New energy power supply virtual equivalent modeling method and system, storage medium and equipment

Abstract

The application relates to the technical field of power systems, and discloses a new energy power source virtual equivalent modeling method, a new energy power source virtual equivalent modeling system, a storage medium and equipment, the method comprising the following steps: establishing a virtual equivalent model of a new energy station, wherein the virtual equivalent model is composed of an equivalent potential and an equivalent impedance in series; determining parameter constraint conditions of the virtual equivalent model, wherein the parameter constraint conditions comprise: setting the amplitude of the equivalent potential to be the same as the amplitude of an AC system potential on the opposite side of a power grid line; setting the impedance angle of the equivalent impedance to be equal to the impedance angle of the power grid line; collecting measured voltage and measured current at a power grid protection point in real time; establishing a variable relationship equation group in polar coordinate form based on the parameter constraint conditions of the virtual equivalent model; and solving the variable relationship equation group to obtain dynamic parameters of the virtual equivalent model. The application can realize accurate equivalent modeling of the new energy station, thereby accurately reflecting the dynamic characteristics of the new energy power source.

Description

Technical Field

[0001] This invention relates to the field of power system technology, and in particular to a method, system, storage medium and device for virtual equivalent modeling of new energy power sources. Background Technology

[0002] With the rapid development of new energy power generation technologies, the large-scale integration of new energy sources (such as wind power and photovoltaics) into the power grid has become an important trend in power system development. The integration of new energy sources into the grid via power electronic converters presents new opportunities for grid fault analysis, relay protection design, and system stability assessment.

[0003] Traditional power system analysis methods typically equate renewable energy power plants to simplified current or voltage source models, but these models are difficult to accurately reflect the dynamic characteristics of renewable energy power sources. Summary of the Invention

[0004] Based on this, it is necessary to propose a virtual equivalent modeling method for new energy power sources to address the above problems.

[0005] A virtual equivalent modeling method for new energy power sources, the method comprising:

[0006] Establish a virtual equivalent model for the new energy power station, wherein the virtual equivalent model consists of the equivalent potential. and equivalent impedance Composed of series connection;

[0007] Determine the parameter constraints of the virtual equivalent model, the parameter constraints including: setting the equivalent potential. The amplitude and the AC system potential on the opposite side of the power grid line The amplitudes are the same; the equivalent impedance is set. impedance angle Impedance angle with power grid lines equal;

[0008] Real-time acquisition of measured voltage at power grid protection point and measuring current Based on the parameter constraints of the virtual equivalent model, a system of variable relationship equations in polar coordinate form is established;

[0009] Solve the system of equations relating the variables to obtain the dynamic parameters of the virtual equivalent model.

[0010] In the above scheme, establishing a system of variable relationship equations in polar coordinates includes:

[0011] Obtain the measured voltage With measuring current The relationship expression between the virtual equivalent model power source and the power source is as follows:

[0012]

[0013] in, To measure the voltage amplitude in real time; To measure the phase of the voltage in real time; The potential amplitude of the virtual equivalent model; The equivalent potential phase of the virtual equivalent model; This represents the equivalent impedance magnitude of the virtual equivalent model; The impedance angle of the virtual equivalent model; To measure the amplitude of the current; To measure the phase of the current;

[0014] Transform the relational expression into a variable relational equation in polar coordinates:

[0015]

[0016] in, This represents the real part of the potential in the virtual equivalent model; This represents the imaginary part of the potential in the virtual equivalent model. This represents the real part of the impedance in the virtual equivalent model. This represents the imaginary part of the impedance in the virtual equivalent model. This represents the real part of the voltage in the virtual equivalent model. This represents the imaginary part of the voltage in the virtual equivalent model. This represents the real part of the power supply current in the virtual equivalent model; This represents the imaginary part of the power supply current in the virtual equivalent model.

