A new steady-state differential current calculation method for power system setting calculation

Abstract

The application discloses a steady-state differential current calculation method for new power system setting calculation. The method comprises the following steps: obtaining phase current steady-state fundamental wave phase value on both sides of a new energy sending-out line in a new power system; calculating zero sequence current steady-state fundamental wave phase on both sides of the sending-out line according to the phase current steady-state fundamental wave phase value; calculating the included angle of the sum of positive and negative sequence components of the current on both sides of the sending-out line according to the zero sequence current steady-state fundamental wave phase; and calculating the steady-state differential current of the new power system according to the zero sequence current steady-state fundamental wave phase and the included angle. The calculated differential current can be used to check the sensitivity of differential protection, and the work efficiency of original sensitivity checking through electromagnetic transient simulation is greatly improved.

Description

Technical Field

[0001] This invention relates to the field of power system technology, and more specifically, to a novel method for calculating steady-state differential current used in power system setting calculations. Background Technology

[0002] In new power systems, renewable energy and other power electronic equipment exhibit characteristics such as phase angle control and amplitude limitation after a fault. However, due to the time required for control response, the fault current cannot immediately enter a controlled state during the fault transient process. The current amplitude is usually greater than the steady-state fault current amplitude after current limiting, and the current phase angle is constantly changing or fluctuating. This causes the fault current angle on both sides of the renewable energy transmission line and the amplitude of the fault point current to also change continuously. The fault transient process is closely related to the control strategy of the renewable energy converter, the voltage change after the fault, and the topology, exhibiting strong controllability and strong nonlinearity, making it difficult to accurately analyze using mathematical models. Existing relay protection setting calculations mainly use equivalent impedance or admittance to calculate the short-circuit current, resulting in low accuracy of the calculated short-circuit current for renewable energy transmission lines.

[0003] Because the control response time of power electronic equipment such as new energy sources is short, the transient short-circuit current characteristics mainly affect the operating performance of the main protection. New energy transmission lines are generally equipped with longitudinal differential protection as the main protection, and its setting is usually calculated to avoid the maximum unbalanced current, unaffected by the transient short-circuit current calculation results. However, in the sensitivity verification of the setting, it is necessary to calculate the actual differential current to determine whether the setting meets the sensitivity requirements. Since the accuracy of the calculated transient short-circuit current of new energy sources is low, the accuracy of the calculated transient differential current is also low. Currently, the transient differential current simulation results from electromagnetic transient simulation models are generally used for sensitivity verification in the setting calculation process. This requires building a detailed electromagnetic transient model, which is labor-intensive, inefficient, and difficult to meet the needs of practical applications. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a novel method for calculating steady-state differential current used in power system setting calculations.

[0005] According to one aspect of the present invention, a novel method for calculating steady-state differential current used in power system setting calculations is provided, comprising:

[0006] Obtain the steady-state fundamental phasor values ​​of phase current on both sides of the new energy transmission line in the new power system;

[0007] Calculate the zero-sequence current steady-state fundamental phasor on both sides of the transmission line based on the steady-state fundamental phasor value of the phase current.

[0008] Calculate the angle between the sum of the positive and negative sequence components of the current on both sides of the transmission line based on the zero-sequence current steady-state fundamental phasor.

[0009] The steady-state differential current of the new power system is calculated based on the steady-state fundamental phasor of the zero-sequence current and the included angle.

[0010] Optionally, based on the steady-state fundamental phasor value of the phase current, the formula for calculating the steady-state fundamental phasor of the zero-sequence current on both sides of the transmitting line is as follows:

[0011]

[0012]

[0013] in, The zero-sequence current steady-state fundamental phasor on both sides of the transmission line. The steady-state fundamental phasor values ​​of the phase current on both sides of the transmission line.

[0014] Optionally, the operation of calculating the angle between the sum of the positive and negative sequence components of the current on both sides of the transmitting line based on the zero-sequence current steady-state fundamental phasor includes:

[0015] Based on the zero-sequence current steady-state fundamental phasor, calculate the positive and negative sequence components of the current on both sides of the transmitting line respectively;

[0016] The angle between the positive and negative sequence components of the current on both sides of the transmitting line is calculated based on the sum of the positive and negative sequence components of the current on both sides of the transmitting line, using the following formula:

[0017]

[0018] in, The zero-sequence current steady-state fundamental phasor on both sides of the transmission line. For phase distinction, representing phases A, B, and C, These are the steady-state fundamental phasors of the phase currents on both sides of the line, with the positive direction pointing towards the line. The positive and negative sequence components of the current on both sides of the transmission line and the included angle.

