New energy short-circuit current calculation method and system, storage medium and electronic device

Abstract

The application relates to a new energy short-circuit current calculation method and system, a storage medium and an electronic device, and comprises the following steps: detecting whether a target new energy power supply fails in real time; when it is detected that the target new energy power supply fails, collecting target data information of the target new energy power supply at the time of failure; and according to the target data information, calculating a new energy short-circuit current of the target new energy power supply by using a pre-acquired fault uncontrolled stage new energy short-circuit current analytical expression, a fault transient stage new energy short-circuit current analytical expression and a fault steady stage new energy short-circuit current analytical expression. The application calculates a new energy short-circuit current calculation method under different fault stages, can cover a new energy short-circuit current in a full time scale, ensures that accurate short-circuit current calculation results can be given under different fault stages, and avoids the risk of protection refusal.

Description

Technical Field

[0001] This application relates to the field of data processing technology, and in particular to a method, system, storage medium, and electronic device for calculating short-circuit current in new energy sources. Background Technology

[0002] As the proportion of new energy access capacity increases, the short-circuit current it provides cannot be ignored. Therefore, traditional protection systems that rely on short-circuit current calculation have new requirements for the accuracy of short-circuit current analysis. However, in the traditional short-circuit current calculation process, the calculation of new energy short-circuit current is often ignored or set to a fixed value. This strategy can still be applied when the proportion of new energy access capacity is small, but when the proportion of new energy access capacity increases, the calculation accuracy of this method decreases, leading to the risk of protection failure to operate.

[0003] Therefore, there is an urgent need for a method to calculate the short-circuit current of new energy sources that can accurately characterize different fault stages. Summary of the Invention

[0004] To address the aforementioned issues, this application provides a method, system, storage medium, and electronic device for calculating short-circuit current of new energy sources. This solves the technical problem in related technologies where the calculation of short-circuit current of new energy sources is often ignored or set to a fixed value, leading to a decrease in the accuracy of the short-circuit current calculation results and the risk of protection failure when the proportion of new energy access capacity increases.

[0005] In a first aspect, this application provides a method for calculating the short-circuit current of a new energy source, the method comprising:

[0006] Real-time detection of whether the target new energy power source is malfunctioning;

[0007] When a fault is detected in the target energy source, target data information at the time of the target new energy source fault is collected.

[0008] Based on the target data information, the short-circuit current of the target renewable energy source is calculated using the pre-acquired analytical expressions for the renewable energy short-circuit current during the uncontrolled fault stage, the transient fault stage, and the steady-state fault stage.

[0009] In some embodiments, the pre-acquired analytical expression for the short-circuit current of the renewable energy source during the uncontrolled fault stage includes:

[0010]

[0011] Where I represents the short-circuit current, the subscript abc represents the three phases corresponding to abc in the three-phase stationary coordinate system, and A m1 A m2 ω is the current amplitude.m1 ω m2 Calculate β for different frequencies m1 β m2 For different phase angles, γ represents the time decay constant.

[0012] In some embodiments, the pre-acquired analytical expression for the short-circuit current of the renewable energy source during the fault transient phase includes:

[0013]

[0014] Where I represents the short-circuit current, the subscript abc represents the three phases corresponding to abc in the three-phase stationary coordinate system, e represents the grid connection point voltage, L is the filter inductance, R is the line resistance, τ represents the time decay component, and B m1 B m2 B m3 ω is the current amplitude. m1 ω m2 ω m3 Calculate β for different frequencies m1 β m2 β m3 Calculate values ​​for different phase angles.

[0015] In some embodiments, the pre-acquired analytical expression for the short-circuit current of the renewable energy source during the fault steady-state stage includes:

[0016]

[0017] Where I represents the short-circuit current, the subscript abc represents the three phases corresponding to abc in the three-phase stationary coordinate system, and C m1 ω is the current amplitude, β is the calculated value of the power frequency quantity, and β is the current amplitude. m Calculate values ​​for different phase angles.

