Segmented voltage regulation strength evaluation method and system for new energy low-voltage ride-through process

Abstract

This invention discloses a method and system for evaluating segmented voltage regulation intensity during the low-voltage ride-through process of a new energy power plant, comprising: acquiring key operating parameters of the new energy power plant; calculating voltage constraints at different stages based on the key operating parameters, determining the voltage constraint range corresponding to each stage, thereby dividing the low-voltage ride-through process into three stages; determining the reactive current corresponding to each stage, determining the reactive power based on the reactive current, and establishing a voltage regulation characteristic analysis model corresponding to each stage based on the reactive power; acquiring the grid connection point voltage amplitude at different sampling times during the low-voltage ride-through process of the new energy power plant, determining the target stage corresponding to each grid connection point voltage amplitude based on the grid connection point voltage amplitude and the voltage constraint range, and determining the voltage regulation intensity of the new energy power plant at different sampling times during the low-voltage ride-through process based on the voltage regulation characteristic analysis model corresponding to the target stage.

Description

Technical Field

[0001] This invention relates to the field of transient voltage regulation analysis technology for new energy power systems, and more specifically, to a method and system for evaluating the segmented voltage regulation intensity during the low-voltage ride-through process of new energy systems. Background Technology

[0002] With the rapid growth of renewable energy installed capacity, the proportion of traditional synchronous generators in the power system has decreased significantly, weakening system inertia and reactive power support capabilities, leading to increasingly prominent voltage insufficiency issues. To characterize the impact of renewable energy grid connection on system voltage stability, existing studies mostly use static indicators such as short-circuit ratio (SCR) and multiple-infeed short-circuit ratio (MRSCR), and evaluate the system's steady-state voltage support capability through equivalent impedance and voltage stability limit analysis. However, these methods are usually based on linearized models, failing to account for the dynamic characteristics of faults and the influence of renewable energy control parameters, making it difficult to accurately reflect the voltage response during faults.

[0003] In scenarios with a high proportion of renewable energy, renewable energy power plants generally possess low voltage ride-through (LVRT) capabilities. Their control strategies during faults directly determine their ability to support system voltage. Under different control parameters, fault depths, and system impedance conditions, the output of renewable energy and system voltage exhibit a significant nonlinear relationship, a process that traditional steady-state analysis cannot cover.

[0004] Therefore, there is an urgent need for a method to evaluate the segmented voltage regulation intensity during the low-voltage ride-through process of new energy sources. Summary of the Invention

[0005] This invention proposes a method and system for evaluating the segmented voltage regulation intensity during the low-voltage ride-through process of new energy sources, in order to solve the problem of how to evaluate the voltage regulation intensity during the low-voltage ride-through process of new energy sources.

[0006] To address the aforementioned problems, according to one aspect of the present invention, a method for evaluating the segmented voltage regulation intensity during the low-voltage ride-through process of new energy sources is provided, the method comprising:

[0007] Obtain key operating parameters for new energy power plants;

[0008] Based on the aforementioned key operating parameters, voltage constraints at different stages are calculated to determine the voltage constraint range for each stage, thereby dividing the low-voltage ride-through process into three stages.

[0009] Determine the reactive current corresponding to each stage, determine the reactive power based on the reactive current, and establish a voltage regulation characteristic analysis model corresponding to each stage based on the reactive power.

[0010] The grid connection point voltage amplitude of the new energy power plant at different sampling times during the low-voltage ride-through process is obtained. Based on the grid connection point voltage amplitude and voltage constraint range, the target stage corresponding to each grid connection point voltage amplitude is determined. Based on the voltage regulation characteristic analysis model corresponding to the target stage, the voltage regulation intensity of the new energy power plant at different sampling times during the low-voltage ride-through process is determined.

[0011] Preferably, the calculation of voltage constraints at different stages based on the key operating parameters, and the determination of the voltage constraint range corresponding to each stage, includes:

[0012] Calculate the first voltage threshold value, including:

[0013] ,

[0014] Calculate the second voltage threshold, including:

[0015] ,

[0016] Set the third voltage threshold: ;

[0017] Based on the first voltage boundary value, the second voltage boundary value, and the third voltage boundary value, the voltage constraint range corresponding to the first stage is determined as follows: V t1 < V t ≤ V set The voltage constraint range corresponding to the second stage is determined to be... V t2 < V t ≤ V t1 The voltage constraint range corresponding to the third stage is determined to be... V t3 ≤ V t ≤ V t2 ;

[0018] in, This is the first voltage threshold value; The target voltage; k lim This is the current limiting factor; I N Rated current; V t This refers to the voltage amplitude at the grid connection point. I Q0 This represents the reactive current from the previous moment. k vq This is the voltage feedback gain coefficient; kiq The coefficients of the integral element; I Qset Set the current value; This is the second voltage threshold value; This is the third voltage threshold value.

