Static voltage stability limit calculation method, device and equipment

Abstract

The application discloses a static voltage stability limit calculation method, device and equipment, wherein the method comprises the following steps: constructing a small system model based on the structure that a new energy power supply, a new energy box-type transformer, a reactive power compensation device and an infinite system are sequentially connected; calculating the short-circuit capacity of the new energy terminal by using system impedance; then determining the short-circuit ratio of the new energy terminal; establishing the quantitative relationship of the system impedance, the short-circuit ratio and the rated capacity of the new energy; determining the grid connection point impedance based on the quantitative relationship and the relationship of the equivalent reactance of the new energy box-type transformer; establishing the mapping relationship between the power factor angle and the capacitive reactive power compensation provided by the reactive power compensation device; and calculating the static voltage stability limit based on the mapping relationship, the voltage of the new energy terminal and the grid connection point impedance. The application forms a static voltage stability limit calculation mode represented by the short-circuit ratio and the reactive power compensation capacity, and accurately improves the contribution of the short-circuit ratio and the reactive power compensation capacity to the static voltage stability limit.

Description

Technical Field

[0001] This application relates to the field of power system technology, and in particular to a method, apparatus and equipment for calculating static voltage stability limits. Background Technology

[0002] In related technologies, existing voltage stability assessment methods based on short-circuit ratio mainly involve: using the short-circuit ratio as a grid strength indicator, primarily assessing the strength of the grid at the renewable energy connection point and determining the basic trend of voltage stability; or static voltage stability analysis, which mainly uses classical static voltage stability criteria to analyze the voltage stability margin of the renewable energy access system; or reactive power compensation impact analysis, which mainly analyzes the supporting role of reactive power compensation equipment such as static var generators on the grid connection point voltage through simulation or simplified models.

[0003] However, most of the voltage stability assessment methods based on the short-circuit ratio mentioned above remain at a qualitative or semi-qualitative level, and cannot accurately calculate the maximum power output limit of new energy power plants under the premise of maintaining voltage stability. The inability to directly and quantitatively calculate the voltage stability limit power using the short-circuit ratio prevents the full realization of its application value. Furthermore, the inability to accurately quantify the contribution of different reactive power compensation capacities to improving the static voltage stability limit makes it difficult to achieve optimal reactive power compensation configuration. Summary of the Invention

[0004] This disclosure provides a method, apparatus, and device for calculating static voltage stability limits, in order to at least solve the above-mentioned technical problems existing in the prior art.

[0005] According to a first aspect of this application, a method for calculating static voltage stability limits is provided, the method comprising:

[0006] A small system model is constructed based on the structure of a new energy power source, a new energy box transformer, a reactive power compensation device, and an infinite system connected in sequence.

[0007] Based on the aforementioned small system model, the short-circuit capacity at the new energy generator terminal is calculated using system impedance; wherein, the system impedance is the equivalent reactance of the system side viewed from the new energy box-type transformer side towards the power grid system side;

[0008] Based on the short-circuit capacity and the rated capacity of the new energy source, the short-circuit ratio at the new energy source generator terminal is determined;

[0009] Establish a quantitative relationship between the system impedance, the short-circuit ratio, and the rated capacity of the new energy source;

[0010] Based on the quantitative relationship and the relationship between the equivalent reactance of the new energy box-type transformer, the grid connection point impedance is determined; the grid connection point impedance is the equivalent reactance viewed from the high-voltage side of the new energy box-type transformer towards the system side;

[0011] Establish a mapping relationship between the power factor angle and the capacitive reactive power compensation provided by the reactive power compensation device; wherein, the capacitive reactive power compensation is the net reactive power injected into the grid by the new energy power station;

[0012] Based on the mapping relationship, the new energy generator terminal voltage, and the grid connection point impedance, the static voltage stability limit is calculated.

[0013] In one possible implementation, the short-circuit capacity at the new energy generator terminal is calculated using the system impedance in the following manner:

[0014]

[0015] in, For the short-circuit capacity of the new energy generator; This represents the system impedance.

[0016] In one possible implementation, the short-circuit ratio at the new energy generator terminal is determined using the following method:

[0017]

[0018] in, Short-circuit ratio; Rated capacity for new energy sources.

