within the power frequency cycle are determined, including:

[0017] Based on the start time, the differential current sampling value at that time, and the pre-set criterion for the time length of the generated unlocking current interval, the time length of the generated unlocking current interval is determined for each current calculation time.

[0018] Based on the start time and the time length of the generation unlocking current interval, determine the generation floating threshold interval and the generation unlocking current interval for each current calculation time.

[0019] Optionally, the criterion for generating the unlocking current interval time length is as follows:

[0020]

[0021] Where t0 is the startup time. The differential current sampling value at startup. A, B, and C are the three phases of the transformer. The differential current sample value is given at time t0+2Δt; Δt is the basic time unit for the criterion, and

[0022] Based on the startup time, the differential current sampling value at that time, and the pre-set criterion for the generation unlocking current interval length, the generation unlocking current interval length for each current calculation time is determined, including:

[0023] If the differential current sample value at the start-up moment satisfies the criterion for the time length of the generation unlocking current interval, then the time length T of the generation unlocking current interval is determined. Σ =3Δt;

[0024] If the differential current sample value at the start-up moment does not meet the criterion for the time length of the generation unlocking current interval, the time length T of the generation unlocking current interval is determined. Σ =2Δt.

[0025] Optionally, based on the differential current sampling values ​​generated for the unlocking current range and the floating threshold range, the unlocking current and floating threshold current at each current calculation moment are determined, including:

[0026] The maximum unlocking current is determined based on the maximum absolute value of the differential current sample value within the generated unlocking current interval at each current calculation moment. The calculation formula is as follows:

[0027]

[0028] in, For the maximum unlocking current, A, B, and C are the three phases of the transformer. For the differential current sampling value, [tT Σ [,t] represents the range for generating the unlocking current, where t is the current calculation time, and T is the current value. Σ The time length for generating the unlocking current interval;

[0029] The maximum floating threshold current is determined based on the maximum absolute value of the differential current sample value within the generated floating threshold interval at each current calculation time. The calculation formula is as follows:

[0030]

[0031] in, The maximum floating threshold current, A, B, and C are the three phases of the transformer. The differential current sampling value is [t0, tT]. Σ ) represents the generation of the floating threshold interval, t0 is the start time, t is the current calculation time, and T is the value of T. Σ The time length for generating the unlocking current interval;

[0032] The floating threshold current at each current calculation moment is determined based on the differential current sampling value corresponding to the maximum unlocking current and the differential current sampling value corresponding to the maximum floating threshold current at each current calculation moment.

[0033] The unlocking current at each current calculation moment is determined based on the differential current sampling value and the maximum unlocking current at each sampling point within the generated unlocking current range at each current calculation moment.

[0034] Optionally, the floating threshold current at each current calculation moment is determined based on the differential current sample value corresponding to the maximum unlocking current and the differential current sample value corresponding to the maximum floating threshold current at each current calculation moment, including:

[0035] If the differential current sample value corresponding to the maximum unlocking current and the differential current sample value corresponding to the maximum floating threshold current at each current calculation moment satisfy the extreme value criterion, then the floating threshold current at that current calculation moment is the maximum floating threshold current. The extreme value criterion is as follows:

[0036]

[0037] in, This is the differential current sampling value corresponding to the maximum unlocking current. A, B, and C are the three phases of the transformer. This is the differential current sample value corresponding to the maximum floating threshold current;

[0038] If the differential current sample value corresponding to the maximum unlocking current and the differential current sample value corresponding to the maximum floating threshold current at each current calculation moment do not satisfy the extreme value criterion, the floating threshold current at that current calculation moment is:

[0039]

[0040] in, For floating threshold current, The maximum floating threshold current, A, B, and C are the three phases of the transformer. This is the maximum unlocking current.

[0041] Optionally, the criterion for releasing the inrush current lockout is:

[0042]

[0043] in, To unlock the current, A, B, and C are the three phases of the transformer. For floating threshold current, To generate the integral result of the differential current sample values ​​within the unlocking current range, n is the number of sampling points within the unlocking current range.

[0044] According to another aspect of the present invention, an apparatus for releasing inrush current lockout of a transformer is provided, comprising:

[0045] The calculation module is used to calculate the differential current sampling value of the transformer 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.