[0019] Optionally, based on the zero-sequence current steady-state fundamental phasor and the included angle, the formula for calculating the steady-state differential current of the new power system is as follows:

[0020]

[0021] Among them, i diff For steady-state differential current, Angle These are the steady-state fundamental phasors of the phase currents on both sides of the line, with the positive direction pointing towards the line. The zero-sequence current steady-state fundamental phasor on both sides of the transmission line.

[0022] According to another aspect of the present invention, a novel steady-state differential current calculation device for power system setting calculation is provided, comprising:

[0023] The acquisition module is used to acquire the steady-state fundamental phasor values ​​of the phase current on both sides of the new energy transmission line in the new power system.

[0024] The first calculation module is used to calculate the zero-sequence current steady-state fundamental phasor on both sides of the transmission line based on the steady-state fundamental phasor value of the phase current.

[0025] The second calculation module is used to calculate the angle between the positive and negative sequence components of the current on both sides of the transmission line based on the zero-sequence current steady-state fundamental phasor.

[0026] The third calculation module is used to calculate the steady-state differential current of the new power system based on the zero-sequence current steady-state fundamental phasor and the included angle.

[0027] 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.

[0028] 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.

[0029] Therefore, this invention adjusts the phase angle difference between the positive and negative sequence components of the steady-state current on both sides to be reversed, while keeping the phase angle difference of the zero sequence component unchanged, and then adds them together to obtain a new differential current. The calculated differential current can be used to verify the sensitivity of the differential protection, greatly improving the efficiency of the original sensitivity verification work that required electromagnetic transient simulation. Attached Figure Description

[0030] Exemplary embodiments of the present invention can be more fully understood by referring to the following figures:

[0031] Figure 1 This is a flowchart illustrating a novel steady-state differential current calculation method for power system setting calculation provided by an exemplary embodiment of the present invention.

[0032] Figure 2 This is a schematic diagram of a new energy transmission line provided in an exemplary embodiment of the present invention;

[0033] Figure 3 This is a schematic diagram of differential current phasors provided in an exemplary embodiment of the present invention;

[0034] Figure 4This is a schematic diagram of the novel steady-state differential current and the actual differential current of the present invention during a metallic single-phase ground fault at the end of a line, provided by an exemplary embodiment of the present invention.

[0035] Figure 5a and Figure 5b These are schematic diagrams of the novel steady-state differential current and the actual differential current of the present invention during a metallic two-phase short-circuit fault at the end of a line, provided by an exemplary embodiment of the present invention.

[0036] Figure 6a and Figure 6b These are schematic diagrams of the novel steady-state differential current and the actual differential current of the present invention during a metallic two-phase ground fault at the end of a line, provided by an exemplary embodiment of the present invention.

[0037] Figure 7a , Figure 7b and Figure 7c These are schematic diagrams of the novel steady-state differential current and the actual differential current of the present invention during a metallic three-phase fault at the end of a line, provided by an exemplary embodiment of the present invention.

[0038] Figure 8 This is a schematic diagram of the structure of a novel steady-state differential current calculation device for power system setting calculation provided in an exemplary embodiment of the present invention;

[0039] Figure 9 This is the structure of an electronic device provided in an exemplary embodiment of the present invention. Detailed Implementation

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] Exemplary methods

[0054] Figure 1 This is a flowchart illustrating a novel steady-state differential current calculation method for power system setting calculations provided by an exemplary embodiment of the present invention. This embodiment can be applied to electronic devices, such as… Figure 1 As shown, the steady-state differential current calculation method 100 used in the new power system setting calculation includes the following steps:

[0055] Step 101: Obtain the steady-state fundamental phasor values ​​of the phase current on both sides of the new energy transmission line in the new power system.

[0056] Among them, for example, collection Figure 2 The steady-state fundamental phasor values ​​of the phase current on both sides of the new energy transmission line are shown.

[0057] Step 102: Calculate the zero-sequence current steady-state fundamental phasor on both sides of the transmission line based on the steady-state fundamental phasor value of the phase current.

[0058] Optionally, based on the steady-state fundamental phasor value of the phase current, the formula for calculating the steady-state fundamental phasor of the zero-sequence current on both sides of the transmitting line is as follows:

[0059]

[0060]

[0061] in, The zero-sequence current steady-state fundamental phasor on both sides of the transmission line. The steady-state fundamental phasor values ​​of the phase current on both sides of the transmission line.

[0062] Step 103: Calculate the angle between the sum of the positive and negative sequence components of the current on both sides of the transmission line based on the zero-sequence current steady-state fundamental phasor.

