Fault point jump prediction method and device for new energy grid-connected point of power system

Abstract

The invention provides a fault point jump prediction method and device for a new energy grid-connected point of an electric power system, and the method comprises the steps: predicting a fault point parameter and a load side equivalent parameter through a pre-constructed fault equivalent model of the new energy grid-connected point of the electric power system according to a power grid side equivalent parameter, generating an algorithm model for predicting the voltage variation before and after the fault; through the power grid side impedance ratio and the load side impedance ratio, according to the power grid side equivalent parameters and the load side equivalent parameters, the voltage variation algorithm model before and after fault prediction is simplified and calculated, a predicted jump result is generated, and the predicted jump result comprises voltage amplitude jump and phase jump of a predicted fault point. The method can determine the voltage amplitude jump and phase jump of a fault point when a common fault occurs, prevents the maximum power angle instability, and maintains the power angle stability of a new energy grid-connected fault point of a power system, thereby better selecting electrical equipment and performing protection work.

Description

Technical Field

[0001] The present invention relates to the field of electric power technology, and in particular to a method and device for predicting fault point jumps at a new energy grid-connected point in an electric power system. Background Art

[0002] Currently, with the continuous integration of new energy sources such as wind power and photovoltaics, which use inverters as interfaces, into the power grid, the grid is gradually exhibiting "double-high" characteristics. Common low-voltage dropout control strategies are somewhat effective in low-voltage dropout scenarios during faults, but most only consider the impact of amplitude drop during faults and fail to consider that changes in external grid topology can also cause voltage phase jumps at the connection point. In power systems, the occurrence and removal of short-circuit faults both change the grid topology, resulting in voltage amplitude and phase jumps at the connection point of voltage source virtual synchronous generators (VSGs). This jump increases the voltage difference between the connection point voltage and the inverter port voltage, leading to inverter overcurrent issues. Therefore, it is urgent to study the mathematical model of phase jumps at the connection point of new energy sources in power systems and determine the maximum phase jump that grid-connected units can withstand. Related art research on phase jumps primarily focuses on the characteristics of phase jumps after a fault occurs and on suppressing phase jumps caused by faults. However, this research exhibits a certain lag, making it difficult to timely control the power angle stability of the connection point. Summary of the Invention

[0003] One object of the present invention is to provide a method for predicting fault point transitions at a power system's renewable energy grid connection point. This method is capable of determining voltage amplitude and phase transitions at the fault point when a common fault occurs, preventing instability of the maximum power angle, and maintaining a stable power angle at the power system's renewable energy grid connection point, thereby enabling better selection of electrical equipment and effective protection. Another object of the present invention is to provide a device for predicting fault point transitions at a power system's renewable energy grid connection point. A further object of the present invention is to provide a computer-readable medium. A further object of the present invention is to provide a computer device.

[0004] In order to achieve the above objectives, the present invention discloses a method for predicting fault point jumps of a new energy grid connection point in a power system, comprising:

[0005] Obtain grid-side equivalent parameters, predicted fault point parameters, and load-side equivalent parameters of new energy grid-connected points in the power system;

[0006] Through the pre-built equivalent model of the fault of the new energy grid connection point of the power system, an algorithm model for predicting the voltage change before and after the fault is generated according to the equivalent parameters of the grid side, the predicted fault point parameters and the equivalent parameters of the load side;

[0007] Through the grid-side impedance ratio and the load-side impedance ratio, according to the grid-side equivalent parameters and the load-side equivalent parameters, the algorithm model of the voltage change before and after the predicted fault is simplified and calculated to generate the predicted jump result. The predicted jump result includes the voltage amplitude jump and phase jump at the predicted fault point.

[0008] Preferably, the fault equivalent model of the new energy grid connection point of the power system includes an equivalent circuit at the time of the fault and an equivalent circuit after the fault;

[0009] Through the pre-built equivalent model of the fault of the new energy grid connection point of the power system, based on the equivalent parameters of the grid side, the predicted fault point parameters and the equivalent parameters of the load side, an algorithm model for predicting the voltage change before and after the fault is generated, including:

[0010] By superposition theorem and based on the equivalent circuit at fault, the equivalent parameters of the grid side, the predicted fault point parameters and the equivalent parameters of the load side are linearly superimposed to generate the voltage quantity model at fault time;

[0011] According to the post-fault equivalent circuit, the equivalent parameters of the grid side and the equivalent parameters of the load side are linearly superimposed to generate a post-fault voltage model;

[0012] Based on the voltage quantity model at the time of fault and the voltage quantity model after fault, an algorithm model for predicting voltage changes before and after fault is generated.

[0013] Preferably, the voltage change algorithm model before and after the predicted fault is simplified and calculated according to the grid-side impedance ratio and the load-side impedance ratio, and the grid-side equivalent parameters and the load-side equivalent parameters to generate a predicted jump result, which includes the voltage amplitude jump and phase jump at the predicted fault point, including:

[0014] If the grid-side impedance ratio is the same as the load-side impedance ratio, the voltage change algorithm model before and after the predicted fault is simplified and calculated based on the grid-side equivalent parameters to generate the first voltage amplitude jump and the first phase jump of the predicted fault point;

[0015] Determining the first voltage amplitude jump and the first phase jump as predicted jump results;

[0016] If the grid-side impedance ratio and the load-side impedance ratio are different, the voltage change algorithm model before and after the predicted fault is simplified and calculated based on the grid-side equivalent parameters, the grid-side impedance ratio, and the load-side equivalent parameters to generate the second voltage amplitude jump and second phase jump at the predicted fault point;

[0017] The second voltage amplitude jump and the second phase jump are determined as predicted jump results.

[0018] Preferably, the voltage variation algorithm model before and after the predicted fault is simplified and calculated based on the grid-side equivalent parameters to generate the first voltage amplitude jump and the first phase jump of the predicted fault point, including:

[0019] Taking the module length of the voltage change algorithm model before and after the predicted fault, the first voltage amplitude jump formula of the predicted fault point is generated;

[0020] Calculating the grid-side equivalent parameters using the first voltage amplitude jump formula to generate the first voltage amplitude jump;

[0021] Perform complex number processing and inverse tangent function processing on the voltage change algorithm model before and after the predicted fault to generate the first phase jump formula for predicting the fault point;

[0022] The first phase jump formula is used to calculate the equivalent parameters on the grid side to generate the first phase jump.