[0019] In one possible implementation, the quantitative relationship between the system impedance, the short-circuit ratio, and the rated capacity of the new energy source is as follows:

[0020] .

[0021] In one possible implementation, based on the quantitative relationship and the relationship between the equivalent reactance of the new energy box-type transformer, the grid connection point impedance is determined in the following manner:

[0022]

[0023] in, The impedance at the grid connection point; This is the equivalent reactance of a new energy box-type transformer.

[0024] In one possible implementation, the mapping relationship between the power factor angle and the capacitive reactive power compensation provided by the reactive power compensation device is as follows:

[0025]

[0026]

[0027] in, The power factor angle; This is the amount of capacitive reactive power compensation.

[0028] In one possible implementation, the amount of capacitive reactive power compensation is jointly determined by the reactive power generating equipment and the reactive power consuming equipment within the renewable energy power station, and is expressed in the following manner:

[0029]

[0030] When ignoring the reactive power loss of the aforementioned new energy transformer, the capacitive reactive power compensation is expressed in the following manner.

[0031]

[0032] in, The reactive power generated by the static var generator; It generates reactive power for new energy generating units; This refers to the reactive power loss of the new energy transformer.

[0033] In one possible implementation, based on the mapping relationship, the new energy generator terminal voltage, and the grid connection point impedance, the static voltage stability limit is calculated using the following method:

[0034]

[0035] in, E represents the static voltage stability limit, and E represents the terminal voltage of the new energy source.

[0036] According to a second aspect of this application, a static voltage stability limit calculation device is provided, the device comprising:

[0037] The model building module is used to build a small system model based on the structure of new energy power source, new energy box transformer, reactive power compensation device and infinite system connected in sequence;

[0038] The first calculation module is used to calculate the short-circuit capacity of the new energy generator terminal based on the small system model and using the system impedance; wherein, the system impedance is the system-side equivalent reactance viewed from the new energy box-type transformer side to the power grid system side;

[0039] The first determining module is used to determine the short-circuit ratio at the new energy generator terminal based on the short-circuit capacity and the rated capacity of the new energy source.

[0040] The first module is used to establish a quantitative relationship between the system impedance, the short-circuit ratio, and the rated capacity of the new energy source;

[0041] The second determining module is used to determine the grid connection point impedance based on the quantitative relationship and the relationship between the equivalent reactance of the new energy box transformer; the grid connection point impedance is the equivalent reactance viewed from the high-voltage side of the new energy box transformer towards the system side;

[0042] The second module is used to establish a mapping relationship between the power factor angle and the capacitive reactive power compensation amount provided by the reactive power compensation device; wherein, the capacitive reactive power compensation amount is the net reactive power injected into the power grid by the new energy power station;

[0043] The second calculation module is used to calculate the static voltage stability limit based on the mapping relationship, the new energy terminal voltage, and the grid connection point impedance.

[0044] According to a third aspect of this application, an electronic device is provided, comprising:

[0045] At least one processor;

[0046] and a memory communicatively connected to the at least one processor; wherein,

[0047] The memory stores instructions that can be executed by the at least one processor to enable the at least one processor to perform the method described in this application.

[0048] According to a fourth aspect of this application, a non-transitory computer-readable storage medium is provided storing computer instructions for causing the computer to perform the methods described in this application.

[0049] According to a fifth aspect of this application, a computer program product is provided, comprising a computer program or instructions that, when executed by a processor, implement the method described in this application.

[0050] Using the technical solution of this application, a small-system model is established with a new energy grid-connected system as the analysis object. First, the inherent quantitative relationship between the grid connection point impedance and the short-circuit ratio, new energy capacity, and the equivalent reactance of the new energy transformer is established. The grid connection point impedance in the static voltage stability limit formula is replaced with an equivalent form jointly characterized by the short-circuit ratio, new energy capacity, and the equivalent reactance of the new energy transformer, resulting in a preliminary analytical relationship where the short-circuit ratio directly reflects the static voltage stability limit. Based on this, and using the mathematical transformation between reactive power compensation capacity and power factor angle, the power factor in the preliminary analytical relationship is replaced with an explicit function of reactive power compensation capacity, deriving an expression for the static voltage stability limit considering SVG compensation capacity and new energy reactive power output. This forms a static voltage stability limit jointly characterized by the short-circuit ratio and reactive power compensation capacity, overcoming the shortcomings of existing technologies where the relationship between the short-circuit ratio and reactive power compensation capacity is ambiguous and the impact of reactive power compensation is difficult to quantify. This application forms a static voltage stability limit calculation method jointly characterized by the short-circuit ratio and reactive power compensation capacity, accurately improving the contribution of the short-circuit ratio and reactive power compensation capacity to the static voltage stability limit.