[0019] Preferably, determining the reactive current corresponding to each stage includes:

[0020] ,

[0021] ,

[0022] ,

[0023] in, , and These are the reactive currents corresponding to the first, second, and third stages, respectively. k vq This is the voltage feedback gain coefficient; V t This refers to the voltage amplitude at the grid connection point. The target voltage; k iq The coefficients of the integral element; I Q0 This represents the reactive current from the previous moment. I Qset Set the current value.

[0024] Preferably, the reactive power is determined based on the reactive current, and a voltage regulation characteristic analysis model for each stage is established based on the reactive power, including:

[0025] For the first stage, the voltage regulation characteristic analysis model is determined using the following methods:

[0026] ,

[0027] ,

[0028] For the second stage, the voltage regulation characteristic analysis model is determined using the following methods:

[0029] ,

[0030] ,

[0031] For the third stage, the voltage regulation characteristic analysis model is determined using the following methods:

[0032] ,

[0033] ,

[0034] in, , and These represent the voltage regulation intensities corresponding to the first, second, and third stages, respectively. , and These are the reactive power corresponding to the first, second, and third stages, respectively. , and These are the reactive currents corresponding to the first, second, and third stages, respectively. k vq This is the voltage feedback gain coefficient; V t This refers to the voltage amplitude at the grid connection point. The target voltage; k iq The coefficients of the integral element; I Q0 This represents the reactive current from the previous moment. I Qset Set the current value.

[0035] Preferably, the method further includes:

[0036] The reactive power corresponding to the voltage regulation intensity of 0 is selected as the maximum reactive power regulation power. Based on the maximum reactive power regulation power, the reactive power regulation limit capability of the new energy device under the current grid connection conditions is characterized, and it serves as a key constraint parameter for the evaluation of system voltage support strength and the design of control strategies.

[0037] According to another aspect of the present invention, a segmented voltage regulation intensity assessment system for low-voltage ride-through of new energy sources is provided, the system comprising:

[0038] The parameter acquisition unit is used to acquire key operating parameters of the new energy power plant.

[0039] The voltage constraint calculation unit is used to calculate the voltage constraint at different stages based on the key operating parameters, and to determine the voltage constraint range corresponding to each stage, so as to divide the low-voltage ride-through process into three stages.

[0040] The model determination unit is used to determine the reactive current corresponding to each stage, determine the reactive power based on the reactive current, and establish a voltage regulation characteristic analysis model corresponding to each stage based on the reactive power.

[0041] The voltage regulation intensity determination unit is used to acquire the grid connection point voltage amplitude at different sampling times during the low-voltage ride-through process of the new energy power station, determine the target stage corresponding to each grid connection point voltage amplitude based on the grid connection point voltage amplitude and the voltage constraint range, and determine the voltage regulation intensity of the new energy power station at different sampling times during the low-voltage ride-through process based on the voltage regulation characteristic analysis model corresponding to the target stage.

[0042] Preferably, the voltage constraint calculation unit calculates voltage constraints at different stages based on the key operating parameters, and determines the voltage constraint range corresponding to each stage, including:

[0043] Calculate the first voltage threshold value, including:

[0044] ,

[0045] Calculate the second voltage threshold, including:

[0046] ,

[0047] Set the third voltage threshold: ;

[0048] Based on the first voltage boundary value, the second voltage boundary value, and the third voltage boundary value, the voltage constraint range corresponding to the first stage is determined as follows: V t1 < V t ≤ V set The voltage constraint range corresponding to the second stage is determined to be... V t2 < V t ≤ V t1 The voltage constraint range corresponding to the third stage is determined to be... V t3 ≤ V t ≤ V t2 ;

[0049] in, This is the first voltage threshold value; The target voltage; k lim This is the current limiting factor; I N Rated current; V t This refers to the voltage amplitude at the grid connection point. I Q0 This represents the reactive current from the previous moment. k vqThis is the voltage feedback gain coefficient; k iq The coefficients of the integral element; I Qset Set the current value; This is the second voltage threshold value; This is the third voltage threshold value.