[0018] Secondly, a short-circuit current calculation system for new energy sources, the system comprising:

[0019] The detection unit is used to detect in real time whether the target new energy power source has a fault;

[0020] The acquisition unit is used to acquire target data information when the target energy source is detected to be faulty.

[0021] The calculation unit is used to calculate the short-circuit current of the target renewable energy source based on the target data information, using pre-acquired analytical expressions for the short-circuit current of renewable energy sources during the uncontrolled fault stage, the transient fault stage, and the steady-state fault stage.

[0022] In some embodiments, the pre-acquired analytical expression for the short-circuit current of the renewable energy source during the uncontrolled fault stage includes:

[0023]

[0024] Where I represents the short-circuit current, the subscript abc represents the three phases corresponding to abc in the three-phase stationary coordinate system, and A m1 A m2 ω is the current amplitude. m1 ω m2 Calculate β for different frequencies m1 β m2 For different phase angles, γ represents the time decay constant.

[0025] In some embodiments, the pre-acquired analytical expression for the short-circuit current of the renewable energy source during the fault transient phase includes:

[0026]

[0027] Where I represents the short-circuit current, the subscript abc represents the three phases corresponding to abc in the three-phase stationary coordinate system, e represents the grid connection point voltage, L is the filter inductance, R is the line resistance, τ represents the time decay component, and B m1 B m2 B m3 ω is the current amplitude. m1 ω m2 ω m3 Calculate β for different frequencies m1 β m2 β m3 Calculate values ​​for different phase angles.

[0028] In some embodiments, the pre-acquired analytical expression for the short-circuit current of the renewable energy source during the fault steady-state stage includes:

[0029]

[0030] Where I represents the short-circuit current, the subscript abc represents the three phases corresponding to abc in the three-phase stationary coordinate system, and C m1 ω is the current amplitude, β is the calculated value of the power frequency quantity, and β is the current amplitude. m Calculate values ​​for different phase angles.

[0031] Thirdly, a storage medium storing a computer program that can be executed by one or more processors to implement the new energy short-circuit current calculation method as described in the first aspect above.

[0032] Fourthly, an electronic device includes a memory and a processor, wherein a computer program is stored on the memory, and the memory and the processor are communicatively connected to each other, and when the computer program is executed by the processor, it performs the new energy short-circuit current calculation method as described in the first aspect above.

[0033] This application provides a method, system, storage medium, and electronic device for calculating the short-circuit current of a new energy source, comprising: real-time detection of whether a target new energy source power supply has a fault; when a fault is detected in the target new energy source power supply, collecting target data information at the time of the fault; and calculating the new energy short-circuit current of the target new energy source power supply based on the target data information through pre-acquired analytical expressions for the new energy short-circuit current in the uncontrolled fault stage, the transient fault stage, and the steady-state fault stage. This application provides a method for calculating the new energy short-circuit current under different fault stages, covering the new energy short-circuit current across the entire time scale, ensuring accurate short-circuit current calculation results under different fault stages, and avoiding the risk of protection failure. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0035] Figure 1 A flowchart illustrating a method for calculating short-circuit current in new energy sources, provided as an embodiment of this application;

[0036] Figure 2 This is a schematic diagram of a new energy power supply simulation model provided in the embodiments of this application;

[0037] Figure 3 Simulation verification diagram of the new energy short-circuit current calculation method considering different fault stages provided in the embodiments of this application;

[0038] Figure 4 A schematic diagram of a new energy short-circuit current calculation system provided in this application embodiment;

[0039] Figure 5 This is a connection block diagram of an electronic device provided in an embodiment of this application. Detailed Implementation

[0040] The following detailed description of the embodiments of this application, in conjunction with the accompanying drawings, will provide a thorough understanding of how this application uses technical means to solve technical problems and achieve corresponding technical effects, enabling its implementation. The embodiments of this application and the various features within them can be combined with each other without conflict, and all resulting technical solutions are within the protection scope of this application.