[0017] In the above scheme, the setting of the equivalent potential The amplitude and the AC system potential on the opposite side of the power grid line The amplitudes are the same; the equivalent impedance is set. impedance angle Impedance angle with power grid lines Equal, specifically including:

[0018]

[0019] in, This represents the real part of the potential in the virtual equivalent model; This represents the imaginary part of the potential in the virtual equivalent model; This represents the real part of the impedance in the virtual equivalent model. This represents the imaginary part of the impedance in the virtual equivalent model. This represents the real part of the voltage in the virtual equivalent model. This represents the imaginary part of the voltage in the virtual equivalent model. This represents the real part of the power supply current in the virtual equivalent model; This represents the imaginary part of the power supply current in the virtual equivalent model. The impedance angle of the power grid line; The potential of the AC system on the opposite side of the power grid line;

[0020] Solving the above expression yields the real part of the potential of the virtual equivalent model. and the imaginary part of the potential Real part of impedance and the imaginary part of impedance .

[0021] In the above scheme, the dynamic parameters of the virtual equivalent model are determined by combining the variable relationship equation in polar coordinates and the expression corresponding to the parameter constraints:

[0022] The equivalent potential phase of the virtual equivalent model is obtained using the following formula. Equivalent impedance magnitude of virtual equivalent model :

[0023]

[0024] in, The equivalent potential phase of the virtual equivalent model; This represents the equivalent impedance magnitude of the virtual equivalent model; This represents the real part of the potential in the virtual equivalent model; This represents the imaginary part of the potential in the virtual equivalent model; This represents the real part of the impedance in the virtual equivalent model. This represents the imaginary part of the impedance in the virtual equivalent model.

[0025] In the above scheme, the real-time acquisition of the measured voltage at the power grid protection point... and measuring current Previously, the method also included:

[0026] Determine the measured voltage Is the amplitude within the range of 0.1 pu to 1.2 pu?

[0027] Determine the measured current Is the amplitude less than the maximum allowable current of the converter?

[0028] If any of the above conditions are not met, the output measurement data will be abnormal and the calculation will be terminated.

[0029] In the above scheme, the equivalent potential phase of the virtual equivalent model is obtained. Equivalent impedance magnitude of virtual equivalent model The method then includes:

[0030] Determine the equivalent impedance magnitude of the virtual equivalent model. Does it satisfy: 0.01pu≤ ≤2.0 pu;

[0031] Determine the phase of the equivalent potential of the virtual equivalent model. Does it satisfy: -180°≤ ≤180°;

[0032] If any of the above conditions are not met, the output parameters will be abnormal, and the measured voltage at the power grid protection point will be re-acquired. and measuring current .

[0033] In the above scheme, the measured voltage at the power grid protection point is collected. and measuring current The method then includes:

[0034] According to the measured voltage and measuring current The phase and amplitude changes are used to determine the fault type of the new energy power station.

[0035] This application also proposes a virtual equivalent modeling system for new energy power sources, the system comprising: a virtual equivalent model construction unit, a constraint determination unit, an equation system construction unit, and a calculation unit;

[0036] The virtual equivalent model construction unit is used to establish a virtual equivalent model of the new energy power station. The virtual equivalent model is composed of the equivalent potential. and equivalent impedance Composed of series connection;

[0037] The constraint determination unit is used to determine the parameter constraints of the virtual equivalent model, the parameter constraints including: setting the equivalent potential. The amplitude and the AC system potential on the opposite side of the power grid line The amplitudes are the same; the equivalent impedance is set. impedance angle Impedance angle with power grid lines equal;

[0038] The equation system construction unit is used to collect the measured voltage at the power grid protection point in real time. and measuring current Based on the parameter constraints of the virtual equivalent model, a system of variable relationship equations in polar coordinate form is established;

[0039] The computing unit is used to solve the system of variable relationship equations to obtain the dynamic parameters of the virtual equivalent model.