[0050] Preferably, the model determination unit determines the reactive current corresponding to each stage, including:

[0051] ,

[0052] ,

[0053] ,

[0054] in, , and These are the reactive currents corresponding to the first, second, and third stages, respectively. k vq This is the voltage feedback gain coefficient; V t This refers to the voltage amplitude at the grid connection point. The target voltage; k iq The coefficients of the integral element; I Q0 This represents the reactive current from the previous moment. I Qset Set the current value.

[0055] Preferably, the model determination unit determines the reactive power based on the reactive current and establishes a voltage regulation characteristic analysis model for each stage based on the reactive power, including:

[0056] For the first stage, the voltage regulation characteristic analysis model is determined using the following methods:

[0057] ,

[0058] ,

[0059] For the second stage, the voltage regulation characteristic analysis model is determined using the following methods:

[0060] ,

[0061] ,

[0062] For the third stage, the voltage regulation characteristic analysis model is determined using the following methods:

[0063] ,

[0064] ,

[0065] in, , and These represent the voltage regulation intensities corresponding to the first, second, and third stages, respectively. , and These are the reactive power corresponding to the first, second, and third stages, respectively. , and These are the reactive currents corresponding to the first, second, and third stages, respectively. k vq This is the voltage feedback gain coefficient; V t This refers to the voltage amplitude at the grid connection point. The target voltage; k iq The coefficients of the integral element; I Q0 This represents the reactive current from the previous moment. I Qset Set the current value.

[0066] Preferably, the system further includes:

[0067] The maximum reactive power regulation unit is used to select the reactive power corresponding to the voltage regulation intensity of 0 as the maximum reactive power regulation, so as to characterize the reactive power regulation limit capability of the new energy device under the current grid connection conditions based on the maximum reactive power regulation, and to serve as a key constraint parameter for system voltage support strength assessment and control strategy design.

[0068] Based on another aspect of the present invention, the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements any of the steps in a method for evaluating the segmented voltage regulation intensity during a low-voltage ride-through process of a new energy source.

[0069] According to another aspect of the present invention, the present invention provides an electronic device, comprising:

[0070] The aforementioned computer-readable storage medium; and

[0071] One or more processors for executing a program in the computer-readable storage medium.

[0072] This invention provides a method and system for assessing the segmented voltage regulation intensity during the low-voltage ride-through process of renewable energy plants. The method includes: acquiring key operating parameters of the renewable energy power plant; calculating voltage constraints at different stages based on the key operating parameters, determining the voltage constraint range for each stage to divide the low-voltage ride-through process into three stages; determining the reactive current for each stage, determining the reactive power based on the reactive current, and establishing a voltage regulation characteristic analysis model for each stage based on the reactive power; acquiring the grid connection point voltage amplitude at different sampling times during the low-voltage ride-through process of the renewable energy power plant, determining the target stage corresponding to each grid connection point voltage amplitude based on the grid connection point voltage amplitude and the voltage constraint range, and determining the voltage regulation intensity of the renewable energy power plant at different sampling times during the low-voltage ride-through process based on the voltage regulation characteristic analysis model corresponding to the target stage. Based on the low-voltage ride-through characteristics, this invention segments the nonlinear problems during faults and further constructs a segmented voltage regulation analysis model considering fault depth and control parameters. This enables a quantitative assessment of the voltage support capability of renewable energy throughout the fault process, providing technical support for voltage intensity analysis and reactive power regulation margin provision during transient periods in high-proportion renewable energy power systems. Attached Figure Description

[0073] Exemplary embodiments of the present invention can be more fully understood by referring to the following figures:

[0074] Figure 1 A flowchart of a segmented voltage regulation intensity assessment method 100 for a new energy low-voltage ride-through process according to an embodiment of the present invention;

[0075] Figure 2 This is a schematic diagram of the structure of a segmented voltage regulation intensity assessment system 200 for low-voltage ride-through of new energy sources according to an embodiment of the present invention. Detailed Implementation

[0076] Exemplary embodiments of the invention will now be described with reference to the accompanying drawings. However, the invention may be embodied in many different forms and is not limited to the embodiments described herein. These embodiments are provided to fully and completely disclose the invention and to fully convey its scope to those skilled in the art. The terminology used in the exemplary embodiments illustrated in the drawings is not intended to limit the invention. In the drawings, the same units / elements are referred to by the same reference numerals.