[0041] As the background technology shows, due to the increasing proportion of new energy access capacity, the short-circuit current it provides cannot be ignored. Therefore, traditional protection systems that rely on short-circuit current calculation have new requirements for the accuracy of short-circuit current analysis. However, in the traditional short-circuit current calculation process, the calculation of new energy short-circuit current is often ignored or set to a fixed value. This strategy can still be applied when the proportion of new energy access capacity is small, but when the proportion of new energy access capacity increases, the calculation accuracy of this method decreases, leading to the risk of protection failure to operate.

[0042] Therefore, there is an urgent need for a method to calculate the short-circuit current of new energy sources that can accurately characterize different fault stages.

[0043] In view of this, this application provides a method, system, storage medium and electronic device for calculating short-circuit current of new energy sources, which solves the technical problem in related technologies that the accuracy of short-circuit current calculation results decreases when the proportion of new energy access capacity increases, due to the frequent neglect of new energy short-circuit current calculation or setting it to a fixed value, thus posing a risk of protection failure.

[0044] Example 1

[0045] Figure 1 This is a flowchart illustrating a method for calculating short-circuit current in new energy sources, as provided in an embodiment of this application. Figure 1 As shown, this method includes:

[0046] S101. Real-time detection of whether the target new energy power source is faulty;

[0047] S102. When a fault is detected in the target energy source, collect the target data information when the target new energy source fails.

[0048] S103. Based on the target data information, calculate the new energy short-circuit current of the target new energy power source using the pre-acquired analytical expressions for the new energy short-circuit current during the uncontrolled fault stage, the transient fault stage, and the steady-state fault stage.

[0049] It should be noted that the target data information refers to the data used to calculate the short-circuit current of the target renewable energy source, including the current amplitude A, based on the pre-acquired analytical expressions for the renewable energy short-circuit current during the uncontrolled fault stage, the transient fault stage, and the steady-state fault stage. m1 A m2 Grid connection point voltage e, filter inductance L, line resistance R, time decay component τ, current amplitude B m1 B m2 B m3 Calculated values ​​ω for different frequencies m1 ω m2 ω m3 Different phase angle calculation values ​​β m1 β m2 β m3 For, the current amplitude C m1 Calculated value of power frequency ω, calculated value of phase angle β m .

[0050] In some embodiments, the pre-acquired analytical expression for the short-circuit current of the renewable energy source during the uncontrolled fault stage includes:

[0051]

[0052] Where I represents the short-circuit current, the subscript abc represents the three phases corresponding to abc in the three-phase stationary coordinate system, and A m1 A m2 ω is the current amplitude. m1 ω m2 Calculate β for different frequencies m1 β m2 For different phase angles, γ represents the time decay constant.

[0053] It should be noted that the process of obtaining the analytical expression for the short-circuit current of the new energy source during the uncontrolled fault stage is as follows:

[0054] Analyze the fault current loop in the uncontrolled stage and give an analytical expression for the short-circuit current based on the fault loop;

[0055] When a three-phase short circuit occurs, since all renewable energy power sources are equipped with LCL filters, the discharge frequency of the renewable energy converter's filter capacitor can be calculated by combining specific parameters to determine the equivalent capacitance, inductance, and resistance parameters, and then theoretically calculating the discharge frequency of the renewable energy converter's filter capacitor. Taking a 220kV outgoing line as an example, the impedance parameters of the main transformer and the line need to be converted to the low-voltage side of the transformer substation. The transformer ratio is large, and the converted impedance parameters of the main transformer and the line are very small, having little impact on the discharge frequency. Therefore, the discharge frequency of the renewable energy converter's filter capacitor mainly depends on the filter parameters. Thus, the discharge frequency range of the renewable energy converter's filter capacitor can be obtained:

[0056]

[0057] From equations (1) and (2), it can be seen that there are large non-power frequency distortion components in this stage. Therefore, it is necessary to solve the equations simultaneously using the line equations. The line equations are satisfied for the RLC loops constructed under different scenarios:

[0058]

[0059] In the formula, I and U represent current and voltage, the subscript abc represents the three-phase values ​​of abc in the three-phase stationary coordinate system, L is the filter inductance, C is the filter capacitance, and R is the line resistance.