[0040] This application also proposes a readable storage medium storing a computer program, which, when executed by a processor, causes the processor to perform the following steps:

[0041] Establish a virtual equivalent model for the new energy power station, wherein the virtual equivalent model consists of the equivalent potential. and equivalent impedance Composed of series connection;

[0042] Determine the parameter constraints of the virtual equivalent model, the parameter constraints including: setting the equivalent potential. The amplitude and the AC system potential on the opposite side of the power grid line The amplitudes are the same; the equivalent impedance is set. impedance angle Impedance angle with power grid lines equal;

[0043] Real-time acquisition of measured voltage at power grid protection point and measuring current Based on the parameter constraints of the virtual equivalent model, a system of variable relationship equations in polar coordinate form is established;

[0044] Solve the system of equations relating the variables to obtain the dynamic parameters of the virtual equivalent model.

[0045] This application also proposes a computer device, including a memory and a processor, wherein the memory stores a computer program, and the computer program is executed by the processor in the following steps:

[0046] Establish a virtual equivalent model for the new energy power station, wherein the virtual equivalent model consists of the equivalent potential. and equivalent impedance Composed of series connection;

[0047] Determine the parameter constraints of the virtual equivalent model, the parameter constraints including: setting the equivalent potential. The amplitude and the AC system potential on the opposite side of the power grid line The amplitudes are the same; the equivalent impedance is set. impedance angle Impedance angle with power grid lines equal;

[0048] Real-time acquisition of measured voltage at power grid protection point and measuring current Based on the parameter constraints of the virtual equivalent model, a system of variable relationship equations in polar coordinate form is established;

[0049] Solve the system of equations relating the variables to obtain the dynamic parameters of the virtual equivalent model.

[0050] The embodiments of this invention have the following beneficial effects: By constructing a virtual equivalent model consisting of equivalent potential and equivalent impedance connected in series, the complex characteristics of new energy power plants are first abstracted into a quantifiable combination of electrical parameters, laying the foundation for accurately describing their external characteristics; by setting constraints that the amplitude of the equivalent potential is the same as the amplitude of the AC system potential on the opposite side of the power grid line, and the equivalent impedance angle is equal to the line impedance angle, the correlation between the model and the power grid topology is strengthened, avoiding the errors caused by the isolated assumptions of parameters in traditional models, making the model more consistent with the actual power grid coupling relationship; based on the real-time collected voltage and current data and the above constraints, a set of variable relationship equations in polar coordinate form is established, transforming the dynamic characteristic analysis into a solvable mathematical problem, which not only retains the ability to capture the time-varying characteristics of parameters, but also simplifies the solution complexity through constraints; finally, the dynamic parameters obtained by solving the set of equations can reflect the key characteristics of the new energy power source, such as the equivalent potential phase and impedance amplitude, in real time under faults or control strategy adjustments, overcoming the defect that traditional fixed parameter models cannot adapt to the dynamic response of converters. It is evident that this scheme improves model accuracy while ensuring real-time performance, providing a more reliable quantitative basis for power grid fault analysis, relay protection optimization, and stability assessment, and effectively enhancing the adaptability of the new power system to the large-scale integration of new energy sources. Attached Figure Description

[0051] 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 some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0052] in:

[0053] Figure 1 This is a schematic diagram of the virtual equivalent modeling method for new energy power sources in one embodiment;

[0054] Figure 2 This is a schematic diagram of a new energy power station;

[0055] Figure 3 To and Figure 2 A schematic diagram of the virtual equivalent model of the corresponding new energy power station. Detailed Implementation

[0056] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0057] In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the invention; however, it will be apparent to those skilled in the art that the invention may be practiced without one or more of these details; in other instances, certain technical features well-known in the art have not been described in order to avoid confusion with the invention. It should be understood that the invention can be practiced in different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided to make the disclosure thorough and complete and to fully convey the scope of the invention to those skilled in the art.

[0058] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. When used herein, the singular forms “a,” “an,” and “the” are also intended to include the plural forms, unless the context clearly indicates otherwise. The terms “comprising” and / or “including,” when used in this specification, identify the presence of said features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups. When used herein, the term “and / or” includes any and all combinations of the associated listed items.