[0077] Unless otherwise stated, the terms used herein (including technical terms) have their common meaning as understood by one of ordinary skill in the art. Furthermore, it is understood that terms defined in commonly used dictionaries should be understood to have a meaning consistent with the context of their relevant field, and not to be interpreted as having an idealized or overly formal meaning.

[0078] Figure 1 This is a flowchart of a segmented voltage regulation intensity assessment method 100 for a new energy low-voltage ride-through process according to an embodiment of the present invention. Figure 1 As shown, the segmented voltage regulation intensity assessment method for the low-voltage ride-through process of new energy provided by this invention, based on the characteristics of low-voltage ride-through, processes the nonlinear problems during the fault period in segments, and further constructs a segmented voltage regulation analysis model that takes into account the fault depth and control parameters. This enables a quantitative assessment of the voltage support capability of new energy throughout the fault process, and can provide technical support for voltage intensity analysis and reactive power regulation margin provision during transient periods in high-proportion new energy power systems. The segmented voltage regulation intensity assessment method 100 for the low-voltage ride-through process of new energy provided by this invention starts from step 101, in which key operating parameters of the new energy power plant are obtained.

[0079] In step 102, voltage constraints at different stages are calculated based on the key operating parameters to determine the voltage constraint range for each stage, so that the low-voltage ride-through process is divided into three stages.

[0080] Preferably, the calculation of voltage constraints at different stages based on the key operating parameters, and the determination of the voltage constraint range corresponding to each stage, includes:

[0081] Calculate the first voltage threshold value, including:

[0082] ,

[0083] Calculate the second voltage threshold, including:

[0084] ,

[0085] Set the third voltage threshold: ;

[0086] Based on the first voltage boundary value, the second voltage boundary value, and the third voltage boundary value, the voltage constraint range corresponding to the first stage is determined as follows: V t1 < V t ≤ V set The voltage constraint range corresponding to the second stage is determined to be... V t2 < V t ≤ V t1 The voltage constraint range corresponding to the third stage is determined to be... V t3 ≤ V t ≤ Vt2 ;

[0087] in, This is the first voltage threshold value; The target voltage; k lim This is the current limiting factor; I N Rated current; V t This refers to the voltage amplitude at the grid connection point. I Q0 This represents the reactive current from the previous moment. k vq This is the voltage feedback gain coefficient; k iq The coefficients of the integral element; I Qset Set the current value; This is the second voltage threshold value; This is the third voltage threshold value.

[0088] In this invention, the low-voltage ride-through process of new energy sources is first divided into multiple stages. Specifically, key operating parameters of the new energy power plant and grid-connected nodes are obtained, including system operating voltage and new energy control parameters. Then, based on the key operating parameters, voltage constraints for different stages are calculated to determine the voltage constraint range for each stage and establish voltage constraint models for different stages.

[0089] Among them, the first-stage voltage constraint model is established. V t1 < V t ≤ V set , V t1 As the lower limit of voltage constraint in the first stage. V set This serves as the upper limit of voltage constraints for the first stage. V t1 The calculation method is as follows:

[0090] (1)

[0091] Among them, the second-stage voltage constraint model is established. V t2 < V t ≤ V t1 , V t2 This serves as the lower limit of the voltage constraint for the second stage. V t1 This serves as the upper limit of voltage constraints for the second stage.V t2 The calculation method is as follows:

[0092] (2)

[0093] Among them, a third-stage voltage constraint model is established. V t3 ≤ V t ≤ V t2 , V t3 As the lower limit of voltage constraint in the third stage V t2 This serves as the upper limit of voltage constraints for the third stage. V t3 for:

[0094] (3)

[0095] in, k lim This is the current limiting factor; I N Rated current; V t The voltage amplitude at the grid connection point (pu); V set The target voltage; I Q The reactive current command output by the controller; I Q0 This represents the reactive current from the previous moment. k vq This is the voltage feedback gain coefficient; k iq The coefficients of the integral element; I Qset This is a constant setting (e.g., 0 indicates no bias is set).

[0096] In step 103, the reactive current corresponding to each stage is determined, the reactive power is determined based on the reactive current, and a voltage regulation characteristic analysis model corresponding to each stage is established based on the reactive power.

[0097] Preferably, determining the reactive current corresponding to each stage includes:

[0098] ,

[0099] ,

[0100] ,

[0101] in, , and These are the reactive currents corresponding to the first, second, and third stages, respectively. k vq This is the voltage feedback gain coefficient; V t This refers to the voltage amplitude at the grid connection point. The target voltage; k iq The coefficients of the integral element; I Q0 This represents the reactive current from the previous moment. I Qset Set the current value.