[0051] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this application, nor is it intended to limit the scope of this application. Other features of this application will become readily apparent from the following description. Attached Figure Description

[0052] The above and other objects, features, and advantages of exemplary embodiments of this application will become readily apparent from the following detailed description taken in conjunction with the accompanying drawings. Several embodiments of this application are illustrated in the drawings by way of example and not limitation, in which:

[0053] In the accompanying drawings, the same or corresponding reference numerals indicate the same or corresponding parts.

[0054] Figure 1 A flowchart illustrating the static voltage stability limit calculation method in an embodiment of this application is shown;

[0055] Figure 2 The diagram shows the structure of a small system model in an embodiment of this application;

[0056] Figure 3 The relationship between short-circuit ratio and static voltage stability limit in embodiments of this application is shown. Figure 1 ;

[0057] Figure 4 The relationship between short-circuit ratio and static voltage stability limit in embodiments of this application is shown. Figure 2 ;

[0058] Figure 5 The relationship between short-circuit ratio and static voltage stability limit in embodiments of this application is shown. Figure 3 ;

[0059] Figure 6 A structural block diagram of the static voltage stability limit calculation device in an embodiment of this application is shown;

[0060] Figure 7 A schematic diagram of the composition structure of an electronic device according to an embodiment of this application is shown. Detailed Implementation

[0061] To make the objectives, features, and advantages of this application more apparent and understandable, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0062] In the following description, the terms "first" and "second" are used merely to distinguish similar objects and do not represent a specific ordering of objects. It is understood that "first" and "second" may be interchanged in a specific order or sequence where permitted, so that the embodiments of this application described herein can be implemented in an order other than that illustrated or described herein.

[0063] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit this application.

[0064] The following description, in conjunction with the accompanying drawings, introduces a method, apparatus, and equipment for calculating static voltage stability limits provided in this application.

[0065] like Figure 1 As shown, this application provides a method for calculating the static voltage stability limit, the method comprising:

[0066] S101 is a small system model based on the structure of a new energy power source, a new energy box-type transformer, a reactive power compensation device, and an infinite system connected in sequence.

[0067] Among them, the new energy power source adopts the doubly-fed wind turbine model, and the active power output of the wind power is denoted as . Reactive power is denoted as The new energy box-type transformer adopts a short-circuit impedance model, neglecting the influence of the excitation branch and resistance, and retaining only the reactance component. Its low-voltage side is connected to the new energy power source. The reactive power compensation device adopts the static var generator (SVG) model, and its reactive power output is denoted as... It is connected in parallel to the high-voltage side of the new energy box-type transformer to provide dynamic reactive power support. The voltage amplitude and frequency of the infinite system are constant, denoted as . It is connected to the high-voltage side of the new energy box-type transformer via the grid connection line.

[0068] In this application, such as Figure 2 As shown, after the new energy power supply is stepped up by the new energy box-type transformer, it is connected in parallel with the reactive power compensation device to the grid connection point. The grid connection point is connected to the infinite power system via the grid connection line. The impedance of the grid connection point is determined by the system impedance. With transformer reactor The difference is composed of, denoted as The small system model provided in this application lays the foundation for establishing the quantitative relationship between system reactance and short-circuit ratio, renewable energy capacity, and for deriving the static voltage stability limit expression for reactive power compensation.

[0069] S102, Based on the aforementioned small system model, calculate the short-circuit capacity at the new energy generator terminal using system impedance; wherein, the system impedance is the equivalent reactance of the system side viewed from the new energy transformer side towards the grid system side. The system impedance includes the transformer reactance and the grid connection point impedance.

[0070] In this application, the system impedance is obtained as The short-circuit capacity of the new energy generator terminal is calculated using the system impedance in the following manner.

[0071] (1)

[0072] in, For the short-circuit capacity of the new energy generator; This represents the system impedance.

[0073] S103, Based on the short-circuit capacity and the rated capacity of the new energy source, determine the short-circuit ratio at the new energy source terminal.