[0046] The first determining module is used to determine the start time of the start criterion when the differential current sampling value meets the preset start criterion.

[0047] The second determining module is used to determine the generation unlocking current range and the generation floating threshold range for each current calculation time within the power frequency cycle based on the start time and the differential current sampling value at that time.

[0048] The third determining module is used to determine the unlocking current and floating threshold current at each current calculation moment based on the differential current sampling values ​​of the generated unlocking current range and the generated floating threshold range.

[0049] The fourth determination module is used to determine whether the transformer is released from inrush current blocking if the unlocking current and floating threshold current at any current calculation moment meet the preset criteria for releasing inrush current blocking.

[0050] 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.

[0051] 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.

[0052] Therefore, the method for releasing inrush current blocking of a transformer provided in this application calculates the differential current sampling value of the transformer corresponding to the sampling point at a first predetermined time interval, and determines the start time of the start criterion based on the start criterion. Then, iteratively calculates and generates the unlocking current interval and the floating threshold interval within the cycle, determining the unlocking current and the floating threshold current at each current calculation time. If the unlocking current and the floating threshold current at any current calculation time satisfy the pre-set release criterion for inrush current blocking, the transformer is released from inrush current blocking. This quickly disconnects the short circuit that develops from small turns to large turns after being blocked by inrush current, thereby accelerating the operation speed of the transformer fault protection and increasing the transformer's service life. Attached Figure Description

[0053] Exemplary embodiments of the present invention can be more fully understood by referring to the following figures:

[0054] 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.

[0055] 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.

[0056] Figure 3 This is a schematic diagram of the time axis of the transformer inrush current blocking criterion release criterion provided in an exemplary embodiment of the present invention;

[0057] Figure 4 This is a schematic diagram illustrating the determination of the generation unlocking current range and the generation of the floating threshold range provided in an exemplary embodiment of the present invention;

[0058] Figure 5 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;

[0059] Figure 6 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;

[0060] Figure 7 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;

[0061] Figure 8 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;

[0062] Figure 9 This is a schematic diagram of the structure of a transformer inrush current release device provided in an exemplary embodiment of the present invention;

[0063] Figure 10 This is the structure of an electronic device provided in an exemplary embodiment of the present invention. Detailed Implementation

[0064] Hereinafter, exemplary embodiments according to the present invention will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments of the present invention. It should be understood that the present invention is not limited to the exemplary embodiments described herein.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] Exemplary methods

[0078] 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:

[0079] Step 101, refer to Figure 1 and Figure 2 As shown, 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 ​​of each side of the transformer.

[0080] Step 102, refer to Figure 1 and Figure 2 As shown, the start time of the start criterion is determined when the differential current sampling value meets the preset start criterion.

[0081] Optionally, the activation criterion is as follows:

[0082]

[0083] The formula for calculating the differential current sample value is as follows:

[0084]

[0085] in, For transformer Phase differential current sampling value, A, B, and C are the three phases of the transformer. I represents the sampled current value on the i-th side of the transformer after balance factor conversion and phase correction. e This is the rated current of the transformer.

[0086] Specifically, the moment when the start criterion is satisfied is the start time t0 of the start criterion.

[0087] Step 103, refer to Figure 1 and Figure 2 As shown, based on the start-up time and the differential current sampling value at that time, the generation unlocking current range and the generation floating threshold range are determined for each current calculation time within the power frequency cycle.

[0088] Optionally, based on the startup time and the differential current sampling value at that time, the generation unlocking current range and the generation floating threshold range for each current calculation time within the power frequency cycle are determined, including:

[0089] Based on the start time, the differential current sampling value at that time, and the pre-set criterion for the time length of the generated unlocking current interval, the time length of the generated unlocking current interval is determined for each current calculation time.

[0090] Based on the start time and the time length of the generation unlocking current interval, determine the generation floating threshold interval and the generation unlocking current interval for each current calculation time.