[0060] Because of the instantaneous voltage drop, the three-phase voltages after the voltage drop are assumed to be known quantities. Therefore, the line equations contain three unknown quantities: the three-phase currents. The analytical expressions for the three-phase currents can be obtained through analysis:

[0061]

[0062] In the formula A m1 A m2 ω is the current amplitude. m1 ω m2 Calculate β for different frequencies m1 β m2 For different phase angles, γ represents the time decay constant.

[0063] In some embodiments, the pre-acquired analytical expression for the short-circuit current of the renewable energy source during the fault transient phase includes:

[0064]

[0065] Where I represents the short-circuit current, the subscript abc represents the three phases corresponding to abc in the three-phase stationary coordinate system, e represents the grid connection point voltage, L is the filter inductance, R is the line resistance, τ represents the time decay component, and B m1 B m2 B m3ω is the current amplitude. m1 ω m2 ω m3 Calculate β for different frequencies m1 β m2 β m3 Calculate values ​​for different phase angles.

[0066] It should be noted that the process of obtaining the analytical expression for the short-circuit current of the new energy source during the fault transient phase is as follows:

[0067] Calculate the analytical expression for the short-circuit current during the transient phase;

[0068] During the transient phase, the LCL capacitor discharge process gradually disappears, so the main factor affecting the short-circuit current is the control response phase. The control equations for the control response phase in the dq rotating coordinate system are as follows:

[0069]

[0070] In the formula, I, U, and e represent current, terminal voltage, and grid connection point voltage, respectively, and k pξ k is the proportional element coefficient under the relevant coordinates. iξ ξ represents the integral element coefficients in the relevant coordinate system, where ξ represents the subscripts d and q, respectively, and the superscript * represents the command value.

[0071] Meanwhile, since the control strategy is in the dq coordinate system, to facilitate calculation, the line equations in the abc three-phase stationary coordinate system are transformed into the dq-axis rotating coordinate system, thus simplifying the short-circuit current calculation. The line equations in the dq-axis rotating coordinate system are as follows:

[0072]

[0073] In the formula, I, U, and e represent current, terminal voltage, and grid connection point voltage, respectively; the subscripts d and q represent the dq axis related signal quantities in the dq rotating coordinate system, respectively; L is the filter inductance; and R is the line resistance.

[0074] By simultaneously solving the line control equations in the dq-axis rotating coordinate system, the coupling terms can be reduced and simplified. Therefore, the short-circuit current calculation equation in the second-order dq-axis rotating coordinate system can be obtained:

[0075]

[0076] Since the command value is a constant, the differential term in the above equation is 0. Using the second-order differential equation obtained in the dq-axis rotating coordinate system, we can solve for the dq-axis short-circuit current during the transient phase. The result is:

[0077]

[0078] In the formula B mσξ The amplitude of each fault component is represented by ξ, where ξ represents the subscripts d and q, respectively, and d and q represent the dq axis components of the dq rotating coordinate system. σ represents the subscripts 1, 2, and 3, which represent the amplitudes of different components. τ represents the time decay component, which is composed of control parameters kp and ki, as well as line parameters R and L.

[0079] The expression for the dq-axis current in the rotating dq-axis coordinate system as the short-circuit current in the three-phase coordinate system is:

[0080]

[0081] In the formula, Bm1, Bm2, and Bm3 are the current amplitudes, ωm1, ωm2, and ωm3 are the calculated values ​​for different frequencies, and βm1, βm2, and βm3 are the calculated values ​​for different phase angles.

[0082] In some embodiments, the pre-acquired analytical expression for the short-circuit current of the renewable energy source during the fault steady-state stage includes:

[0083]

[0084] Where I represents the short-circuit current, the subscript abc represents the three phases corresponding to abc in the three-phase stationary coordinate system, and C m1 ω is the current amplitude, β is the calculated value of the power frequency quantity, and β is the current amplitude. m Calculate values ​​for different phase angles.

[0085] It should be noted that the process of obtaining the analytical expression for the short-circuit current of the new energy source during the fault steady-state stage is as follows:

[0086] Calculate the analytical expression for the short-circuit current in the steady-state stage, and integrate the analytical expressions for the short-circuit current in the three fault stages.