[0074] In this application, the short-circuit ratio at the new energy generator terminal is determined using the following method:

[0075] (2)

[0076] in, Short-circuit ratio; Rated capacity for new energy sources.

[0077] S104, establish the quantitative relationship between the system impedance, the short-circuit ratio, and the rated capacity of the new energy source.

[0078] In this application, based on short-circuit capacity With new energy capacity The short-circuit ratio at the generator terminal of a new energy vehicle is defined as... This establishes a quantitative relationship between system impedance, short-circuit ratio, and new energy capacity.

[0079] (3)

[0080] In new energy grid-connected systems, the impedance at the grid connection point The equivalent reactance seen from the high-voltage side of the transformer towards the system side; system impedance. The equivalent reactance seen from the low-voltage side of the transformer towards the system side; system impedance. Typically includes: grid connection point impedance and the equivalent reactance of new energy transformer substations .

[0081] S105, Based on the quantitative relationship and the relationship between the equivalent reactance of the new energy box transformer, determine the grid connection point impedance; the grid connection point impedance is the equivalent reactance viewed from the high-voltage side of the new energy box transformer towards the system side.

[0082] In this application, to accurately analyze the static voltage stability limit, the grid connection point impedance is expressed as the difference between the system-side impedance and the transformer substation impedance.

[0083] (4)

[0084] in, The impedance at the grid connection point; This is the equivalent reactance of a new energy box-type transformer.

[0085] S106, establish a mapping relationship between the power factor angle and the capacitive reactive power compensation provided by the reactive power compensation device; wherein, the capacitive reactive power compensation is the net reactive power injected into the power grid by the new energy power station.

[0086] In this application, firstly, the power factor at the connection point of the new energy power station is calculated. , This is the reactive power compensation amount. Rated power for new energy sources

[0087] (5)

[0088] Considering the capacitive reactive power compensation provided by the reactive power compensation device Because capacitive reactive power compensation makes the reactive power at the grid connection point negative, i.e., the net reactive power compensation amount... Then the power factor angle satisfy Then the power factor is expressed as:

[0089] (6)

[0090] (7)

[0091] S107. Based on the mapping relationship, the new energy generator terminal voltage and the grid connection point impedance, calculate the static voltage stability limit.

[0092] In this application, a static voltage stability limit is defined. ,in, For the voltage at the new energy generator terminal, The power factor angle, Given the grid connection point impedance, the formula for calculating the static voltage stability limit is:

[0093] (8)

[0094] Furthermore, the grid connection point impedance Replace with short-circuit ratio New energy capacity Equivalent reactance of new energy transformers From the expression, we obtain the static voltage stability limit formula directly characterized by the short-circuit ratio, which is:

[0095] (9)

[0096] Furthermore, substituting formulas (6) and (7) into formula (9), we obtain the static voltage stability limit characterized by reactive power compensation.

[0097] (10)

[0098] Furthermore, in this application, the reactive power emitted by the SVG is defined as... The reactive power loss of the new energy transformer is The new energy unit generates reactive power. Then the capacitive reactive power compensation amount The difference between reactive power generation and reactive power consumption is obtained.

[0099] (11)

[0100] Among them, the reactive power loss of the new energy transformer is very small and can be ignored. Therefore, only the reactive power generated by the new energy unit and the reactive power generated by the SVG are considered.

[0101] (12)

[0102] in, The reactive power generated by the Static Var Generator (SVG); It generates reactive power for new energy generating units; This refers to the reactive power loss of the new energy transformer.

[0103] Substituting formula (12) into formula (10), we obtain the static voltage stability limit relationship expressed in terms of the new energy short-circuit ratio and reactive power compensation.

[0104] (13)

[0105] To clearly demonstrate the accuracy of the static voltage stability limit calculation method provided in this application, this application has verified the method.

[0106] Utilize Figure 2 The small system model shown is analyzed. Specifically, the baseline capacity of the small system model is... New energy installed capacity New energy sources generate reactive power (5% of new energy installed capacity), SVG capacity of reactive power compensation devices (30% of the installed capacity of new energy), impedance of new energy transformer substation Short-circuit ratio of new energy generator terminals Substituting this into the formula, we obtain the static stability limit as 1479 MW.