[0102] Preferably, the reactive power is determined based on the reactive current, and a voltage regulation characteristic analysis model for each stage is established based on the reactive power, including:

[0103] For the first stage, the voltage regulation characteristic analysis model is determined using the following methods:

[0104] ,

[0105] ,

[0106] For the second stage, the voltage regulation characteristic analysis model is determined using the following methods:

[0107] ,

[0108] ,

[0109] For the third stage, the voltage regulation characteristic analysis model is determined using the following methods:

[0110] ,

[0111] ,

[0112] in, , and These represent the voltage regulation intensities corresponding to the first, second, and third stages, respectively. , and These are the reactive power corresponding to the first, second, and third stages, respectively. , and These are the reactive currents corresponding to the first, second, and third stages, respectively. k vq This is the voltage feedback gain coefficient;V t This refers to the voltage amplitude at the grid connection point. The target voltage; k iq The coefficients of the integral element; I Q0 This represents the reactive current from the previous moment. I Qset Set the current value.

[0113] In this invention, for the first stage V t1 < V t ≤ V set The current constraint model for the first stage is as follows:

[0114] (4)

[0115] (5)

[0116] (6)

[0117] in, and These are the reactive current and active current in the first stage, respectively.

[0118] According to formula (5), the reactive power of the first stage can be obtained as follows:

[0119] (7)

[0120] At this point, the voltage regulation characteristic analysis model corresponding to the first stage can be established as follows:

[0121] (8)

[0122] For the second phase V t2 < V t ≤ V t1 The current constraint model for the second stage is as follows:

[0123] (9)

[0124] (10)

[0125] (11)

[0126] in, and These are the reactive current and active current in the second stage, respectively.

[0127] According to formula (10), the reactive power in the second stage can be obtained as follows:

[0128] (12)

[0129] At this point, the voltage regulation characteristic analysis model corresponding to the second stage can be established as follows:

[0130] (13)

[0131] For the third stage V t3 ≤ V t ≤ V t2 The current constraint model for the third stage is as follows:

[0132] (14)

[0133] (15)

[0134] in, and These are the reactive current and active current in the third stage, respectively.

[0135] According to formula (15), the reactive power in the third stage can be obtained as follows:

[0136] (16)

[0137] At this point, the voltage regulation characteristic analysis model corresponding to the third stage can be established as follows:

[0138] (17)

[0139] In step 104, the grid connection point voltage amplitude of the new energy power station at different sampling times during the low-voltage ride-through process is obtained. Based on the grid connection point voltage amplitude and voltage constraint range, the target stage corresponding to each grid connection point voltage amplitude is determined. Based on the voltage regulation characteristic analysis model corresponding to the target stage, the voltage regulation intensity of the new energy power station at different sampling times during the low-voltage ride-through process is determined.

[0140] In this invention, for the grid connection point voltage amplitude at any sampling moment during the low-voltage ride-through process of a new energy power station, the stage of the low-voltage ride-through process in which the new energy power station is located at this time is determined as the target stage based on the grid connection point voltage amplitude, and the voltage regulation intensity is calculated based on the voltage regulation characteristic analysis model corresponding to the target stage, thereby obtaining the voltage regulation intensity corresponding to each sampling moment during the low-voltage ride-through process.

[0141] Preferably, the method further includes:

[0142] The reactive power corresponding to the voltage regulation intensity of 0 is selected as the maximum reactive power regulation power. Based on the maximum reactive power regulation power, the reactive power regulation limit capability of the new energy device under the current grid connection conditions is characterized, and it serves as a key constraint parameter for the evaluation of system voltage support strength and the design of control strategies.

[0143] In this invention, the reactive power corresponding to the voltage regulation intensity of 0 can also be taken as the maximum reactive power regulation power. Based on the maximum reactive power regulation power, the reactive power regulation limit capability of the new energy device under the current grid connection conditions can be characterized, and it can be used as a key constraint parameter for the evaluation of system voltage support strength and the design of control strategy, thereby providing a quantitative basis for the regulation of new energy output, the coordinated allocation of reactive resources and voltage stability control.

[0144] The present invention provides a segmented voltage regulation strength assessment method for the low-voltage ride-through process of new energy, which achieves accurate quantification of the voltage regulation capability of the new energy grid-connected system during faults through staged current limiting modeling and dynamic voltage regulation characteristic analysis.