[0091] Optionally, the criterion for generating the unlocking current interval time length is as follows:

[0092]

[0093] Where t0 is the startup time. The differential current sampling value at startup. A, B, and C are the three phases of the transformer; The differential current sample value is given at time t0+2Δt; Δt is the basic time unit for the criterion, and

[0094] Based on the startup time, the differential current sampling value at that time, and the pre-set criterion for the generation unlocking current interval length, the generation unlocking current interval length for each current calculation time is determined, including:

[0095] If the differential current sample value at the start-up moment satisfies the criterion for the time length of the generation unlocking current interval, then the time length T of the generation unlocking current interval is determined. Σ =3Δt;

[0096] If the differential current sample value at the start-up moment does not meet the criterion for the time length of the generation unlocking current interval, the time length T of the generation unlocking current interval is determined. Σ =2Δt.

[0097] Specifically, refer to Figure 3 As shown, the current calculation time is t, and the generated unlocking current range is [tT]. Σ The starting criterion is that the starting time is t0, and the floating threshold interval is [t0, tT]. Σ ).

[0098] The floating threshold range and the unlocking current range are calculated within one power frequency cycle, that is, the calculation starts from time t0+5Δt and ends at the end of one calculation cycle t0+5Δt+T.

[0099] refer to Figure 4 As shown, in T Σ When t = 3Δt, and t = t0 + 5Δt, the generated unlocking current range is [t0 + 2Δt, t0 + 5Δt], and the generated floating threshold range is [t0, t0 + 2Δt), where Δt can be, but is not limited to, 2.5ms.

[0100] In T Σ When t = 2Δt, and t = t0 + 5Δt, the range for generating the unlocking current is [t0 + 3Δt, t0 + 5Δt], and the range for generating the floating threshold is [t0, t0 + 3Δt].

[0101] Step 104, refer to Figure 1 and Figure 2 As shown, the unlocking current and floating threshold current at each current calculation moment are determined based on the differential current sampling values ​​of the generated unlocking current range and the generated floating threshold range.

[0102] Optionally, based on the differential current sampling values ​​generated for the unlocking current range and the floating threshold range, the unlocking current and floating threshold current at each current calculation moment are determined, including:

[0103] The maximum unlocking current is determined based on the maximum absolute value of the differential current sample value within the generated unlocking current interval at each current calculation moment. The calculation formula is as follows:

[0104]

[0105] in, For the maximum unlocking current, A, B, and C are the three phases of the transformer. For the differential current sampling value, [tT Σ [,t] represents the range for generating the unlocking current, where t is the current calculation time, and T is the current value. Σ The time length for generating the unlocking current interval;

[0106] The maximum floating threshold current is determined based on the maximum absolute value of the differential current sample value within the generated floating threshold interval at each current calculation time. The calculation formula is as follows:

[0107]

[0108] in, The maximum floating threshold current, A, B, and C are the three phases of the transformer. The differential current sampling value is [t0, tT]. Σ ) represents the generation of the floating threshold interval, t0 is the start time, t is the current calculation time, and T is the value of T. Σ The time length for generating the unlocking current interval;

[0109] The floating threshold current at each current calculation moment is determined based on the differential current sampling value corresponding to the maximum unlocking current and the differential current sampling value corresponding to the maximum floating threshold current at each current calculation moment.

[0110] The unlocking current at each current calculation moment is determined based on the differential current sampling value and the maximum unlocking current at each sampling point within the generated unlocking current range at each current calculation moment.

[0111] Optionally, the floating threshold current at each current calculation moment is determined based on the differential current sample value corresponding to the maximum unlocking current and the differential current sample value corresponding to the maximum floating threshold current at each current calculation moment, including:

[0112] If the differential current sample value corresponding to the maximum unlocking current and the differential current sample value corresponding to the maximum floating threshold current at each current calculation moment satisfy the extreme value criterion, then the floating threshold current at that current calculation moment is the maximum floating threshold current. The extreme value criterion is as follows:

[0113]

[0114] in, This is the differential current sampling value corresponding to the maximum unlocking current. A, B, and C are the three phases of the transformer; This is the differential current sample value corresponding to the maximum floating threshold current;

[0115] If the differential current sample value corresponding to the maximum unlocking current and the differential current sample value corresponding to the maximum floating threshold current at each current calculation moment do not satisfy the extreme value criterion, the floating threshold current at that current calculation moment is:

[0116]

[0117] in, For floating threshold current, The maximum floating threshold current, A, B, and C are the three phases of the transformer. This is the maximum unlocking current.