[0023] Preferably, based on the grid-side equivalent parameters, the grid-side impedance ratio, and the load-side equivalent parameters, the voltage change algorithm model before and after the fault prediction is simplified and calculated to generate the second voltage amplitude jump and the second phase jump of the predicted fault point, including:

[0024] According to the grid-side impedance ratio, the voltage change algorithm model before and after the fault is predicted is modulo lengthed to generate the second voltage amplitude jump formula for the predicted fault point;

[0025] Calculating the grid-side equivalent parameters and the grid-side impedance ratio using the second voltage amplitude jump formula to generate the second voltage amplitude jump;

[0026] Based on the grid-side impedance ratio, the voltage change algorithm model before and after the fault is processed by complex number processing and inverse tangent function processing to generate the second phase jump formula for predicting the fault point;

[0027] The grid side equivalent parameters and the grid side impedance ratio are calculated by the second phase jump formula to generate the second phase jump.

[0028] Preferably, the voltage change algorithm model before and after the fault prediction is simplified and calculated according to the grid-side impedance ratio and the load-side impedance ratio, and the grid-side equivalent parameters and the load-side equivalent parameters to generate a predicted jump result, wherein the predicted jump result includes the voltage amplitude jump and phase jump at the predicted fault point, and further includes:

[0029] Determine whether the voltage amplitude jump at the predicted fault point is greater than a preset voltage jump threshold, and whether the phase jump is greater than a preset phase jump threshold;

[0030] If the voltage amplitude jump is greater than the preset voltage jump threshold, or the phase jump is greater than the preset phase jump threshold, the new energy grid connection point of the power system is optimized according to the preset early warning strategy, and the steps of obtaining the grid-side equivalent parameters of the new energy grid connection point of the power system, predicting the fault point parameters and the load-side equivalent parameters are repeated.

[0031] The present invention also discloses a fault point jump prediction device for a new energy grid connection point in an electric power system, comprising:

[0032] A parameter acquisition unit, used to obtain grid-side equivalent parameters of the new energy grid connection point of the power system, predicted fault point parameters and load-side equivalent parameters;

[0033] An algorithm model building unit is used to generate an algorithm model for predicting voltage changes before and after a fault based on a pre-built equivalent model of a fault at a new energy grid connection point in the power system, equivalent parameters on the grid side, parameters of a predicted fault point, and equivalent parameters on the load side;

[0034] The jump prediction unit is used to simplify and calculate the voltage change algorithm model before and after the predicted fault based on the grid-side impedance ratio and the load-side impedance ratio, the grid-side equivalent parameters and the load-side equivalent parameters, and generate a predicted jump result. The predicted jump result includes the voltage amplitude jump and phase jump at the predicted fault point.

[0035] Preferably, the fault equivalent model of the new energy grid connection point of the power system includes an equivalent circuit at the time of the fault and an equivalent circuit after the fault;

[0036] The algorithm model construction unit is specifically used to linearly superimpose the equivalent parameters of the power grid side, the predicted fault point parameters and the equivalent parameters of the load side according to the equivalent circuit at the time of fault through the superposition theorem to generate a voltage quantity model at the time of fault; linearly superimpose the equivalent parameters of the power grid side and the equivalent parameters of the load side according to the equivalent circuit after the fault to generate a voltage quantity model after the fault; and generate an algorithm model for predicting the voltage change before and after the fault based on the voltage quantity model at the time of fault and the voltage quantity model after the fault.

[0037] Preferably, the jump prediction unit is specifically used to simplify and calculate the voltage change algorithm model before and after the predicted fault according to the grid-side equivalent parameters if the grid-side impedance ratio and the load-side impedance ratio are the same, to generate a first voltage amplitude jump and a first phase jump of the predicted fault point; determine the first voltage amplitude jump and the first phase jump as the predicted jump results; if the grid-side impedance ratio and the load-side impedance ratio are different, simplify and calculate the voltage change algorithm model before and after the predicted fault according to the grid-side equivalent parameters, the grid-side impedance ratio and the load-side equivalent parameters, to generate a second voltage amplitude jump and a second phase jump of the predicted fault point; determine the second voltage amplitude jump and the second phase jump as the predicted jump results.

[0038] Preferably, the jump prediction unit is specifically used to take the modulus length of the voltage change algorithm model before and after the predicted fault to generate a first voltage amplitude jump formula for the predicted fault point; calculate the equivalent parameters on the grid side through the first voltage amplitude jump formula to generate a first voltage amplitude jump; perform complex number processing and inverse tangent function processing on the voltage change algorithm model before and after the predicted fault to generate a first phase jump formula for the predicted fault point; calculate the equivalent parameters on the grid side through the first phase jump formula to generate a first phase jump.

[0039] Preferably, the jump prediction unit is specifically used to take the modulus length of the voltage change algorithm model before and after the predicted fault according to the grid side impedance ratio, and generate a second voltage amplitude jump formula for predicting the fault point; calculate the grid side equivalent parameters and the grid side impedance ratio through the second voltage amplitude jump formula to generate a second voltage amplitude jump; perform complex number processing and inverse tangent function processing on the voltage change algorithm model before and after the predicted fault according to the grid side impedance ratio to generate a second phase jump formula for predicting the fault point; calculate the grid side equivalent parameters and the grid side impedance ratio through the second phase jump formula to generate a second phase jump.

[0040] Preferably, the device further comprises:

[0041] A judgment unit, used to judge whether the voltage amplitude jump at the predicted fault point is greater than a preset voltage jump threshold, and whether the phase jump is greater than a preset phase jump threshold;

[0042] The early warning unit is used to optimize the new energy grid connection point of the power system according to the preset early warning strategy if the voltage amplitude jump is greater than the preset voltage jump threshold, or the phase jump is greater than the preset phase jump threshold, and trigger the parameter acquisition unit to repeatedly execute the steps of obtaining the grid-side equivalent parameters of the new energy grid connection point of the power system, predicting the fault point parameters and the load-side equivalent parameters.

[0043] The present invention also discloses a computer-readable medium on which a computer program is stored. When the program is executed by a processor, the method described above is implemented.

[0044] The present invention also discloses a computer device, including a memory and a processor, wherein the memory is used to store information including program instructions, the processor is used to control the execution of program instructions, and the processor implements the above method when executing the program.

[0045] The present invention also discloses a computer program product, comprising a computer program / instruction, which implements the above method when the computer program / instruction is executed by a processor.