[0063] Optionally, the operation of calculating the angle between the sum of the positive and negative sequence components of the current on both sides of the transmitting line based on the zero-sequence current steady-state fundamental phasor includes:

[0064] Based on the zero-sequence current steady-state fundamental phasor, calculate the positive and negative sequence components of the current on both sides of the transmitting line respectively;

[0065] The angle between the positive and negative sequence components of the current on both sides of the transmitting line is calculated based on the sum of the positive and negative sequence components of the current on both sides of the transmitting line, using the following formula:

[0066]

[0067] in, The zero-sequence current steady-state fundamental phasor on both sides of the transmission line. For phase distinction, representing phases A, B, and C, These are the steady-state fundamental phasors of the phase currents on both sides of the line, with the positive direction pointing towards the line. The positive and negative sequence components of the current on both sides of the transmission line and the included angle.

[0068] Step 104: Calculate the steady-state differential current of the new power system based on the zero-sequence current steady-state fundamental phasor and the included angle.

[0069] Optionally, based on the zero-sequence current steady-state fundamental phasor and the included angle, the formula for calculating the steady-state differential current of the new power system is as follows:

[0070]

[0071] Among them, i diff For steady-state differential current, Angle These are the steady-state fundamental phasors of the phase currents on both sides of the line, with the positive direction pointing towards the line. The zero-sequence current steady-state fundamental phasor on both sides of the transmission line.

[0072] Specifically, refer to Figure 2 and Figure 3 As shown, to ensure that the calculated differential current is not greater than the actual differential current and is as close to the actual differential current as possible, this scheme adjusts the phase angle difference between the positive and negative sequence components of the steady-state currents on both sides to be opposite, while keeping the phase angle difference of the zero sequence component unchanged. The new differential current is obtained by adding them together, which means shifting the phasor on the N side. This means adjusting the sum of the positive and negative sequence phasors calculated on the N side to the opposite angle to that on the M side.

[0073] also, Figure 4 The novel steady-state differential current and actual differential current of this invention are shown in the case of a metallic single-phase ground fault at the end of the line, for reference. Figure 2 and Figure 4 As shown, during a phase A ground fault at the terminal, the amplitudes of the currents at both ends, the amplitude of the differential current, and the novel steady-state differential current are compared, for example... Figure 3As shown in the figure, the amplitude of the new steady-state differential current is approximately 8.8205 kA, as indicated by the red horizontal line. The minimum value of the fault phase differential current between 20 ms and 50 ms is 13.7198 kA, which is greater than the amplitude of the new steady-state differential current. After 14 ms from the fault, the amplitude of the phase A differential current exceeds the amplitude of the new steady-state differential current, and the amplitude of the phase A differential current after stabilization is approximately 13.92 kA.

[0074] Furthermore, Figure 5 shows the novel steady-state differential current and the actual differential current of this invention during a metallic two-phase short-circuit fault at the end of the line, for reference. Figure 2 As shown in Figure 5, Figure 8 compares the amplitudes of the currents at both ends, the differential current amplitude, and the amplitude of the novel steady-state differential current when an A / B phase fault occurs at the end. The amplitudes of the novel steady-state differential current for phases A and B are approximately 12.1921 kA and 12.1990 kA, respectively, as shown by the red horizontal line in the figure. The minimum values ​​of the differential current of the fault phases between 20 ms and 50 ms are 12.2422 kA and 12.2396 kA, respectively. The minimum values ​​of the differential currents of phases A and B between 20 ms and 50 ms are greater than the amplitude of the novel steady-state differential current. 17 ms after the fault, the amplitude of the differential current of phase A exceeds the amplitude of the novel steady-state differential current, and the amplitude of the differential current of phase A after stabilization is approximately 12.7 kA. 17 ms after the fault, the amplitude of the differential current of phase B exceeds the amplitude of the novel steady-state differential current, and the amplitude of the differential current of phase B after stabilization is approximately 12.7 kA.

[0075] Furthermore, Figure 6 shows the novel steady-state differential current and the actual differential current of this invention during a metallic two-phase ground fault at the end of the line, for reference. Figure 2 As shown in Figure 6, the comparison of the current amplitude, differential current amplitude, and new steady-state differential current amplitude during a phase-AB ground fault is illustrated. The new steady-state differential current amplitudes for phases A and B are approximately 12.3437 kA and 12.3018 kA, respectively, as indicated by the red horizontal line in the figure. The minimum values ​​of the fault phase differential current between 20 ms and 50 ms are 14.3472 kA and 13.4431 kA, respectively, which are greater than the amplitude of the new steady-state differential current. After 17 ms of the fault, the amplitude of the phase A differential current exceeds the amplitude of the new steady-state differential current, and the stable amplitude of the phase A differential current is approximately 14.52 kA. After 14 ms of the fault, the amplitude of the phase B differential current exceeds the amplitude of the new steady-state differential current, and the stable amplitude of the phase B differential current is approximately 14.18 kA.