[0059] To fully understand the present invention, a detailed structure will be presented in the following description in order to illustrate the technical solution proposed by the present invention; optional embodiments of the present invention are described in detail below, however, in addition to these detailed descriptions, the present invention may have other embodiments.

[0060] like Figure 1 As shown, in one embodiment, a virtual equivalent modeling method for new energy power sources is provided. This method includes steps S101 to S104, which are detailed below:

[0061] S101. Establish a virtual equivalent model for the new energy power station. The virtual equivalent model consists of the equivalent potential. and equivalent impedance Composed of series connection;

[0062] like Figure 2 The image shows a schematic diagram of a new energy power station. Figure 3This diagram illustrates a virtual equivalent model of a renewable energy power plant. It transforms the power plant (comprising multiple distributed power sources, converters, and control systems) into a single equivalent circuit model, reducing the complexity of system analysis and facilitating overall power system modeling. Specifically, through a series structure of equivalent potential and equivalent impedance, the output characteristics of the renewable energy power plant are equated to a traditional power source form, allowing traditional power system analysis methods (such as power flow calculations and fault analysis) to be directly applied to renewable energy scenarios.

[0063] Virtual equivalent models can reflect the overall electrical behavior of new energy power plants under different operating conditions (such as voltage support capability and fault current characteristics) without the need for detailed modeling of complex internal control logic.

[0064] S102. Determine the parameter constraints of the virtual equivalent model. The parameter constraints include: setting the equivalent potential. The amplitude and the AC system potential on the opposite side of the power grid line The amplitudes are the same; set the equivalent impedance. impedance angle Impedance angle with power grid lines equal;

[0065] The constraints are based on actual power grid characteristics (line impedance angle, system potential), which tightly couples the model parameters with the power grid topology and improves the equivalent accuracy of the model on the power grid side.

[0066] By associating the equivalent potential amplitude with the system potential on the opposite side (which is typically 1.0 pu) and the impedance angle with the line impedance angle, the four parameters (potential amplitude, phase, impedance amplitude, and impedance angle) that originally needed to be solved independently are simplified to two (potential phase and impedance amplitude), significantly reducing the computational complexity.

[0067] In some embodiments, an equivalent potential is set. The amplitude and the AC system potential on the opposite side of the power grid line The amplitudes are the same; set the equivalent impedance. impedance angle Impedance angle with power grid lines Equal, specifically including:

[0068]

[0069] in, This represents the real part of the potential in the virtual equivalent model; This represents the imaginary part of the potential in the virtual equivalent model; This represents the real part of the impedance in the virtual equivalent model. This represents the imaginary part of the impedance in the virtual equivalent model. This represents the real part of the voltage in the virtual equivalent model. This represents the imaginary part of the voltage in the virtual equivalent model. This represents the real part of the power supply current in the virtual equivalent model; This represents the imaginary part of the power supply current in the virtual equivalent model. The impedance angle of the power grid line; The potential of the AC system on the opposite side of the power grid line;

[0070] Solving the above expression yields the real part of the potential of the virtual equivalent model. and the imaginary part of the potential Real part of impedance and the imaginary part of impedance .

[0071] S103. Real-time acquisition of measured voltage at the power grid protection point. and measuring current Based on the parameter constraints of the virtual equivalent model, a system of variable relationship equations in polar coordinate form is established;

[0072] The equations in polar coordinates directly correspond to the physical relationships of the circuit, preserving amplitude and phase information, avoiding the complexity of complex number operations in rectangular coordinates, and facilitating an intuitive understanding of the physical meaning between parameters. They can be seamlessly integrated into existing power grid simulation platforms and support the analysis of large-scale new energy grid-connected scenarios.

[0073] In some embodiments, the measured voltage at the power grid protection point is acquired in real time. and measuring current Previously, the method also included:

[0074] Determine the measured voltage Is the amplitude within the range of 0.1 pu to 1.2 pu?

[0075] Determine the measured current Is the amplitude less than the maximum allowable current of the converter?