[0046] The present invention obtains grid-side equivalent parameters, predicted fault point parameters and load-side equivalent parameters of a new energy grid-connected point in an electric power system; generates an algorithm model for predicting voltage changes before and after a fault according to the grid-side equivalent parameters, predicted fault point parameters and load-side equivalent parameters through a pre-constructed new energy grid-connected point fault equivalent model in an electric power system; simplifies and calculates the algorithm model for predicting voltage changes before and after a fault according to the grid-side equivalent parameters and the load-side equivalent parameters through the grid-side impedance ratio and the load-side impedance ratio, and generates a predicted jump result. The predicted jump result includes a voltage amplitude jump and a phase jump at the predicted fault point, and can determine the voltage amplitude jump and phase jump at the fault point when a common fault occurs, prevent the maximum power angle from becoming instable, and maintain the power angle stability of the new energy grid-connected fault point in the electric power system, thereby better selecting electrical equipment and performing protection work. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0048] Figure 1 A flowchart of a method for predicting a fault point jump of a new energy grid-connected point in a power system provided by an embodiment of the present invention;

[0049] Figure 2 A schematic diagram of an equivalent circuit in a fault condition provided by an embodiment of the present invention;

[0050] Figure 3 A schematic diagram of a post-fault equivalent circuit provided by an embodiment of the present invention;

[0051] Figure 4 A flowchart of another method for predicting fault point jumps of a new energy grid-connected point in a power system provided by an embodiment of the present invention;

[0052] Figure 5 A schematic diagram of the structure of a fault point jump prediction device for a new energy grid-connected point in a power system provided by an embodiment of the present invention;

[0053] Figure 6 A schematic structural diagram of a computer device provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0054] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0055] It should be noted that the method and device for predicting the fault point jump of a new energy grid-connected point in a power system disclosed in the present application can be used in the field of artificial intelligence technology, and can also be used in any field other than the field of artificial intelligence technology. The application field of the method and device for predicting the fault point jump of a new energy grid-connected point in a power system disclosed in the present application is not limited.

[0056] To facilitate understanding of the technical solution provided by this application, the relevant contents of the technical solution of this application are first described below. In order to reduce the overcurrent problem caused by overcurrent when a new energy grid connection point fails, and the resulting power angle instability, it is necessary to establish a mathematical model to calculate the maximum phase jump caused by grid connection point failure, further rationally select electrical equipment, and complete the preliminary work of controlling power angle instability.

[0057] The following uses the fault point jump prediction device of the power system renewable energy grid connection point as an example to illustrate the implementation process of the fault point jump prediction method of the power system renewable energy grid connection point provided by the embodiment of the present invention. It is understood that the execution subject of the fault point jump prediction method of the power system renewable energy grid connection point provided by the embodiment of the present invention includes but is not limited to the fault point jump prediction device of the power system renewable energy grid connection point.

[0058] Figure 1 A flowchart of a method for predicting a fault point jump of a new energy grid-connected point in a power system provided by an embodiment of the present invention is shown in FIG. Figure 1 As shown, the method includes:

[0059] Step 101: Obtain grid-side equivalent parameters, predicted fault point parameters, and load-side equivalent parameters of a new energy grid-connected point in a power system.

[0060] Step 102: Generate an algorithm model for predicting voltage changes before and after a fault by using a pre-built equivalent model of a new energy grid-connected point fault in the power system, grid-side equivalent parameters, predicted fault point parameters, and load-side equivalent parameters.

[0061] In the embodiment of the present invention, the fault equivalent model of the renewable energy grid-connected point in the power system includes an equivalent circuit at the time of the fault and an equivalent circuit after the fault. Figure 2 A schematic diagram of an equivalent circuit in a fault condition provided by an embodiment of the present invention is shown in FIG. Figure 2 As shown, the ground impedance Z DNormal access to the system, the grid side voltage is equivalent to This is the power supply on the grid side, providing voltage U1 with a phase angle of It represents the voltage source of the power grid; the grid-side line impedance is equivalent to Z1=R1+jX1, which is the impedance of the grid-side line, consisting of resistance R1 and reactance X1. Resistance R1 represents the line loss, reactance X1 represents the line reactance, and R1+jX1 is the complex number representation of the grid-side line impedance equivalent parameter Z1; let the voltage at the predicted fault point be This is the voltage at the predicted fault point, with a phase angle of Predicted fault point voltage U D1 is the voltage at the point when the fault occurs; the predicted grounding impedance at the fault point is Z D , which is the ground impedance of the predicted fault point, indicating the impedance between the predicted fault point and the ground; the equivalent line impedance on the load side is Z2, which is the equivalent line impedance on the load side, indicating the line impedance from the predicted fault point to the load side; the distributed power supply at the load is equivalent to This is the distributed power supply on the load side, providing voltage U2 with a phase angle of It represents the voltage source on the load side. Connect to the fault point through the line impedance R1+jX1, and predict the fault point through the ground impedance Z D Grounding, the predicted fault point is connected to the distributed power supply at the load through the equivalent line impedance Z2 on the load side

[0062] Figure 3 A schematic diagram of a post-fault equivalent circuit provided by an embodiment of the present invention is shown in FIG. Figure 3 As shown in the figure, after the fault occurs at the predicted fault point, the equivalent circuit after the grounded load is cut off is calculated, and the grid side voltage is equivalent to This is the power supply on the grid side, providing voltage U1 with a phase angle of It represents the voltage source of the power grid; the grid side line impedance is equivalent to Z1, which is the equivalent impedance of the grid side line, representing the line impedance from the grid side power supply to the fault point; let the voltage at the predicted fault point be This is the voltage at the predicted fault point, with a phase angle of Predicted fault point voltage U D2 is the voltage at the point when the fault occurs; the equivalent line impedance on the load side is Z2, which is the equivalent line impedance on the load side, indicating the line impedance from the predicted fault point to the load side; the distributed power supply at the load is equivalent to This is the distributed power supply on the load side, providing voltage U2 with a phase angle of It represents the voltage source on the load side. The fault point is connected to the fault point through the line impedance Z1, and the fault point is connected to the distributed power supply at the load through the equivalent line impedance Z2 on the load side.

[0063] Step 103: Simplify and calculate the voltage change algorithm model before and after the predicted fault based on the grid-side impedance ratio and the load-side impedance ratio, the grid-side equivalent parameters and the load-side equivalent parameters, and generate a predicted jump result. The predicted jump result includes the voltage amplitude jump and phase jump at the predicted fault point.

[0064] In the technical solution provided by the embodiment of the present invention, the grid-side equivalent parameters, predicted fault point parameters and load-side equivalent parameters of the power system's new energy grid-connected point are obtained; through a pre-constructed power system new energy grid-connected point fault equivalent model, an algorithm model for predicting voltage changes before and after the fault is generated according to the grid-side equivalent parameters, predicted fault point parameters and load-side equivalent parameters; through the grid-side impedance ratio and the load-side impedance ratio, the algorithm model for predicting voltage changes before and after the fault is simplified and calculated according to the grid-side equivalent parameters and the load-side equivalent parameters to generate a predicted jump result. The predicted jump result includes a voltage amplitude jump and a phase jump at the predicted fault point, and can determine the voltage amplitude jump and phase jump at the fault point when a common fault occurs, prevent the maximum power angle from becoming instable, and maintain the power angle stability of the power system's new energy grid-connected fault point, thereby better selecting electrical equipment and performing protection work.