[0087] The analytical expression for the short-circuit current in the steady-state phase needs to consider the command value of the new energy source after the fault occurs. The value of the command value needs to take into account the degree of voltage drop at the grid connection point in the actual scenario, as shown in the following formula:

[0088]

[0089] In the formula, Im is the maximum current amplitude allowed to pass through the new energy converter, and IN is the rated current provided by the new energy converter.

[0090] The expression for the dq-axis current in the rotating dq-axis coordinate system as the short-circuit current in the three-phase coordinate system is:

[0091]

[0092] In the formula, Cm1 is the current amplitude, ω is the calculated value of the power frequency quantity, and βm is the calculated value of different phase angles.

[0093] From equations (4), (9), and (11), it can be seen that the analytical expressions for short-circuit current at different time scales can be integrated into three parts, as shown in the following equations:

[0094]

[0095] In summary, the analytical expressions for the short-circuit current of new energy sources at different stages after a fault are shown in equation (12).

[0096] The following example illustrates the implementation process and effects of the above method in detail. This example demonstrates how a system was built in PSCAD / EMTDC. Figure 2 New energy power source simulation models, such as Figure 2 The diagram shown is a schematic of a simulation model for a new energy power source. The parameters of the new energy power source in this simulation model are shown in Table I.

[0097]

[0098] Table I Simulation Parameters for New Energy Power Sources

[0099] Before the renewable energy source fails, it operates at full capacity. Assuming the failure occurs at time 0, with a voltage drop of 70%, what are the calculated and actual values ​​of the short-circuit current supplied by the renewable energy source under this fault condition? Figure 3 The figure shown is a simulation verification diagram of the calculation method for short-circuit current of new energy sources that takes into account different fault stages.

[0100] Depend on Figure 3 It can be seen that when a fault occurs, the calculated value of the short-circuit current of the new energy source is highly consistent with the actual value in the three stages of uncontrolled stage, transient stage and steady-state stage, which verifies the accuracy of the new energy source short-circuit current calculation method of this application.

[0101] In summary, this application provides a method for calculating the short-circuit current of a new energy source, comprising: real-time detection of whether a target new energy source has a fault; when a fault is detected in the target new energy source, collecting target data information at the time of the fault; and calculating the short-circuit current of the target new energy source based on the target data information using pre-acquired analytical expressions for the short-circuit current of the new energy source during the uncontrolled fault stage, the transient fault stage, and the steady-state fault stage. This application provides a method for calculating the short-circuit current of the new energy source under different fault stages, covering the short-circuit current of the new energy source across the entire time scale, ensuring accurate short-circuit current calculation results under different fault stages, and avoiding the risk of protection failure.

[0102] Example 2

[0103] Based on the above-described method for calculating the short-circuit current of new energy sources disclosed in the embodiments of the present invention, Figure 4 Specifically, a new energy short-circuit current calculation system applying this new energy short-circuit current calculation method is disclosed.

[0104] like Figure 4 As shown in the figure, an embodiment of the present invention discloses a new energy short-circuit current calculation system, the system comprising:

[0105] Detection unit 401 is used to detect in real time whether the target new energy power source has a fault;

[0106] The acquisition unit 402 is used to acquire target data information when the target new energy power supply fails, when a fault is detected in the target system energy power supply.

[0107] The calculation unit 403 is used to calculate the new energy short-circuit current of the target new energy power source based on the target data information and through the pre-acquired analytical expressions for the new energy short-circuit current in the uncontrolled fault stage, the transient fault stage, and the steady-state fault stage.

[0108] In some embodiments, the pre-acquired analytical expression for the short-circuit current of the renewable energy source during the uncontrolled fault stage includes:

[0109]

[0110] Where I represents the short-circuit current, the subscript abc represents the three phases corresponding to abc in the three-phase stationary coordinate system, and A m1 A m2 ω is the current amplitude. m1 ω m2 Calculate β for different frequencies m1 β m2 For different phase angles, γ represents the time decay constant.