[0145] This invention achieves significant improvements in analytical accuracy, computational efficiency, and engineering applicability. By introducing a phased current-limiting model for low-voltage ride-through (LVRT) of renewable energy sources, this invention takes into account the nonlinear current response and control parameter characteristics of renewable energy sources throughout the entire fault process, enabling the evaluation results to reflect the actual voltage support capability under different control strategies and different fault depths.

[0146] In terms of engineering applicability and scalability, the phased voltage regulation model proposed in this invention is not only applicable to different types of new energy units such as wind power and photovoltaics, but can also be extended to voltage support analysis of flexible DC transmission systems. It can output the maximum reactive power regulation capacity of new energy sources and the dynamic fault support curve, providing quantitative basis for reactive power allocation in the power grid planning stage and dispatching decisions in the operation stage.

[0147] In summary, this invention not only significantly improves the accuracy, efficiency, and applicability of voltage support strength assessment during faults in renewable energy grid-connected systems, but also provides theoretical support and engineering means for the safe operation, planning, design, and control optimization of high-proportion renewable energy power systems, demonstrating significant technological advancement and application promotion value.

[0148] Figure 2 This is a schematic diagram of a segmented voltage regulation intensity assessment system 200 for low-voltage ride-through of new energy sources according to an embodiment of the present invention. Figure 2As shown, the segmented voltage regulation intensity assessment system 200 for the low-voltage ride-through process of new energy provided by the present invention includes: a parameter acquisition unit 201, a voltage constraint calculation unit 202, a model determination unit 203, and a voltage regulation intensity determination unit 204.

[0149] Preferably, the parameter acquisition unit 201 is used to acquire key operating parameters of the new energy power plant.

[0150] Preferably, the voltage constraint calculation unit 202 is used to calculate the voltage constraint for different stages based on the key operating parameters, and determine the voltage constraint range corresponding to each stage, so as to divide the low-voltage ride-through process into three stages.

[0151] Preferably, the voltage constraint calculation unit 202 calculates voltage constraints at different stages based on the key operating parameters, and determines the voltage constraint range corresponding to each stage, including:

[0152] Calculate the first voltage threshold value, including:

[0153] ,

[0154] Calculate the second voltage threshold, including:

[0155] ,

[0156] Set the third voltage threshold: ;

[0157] Based on the first voltage boundary value, the second voltage boundary value, and the third voltage boundary value, the voltage constraint range corresponding to the first stage is determined as follows: V t1 < V t ≤ V set The voltage constraint range corresponding to the second stage is determined to be... V t2 < V t ≤ V t1 The voltage constraint range corresponding to the third stage is determined to be... V t3 ≤ V t ≤ V t2 ;

[0158] in, This is the first voltage threshold value; The target voltage; k lim This is the current limiting factor;I N Rated current; V t This refers to the voltage amplitude at the grid connection point. I Q0 This represents the reactive current from the previous moment. k vq This is the voltage feedback gain coefficient; k iq The coefficients of the integral element; I Qset Set the current value; This is the second voltage threshold value; This is the third voltage threshold value.

[0159] Preferably, the model determination unit 203 is used to determine the reactive current corresponding to each stage, determine the reactive power based on the reactive current, and establish a voltage regulation characteristic analysis model corresponding to each stage based on the reactive power.

[0160] Preferably, the model determining unit 203 determines the reactive current corresponding to each stage, including:

[0161] ,

[0162] ,

[0163] ,

[0164] in, , and These are the reactive currents corresponding to the first, second, and third stages, respectively. k vq This is the voltage feedback gain coefficient; V t This refers to the voltage amplitude at the grid connection point. The target voltage; k iq The coefficients of the integral element; I Q0 This represents the reactive current from the previous moment. I Qset Set the current value.

[0165] Preferably, the model determination unit 203 determines the reactive power based on the reactive current and establishes a voltage regulation characteristic analysis model for each stage based on the reactive power, including:

[0166] For the first stage, the voltage regulation characteristic analysis model is determined using the following methods:

[0167] ,

[0168] ,

[0169] For the second stage, the voltage regulation characteristic analysis model is determined using the following methods:

[0170] ,

[0171] ,

[0172] For the third stage, the voltage regulation characteristic analysis model is determined using the following methods:

[0173] ,

[0174] ,

[0175] in, , and These represent the voltage regulation intensities corresponding to the first, second, and third stages, respectively. , and These are the reactive power corresponding to the first, second, and third stages, respectively. , and These are the reactive currents corresponding to the first, second, and third stages, respectively. k vq This is the voltage feedback gain coefficient; V t This refers to the voltage amplitude at the grid connection point. The target voltage; k iq The coefficients of the integral element; I Q0 This represents the reactive current from the previous moment. I Qset Set the current value.