[0065] Figure 4 A flowchart of another method for predicting a fault point jump of a new energy grid-connected point in a power system provided by an embodiment of the present invention is shown in FIG. Figure 4 As shown, the method includes:

[0066] Step 201: Obtain grid-side equivalent parameters, predicted fault point parameters, and load-side equivalent parameters of a new energy grid-connected point in the power system.

[0067] In the embodiment of the present invention, each step is performed by a fault point jump prediction device of a new energy grid connection point of a power system.

[0068] In the embodiment of the present invention, the grid side equivalent parameters include but are not limited to the grid side voltage equivalent parameters And the equivalent parameter Z1 of the grid side line impedance. The predicted fault point parameters include but are not limited to setting the voltage after the predicted fault point fails to be Assume that the voltage at the predicted fault point when a fault occurs is And the predicted fault point grounding impedance Z D The load side equivalent parameters include but are not limited to the load side line impedance equivalent parameter Z2 and the load side distributed power supply equivalent parameter

[0069] It is worth noting that the predicted fault point is a pre-determined fault point for common faults, which can be determined based on historical experience, thereby achieving the effect of preventing maximum power angle instability.

[0070] Step 202: By using the superposition theorem and according to the equivalent circuit at the time of fault, the grid side equivalent parameters, the predicted fault point parameters and the load side equivalent parameters are linearly superimposed to generate a voltage quantity model at the time of fault.

[0071] Specifically, the voltage at the fault point can be predicted by the superposition theorem, that is, the grid side voltage equivalent parameter Equivalent parameters of distributed power supply on the load side Linear superposition under common excitation:

[0072]

[0073] After simplification, the voltage model during fault is obtained:

[0074]

[0075] in, is the grid side voltage equivalent parameter; Z2 is the load side line impedance equivalent parameter; Z D is the ground impedance of the predicted fault point; Z1 is the equivalent parameter of the grid side line impedance; is the equivalent parameter of distributed power supply on the load side; It is the voltage at the predicted fault point when a fault occurs.

[0076] Step 203: Based on the post-fault equivalent circuit, linearly superimpose the grid-side equivalent parameters and the load-side equivalent parameters to generate a post-fault voltage model.

[0077] In the embodiment of the present invention, when the predicted fault point fails, the corresponding grounded load is cut off, and the grid side voltage is equivalent to The line impedance on the grid side is equivalent to Z1, and the voltage at the fault point is The equivalent line impedance on the load side is Z2, and the distributed power supply at the load is equivalent to

[0078] Specifically, the voltage at the fault point after the grounded load is removed is predicted to be:

[0079]

[0080] After simplification, the post-fault voltage model is obtained:

[0081]

[0082] in, is the grid side voltage equivalent parameter; Z2 is the load side line impedance equivalent parameter; Z1 is the grid side line impedance equivalent parameter; is the equivalent parameter of distributed power supply on the load side; It is the voltage at the predicted fault point after a fault occurs.

[0083] Step 204: Generate an algorithm model for predicting voltage changes before and after the fault based on the voltage model at the time of the fault and the voltage model after the fault.

[0084] Specifically, the voltage model before and after the fault is subtracted from the voltage model after the fault to generate an algorithm model for predicting the voltage change before and after the fault:

[0085]

[0086] in, To predict the voltage change before and after the fault occurs at the fault point; is the grid side voltage equivalent parameter; Z2 is the load side line impedance equivalent parameter; Z1 is the grid side line impedance equivalent parameter; is the equivalent parameter of distributed power supply on the load side; Z D To predict the ground impedance at the fault point.

[0087] Step 205 , determine whether the grid-side impedance ratio and the load-side impedance ratio are the same. If they are the same, execute step 206 ; if they are different, execute step 208 .

[0088] In the embodiment of the present invention, the grid-side impedance ratio is the ratio of the grounding resistance to the grid-side line impedance; and the load-side impedance ratio is the ratio of the grounding resistance to the load-side line impedance.

[0089] It is worth noting that in the dual-machine parallel scenario, the machine capacity and parameters are consistent and the impedance ratio is the same, while the impedance ratio is different in other situations.

[0090] Specifically, if the grid-side impedance ratio and the load-side impedance ratio are the same, it indicates that the ratio between the grounding resistance and the grid-side line impedance is consistent with the ratio between the grounding resistance and the load-side line impedance, and step 206 is continued; if the grid-side impedance ratio and the load-side impedance ratio are different, it indicates that the ratio between the grounding resistance and the grid-side line impedance is inconsistent with the ratio between the grounding resistance and the load-side line impedance, and step 208 is continued.

[0091] Step 206: Simplify and calculate the voltage variation algorithm model before and after the predicted fault based on the grid-side equivalent parameters to generate a first voltage amplitude jump and a first phase jump of the predicted fault point.

[0092] In the embodiment of the present invention, step 206 specifically includes:

[0093] Step 2061: Take the module length of the voltage variation algorithm model before and after the predicted fault to generate a first voltage amplitude jump formula for predicting the fault point.

[0094] In the embodiment of the present invention, but Assume U1=U2,Z1=Z2,Z D =4Z1=4Z2. Simplifying the algorithm model for predicting voltage changes before and after a fault, we obtain:

[0095]

[0096] Take the modulus lengths before and after the simplified algorithm model equation to generate the first voltage amplitude jump formula for predicting the fault point:

[0097]

[0098] Among them, DU D1 is the first voltage amplitude jump; U1 is the grid side voltage, is the grid side voltage phase angle.

[0099] The voltage amplitude variation range of the fault point is obtained as follows:

[0100]

[0101] Among them, DU D1 is the first voltage amplitude jump; U1 is the grid side voltage.

[0102] Step 2062: Calculate the grid-side equivalent parameters using the first voltage amplitude jump formula to generate a first voltage amplitude jump.

[0103] Specifically, the grid side voltage and the grid side voltage phase angle in the grid side equivalent parameters are substituted into the first voltage amplitude jump formula for calculation to generate the first voltage amplitude jump.

[0104] Step 2063: Perform complex number processing and arctangent function processing on the voltage change algorithm model before and after the predicted fault to generate a first phase jump formula for predicting the fault point.

[0105] In the embodiment of the present invention, the imaginary part of the right side of the voltage change algorithm model equation before and after the fault prediction is taken and take the real part Divide the imaginary part by the real part and process it through the inverse tangent function to get the phase jump difference before and after the fault. Since U1 = U2, the first phase jump formula for predicting the fault point is obtained after simplification:

[0106]

[0107] in, To predict the first phase jump of the fault point, is the first phase angle for predicting the fault point, is the grid side voltage phase angle.

[0108] Step 2064: Calculate the grid-side equivalent parameters using the first phase jump formula to generate a first phase jump.

[0109] Specifically, the grid side voltage phase angle in the grid side equivalent parameters is substituted into the first phase jump formula for calculation to generate the first phase jump.

[0110] Step 207 : Determine the first voltage amplitude jump and the first phase jump as predicted jump results, and proceed to step 210 .