[0076] If any of the above conditions are not met, the output measurement data will be abnormal and the calculation will be terminated.

[0077] Specifically, limiting the voltage amplitude range eliminates voltage data distortion caused by sensor failures, line interference, etc. (such as false measurements of overvoltage or undervoltage), ensuring that subsequent modeling is based on the actual grid voltage state. Comparing the current amplitude with the converter's maximum allowable current prevents abnormal data under overcurrent conditions (such as atypical current signals when the converter's current-limiting protection operates) from entering the calculation process, thus preventing interference with the model parameter solution. By intercepting abnormal data in advance, this step ensures the reliability of the subsequent variable relationship equations from the source, reduces model parameter deviations caused by incorrect input data, thereby improving the calculation accuracy and reliability of the virtual equivalent model, while avoiding the waste of ineffective computing resources and enhancing the robustness of the method in engineering applications.

[0078] In some embodiments, the measured voltage at the power grid protection point is collected. and measuring current The method then includes:

[0079] According to the measured voltage and measuring current The phase and amplitude changes are used to determine the fault type of the new energy power station.

[0080] Different fault types (such as single-phase grounding and two-phase short circuits) will cause characteristic changes in measured voltage and current. For example, in a single-phase grounding fault, the single-phase voltage drops significantly, while in a two-phase short circuit, the fault phase current increases sharply and the phase shifts. Identifying these changes can accurately pinpoint the fault type, ensuring that subsequent modeling processes can adapt to the specificities of the fault scenario. For single-phase grounding faults, the parameter solution logic corresponding to the fault type can be used first; for two-phase short circuits, the equations can be adjusted to account for the influence of negative sequence current, thereby improving the model's adaptability to different fault scenarios.

[0081] Once the fault type is identified, the dynamic response characteristics of new energy power plants under that fault can be evaluated in a targeted manner (such as the role of the low voltage ride-through control strategy of the converter in a single-phase ground fault). This makes the dynamic parameters of the solved virtual equivalent model more closely match the actual fault conditions, providing more accurate basic data for relay protection setting adjustment (such as optimizing protection action thresholds according to the fault type) and power grid stability assessment (such as analyzing the transient characteristics of the system under specific faults). This further enhances the practicality and reliability of the technical solution in fault analysis scenarios.

[0082] In some embodiments, establishing a system of variable relationship equations in polar coordinates includes:

[0083] Obtain the measured voltage With measuring current The relationship expression between the virtual equivalent model power source and the power source is as follows:

[0084]

[0085] in, To measure the voltage amplitude in real time; To measure the phase of the voltage in real time; The potential amplitude of the virtual equivalent model; The equivalent potential phase of the virtual equivalent model; This represents the equivalent impedance magnitude of the virtual equivalent model; The impedance angle of the virtual equivalent model; To measure the amplitude of the current; To measure the phase of the current;

[0086] Transform the relational expression into a variable relational equation in polar coordinates:

[0087]

[0088] in, This represents the real part of the potential in the virtual equivalent model; This represents the imaginary part of the potential in the virtual equivalent model; This represents the real part of the impedance in the virtual equivalent model. This represents the imaginary part of the impedance in the virtual equivalent model. This represents the real part of the voltage in the virtual equivalent model. This represents the imaginary part of the voltage in the virtual equivalent model. This represents the real part of the power supply current in the virtual equivalent model; This represents the imaginary part of the power supply current in the virtual equivalent model.

[0089] S104. Solve the system of equations relating the variables to obtain the dynamic parameters of the virtual equivalent model.

[0090] By solving the system of equations, the equivalent potential phase and equivalent impedance amplitude can be obtained in real time. These parameters are updated as the power grid operating conditions change, and can be directly used for power grid fault location (such as identifying fault types based on impedance changes) and adaptive adjustment of relay protection settings, thereby improving the accuracy of protection device operation.

[0091] Furthermore, virtual equivalent models can serve as a power system stability analysis tool to assess the impact of high penetration of new energy sources on the transient and steady-state stability of the power grid, providing a basis for power grid planning and control.