[0111] In some embodiments, the pre-acquired analytical expression for the short-circuit current of the renewable energy source during the fault transient phase includes:

[0112]

[0113] Where I represents the short-circuit current, the subscript abc represents the three phases corresponding to abc in the three-phase stationary coordinate system, e represents the grid connection point voltage, L is the filter inductance, R is the line resistance, τ represents the time decay component, and B m1 B m2 B m3 ω is the current amplitude. m1 ωm2 ω m3 Calculate β for different frequencies m1 β m2 β m3 Calculate values ​​for different phase angles.

[0114] In some embodiments, the pre-acquired analytical expression for the short-circuit current of the renewable energy source during the fault steady-state stage includes:

[0115]

[0116] Where I represents the short-circuit current, the subscript abc represents the three phases corresponding to abc in the three-phase stationary coordinate system, and C m1 ω is the current amplitude, β is the calculated value of the power frequency quantity, and β is the current amplitude. m Calculate values ​​for different phase angles.

[0117] The specific working process of the detection unit 401, acquisition unit 402 and calculation unit 403 in the new energy short-circuit current calculation system disclosed in the above embodiments of the present invention can be found in the corresponding content of the new energy short-circuit current calculation method disclosed in the above embodiments of the present invention, and will not be repeated here.

[0118] In summary, this application provides a new energy short-circuit current calculation system, comprising: real-time detection of whether a target new energy power source has a fault; when a fault is detected in the target new energy power source, collecting target data information at the time of the fault; and calculating the new energy short-circuit current of the target new energy power source based on the target data information using pre-acquired analytical expressions for the new energy short-circuit current during the uncontrolled fault stage, the transient fault stage, and the steady-state fault stage. This application calculates the new energy short-circuit current under different fault stages, covering the new energy short-circuit current across the entire time scale, ensuring accurate short-circuit current calculation results under different fault stages, and avoiding the risk of protection failure.

[0119] Example 3

[0120] This embodiment also provides a computer-readable storage medium, such as flash memory, hard disk, multimedia card, card-type memory (e.g., SD or DX memory), random access memory (RAM), static random access memory (SRAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), programmable read-only memory (PROM), magnetic memory, disk, optical disk, server, App application store, etc., which stores a computer program. When the computer program is executed by a processor, it can implement the method steps as described in Embodiment 1. This embodiment will not repeat the description here.

[0121] Example 4

[0122] Figure 5 A connection block diagram of an electronic device 500 provided in this application embodiment is shown below. Figure 5 As shown, the electronic device 500 may include: a processor 501, a memory 502, a multimedia component 503, an input / output (I / O) interface 504, and a communication component 505.

[0123] The processor 501 is used to execute all or part of the steps in the new energy short-circuit current calculation method as described in Embodiment 1. The memory 502 is used to store various types of data, which may include, for example, instructions for any application or method in the electronic device, as well as application-related data.

[0124] The processor 501 may be implemented as an application-specific integrated circuit (ASIC), a digital signal processor (DSP), a digital signal processing device (DSPD), a programmable logic device (PLD), a field-programmable gate array (FPGA), a controller, a microcontroller, a microprocessor, or other electronic components, and is used to execute the new energy short-circuit current calculation method in Embodiment 1 above.

[0125] The memory 502 can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk.

[0126] Multimedia component 503 may include a screen, which may be a touchscreen, and an audio component for outputting and / or inputting audio signals. For example, the audio component may include a microphone for receiving external audio signals. The received audio signals may be further stored in memory or transmitted via a communication component. The audio component also includes at least one speaker for outputting audio signals.

[0127] I / O interface 504 provides an interface between processor 501 and other interface modules, such as keyboards, mice, and buttons. These buttons can be virtual or physical buttons.

[0128] Communication component 505 is used for wired or wireless communication between the electronic device 500 and other devices. Wireless communication includes, for example, Wi-Fi, Bluetooth, Near Field Communication (NFC), 2G, 3G, or 4G, or one or more combinations thereof. Therefore, the corresponding communication component 505 may include: a Wi-Fi module, a Bluetooth module, or an NFC module.