[0111] In the embodiment of the present invention, the predicted jump result is a phase jump and a voltage amplitude jump of the predicted fault point, specifically a voltage difference vector, and both the phase jump and the voltage amplitude jump are components of the voltage difference vector.

[0112] Step 208: Simplify and calculate the voltage variation algorithm model before and after the predicted fault based on the grid-side equivalent parameters, the grid-side impedance ratio, and the load-side equivalent parameters to generate a second voltage amplitude jump and a second phase jump at the predicted fault point.

[0113] In the embodiment of the present invention, step 208 specifically includes:

[0114] Step 2081: Based on the grid-side impedance ratio, the voltage variation algorithm model before and after the predicted fault is modulo-lengthed to generate a second voltage amplitude jump formula for predicting the fault point.

[0115] In the embodiment of the present invention, if the drop degree is unknown and the impedance ratio is inconsistent, it is assumed that U1=U2, |Z1|=|Z2|, Z D =aZ1 Where a is the grid side impedance ratio, is the grid-side line impedance phase angle, is the load side line impedance phase angle. Simplifying the algorithm model for predicting voltage changes before and after a fault, we get:

[0116]

[0117] The modulus lengths before and after the simplified algorithm model equation are taken to generate the second voltage amplitude jump formula for predicting the fault point:

[0118]

[0119] Among them, DU D2is the second voltage amplitude jump; U1 is the grid side voltage, is the grid side voltage phase angle, a is the grid side impedance ratio, is the grid-side line impedance phase angle.

[0120] Step 2082: Calculate the grid-side equivalent parameters and the grid-side impedance ratio using the second voltage amplitude jump formula to generate a second voltage amplitude jump.

[0121] Specifically, the grid side impedance ratio, the grid side line impedance phase angle, the grid side voltage and the grid side voltage phase angle in the grid side equivalent parameters are substituted into the second voltage amplitude jump formula for calculation to generate the second voltage amplitude jump.

[0122] Step 2083: Based on the grid-side impedance ratio, perform complex number processing and inverse tangent function processing on the voltage change algorithm model before and after the fault prediction to generate a second phase jump formula for predicting the fault point.

[0123] In the embodiment of the present invention, the imaginary part on the right side of the algorithm model equation for predicting the voltage change before and after the fault is divided by the real part, and then processed by the inverse tangent function to obtain the phase jump difference before and after the fault. Since U1=U2, |Z1|=|Z2|, After simplification, the second phase jump formula for predicting the fault point is obtained:

[0124]

[0125] in, To predict the second phase jump of the fault point, To predict the second phase angle of the fault point, is the grid side voltage phase angle, is the grid-side line impedance phase angle.

[0126] Step 2084: Calculate the grid-side equivalent parameters and the grid-side impedance ratio using the second phase jump formula to generate a second phase jump.

[0127] Specifically, the grid-side line impedance phase angle and the grid-side voltage phase angle in the grid-side equivalent parameters are substituted into the second phase jump formula for calculation to generate the second phase jump.

[0128] Step 209: Determine the second voltage amplitude jump and the second phase jump as predicted jump results.

[0129] In the embodiment of the present invention, the predicted jump result is a phase jump and a voltage amplitude jump of the predicted fault point, specifically a voltage difference vector, and both the phase jump and the voltage amplitude jump are components of the voltage difference vector.

[0130] From the above formulas, we can see that the impedance ratio and angle both influence the denominator of the amplitude and phase jump calculations, meaning that decreasing the amplitude change increases the power angle change. While a constant amplitude drop only affects the voltage amplitude, a drop that varies with the impedance ratio affects both the amplitude and the phase angle.

[0131] Step 210: Determine whether the voltage amplitude jump at the predicted fault point is greater than a preset voltage jump threshold, and whether the phase jump is greater than a preset phase jump threshold. If at least one of the two is yes, execute step 211; if both are no, the process ends.

[0132] In the embodiment of the present invention, both the voltage jump threshold and the phase jump threshold can be set according to actual needs, and the embodiment of the present invention does not limit this.

[0133] Specifically, if the voltage amplitude jump is greater than the preset voltage jump threshold, or the phase jump is greater than the preset phase jump threshold, it indicates that system power angle oscillation is about to occur, and step 211 is continued; if the voltage amplitude jump is less than or equal to the preset voltage jump threshold, and the phase jump is less than or equal to the preset phase jump threshold, it indicates that system power angle oscillation will not occur, and the process ends.

[0134] Step 211: Optimize the new energy grid connection points of the power system according to the preset early warning strategy, and repeat step 201.

[0135] In the embodiment of the present invention, the early warning strategy can be set according to actual needs, and the embodiment of the present invention does not limit this. As an optional solution, the early warning strategy includes but is not limited to optimizing power supply impedance parameters, adding a new power supply, and changing the line model (i.e., changing the line parameters).

[0136] In an embodiment of the present invention, the above-mentioned model can be used to more accurately calculate the amplitude jump and phase jump of the fault point of the new energy grid connection of the power system. By predicting the maximum phase jump of the fault point, the maximum phase jump disturbance that the energy storage unit can withstand can be determined. When it is found that the system power angle oscillation is about to occur, the new energy grid connection point of the power system is optimized, and step 201 is repeatedly executed until it is determined that the system power angle oscillation will not occur. In this way, it is determined in advance that the system power angle oscillation exceeds the tolerable range to avoid instability.

[0137] The following example uses an idealized equivalent model of a power system integrating renewable energy to verify the accuracy of phase jump calculations under fault conditions. The model includes two grounded voltage sources equivalent to a grid-side power source and a load-side distributed power source, grid-side line impedance, and load-side line impedance. The ground impedance is connected at the designated fault point via a three-phase circuit breaker.

[0138] Two examples with the same impedance ratio are designed, namely Example 1 and Example 2. The simulation experiment system parameters are shown in Table 1 to verify the accuracy of the above mathematical model:

[0139] Table 1

[0140] - <![CDATA[|U1| / V]]> <![CDATA[∠U1 (angular measure)]]> Failure time / s Impedance ratio Ground impedance value Calculation example 1 220 0 1-2 4 0.1Ω+(1e-3)H Calculation example 2 220 90 1-2 4 0.1Ω+(1e-3)H

[0141] Where |U1| is the grid-side voltage amplitude, in V; ∠U1 is the grid-side voltage phase angle, in degrees; the fault duration is in seconds (s); the impedance ratio is 4; and in the ground impedance value, ohm (Ω) is the unit of resistance, and henry (H) is the unit of inductance. Impedance, often represented by Z, is a complex number whose real part is called resistance and imaginary part is called reactance. The resistance of a capacitor to AC in a circuit is called capacitive reactance, and the resistance of an inductor to AC in a circuit is called inductive reactance. The combined resistance of capacitance and inductance to AC in a circuit is called reactance.