[0118] Step 105, refer to Figure 1 and Figure 2As shown, if the unlocking current and floating threshold current at any given calculation time satisfy the pre-set criteria for releasing the inrush current lockout, the transformer is determined to release the inrush current lockout.

[0119] Optionally, the criterion for releasing the inrush current lockout is:

[0120]

[0121] in, To unlock the current, A, B, and C are the three phases of the transformer. For floating threshold current, To generate the integral result of the differential current sample values ​​within the unlocking current range, n is the number of sampling points within the unlocking current range.

[0122] Specifically, the transformer is determined to be released from inrush current blockade if the unlocking current and floating threshold current at any given calculation time satisfy the pre-set criteria for releasing inrush current blockade.

[0123] In addition, refer to Figure 5 The example shown is an application to the developmental faults of a transformer.

[0124] 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 fault phase is phase B, and the transformer has been in the state of inrush current blocking differential protection since the beginning of the fault. The fault develops into a severe inter-turn fault in 28ms. The criterion for releasing the inrush current blocking of the transformer progressive fault is met in 32.5ms, and the inrush current blocking of the transformer is released.

[0125] In addition, refer to Figure 6 As shown, this is an example of an application to transformers that experience inrush current during no-load charging.

[0126] When the transformer is charged under no-load conditions, an inrush current occurs. Taking phase A, which has the most severe inrush current, as an example, during the period when the inrush current occurs, the criteria for releasing the inrush current blockade due to the transformer's developmental fault are never met. The transformer is in the state of inrush current blockade differential protection and no false tripping occurs.

[0127] In addition, refer to Figure 7 The example shown illustrates the application of current generation and inrush current to transformers.

[0128] When an adjacent transformer is charged under no-load conditions, the transformer will experience inrush current. Taking phase A, which has the most severe inrush current, as an example, during the period when the inrush current occurs, the criteria for releasing the inrush current blocking due to the transformer's developmental fault are never met, and the transformer is in the state of inrush current blocking differential protection, without any false tripping.

[0129] In addition, refer to Figure 8 The example shown is applied to a transformer experiencing restorative inrush current.

[0130] When a transformer on the same bus fails, during the process of restoring the voltage of the bus after the fault is cleared, the transformer running under no-load will experience restorative inrush current. Taking phase A, which has the most severe inrush current, as an example, during the period when the restorative inrush current occurs, the criteria for releasing the excitation inrush current blockade of the transformer due to the developmental fault are never met. The transformer is in the state of excitation inrush current blockade differential protection and no false tripping occurs.

[0131] Therefore, the method for releasing inrush current blocking of a transformer provided in this application calculates the differential current sampling value of the transformer corresponding to the sampling point at a first predetermined time interval, and determines the start time of the start criterion based on the start criterion. Then, it iteratively calculates and generates the unlocking current interval and the floating threshold interval within the cycle, determining the unlocking current and the floating threshold current at each current calculation time. If the unlocking current and the floating threshold current at any current calculation time satisfy the pre-set release criterion for inrush current blocking, the transformer is released from inrush current blocking. This quickly disconnects the short circuit that develops from small turns to large turns after being blocked by inrush current, thereby accelerating the operation speed of the transformer fault protection.

[0132] Exemplary device

[0133] Figure 9 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 9 As shown, the device 900 includes:

[0134] The calculation module 910 is used to calculate the differential current sampling value of the transformer 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.

[0135] The first determining module 920 is used to determine the start time of the start criterion when the differential current sampling value meets the preset start criterion.

[0136] The second determining module 930 is used to determine the generation unlocking current range and the generation floating threshold range for each current calculation time within the power frequency cycle based on the start time and the differential current sampling value at that time.

[0137] The third determining module 940 is used to determine the unlocking current and the floating threshold current at each current calculation moment based on the differential current sampling values ​​of the generated unlocking current range and the generated floating threshold range.

[0138] The fourth determination module 950 is used to determine that the transformer is released from inrush current blocking if the unlocking current and floating threshold current at any current calculation moment meet the preset release criterion for inrush current blocking.

[0139] Optionally, the activation criterion is as follows:

[0140]

[0141] The formula for calculating the differential current sample value is as follows:

[0142]

[0143] in, For transformer Phase differential current sampling value, A, B, and C are the three phases of the transformer. I represents the sampled current value on the i-th side of the transformer after balance factor conversion and phase correction. e This is the rated current of the transformer.