[0092] In some embodiments, the dynamic parameters of the virtual equivalent model are determined by combining the variable relationship equation in polar coordinates and the expression corresponding to the parameter constraints:

[0093] The equivalent potential phase of the virtual equivalent model is obtained using the following formula. Equivalent impedance magnitude of virtual equivalent model :

[0094]

[0095] in, The equivalent potential phase of the virtual equivalent model; This represents the equivalent impedance magnitude of the virtual equivalent model; This represents the real part of the potential in the virtual equivalent model; This represents the imaginary part of the potential in the virtual equivalent model; This represents the real part of the impedance in the virtual equivalent model. This represents the imaginary part of the impedance in the virtual equivalent model.

[0096] In some embodiments, the equivalent potential phase of the virtual equivalent model is obtained. Equivalent impedance magnitude of virtual equivalent model The method then includes:

[0097] Determine the equivalent impedance magnitude of the virtual equivalent model Does it satisfy: 0.01pu≤ ≤2.0 pu;

[0098] Determine the phase of the equivalent potential in the virtual equivalent model Does it satisfy: -180°≤ ≤180°;

[0099] If any of the above conditions are not met, the output parameters will be abnormal, and the measured voltage at the power grid protection point will be re-acquired. and measuring current .

[0100] In power systems, the equivalent impedance of renewable energy power plants typically has well-defined physical boundaries. For example, a lower limit of 0.01 pu can eliminate short-circuit artifacts caused by calculation errors, while an upper limit of 2.0 pu avoids open-circuit misjudgments due to parameter divergence, ensuring that the model reflects the true circuit characteristics. The periodicity of the potential phase dictates that its physical meaning only needs to be described within the range of -180° to +180°, but numerical calculations may produce results outside this range (e.g., 365° is equivalent to 5°). Angle normalization can eliminate such non-physical interpretations, ensuring that the parameters conform to the standard representation for power system analysis.

[0101] When a parameter out of bounds is detected, the system forms a closed-loop feedback mechanism by re-acquiring data to avoid subsequent calculations based on erroneous parameters. For example, if a voltage abruptly changes to an abnormal value due to interference during a sampling, the calculated impedance amplitude may far exceed the reasonable range. In this case, triggering data re-acquisition can effectively eliminate accidental interference and improve the robustness of the virtual equivalent model.

[0102] In summary, this application constructs a virtual equivalent model for new energy sources, which enables effective comparison with the parameter characteristics of traditional power sources. It is applicable to the optimization of relay protection and grid stability assessment in new power systems, provides a new approach for fault analysis and protection design, and can improve the reliability of grid operation.

[0103] This application also proposes a virtual equivalent modeling system for new energy power sources, which includes: a virtual equivalent model construction unit, a constraint determination unit, an equation system construction unit, and a calculation unit;

[0104] The virtual equivalent model construction unit is used to establish a virtual equivalent model of the renewable energy power plant. The virtual equivalent model consists of the equivalent potential. and equivalent impedance Composed of series connection;

[0105] The constraint determination unit is used to determine the parameter constraints of the virtual equivalent model. The parameter constraints include: setting the equivalent potential. The amplitude and the AC system potential on the opposite side of the power grid line The amplitudes are the same; set the equivalent impedance. impedance angle Impedance angle with power grid lines equal;

[0106] The equation system construction unit is used to acquire the measured voltage at the power grid protection point in real time. and measuring current Based on the parameter constraints of the virtual equivalent model, a system of variable relationship equations in polar coordinate form is established;

[0107] The computational unit is used to solve the system of equations relating variables and obtain the dynamic parameters of the virtual equivalent model.