[0076] Furthermore, Figure 7 shows the novel steady-state differential current and the actual differential current of this invention during a metallic three-phase fault at the end of the line, with reference to... Figure 2As shown in Figure 7, when a three-phase (A, B, and C) fault occurs at the terminal, the comparison of the current amplitude, differential current amplitude, and new steady-state differential current amplitude at both ends is illustrated. The new steady-state differential current amplitudes for phases A, B, and C are approximately 14.0091 kA, 14.1293 kA, and 14.1260 kA, respectively, as indicated by the red horizontal line in the figure. The minimum values ​​of the differential current in the fault phases between 20 ms and 50 ms are 14.3643 kA, 13.9891 kA, and 14.0089 kA, respectively. The minimum value of the differential current in phase A between 20 ms and 50 ms is greater than the amplitude of the new steady-state differential current, while the minimum values ​​of the differential currents in phases B and C between 20 ms and 50 ms are less than the amplitude of the new steady-state differential current. After 18 ms from the fault, the amplitude of the differential current in phase A exceeds the amplitude of the new steady-state differential current, and the amplitude of the differential current in phase A after stabilization is approximately 14.6 kA. 16ms after the fault, the amplitude of the phase B differential current exceeds the amplitude of the new steady-state differential current. The phase B differential current oscillates slightly after the fault, and its minimum value is slightly less than the amplitude of the new steady-state differential current after 40ms. 18ms after the fault, the amplitude of the phase C differential current exceeds the amplitude of the new steady-state differential current. The phase C differential current oscillates slightly after the fault, and its minimum value is slightly less than the amplitude of the new steady-state differential current after 40ms.

[0077] Therefore, the differential current calculated by this invention is less than the minimum differential current 20-50ms after the fault under various types of metallic fault conditions, and is as close as possible to the actual differential current. The differential current calculated by this invention can be used to verify the sensitivity of differential protection, which greatly improves the efficiency of the original sensitivity verification work that required electromagnetic transient simulation.

[0078] Exemplary device

[0079] Figure 8 This is a schematic diagram of the structure of a novel steady-state differential current calculation device for power system setting calculation provided in an exemplary embodiment of the present invention. Figure 8 As shown, the device 800 includes:

[0080] The acquisition module 810 is used to acquire the steady-state fundamental phasor values ​​of the phase current on both sides of the new energy transmission line in the new power system.

[0081] The first calculation module 820 is used to calculate the zero-sequence current steady-state fundamental phasor on both sides of the transmission line based on the steady-state fundamental phasor value of the phase current.

[0082] The second calculation module 830 is used to calculate the angle between the positive and negative sequence components of the current on both sides of the transmission line based on the zero-sequence current steady-state fundamental phasor.

[0083] The third calculation module 840 is used to calculate the steady-state differential current of the new power system based on the zero-sequence current steady-state fundamental phasor and the included angle.

[0084] Optionally, based on the steady-state fundamental phasor value of the phase current, the formula for calculating the steady-state fundamental phasor of the zero-sequence current on both sides of the transmitting line is as follows:

[0085]

[0086]

[0087] in, The zero-sequence current steady-state fundamental phasor on both sides of the transmission line. The steady-state fundamental phasor values ​​of the phase current on both sides of the transmission line.

[0088] Optionally, the second computing module includes:

[0089] The first calculation submodule is used to calculate the positive and negative sequence components of the current on both sides of the transmission line based on the zero-sequence current steady-state fundamental phasor;

[0090] The second calculation submodule is used to calculate the angle between the positive and negative sequence components of the current on both sides of the transmission line, based on the sum of the positive and negative sequence components of the current on both sides of the transmission line. The formula is as follows:

[0091]

[0092] in, The zero-sequence current steady-state fundamental phasor on both sides of the transmission line. For phase distinction, representing phases A, B, and C, These are the steady-state fundamental phasors of the phase currents on both sides of the line, with the positive direction pointing towards the line. The positive and negative sequence components of the current on both sides of the transmission line and the included angle.

[0093] Optionally, based on the zero-sequence current steady-state fundamental phasor and the included angle, the formula for calculating the steady-state differential current of the new power system is as follows:

[0094]

[0095] Among them, i diff For steady-state differential current, Angle These are the steady-state fundamental phasors of the phase currents on both sides of the line, with the positive direction pointing towards the line. The zero-sequence current steady-state fundamental phasor on both sides of the transmission line.