[0129] In summary, this application provides a method, system, storage medium, and electronic device for calculating the short-circuit current of a new energy source. The method includes: real-time detection of whether a target new energy source power supply has experienced a fault; when a fault is detected in the target new energy source power supply, collecting target data information at the time of the fault; and calculating the new energy source short-circuit current of the target new energy source power supply based on the target data information using pre-acquired analytical expressions for the new energy source short-circuit current during the uncontrolled fault stage, the transient fault stage, and the steady-state fault stage. This application provides a method for calculating the new energy source short-circuit current under different fault stages, covering the new energy source short-circuit current across the entire time scale, ensuring accurate short-circuit current calculation results under different fault stages, and avoiding the risk of protection failure.

[0130] In the several embodiments provided in this application, it should be understood that the disclosed methods can also be implemented in other ways. The method embodiments described above are merely illustrative.

[0131] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0132] Although the embodiments disclosed in this application are as described above, the above content is merely for the purpose of facilitating understanding of this application and is not intended to limit this application. Any person skilled in the art to which this application pertains may make any modifications and changes in the form and details of the implementation without departing from the spirit and scope disclosed in this application; however, the scope of patent protection of this application shall still be determined by the scope defined in the appended claims.

Claims

1. A method for calculating short-circuit current in new energy sources, characterized in that, The method includes: Real-time detection of whether the target new energy power source is malfunctioning; When a fault is detected in the target new energy power source, target data information at the time of the fault is collected. Based on the target data information, the short-circuit current of the target renewable energy source is calculated using pre-acquired analytical expressions for the renewable energy short-circuit current during the uncontrolled fault stage, the transient fault stage, and the steady-state fault stage. The pre-acquired analytical expressions for the renewable energy short-circuit current during the uncontrolled fault stage include: in, Indicates short-circuit current, subscript Represents the three-phase stationary coordinate system The corresponding three phases, , The current amplitude, , Calculate values ​​for different frequencies. , Calculate values ​​for different phase angles. Represents the time decay constant; the pre-acquired analytical expression for the short-circuit current of the renewable energy source during the fault transient stage includes: in, L For filter inductance, R For line resistance, Indicates the time decay component. , , The current amplitude, , , Calculate values ​​for different frequencies. , , For different phase angles, the pre-acquired analytical expression for the short-circuit current of new energy sources in the fault steady-state stage includes: in, The current amplitude, This is a calculated value for power frequency. Calculate values ​​for different phase angles.

2. A short-circuit current calculation system for new energy sources, characterized in that, The system includes: The detection unit is used to detect in real time whether the target new energy power source has a fault; The acquisition unit is used to acquire target data information when the target new energy power source is detected to have a fault. The calculation unit is configured to calculate the short-circuit current of the target renewable energy source based on the target data information, using pre-acquired analytical expressions for the short-circuit current of the renewable energy source during the uncontrolled fault stage, the transient fault stage, and the steady-state fault stage; the pre-acquired analytical expressions for the short-circuit current of the renewable energy source during the uncontrolled fault stage include: in, I Indicates short-circuit current, subscript Represents the three-phase stationary coordinate system The corresponding three phases, , The current amplitude, , Calculate values ​​for different frequencies. , Calculate values ​​for different phase angles. Represents the time decay constant; the pre-acquired analytical expression for the short-circuit current of the renewable energy source during the fault transient stage includes: in, L For filter inductance, R For line resistance, Indicates the time decay component. , , The current amplitude, , , Calculate values ​​for different frequencies. , , For different phase angles, the pre-acquired analytical expression for the short-circuit current of new energy sources in the fault steady-state stage includes: in, The current amplitude, This is a calculated value for power frequency. Calculate values ​​for different phase angles.

3. A storage medium, characterized in that, The computer program stored in the storage medium can be executed by one or more processors and can be used to implement the new energy short-circuit current calculation method as described in claim 1.

4. An electronic device, characterized in that, It includes a memory and a processor. The memory stores a computer program, and the memory and the processor are interconnected. When the computer program is executed by the processor, it performs the new energy short-circuit current calculation method as described in claim 1.

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