[0108] This application also proposes a readable storage medium storing a computer program, which, when executed by a processor, causes the processor to perform the following steps:

[0109] Establish a virtual equivalent model for the new energy power station. The virtual equivalent model consists of the equivalent potential. and equivalent impedance Composed of series connection;

[0110] Determine the parameter constraints of the virtual equivalent model. The parameter constraints include: setting the equivalent potential. The amplitude and the AC system potential on the opposite side of the power grid line The amplitudes are the same; set the equivalent impedance. impedance angle Impedance angle with power grid lines equal;

[0111] Real-time acquisition of measured voltage at power grid protection point and measuring current Based on the parameter constraints of the virtual equivalent model, a system of variable relationship equations in polar coordinate form is established;

[0112] Solve the system of equations relating the variables to obtain the dynamic parameters of the virtual equivalent model.

[0113] This application also proposes a computer device, including a memory and a processor, wherein the memory stores a computer program, and the computer program is executed by the processor in the following steps:

[0114] Establish a virtual equivalent model for the new energy power station. The virtual equivalent model consists of the equivalent potential. and equivalent impedance Composed of series connection;

[0115] Determine the parameter constraints of the virtual equivalent model. The parameter constraints include: setting the equivalent potential. The amplitude and the AC system potential on the opposite side of the power grid line The amplitudes are the same; set the equivalent impedance. impedance angle Impedance angle with power grid lines equal;

[0116] Real-time acquisition of measured voltage at power grid protection point and measuring current Based on the parameter constraints of the virtual equivalent model, a system of variable relationship equations in polar coordinate form is established;

[0117] Solve the system of equations relating the variables to obtain the dynamic parameters of the virtual equivalent model.

[0118] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, storage, databases, or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory.

[0119] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0120] The embodiments described above are merely illustrative of several implementation methods of this application, and their descriptions are relatively specific and detailed. However, they should not be construed as limiting the scope of this application's patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. The embodiments disclosed above are merely preferred embodiments of the present invention and should not be construed as limiting the scope of the present invention. Therefore, equivalent variations made according to the claims of this invention are still within the scope of this invention.

Claims

1. A new energy power supply virtual equivalent modeling method, characterized in that, The method comprises: establishing a virtual equivalent model of the new energy station, the virtual equivalent model being composed of an equivalent potential and an equivalent impedance in series; determining a parameter constraint of the virtual equivalent model, the parameter constraint comprising: setting a magnitude of the equivalent potential to be the same as a magnitude of an alternating current system potential on a side opposite to the grid line of a power grid; setting an impedance angle of the equivalent impedance to be equal to an impedance angle of the grid line , and specifically comprising: wherein, is a real part of the potential of the virtual equivalent model; is an imaginary part of the potential of the virtual equivalent model; is a real part of the impedance of the virtual equivalent model; is an imaginary part of the impedance of the virtual equivalent model; is a real part of the voltage of the virtual equivalent model; is an imaginary part of the voltage of the virtual equivalent model; is a real part of the source current of the virtual equivalent model; is an imaginary part of the source current of the virtual equivalent model; is an impedance angle of the grid line; is an opposite side AC system potential of the grid line; Solving the above expressions gives the real part of the potential of the virtual equivalent model and the imaginary part of the potential , the real part of the impedance and the imaginary part of the impedance ; Real-time acquisition of measured voltages at the protection location of the power grid and measured currents , establishing a polar form variable relationship equation group based on the parameter constraint conditions of the virtual equivalent model, comprising: Obtaining a measurement voltage a relationship expression between the measurement current and the virtual equivalent model power source wherein, is the amplitude of the measured voltage; is the phase of the measured voltage; is the amplitude of the equivalent potential of the virtual equivalent model; is the phase of the equivalent potential of the virtual equivalent model; is the amplitude of the equivalent impedance of the virtual equivalent model; is the angle of the equivalent impedance of the virtual equivalent model; is the amplitude of the measured current; is the phase of the measured current; Converting the relational expression into a variable relational equation in polar coordinate form: Solving the variable relational equation set to obtain dynamic parameters of the virtual equivalent model.