[0144] Optionally, the second determining module 930 includes:

[0145] The first determining submodule is used to determine the length of the generating unlocking current interval for each current calculation moment based on the start time, the differential current sampling value at that time, and the pre-set criterion for the length of the generating unlocking current interval.

[0146] The second determining submodule is used to determine the generation floating threshold range and the generation unlocking current range for each current calculation moment based on the startup time and the time length of the generation unlocking current range.

[0147] Optionally, the criterion for generating the unlocking current interval time length is as follows:

[0148]

[0149] Where t0 is the startup time. The differential current sampling value at startup. A, B, and C are the three phases of the transformer; The differential current sample value is given at time t0+2Δt; Δt is the basic time unit for the criterion, and

[0150] The first determined submodule includes:

[0151] The first determining unit is used to determine the time length T of the generated unlocking current interval, provided that the differential current sample value at the start-up time satisfies the criterion for the time length of the generated unlocking current interval. Σ =3Δt;

[0152] The second determining unit is used to determine the time length T of the generated unlocking current interval when the differential current sample value at the start-up time does not meet the criterion for the time length of the generated unlocking current interval. Σ =2Δt.

[0153] Optionally, the third determining module 940 includes:

[0154] The third determining submodule is used to determine the maximum unlocking current based on the maximum absolute value of the differential current sample value within the generated unlocking current interval at each current calculation time. The calculation formula is as follows:

[0155]

[0156] in, For the maximum unlocking current, A, B, and C are the three phases of the transformer. For the differential current sampling value, [tT Σ [,t] represents the range for generating the unlocking current, where t is the current calculation time, and T is the current value. Σ The time length for generating the unlocking current interval;

[0157] The fourth determination submodule is used to determine the maximum floating threshold current based on the maximum absolute value of the differential current sample value within the generated floating threshold interval at each current calculation time. The calculation formula is as follows:

[0158]

[0159] in, The maximum floating threshold current, A, B, and C are the three phases of the transformer. The differential current sampling value is [t0, tT]. Σ ) represents the generation of the floating threshold interval, t0 is the start time, t is the current calculation time, and T is the value of T. Σ The time length for generating the unlocking current interval;

[0160] The fifth determination submodule is used to determine the floating threshold current at each current calculation time based on the differential current sampling value corresponding to the maximum unlocking current and the differential current sampling value corresponding to the maximum floating threshold current at each current calculation time.

[0161] The sixth determination submodule is used to determine the unlocking current at each current calculation time based on the differential current sampling value of each sampling point within the generated unlocking current range and the maximum unlocking current at each current calculation time.

[0162] Optionally, the fifth determining submodule includes:

[0163] The third determining unit is used to determine the floating threshold current at each current calculation moment as the maximum floating threshold current if the differential current sample value corresponding to the maximum unlocking current and the differential current sample value corresponding to the maximum floating threshold current satisfy the extreme value criterion. The extreme value criterion is as follows:

[0164]

[0165] in, This is the differential current sampling value corresponding to the maximum unlocking current. A, B, and C are the three phases of the transformer; This is the differential current sample value corresponding to the maximum floating threshold current;

[0166] The fourth determining unit is used to determine the floating threshold current at each current calculation moment when the differential current sample value corresponding to the maximum unlocking current and the differential current sample value corresponding to the maximum floating threshold current do not satisfy the extreme value criterion.

[0167]

[0168] in, For floating threshold current, The maximum floating threshold current, A, B, and C are the three phases of the transformer. This is the maximum unlocking current.

[0169] Optionally, the criterion for releasing the inrush current lockout is:

[0170]

[0171] in, To unlock the current, A, B, and C are the three transformers.

[0172] Mutually, For floating threshold current, To generate the integral result of the differential current sample values ​​within the unlocking current range, n is the number of sampling points within the unlocking current range.

[0173] Exemplary electronic devices

[0174] Figure 10 This is the structure of an electronic device provided in an exemplary embodiment of the present invention. For example... Figure 10 As shown, the electronic device 100 includes one or more processors 101 and memory 102.