[0142] The voltage change before and after the fault is predicted by the algorithm model provided by the embodiment of the present invention. The results of the first voltage amplitude jump and the first phase jump at the fault point are simplified and calculated, as shown in Table 2:

[0143] Table 2

[0144]

[0145] In Example 1, the voltage amplitude at the fault point before the short circuit is 220V, and the voltage phase angle after the short circuit is 0. The voltage amplitude at the fault point after the short circuit is 195.5V, and the voltage phase angle after the short circuit is 0. In Example 2, the voltage amplitude at the fault point before the short circuit is 155V, and the voltage phase angle after the short circuit is 45. The voltage amplitude at the fault point after the short circuit is 137V, and the voltage phase angle after the short circuit is 45. The analysis of Examples 1 and 2 shows that the voltage phase angle at the fault point remains unchanged after the short circuit, meaning that the impedance constant-amplitude drop only affects the voltage amplitude.

[0146] Two examples with inconsistent impedance ratios are designed, namely Example 3 and Example 4. The simulation experiment system parameters are shown in Table 3 to verify the accuracy of the above mathematical model:

[0147] Table 3

[0148] - <![CDATA[|U1| / V]]> <![CDATA[∠U1 (in degrees)]]> Failure time / s Line impedance Ground impedance value Calculation example 3 220 0 1-2 0.1Ω+1e-3H 0.4Ω+1e-3H Calculation example 4 220 90 1-2 0.1Ω+1e-3H 0.4Ω+1e-3H

[0149] By analyzing the voltage amplitude and phase angle at the fault point in Examples 3 and 4 of the above embodiment, it can be seen that when the impedance ratios are inconsistent, the voltage amplitude and phase angle at the fault point after the short circuit both drop accordingly, that is, the impedance equal-amplitude drop only affects the voltage amplitude.

[0150] The proposed calculation model for voltage phase jumps at fault points in power system grid-connected renewable energy systems can help determine the selection of electrical equipment based on the pre-calculated overcurrent caused by the maximum phase jump at the grid-connected point during a fault, thereby reducing damage to electrical equipment caused by the fault. This will also help mitigate power angle instability in the system.

[0151] It is worth noting that the acquisition, storage, use, and processing of data in the technical solutions of this application are in compliance with the relevant provisions of laws and regulations. The user information in the embodiments of this application is obtained through legal and compliant channels, and the acquisition, storage, use, and processing of user information are authorized and agreed by the customer.

[0152] It is worth noting that the information collected in this application is information and data authorized by the user or fully authorized by all parties, and the collection, storage, use, processing, transmission, provision, disclosure and application of relevant data comply with the relevant laws, regulations and standards of relevant countries and regions, take necessary confidentiality measures, do not violate public order and good customs, and provide corresponding operation entrances for users to choose to authorize or refuse.

[0153] It is worth noting that the technical solution provided in this application provides users with corresponding operation entrances for them to choose to agree or reject the automated decision-making results; if the user chooses to reject, the expert decision-making process will be entered.

[0154] In the technical solution of the fault point jump prediction method of the power system new energy grid-connected point provided by the embodiment of the present invention, the grid-side equivalent parameters, predicted fault point parameters and load-side equivalent parameters of the power system new energy grid-connected point are obtained; through the pre-constructed power system new energy grid-connected point fault equivalent model, according to the grid-side equivalent parameters, predicted fault point parameters and load-side equivalent parameters, an algorithm model for predicting the voltage change before and after the fault is generated; through the grid-side impedance ratio and the load-side impedance ratio, according to the grid-side equivalent parameters and the load-side equivalent parameters, the algorithm model for predicting the voltage change before and after the fault is simplified and calculated to generate a predicted jump result. The predicted jump result includes the voltage amplitude jump and phase jump of the predicted fault point, which can determine the voltage amplitude jump and phase jump of the fault point when a common fault occurs, prevent the maximum power angle from becoming instable, and maintain the power angle stability of the power system new energy grid-connected fault point, so as to better select electrical equipment and perform protection work.

[0155] Figure 5 A schematic diagram of a fault point jump prediction device for a power system renewable energy grid connection point provided by an embodiment of the present invention is provided. The device is used to execute the above-mentioned fault point jump prediction method for a power system renewable energy grid connection point. Figure 5 As shown, the device includes: a parameter acquisition unit 11, an algorithm model construction unit 12 and a jump prediction unit 13.

[0156] The parameter acquisition unit 11 is used to obtain the grid-side equivalent parameters, predicted fault point parameters and load-side equivalent parameters of the new energy grid connection point of the power system.

[0157] The algorithm model construction unit 12 is used to generate an algorithm model for predicting voltage changes before and after a fault based on a pre-constructed equivalent model of a new energy grid-connected point fault in the power system, grid-side equivalent parameters, predicted fault point parameters, and load-side equivalent parameters.

[0158] The jump prediction unit 13 is used to simplify and calculate the voltage change algorithm model before and after the predicted fault based on the grid side impedance ratio and the load side impedance ratio, according to the grid side equivalent parameters and the load side equivalent parameters, and generate a predicted jump result. The predicted jump result includes the voltage amplitude jump and phase jump at the predicted fault point.

[0159] In an embodiment of the present invention, the fault equivalent model of the new energy grid-connected point of the power system includes an equivalent circuit at the time of the fault and an equivalent circuit after the fault; the algorithm model construction unit 12 is specifically used to linearly superimpose the grid-side equivalent parameters, the predicted fault point parameters and the load-side equivalent parameters according to the equivalent circuit at the time of the fault through the superposition theorem to generate a voltage quantity model at the time of the fault; linearly superimpose the grid-side equivalent parameters and the load-side equivalent parameters according to the equivalent circuit after the fault to generate a voltage quantity model after the fault; and generate an algorithm model for predicting the voltage change before and after the fault based on the voltage quantity model at the time of the fault and the voltage quantity model after the fault.

[0160] In an embodiment of the present invention, the jump prediction unit 13 is specifically used to simplify and calculate the voltage change algorithm model before and after the predicted fault according to the grid-side equivalent parameters if the grid-side impedance ratio and the load-side impedance ratio are the same, to generate a first voltage amplitude jump and a first phase jump of the predicted fault point; determine the first voltage amplitude jump and the first phase jump as the predicted jump result; if the grid-side impedance ratio and the load-side impedance ratio are different, simplify and calculate the voltage change algorithm model before and after the predicted fault according to the grid-side equivalent parameters, the grid-side impedance ratio and the load-side equivalent parameters, to generate a second voltage amplitude jump and a second phase jump of the predicted fault point; determine the second voltage amplitude jump and the second phase jump as the predicted jump result.