[0107] If the SVG capacity is 20%, 25%, and 30% of the installed capacity of new energy sources, respectively, the relationship between the short-circuit ratio of new energy sources and the static voltage stability limit can be obtained by substituting into the formula, as follows: Figure 3 As shown, the static stability limit increases with the increase of reactive power compensation capacity and short-circuit ratio. This is because increasing the SVG capacity can directly improve the system voltage regulation capability and increase the system strength by increasing the short-circuit ratio, thereby effectively improving the static voltage stability limit of the system.

[0108] If the SVG capacity is 30% of the installed capacity of new energy, and the reactive power generated by new energy is 0%, 5%, and 10% of the installed capacity respectively, then the relationship between the short-circuit ratio of new energy and the static voltage stability limit is as follows: Figure 4 As shown, the static stability limit increases with the increase of reactive power generated by new energy sources and the short-circuit ratio. This is because the increased reactive power generated by new energy sources can improve the system strength by increasing the short-circuit ratio, which directly enhances voltage stability and increases the static voltage stability limit.

[0109] If the SVG capacity is 30% of the installed capacity of new energy, and the impedances of the new energy transformer are 0.06, 0.12, and 0.18 respectively, then the relationship between the short-circuit ratio of new energy and the static voltage stability limit is as follows: Figure 5 As shown, the static stability limit increases with the increase of the impedance and short-circuit ratio of the new energy transformer box. This is because, with the increase of the impedance of the new energy transformer box, a stronger system short-circuit ratio is required to maintain a higher static voltage stability limit.

[0110] like Figure 6 As shown, this application provides a static voltage stability limit calculation device, the device comprising:

[0111] Model building module 601 is used to build a small system model based on the structure of new energy power source, new energy box transformer, reactive power compensation device and infinite system connected in sequence.

[0112] The first calculation module 602 is used to calculate the short-circuit capacity of the new energy generator terminal based on the small system model and using the system impedance; wherein, the system impedance is the system-side equivalent reactance viewed from the new energy box-type transformer side to the power grid system side;

[0113] The first determining module 603 is used to determine the short-circuit ratio at the new energy generator terminal based on the short-circuit capacity and the rated capacity of the new energy source.

[0114] The first module 604 is used to establish a quantitative relationship between the system impedance, the short-circuit ratio, and the rated capacity of the new energy source;

[0115] The second determining module 605 is used to determine the grid connection point impedance based on the quantitative relationship and the relationship between the equivalent reactance of the new energy box transformer; the grid connection point impedance is the equivalent reactance viewed from the high-voltage side of the new energy box transformer towards the system side;

[0116] The second module 606 is used to establish a mapping relationship between the power factor angle and the capacitive reactive power compensation amount provided by the reactive power compensation device; wherein, the capacitive reactive power compensation amount is the net reactive power injected into the power grid by the new energy power station;

[0117] The second calculation module 607 is used to calculate the static voltage stability limit based on the mapping relationship, the new energy generator terminal voltage and the grid connection point impedance.

[0118] This application provides a static voltage stability limit calculation device. A model building module 601 constructs a small system model based on the sequential connection of a new energy power source, a new energy box-type transformer, a reactive power compensation device, and an infinite bus system. A first calculation module 602 calculates the short-circuit capacity at the new energy generator terminal based on the small system model and using the system impedance. The system impedance is the equivalent reactance of the system side viewed from the new energy box-type transformer side towards the power grid system side. A first determination module 603 determines the short-circuit ratio at the new energy generator terminal based on the short-circuit capacity and the rated capacity of the new energy source. A first establishment module 604 establishes the system impedance and the short-circuit... The second determining module 605 determines the grid connection point impedance based on the quantitative relationship between the new energy source rated capacity and the equivalent reactance of the new energy source box transformer. The grid connection point impedance is the equivalent reactance viewed from the high-voltage side of the new energy source box transformer towards the system side. The second establishing module 606 establishes a mapping relationship between the power factor angle and the capacitive reactive power compensation provided by the reactive power compensation device. The capacitive reactive power compensation is the net reactive power injected into the grid by the new energy source power station. The second calculation module 607 calculates the static voltage stability limit based on the mapping relationship, the new energy source terminal voltage, and the grid connection point impedance.

[0119] According to embodiments of this application, this application also provides an electronic device and a readable storage medium.