2. The new energy power source virtual equivalent modeling method according to claim 1, characterized in that, Determine the dynamic parameters of the virtual equivalent model in combination with the variable relational equation in polar coordinate form and the expression corresponding to the parameter constraint condition: The equivalent potential phase of the virtual equivalent model is obtained according to the following formula and the equivalent impedance amplitude of the virtual equivalent model : 。 3. The new energy power source virtual equivalent modeling method according to claim 1, characterized in that, The real-time acquisition of the measured voltage at the protection of the power grid and the measured current Prior to this, the method further comprises: determining whether the magnitude of the measured voltage is within the range 0.1 p.u. to 1.2 p.u.; Determine the measured current Is the amplitude less than the maximum allowable current of the converter? If any of the above conditions is not met, output measurement data anomaly and abort the calculation.

4. The new energy power source virtual equivalent modeling method according to claim 2, characterized in that, acquiring an equivalent potential phase of the virtual equivalent model and an equivalent impedance magnitude of the virtual equivalent model Afterwards, the method further comprises: determining an equivalent impedance amplitude of the virtual equivalent model whether 0.01 p.u. ≤ |Z| ≤ 2.0 p.u. is fulfilled ≤2.0p.u. determining a phase of an equivalent potential of the virtual equivalent model whether -180°≤ ≤180° If any of the above conditions are not met, output a parameter exception and reacquire the measured voltage at the power grid protection and measured current .

5. The new energy power source virtual equivalent modeling method according to claim 1, characterized in that, the measured voltage at the acquisition grid protection and the measured current After that, the method further comprises: determining a new energy plant failure type based on the measured voltage and phase and amplitude changes of the measured current ​ 6. A new energy power source virtual equivalent modeling system, characterized in that, The system comprises a virtual equivalent model construction unit, a constraint condition determination unit, an equation set construction unit and a calculation unit; The virtual equivalent model construction unit is configured to establish a virtual equivalent model of the new energy station, wherein the virtual equivalent model is composed of equivalent potentials and equivalent impedances in series. The constraint determination unit is used to determine the parameter constraints of the virtual equivalent model, the parameter constraints including: setting the equivalent potential. The amplitude and the AC system potential on the opposite side of the power grid line The amplitudes are the same; the equivalent impedance is set. impedance angle Impedance angle with power grid lines Equal, specifically including: wherein, is a real part of the potential of the virtual equivalent model; is an imaginary part of the potential of the virtual equivalent model; is a real part of the impedance of the virtual equivalent model; is an imaginary part of the impedance of the virtual equivalent model; is a real part of the voltage of the virtual equivalent model; is an imaginary part of the voltage of the virtual equivalent model; is a real part of the source current of the virtual equivalent model; is an imaginary part of the source current of the virtual equivalent model; is an impedance angle of the grid line; is an opposite side AC system potential of the grid line; Solving the above expressions gives the real part of the potential of the virtual equivalent model and the imaginary part of the potential , the real part of the impedance and the imaginary part of the impedance ; The equation set construction unit is configured to collect, in real time, measured voltages at a power grid protection device and measured currents , and to establish, based on parameter constraints of the virtual equivalent model, a polar coordinate form variable relationship equation set, including: Obtaining a measurement voltage a relationship expression between the measurement current and the virtual equivalent model power source wherein, is the magnitude of the measured voltage; is the phase of the measured voltage; is the magnitude of the equivalent potential of the virtual equivalent model; is the phase of the equivalent potential of the virtual equivalent model; is the magnitude of the equivalent impedance of the virtual equivalent model; is the angle of the equivalent impedance of the virtual equivalent model; is the magnitude of the measured current; is the phase of the measured current; Converting the relational expression into a variable relational equation in polar coordinate form: The calculation unit is configured to solve the variable relational equation set to obtain dynamic parameters of the virtual equivalent model.

7. A readable storage medium, storing a computer program, characterized in that, The computer program, when executed by the processor, causes the processor to perform the steps of the method of any one of claims 1 to 5.

8. A computer device comprising a memory and a processor, the memory storing a computer program, characterized in that, The computer program, when executed by the processor, causes the processor to perform the steps of the method of any one of claims 1 to 5.

Images