[0161] In an embodiment of the present invention, the jump prediction unit 13 is specifically used to take the modulus length of the voltage change algorithm model before and after the predicted fault, and generate a first voltage amplitude jump formula for predicting the fault point; calculate the equivalent parameters on the grid side through the first voltage amplitude jump formula to generate the first voltage amplitude jump; perform complex number processing and inverse tangent function processing on the voltage change algorithm model before and after the predicted fault, and generate a first phase jump formula for predicting the fault point; calculate the equivalent parameters on the grid side through the first phase jump formula to generate the first phase jump.

[0162] In an embodiment of the present invention, the jump prediction unit 13 is specifically used to take the modulus length of the voltage change algorithm model before and after the predicted fault according to the grid-side impedance ratio, and generate a second voltage amplitude jump formula for predicting the fault point; the grid-side equivalent parameters and the grid-side impedance ratio are calculated through the second voltage amplitude jump formula to generate a second voltage amplitude jump; according to the grid-side impedance ratio, the voltage change algorithm model before and after the predicted fault is processed by complex numbers and inverse tangent functions to generate a second phase jump formula for predicting the fault point; the grid-side equivalent parameters and the grid-side impedance ratio are calculated through the second phase jump formula to generate a second phase jump.

[0163] In the embodiment of the present invention, the device further includes: a judgment unit 14 and an early warning unit 15 .

[0164] The judging unit 14 is configured to judge whether a voltage amplitude jump at the predicted fault point is greater than a preset voltage jump threshold, and whether a phase jump is greater than a preset phase jump threshold.

[0165] The early warning unit 15 is used to optimize the new energy grid connection point of the power system according to the preset early warning strategy if the voltage amplitude jump is greater than the preset voltage jump threshold, or the phase jump is greater than the preset phase jump threshold, and trigger the parameter acquisition unit 11 to repeatedly execute the steps of obtaining the grid-side equivalent parameters of the new energy grid connection point of the power system, predicting the fault point parameters and the load-side equivalent parameters.

[0166] In the scheme of the embodiment of the present invention, the grid-side equivalent parameters, predicted fault point parameters and load-side equivalent parameters of the power system's new energy grid-connected point are obtained; through a pre-constructed power system new energy grid-connected point fault equivalent model, an algorithm model for predicting the voltage change before and after the fault is generated according to the grid-side equivalent parameters, predicted fault point parameters and load-side equivalent parameters; through the grid-side impedance ratio and the load-side impedance ratio, the algorithm model for predicting the voltage change before and after the fault is simplified and calculated according to the grid-side equivalent parameters and the load-side equivalent parameters to generate a predicted jump result. The predicted jump result includes the voltage amplitude jump and phase jump of the predicted fault point, which can determine the voltage amplitude jump and phase jump of the fault point when a common fault occurs, prevent the maximum power angle from becoming instable, and maintain the power angle stability of the power system's new energy grid-connected fault point, thereby better selecting electrical equipment and performing protection work.

[0167] The systems, devices, modules, or units described in the above embodiments may be implemented by computer chips or entities, or by products having certain functions. A typical implementation device is a computer device. Specifically, the computer device may be, for example, a personal computer, a laptop computer, a cellular phone, a camera phone, a smartphone, a personal digital assistant, a media player, a navigation device, an email device, a game console, a tablet computer, a wearable device, or a combination of any of these devices.

[0168] An embodiment of the present invention provides a computer device including a memory and a processor, the memory being used to store information including program instructions, the processor being used to control the execution of the program instructions, and the program instructions being loaded and executed by the processor to implement the various steps of the embodiment of the above-mentioned method for predicting the fault point jump of a new energy grid-connected point in the power system. For a specific description, please refer to the embodiment of the above-mentioned method for predicting the fault point jump of a new energy grid-connected point in the power system.

[0169] Reference below Figure 6 , which shows a structural diagram of a computer device 600 suitable for implementing an embodiment of the present application.

[0170] like Figure 6 As shown, the computer device 600 includes a central processing unit (CPU) 601, which can perform various appropriate tasks and processes according to a program stored in a read-only memory (ROM) 602 or a program loaded from a storage portion 608 into a random access memory (RAM) 603. Various programs and data required for the operation of the computer device 600 are also stored in the RAM 603. The CPU 601, ROM 602, and RAM 603 are connected to each other via a bus 604. An input / output (I / O) interface 605 is also connected to the bus 604.

[0171] The following components are connected to the I / O interface 605: an input section 606 including a keyboard, a mouse, and the like; an output section 607 including devices such as a cathode ray tube (CRT), a liquid crystal display (LCD), and a speaker; a storage section 608 including devices such as a hard disk; and a communication section 609 including a network interface card such as a LAN card or a modem. The communication section 609 performs communication processing via a network such as the Internet. A drive 610 is also connected to the I / O interface 605 as needed. Removable media 611, such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory, is installed in the drive 610 as needed, so that computer programs read therefrom can be installed in the storage section 608 as needed.

[0172] In particular, according to embodiments of the present invention, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments of the present invention include a computer program product comprising a computer program tangibly embodied on a machine-readable medium, the computer program including program code for executing the methods illustrated in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via communication portion 609 and / or installed from removable media 611.

[0173] Computer-readable media includes permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. The information can be computer-readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassettes, magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer-readable media does not include transitory computer-readable media (transitory media), such as modulated data signals and carrier waves.

[0174] For the convenience of description, the above devices are described as being divided into various units according to their functions. Of course, when implementing this application, the functions of each unit can be implemented in the same or multiple software and / or hardware.

[0175] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowcharts and / or block diagrams, as well as combinations of processes and / or blocks in the flowcharts 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, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowcharts and / or block diagrams. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0176] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0177] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0178] It should also be noted that the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, commodity, or apparatus that includes a series of elements includes not only those elements but also other elements not explicitly listed, or includes elements inherent to such process, method, commodity, or apparatus. In the absence of further limitations, an element defined by the phrase "comprises a ..." does not exclude the presence of other identical elements in the process, method, commodity, or apparatus that includes the element.

[0179] The acquisition, storage, use, and processing of data in this application's technical solution comply with relevant national laws and regulations.

[0180] It should be noted that in the embodiments of the present application, certain software, components, models and other existing solutions in the industry may be mentioned. They should be regarded as exemplary. Their purpose is only to illustrate the feasibility of implementing the technical solution of the present application, but it does not mean that the applicant has or will necessarily use the solution.

[0181] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Furthermore, the present application may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0182] The present application may be described in the general context of computer-executable instructions executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform specific tasks or implement specific abstract data types. The present application may also be practiced in distributed computing environments where tasks are performed by remote processing devices connected through a communications network. In a distributed computing environment, program modules may be located in local and remote computer storage media, including storage devices.