[0175] The processor 101 may be a central processing unit (CPU) or other form of processing unit with data processing capabilities and / or instruction execution capabilities, and may control other components in the electronic device to perform desired functions.

[0176] The memory 102 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 101 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 103 and an output device 104, these components being interconnected via a bus system and / or other forms of connection mechanisms (not shown).

[0177] In addition, the input device 103 may also include, for example, a keyboard, a mouse, etc.

[0178] The output device 104 can output various information to the outside. The output device 104 may include, for example, a display, a speaker, a printer, and a communication network and its connected remote output devices, etc.

[0179] Of course, for the sake of simplicity, Figure 10 Only 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.

[0180] Exemplary computer program products and computer-readable storage media

[0181] 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 of the methods according to various embodiments of the present invention described in the "Exemplary Methods" section above.

[0182] 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.

[0183] 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.

[0184] 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.

[0185] 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.

[0186] 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.

[0187] 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.

[0188] 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.

[0189] 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.

[0190] 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 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 value on each side of the transformer. If the differential current sampling value meets the preset start criterion, the start time of the start criterion is determined; Based on the start time and the differential current sampling value at that time, determine the generation unlocking current range and the generation floating threshold range for each current calculation time within the power frequency cycle; Based on the differential current sampling values ​​of the generated unlocking current range and the generated floating threshold range, determine the unlocking current and floating threshold current at each current calculation moment; If the unlocking current and the floating threshold current at any given calculation time satisfy the preset criteria for releasing the inrush current lockout, the transformer is determined to release the inrush current lockout. The activation criteria are as follows: The formula for calculating the differential current sample value is as follows: in, This is the sampled value of the 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. This is the transformer's rated current. Based on the startup time and the differential current sampling value at that time, the generation unlocking current range and the generation floating threshold range for each current calculation time within the power frequency cycle are determined, including: Based on the start time, the differential current sampling value at that time, and the pre-set generation unlocking current interval time length criterion, the generation unlocking current interval time length at each current calculation time is determined; Based on the start time and the time length of the generated unlocking current interval, determine the generated floating threshold interval and the generated unlocking current interval for each current calculation time. The criterion for determining the time length of the generated unlocking current interval is as follows: in, t 0 represents the start time. The differential current sampling value at startup. A, B, and C are the three phases of the transformer; for Differential current sampling value at any time; The basic unit of time for the criterion, and Based on the start-up time, the differential current sample value at that time, and a pre-set criterion for the time length of the generated unlocking current interval, the time length of the generated unlocking current interval at each current calculation time is determined, including: If, at the start-up time, the differential current sample value at that time satisfies the time length criterion for generating the unlocking current interval, the time length of the generating unlocking current interval is determined. ; If, at the start-up time, the differential current sample value at that time does not meet the criterion for the time length of the generated unlocking current interval, the time length of the generated unlocking current interval is determined. .

2. The method according to claim 1, characterized in that, Based on the differential current sampling values ​​of the generated unlocking current range and the generated floating threshold range, determine the unlocking current and floating threshold current at each current calculation moment, including: The maximum unlocking current is determined based on the maximum absolute value of the differential current sample value within the generated unlocking current interval at each current calculation moment. The calculation formula is as follows: in, For the maximum unlocking current, This is the sampled value of the differential current. A, B, and C are the three phases of the transformer. To generate the unlocking current range, t For the current calculation time, T Σ The time length for generating the unlocking current interval; The maximum floating threshold current is determined based on the maximum absolute value of the differential current sample value within the generated floating threshold interval at each current calculation time. The calculation formula is as follows: in, The maximum floating threshold current, This is the sampled value of the differential current. To generate a floating threshold range, t 0 represents the start time. t For the current calculation time, T Σ The time length for generating the unlocking current interval; The floating threshold current at each current calculation moment is determined based on the differential current sampling value corresponding to the maximum unlocking current and the differential current sampling value corresponding to the maximum floating threshold current at each current calculation moment. The unlocking current at each current calculation moment is determined based on the differential current sample value at each sampling point within the generated unlocking current interval and the maximum unlocking current.