[0120] The electronic device includes at least one processor and a memory communicatively connected to the at least one processor. The memory stores instructions executable by the at least one processor, which, when executed, enable the at least one processor to perform the static voltage stability limit calculation method described in this application. The computer instructions are used to cause the computer to perform the static voltage stability limit calculation method described in this application.

[0121] This application also provides a computer program product, including a computer program / instructions, which, when executed by a processor, implements the static voltage stability limit calculation method of this application.

[0122] Figure 7 A schematic block diagram of an example electronic device 800 that can be used to implement embodiments of this application is shown. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other computer-suitable devices. The electronic device may also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable devices, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the application described and / or claimed herein.

[0123] like Figure 7 As shown, the electronic device 800 includes a computing unit 801, which can perform various appropriate actions and processes based on a computer program stored in a read-only memory (ROM) 802 or a computer program loaded from a storage unit 808 into a random access memory (RAM) 803. The RAM 803 may also store various programs and data required for the operation of the electronic device 800. The computing unit 801, ROM 802, and RAM 803 are interconnected via a bus 804. An input / output (I / O) interface 805 is also connected to the bus 804.

[0124] Multiple components in electronic device 800 are connected to I / O interface 805, including: input unit 806, such as keyboard, mouse, etc.; output unit 807, such as various types of displays, speakers, etc.; storage unit 808, such as disk, optical disk, etc.; and communication unit 809, such as network card, modem, wireless transceiver, etc. Communication unit 809 allows electronic device 800 to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0125] The computing unit 801 can be a variety of general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of the computing unit 801 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various computing units running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. The computing unit 801 performs the various methods and processes described above, such as the static voltage stability limit calculation method. For example, in some embodiments, the static voltage stability limit calculation method can be implemented as a computer software program tangibly contained in a machine-readable medium, such as storage unit 808. In some embodiments, part or all of the computer program can be loaded and / or installed on the electronic device 800 via ROM 802 and / or communication unit 809. When the computer program is loaded into RAM 803 and executed by the computing unit 801, one or more steps of the static voltage stability limit calculation method described above can be performed. Alternatively, in other embodiments, the computing unit 801 can be configured to perform the static voltage stability limit calculation method by any other suitable means (e.g., by means of firmware).

[0126] Various embodiments of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), systems-on-a-chip (SoCs), payload-programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include implementations in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which may be a dedicated or general-purpose programmable processor, capable of receiving data and instructions from a storage system, at least one input device, and at least one output device, and transmitting data and instructions to the storage system, the at least one input device, and the at least one output device.

[0127] The program code used to implement the methods of this application may be written in any combination of one or more programming languages. This program code may be provided to a processor or controller of a general-purpose computer, special-purpose computer, or other programmable data processing device, such that when executed by the processor or controller, the functions / operations specified in the flowcharts and / or block diagrams are implemented. The program code may be executed entirely on a machine, partially on a machine, as a standalone software package partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0128] In the context of this application, a machine-readable medium can be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, apparatus, or device. A machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. Machine-readable media can be, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0129] To provide interaction with a user, the systems and techniques described herein can be implemented on a computer having: a display device for displaying information to the user (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor); and a keyboard and pointing device (e.g., a mouse or trackball) through which the user provides input to the computer. Other types of devices can also be used to provide interaction with the user; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including sound input, voice input, or tactile input).

[0130] The systems and technologies described herein can be implemented in computing systems that include back-end components (e.g., as data servers), or middleware components (e.g., application servers), or front-end components (e.g., user computers with graphical user interfaces or web browsers through which users can interact with implementations of the systems and technologies described herein), or any combination of such back-end, middleware, or front-end components. The components of the system can be interconnected via digital data communication (e.g., communication networks) of any form or medium. Examples of communication networks include local area networks (LANs), wide area networks (WANs), and the Internet.

[0131] Computer systems can include clients and servers. Clients and servers are generally located far apart and typically interact via communication networks. Client-server relationships are created by computer programs running on the respective computers and having a client-server relationship with each other. Servers can be cloud servers, servers in distributed systems, or servers incorporating blockchain technology.