[0176] Preferably, the voltage regulation intensity determination unit 204 is used to acquire the grid connection point voltage amplitude at different sampling times during the low-voltage ride-through process of the new energy power station, determine the target stage corresponding to each grid connection point voltage amplitude based on the grid connection point voltage amplitude and the voltage constraint range, and determine the voltage regulation intensity of the new energy power station at different sampling times during the low-voltage ride-through process based on the voltage regulation characteristic analysis model corresponding to the target stage.

[0177] Preferably, the system further includes:

[0178] The maximum reactive power regulation unit is used to select the reactive power corresponding to the voltage regulation intensity of 0 as the maximum reactive power regulation, so as to characterize the reactive power regulation limit capability of the new energy device under the current grid connection conditions based on the maximum reactive power regulation, and to serve as a key constraint parameter for system voltage support strength assessment and control strategy design.

[0179] The segmented voltage regulation intensity assessment system 200 for the low-voltage ride-through process of new energy in this embodiment corresponds to the segmented voltage regulation intensity assessment method 100 for the low-voltage ride-through process of new energy in another embodiment of this invention, and will not be described again here.

[0180] Based on another aspect of the present invention, the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements any of the steps in a method for evaluating the segmented voltage regulation intensity during a low-voltage ride-through process of a new energy source.

[0181] According to another aspect of the present invention, the present invention provides an electronic device, comprising:

[0182] The aforementioned computer-readable storage medium; and

[0183] One or more processors for executing a program in the computer-readable storage medium.

[0184] The present invention has been described with reference to a few embodiments. However, it will be apparent to those skilled in the art that other embodiments besides those disclosed above fall equivalently within the scope of the present invention.

[0185] Generally, all terms used in this invention are interpreted according to their ordinary meaning in the art, unless otherwise expressly defined herein. All references to “a / the / the [device, component, etc.]” ​​are openly interpreted as at least one instance of said device, component, etc., unless otherwise expressly stated. The steps of any method disclosed herein need not be performed in the exact order disclosed, unless explicitly stated otherwise.

[0186] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0187] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0188] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0189] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0190] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for evaluating the segmented voltage regulation intensity during the low-voltage ride-through process of new energy sources, characterized in that, The method includes: Obtain key operating parameters for new energy power plants; Based on the aforementioned key operating parameters, voltage constraints at different stages are calculated to determine the voltage constraint range for each stage, thereby dividing the low-voltage ride-through process into three stages. Determine the reactive current corresponding to each stage, determine the reactive power based on the reactive current, and establish a voltage regulation characteristic analysis model corresponding to each stage based on the reactive power. The grid connection point voltage amplitude of the new energy power plant at different sampling times during the low-voltage ride-through process is obtained. Based on the grid connection point voltage amplitude and voltage constraint range, the target stage corresponding to each grid connection point voltage amplitude is determined. Based on the voltage regulation characteristic analysis model corresponding to the target stage, the voltage regulation intensity of the new energy power plant at different sampling times during the low-voltage ride-through process is determined. Specifically, the calculation of voltage constraints at different stages based on the key operating parameters is used to determine the voltage constraint range for each stage, including: Calculate the first voltage threshold value, including: ， Calculate the second voltage threshold, including: ， Set the third voltage threshold: ; Based on the first voltage boundary value, the second voltage boundary value, and the third voltage boundary value, the voltage constraint range corresponding to the first stage is determined as follows: V t1 < V t ≤ V set The voltage constraint range corresponding to the second stage is determined to be... V t2 < V t ≤ V t1 The voltage constraint range corresponding to the third stage is determined to be... V t3 ≤ V t ≤ V t2 ; in, This is the first voltage threshold value; The target voltage; k lim This is the current limiting factor; I N Rated current; V t This refers to the voltage amplitude at the grid connection point. I Q0 This represents the reactive current from the previous moment. k vq This is the voltage feedback gain coefficient; k iq The coefficients of the integral element; I Qset Set the current value; This is the second voltage threshold value; This is the third voltage threshold value; The determination of the reactive current corresponding to each stage includes: ， ， ， in, , and These are the reactive currents corresponding to the first, second, and third stages, respectively. Specifically, reactive power is determined based on the reactive current, and a voltage regulation characteristic analysis model for each stage is established based on the reactive power, including: For the first stage, the voltage regulation characteristic analysis model is determined using the following methods: ， ， For the second stage, the voltage regulation characteristic analysis model is determined using the following methods: ， ， For the third stage, the voltage regulation characteristic analysis model is determined using the following methods: ， ， in, , and These represent the voltage regulation intensities corresponding to the first, second, and third stages, respectively. , and These represent the reactive power corresponding to the first, second, and third stages, respectively.