[0096] Exemplary electronic devices

[0097] 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.

[0098] The processor 91 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.

[0099] 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).

[0100] In addition, the input device 93 may also include, for example, a keyboard, a mouse, etc.

[0101] 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.

[0102] Of course, for the sake of simplicity, Figure 9 Only some of the components of the 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.

[0103] Exemplary computer program products and computer-readable storage media

[0104] 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.

[0105] 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.

[0106] 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 for information mining of historical change records according to various embodiments of the present invention as described in the "Exemplary Methods" section above.

[0107] 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.

[0108] 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.

[0109] 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.

[0110] 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.

[0111] 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.

[0112] 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.

[0113] 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 novel method for calculating steady-state differential current in power system setting calculations, characterized in that, include: Obtain the steady-state fundamental phasor values ​​of phase current on both sides of the new energy transmission line in the new power system; Based on the steady-state fundamental phasor value of the phase current, calculate the steady-state fundamental phasor of the zero-sequence current on both sides of the transmission line; Based on the zero-sequence current steady-state fundamental phasor, calculate the angle between the positive and negative sequence components of the current on both sides of the transmitting line. Based on the zero-sequence current steady-state fundamental phasor and the included angle, the steady-state differential current of the novel power system is calculated; the formula for the steady-state differential current is as follows: in, For steady-state differential current, Angle , These are the steady-state fundamental phasors of the phase currents on both sides of the line, with the positive direction pointing towards the line. , The zero-sequence current steady-state fundamental phasor on both sides of the transmission line.

2. The method according to claim 1, characterized in that, Based on the steady-state fundamental phasor value of the phase current, the formula for calculating the steady-state fundamental phasor of the zero-sequence current on both sides of the transmitting line is as follows: in, , The zero-sequence current steady-state fundamental phasor on both sides of the transmission line. , , , , , The steady-state fundamental phasor value of the phase current on both sides of the transmission line.

3. The method according to claim 1, characterized in that, The operation of calculating the angle between the sum of the positive and negative sequence components of the current on both sides of the transmitting line based on the zero-sequence current steady-state fundamental phasor includes: Based on the zero-sequence current steady-state fundamental phasor, calculate the positive and negative sequence components of the current on both sides of the transmitting line respectively; The angle between the positive and negative sequence components of the current on both sides of the transmitting line is calculated based on the sum of the positive and negative sequence components of the current on both sides of the transmitting line, using the following formula: in, , The zero-sequence current steady-state fundamental phasor on both sides of the transmission line. For phase differentiation, representing phases A, B, and C, , These are the steady-state fundamental phasors of the phase currents on both sides of the line, with the positive direction pointing towards the line. The positive and negative sequence components of the current on both sides of the transmission line and the included angle.

4. A novel steady-state differential current calculation device for power system setting calculation, used to implement the method described in claim 1, characterized in that, include: The acquisition module is used to acquire the steady-state fundamental phasor values ​​of the phase current on both sides of the new energy transmission line in the new power system. The first calculation module is used to calculate the zero-sequence current steady-state fundamental phasor on both sides of the transmission line based on the steady-state fundamental phasor value of the phase current. The second calculation module is used to calculate the angle between the sum of the positive and negative sequence components of the current on both sides of the transmitting line based on the zero-sequence current steady-state fundamental phasor. The third calculation module is used to calculate the steady-state differential current of the new power system based on the zero-sequence current steady-state fundamental phasor and the included angle.

5. The apparatus according to claim 4, characterized in that, Based on the steady-state fundamental phasor value of the phase current, the formula for calculating the steady-state fundamental phasor of the zero-sequence current on both sides of the transmitting line is as follows: in, , The zero-sequence current steady-state fundamental phasor on both sides of the transmission line. , , , , , The steady-state fundamental phasor value of the phase current on both sides of the transmission line.

6. The apparatus according to claim 4, characterized in that, The second calculation module includes: The first calculation submodule is used to calculate the sum of the positive and negative sequence components of the current on both sides of the transmitting line based on the zero-sequence current steady-state fundamental phasor; The second calculation submodule is used to calculate the angle between the sum of the positive and negative sequence components of the current on both sides of the transmission line, based on the sum of the positive and negative sequence components of the current on both sides of the transmission line, using the following formula: in, , The zero-sequence current steady-state fundamental phasor on both sides of the transmission line. For phase differentiation, representing phases A, B, and C, , These are the steady-state fundamental phasors of the phase currents on both sides of the line, with the positive direction pointing towards the line. The positive and negative sequence components of the current on both sides of the transmission line and the included angle.

7. 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 1-3.

8. 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 1-3.

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