[0132] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for calculating the static voltage stability limit, characterized in that, The method includes: A small system model is constructed based on the structure of a new energy power source, a new energy box transformer, a reactive power compensation device, and an infinite system connected in sequence. Based on the aforementioned small system model, the short-circuit capacity at the new energy generator terminal is calculated using system impedance; wherein, the system impedance is the equivalent reactance of the system side viewed from the new energy box-type transformer side towards the power grid system side; Based on the short-circuit capacity and the rated capacity of the new energy source, the short-circuit ratio at the new energy source generator terminal is determined; Establish a quantitative relationship between the system impedance, the short-circuit ratio, and the rated capacity of the new energy source; Based on the quantitative relationship and the relationship between the equivalent reactance of the new energy box-type transformer, the grid connection point impedance is determined; the grid connection point impedance is the equivalent reactance viewed from the high-voltage side of the new energy box-type transformer towards the system side; Establish a mapping relationship between the power factor angle and the capacitive reactive power compensation provided by the reactive power compensation device; wherein, the capacitive reactive power compensation is the net reactive power injected into the grid by the new energy power station; Based on the mapping relationship, the new energy generator terminal voltage, and the grid connection point impedance, the static voltage stability limit is calculated.

2. The method according to claim 1, characterized in that, The short-circuit capacity of the new energy generator terminal is calculated using system impedance in the following manner. in, For the short-circuit capacity of the new energy generator; This represents the system impedance.

3. The method according to claim 2, characterized in that, The short-circuit ratio at the new energy generator terminal is determined using the following method. in, Short-circuit ratio; Rated capacity for new energy sources.

4. The method according to claim 1, characterized in that, The quantitative relationship between the system impedance, the short-circuit ratio, and the rated capacity of the new energy source is as follows: .

5. The method according to claim 4, characterized in that, Based on the aforementioned quantitative relationship and the relationship between the equivalent reactance of the new energy box-type transformer, the grid connection point impedance is determined using the following method. in, The impedance at the grid connection point; This is the equivalent reactance of a new energy box-type transformer.

6. The method according to claim 1, characterized in that, The mapping relationship between the power factor angle and the capacitive reactive power compensation provided by the reactive power compensation device is as follows: in, The power factor angle; This is the amount of capacitive reactive power compensation.

7. The method according to claim 6, characterized in that, The amount of capacitive reactive power compensation is jointly determined by the reactive power generating equipment and reactive power consuming equipment in the renewable energy power station, and is expressed in the following way. When ignoring the reactive power loss of the aforementioned new energy transformer, the capacitive reactive power compensation is expressed in the following manner. in, The reactive power generated by the static var generator; It generates reactive power for new energy generating units; This refers to the reactive power loss of the new energy transformer.

8. The method according to claim 7, characterized in that, Based on the aforementioned mapping relationship, the new energy generator terminal voltage, and the grid connection point impedance, the static voltage stability limit is calculated using the following method. in, E represents the static voltage stability limit, and E represents the terminal voltage of the new energy source.

9. A static voltage stability limit calculation device, characterized in that, The device includes: The model building module is used to build a small system model based on the structure of new energy power source, new energy box transformer, reactive power compensation device and infinite system connected in sequence; The first calculation module is used to calculate the short-circuit capacity of the new energy generator terminal based on the small system model and using the system impedance; wherein, the system impedance is the system-side equivalent reactance viewed from the new energy box-type transformer side to the power grid system side; The first determining module is used to determine the short-circuit ratio at the new energy generator terminal based on the short-circuit capacity and the rated capacity of the new energy source. The first module is used to establish a quantitative relationship between the system impedance, the short-circuit ratio, and the rated capacity of the new energy source; The second determining module is used to determine the grid connection point impedance based on the quantitative relationship and the relationship between the equivalent reactance of the new energy box transformer; the grid connection point impedance is the equivalent reactance viewed from the high-voltage side of the new energy box transformer towards the system side; The second module is used to establish a mapping relationship between the power factor angle and the capacitive reactive power compensation amount provided by the reactive power compensation device; wherein, the capacitive reactive power compensation amount is the net reactive power injected into the power grid by the new energy power station; The second calculation module is used to calculate the static voltage stability limit based on the mapping relationship, the new energy terminal voltage, and the grid connection point impedance.

10. An electronic device, characterized in that, At least one processor; and a memory communicatively connected to the at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor to enable the at least one processor to perform the method according to any one of claims 1 to 8.

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