3. The method according to claim 2, characterized in that, Based on the differential current sample value corresponding to the maximum unlocking current and the differential current sample value corresponding to the maximum floating threshold current at each current calculation time, the floating threshold current at each current calculation time is determined, including: If the differential current sample value corresponding to the maximum unlocking current and the differential current sample value corresponding to the maximum floating threshold current at each current calculation moment satisfy the extreme value criterion, then the floating threshold current at that current calculation moment is the maximum floating threshold current, wherein the extreme value criterion is as follows: in, This is the differential current sampling value corresponding to the maximum unlocking current. A, B, and C are the three phases of the transformer. The differential current sample value corresponding to the maximum floating threshold current; If the differential current sample value corresponding to the maximum unlocking current and the differential current sample value corresponding to the maximum floating threshold current at each current calculation moment do not satisfy the extreme value criterion, the floating threshold current at that current calculation moment is: in, For floating threshold current, The maximum floating threshold current, This refers to the maximum unlocking current.

4. The method according to claim 2, characterized in that, The criterion for releasing the inrush current lockout is: in, To unlock the current, For floating threshold current, A, B, and C are the three phases of the transformer. To generate the integral result of the differential current sample values ​​within the unlocking current range, n is the number of sampling points within the unlocking current range.

5. A device for releasing inrush current lockout in a transformer, used to implement the method of claim 1, characterized in that, include: The calculation module is used to calculate the differential current sampling value of the transformer 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 first determining module is used to determine the start time of the start criterion when the differential current sampling value meets the preset start criterion. The second determining module is used to determine the generation unlocking current range and the generation floating threshold range for each current calculation time within the power frequency cycle based on the start time and the differential current sampling value at that time. The third determining module is used to determine the unlocking current and the floating threshold current at each current calculation moment based on the differential current sampling value of the generated unlocking current range and the generated floating threshold range. The fourth determining module is used to determine that the transformer is released from inrush current blocking if the unlocking current and the floating threshold current at any current calculation moment satisfy a pre-set release criterion for inrush current blocking.

6. The apparatus according to claim 5, characterized in that, The third determining module includes: The maximum unlocking current is determined based on the maximum absolute value of the differential current sample value within the generated unlocking current interval at each current calculation moment. The calculation formula is as follows: in, For the maximum unlocking current, This is the sampled value of the differential current. A, B, and C are the three phases of the transformer. To generate the unlocking current range, t For the current calculation time, T Σ The time length for generating the unlocking current interval; The maximum floating threshold current is determined based on the maximum absolute value of the differential current sample value within the generated floating threshold interval at each current calculation time. The calculation formula is as follows: in, The maximum floating threshold current, This is the sampled value of the differential current. To generate a floating threshold range, t 0 represents the start time. t For the current calculation time, T Σ The time length for generating the unlocking current interval; The floating threshold current at each current calculation moment is determined based on the differential current sampling value corresponding to the maximum unlocking current and the differential current sampling value corresponding to the maximum floating threshold current at each current calculation moment. The unlocking current at each current calculation moment is determined based on the differential current sample value at each sampling point within the generated unlocking current interval and the maximum unlocking current.

7. The apparatus according to claim 6, characterized in that, Based on the differential current sample value corresponding to the maximum unlocking current and the differential current sample value corresponding to the maximum floating threshold current at each current calculation time, the floating threshold current at each current calculation time is determined, including: If the differential current sample value corresponding to the maximum unlocking current and the differential current sample value corresponding to the maximum floating threshold current at each current calculation moment satisfy the extreme value criterion, then the floating threshold current at that current calculation moment is the maximum floating threshold current, wherein the extreme value criterion is as follows: in, This is the differential current sampling value corresponding to the maximum unlocking current. A, B, and C are the three phases of the transformer. The differential current sample value corresponding to the maximum floating threshold current; If the differential current sample value corresponding to the maximum unlocking current and the differential current sample value corresponding to the maximum floating threshold current at each current calculation moment do not satisfy the extreme value criterion, the floating threshold current at that current calculation moment is: in, For floating threshold current, The maximum floating threshold current, This refers to the maximum unlocking current.

8. The apparatus according to claim 6, characterized in that, The criterion for releasing the inrush current lockout is: in, To unlock the current, For floating threshold current, A, B, and C are the three phases of the transformer. To generate the integral result of the differential current sample values ​​within the unlocking current range, n is the number of sampling points within the unlocking current range.

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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