2. The method according to claim 1, characterized in that, The method further includes: The reactive power corresponding to the voltage regulation intensity of 0 is selected as the maximum reactive power regulation power. Based on the maximum reactive power regulation power, the reactive power regulation limit capability of the new energy device under the current grid connection conditions is characterized, and it serves as a key constraint parameter for the evaluation of system voltage support strength and the design of control strategies.

3. A segmented voltage regulation intensity assessment system for low-voltage ride-through of new energy sources, characterized in that, The system includes: The parameter acquisition unit is used to acquire key operating parameters of the new energy power plant. The voltage constraint calculation unit is used to calculate the voltage constraint at different stages based on the key operating parameters, and to determine the voltage constraint range corresponding to each stage, so as to divide the low-voltage ride-through process into three stages. The model determination unit is used to determine the reactive current corresponding to each stage, determine the reactive power based on the reactive current, and establish a voltage regulation characteristic analysis model corresponding to each stage based on the reactive power. The voltage regulation intensity determination unit is used to acquire the grid connection point voltage amplitude at different sampling times during the low-voltage ride-through process of the new energy power station, determine the target stage corresponding to each grid connection point voltage amplitude based on the grid connection point voltage amplitude and the voltage constraint range, and determine the voltage regulation intensity of the new energy power station at different sampling times during the low-voltage ride-through process based on the voltage regulation characteristic analysis model corresponding to the target stage. The voltage constraint calculation unit calculates voltage constraints at different stages based on the key operating parameters, determining the voltage constraint range for each stage, including: Calculate the first voltage threshold value, including: ， Calculate the second voltage threshold, including: ， Set the third voltage threshold: ; Based on the first voltage boundary value, the second voltage boundary value, and the third voltage boundary value, the voltage constraint range corresponding to the first stage is determined as follows: V t1 < V t ≤ V set The voltage constraint range corresponding to the second stage is determined to be... V t2 < V t ≤ V t1 The voltage constraint range corresponding to the third stage is determined to be... V t3 ≤ V t ≤ V t2 ; in, This is the first voltage threshold value; The target voltage; k lim This is the current limiting factor; I N Rated current; V t This refers to the voltage amplitude at the grid connection point. I Q0 This represents the reactive current from the previous moment. k vq This is the voltage feedback gain coefficient; k iq The coefficients of the integral element; I Qset Set the current value; This is the second voltage threshold value; This is the third voltage threshold value; The model determination unit determines the reactive current corresponding to each stage, including: ， ， ， in, , and These are the reactive currents corresponding to the first, second, and third stages, respectively. The model determination unit determines the reactive power based on the reactive current and establishes a voltage regulation characteristic analysis model for each stage based on the reactive power, including: For the first stage, the voltage regulation characteristic analysis model is determined using the following methods: ， ， For the second stage, the voltage regulation characteristic analysis model is determined using the following methods: ， ， For the third stage, the voltage regulation characteristic analysis model is determined using the following methods: ， ， in, , and These represent the voltage regulation intensities corresponding to the first, second, and third stages, respectively. , and These represent the reactive power corresponding to the first, second, and third stages, respectively.

4. The system according to claim 3, characterized in that, The system also includes: The maximum reactive power regulation unit is used to select the reactive power corresponding to the voltage regulation intensity of 0 as the maximum reactive power regulation, so as to characterize the reactive power regulation limit capability of the new energy device under the current grid connection conditions based on the maximum reactive power regulation, and to serve as a key constraint parameter for system voltage support strength assessment and control strategy design.

5. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the steps of the method as described in any one of claims 1-2.

6. An electronic device, characterized in that, include: The computer-readable storage medium as described in claim 5; as well as One or more processors for executing a program in the computer-readable storage medium.

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