[0183] The various embodiments in this specification are described in a progressive manner. Similar parts between the various embodiments can be referred to in conjunction with each other. Each embodiment focuses on the differences between the other embodiments. In particular, the system embodiments are generally similar to the method embodiments, so the description is relatively simple. For relevant parts, refer to the description of the method embodiments.

[0184] The foregoing is merely an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application should all be included within the scope of the claims of the present application.

Claims

1. A method for predicting fault point jumps at a new energy grid connection point in a power system, characterized in that: The method comprises: Obtain grid-side equivalent parameters, predicted fault point parameters, and load-side equivalent parameters of new energy grid-connected points in the power system; By using a pre-built equivalent model of a fault at a new energy grid connection point in the power system, an algorithm model for predicting voltage changes before and after a fault is generated based on the equivalent parameters on the grid side, the predicted fault point parameters, and the equivalent parameters on the load side; Through the grid-side impedance ratio and the load-side impedance ratio, according to the grid-side equivalent parameters and the load-side equivalent parameters, the voltage change algorithm model before and after the predicted fault is simplified and calculated to generate a predicted jump result, which includes the voltage amplitude jump and phase jump at the predicted fault point.

2. The method for predicting fault point jump of a new energy grid connection point in a power system according to claim 1, characterized in that: The fault equivalent model of the new energy grid connection point of the power system includes an equivalent circuit at the time of the fault and an equivalent circuit after the fault; The pre-built equivalent model of the fault equivalent of the new energy grid connection point of the power system is used to generate an algorithm model for predicting the voltage change before and after the fault according to the equivalent parameters on the grid side, the predicted fault point parameters and the equivalent parameters on the load side, including: By using the superposition theorem, according to the equivalent circuit at the time of fault, the equivalent parameters on the grid side, the predicted fault point parameters and the equivalent parameters on the load side are linearly superimposed to generate a voltage quantity model at the time of fault; According to the post-fault equivalent circuit, linearly superimpose the grid-side equivalent parameters and the load-side equivalent parameters to generate a post-fault voltage quantity model; The algorithm model for predicting voltage changes before and after a fault is generated based on the voltage model at the time of the fault and the voltage model after the fault.

3. The method for predicting fault point jump of a new energy grid connection point in a power system according to claim 1, characterized in that: The voltage change algorithm model for predicting the voltage before and after the fault is simplified and calculated based on the grid-side impedance ratio and the load-side impedance ratio, and the grid-side equivalent parameters and the load-side equivalent parameters to generate a predicted jump result, wherein the predicted jump result includes the voltage amplitude jump and phase jump at the predicted fault point, including: If the grid-side impedance ratio and the load-side impedance ratio are the same, simplifying and calculating the voltage change algorithm model before and after the predicted fault based on the grid-side equivalent parameters to generate a first voltage amplitude jump and a first phase jump at the predicted fault point; determining the first voltage amplitude jump and the first phase jump as predicted jump results; If the grid-side impedance ratio and the load-side impedance ratio are different, simplifying and calculating the voltage change algorithm model before and after the predicted fault based on the grid-side equivalent parameters, the grid-side impedance ratio, and the load-side equivalent parameters to generate a second voltage amplitude jump and a second phase jump at the predicted fault point; The second voltage amplitude jump and the second phase jump are determined as predicted jump results.

4. The method for predicting fault point jump of a new energy grid connection point in a power system according to claim 3, characterized in that: The method of simplifying and calculating the voltage change algorithm model before and after the predicted fault based on the grid-side equivalent parameters to generate a first voltage amplitude jump and a first phase jump of the predicted fault point includes: Taking the module length of the voltage change algorithm model before and after the predicted fault to generate a first voltage amplitude jump formula for predicting the fault point; Calculating the grid-side equivalent parameters using the first voltage amplitude jump formula to generate a first voltage amplitude jump; Performing complex number processing and arc tangent function processing on the voltage change algorithm model before and after the predicted fault to generate a first phase jump formula for predicting the fault point; The grid-side equivalent parameters are calculated using the first phase jump formula to generate a first phase jump.

5. The method for predicting fault point jump of a new energy grid connection point in a power system according to claim 3, characterized in that: The method simplifies and calculates the voltage change algorithm model before and after the predicted fault based on the grid-side equivalent parameters, the grid-side impedance ratio, and the load-side equivalent parameters to generate a second voltage amplitude jump and a second phase jump at the predicted fault point, including: According to the grid-side impedance ratio, taking the module length of the voltage change algorithm model before and after the predicted fault, and generating a second voltage amplitude jump formula for predicting the fault point; Calculating the grid-side equivalent parameter and the grid-side impedance ratio using the second voltage amplitude jump formula to generate a second voltage amplitude jump; According to the grid-side impedance ratio, performing complex number processing and inverse tangent function processing on the voltage change algorithm model before and after the fault prediction, to generate a second phase jump formula for predicting the fault point; The grid-side equivalent parameter and the grid-side impedance ratio are calculated using the second phase jump formula to generate a second phase jump.

6. The method for predicting fault point jump of a new energy grid connection point in a power system according to claim 1, characterized in that: The voltage change algorithm model for predicting the voltage before and after the fault is simplified and calculated based on the grid-side impedance ratio and the load-side impedance ratio, and the grid-side equivalent parameters and the load-side equivalent parameters to generate a predicted jump result, wherein the predicted jump result includes the voltage amplitude jump and phase jump at the predicted fault point, and further includes: Determining whether the voltage amplitude jump at the predicted fault point is greater than a preset voltage jump threshold, and whether the phase jump is greater than a preset phase jump threshold; If the voltage amplitude jump is greater than the preset voltage jump threshold, or the phase jump is greater than the preset phase jump threshold, the new energy grid connection point of the power system is optimized according to the preset early warning strategy, and the steps of obtaining the grid-side equivalent parameters of the new energy grid connection point of the power system, predicting the fault point parameters and the load-side equivalent parameters are repeated.

7. A fault point jump prediction device for a new energy grid connection point in a power system, characterized in that: The device comprises: A parameter acquisition unit, used to obtain grid-side equivalent parameters of the new energy grid connection point of the power system, predicted fault point parameters and load-side equivalent parameters; An algorithm model building unit is used to generate an algorithm model for predicting voltage changes before and after a fault based on a pre-built equivalent model of a new energy grid-connected point fault in the power system and the equivalent parameters on the grid side, the predicted fault point parameters, and the equivalent parameters on the load side; The jump prediction unit is used to simplify and calculate the voltage change algorithm model before and after the predicted fault based on the grid-side impedance ratio and the load-side impedance ratio, according to the grid-side equivalent parameters and the load-side equivalent parameters, to generate a predicted jump result, wherein the predicted jump result includes the voltage amplitude jump and phase jump at the predicted fault point.

8. The fault point jump prediction device for a new energy grid connection point in a power system according to claim 7, characterized in that: The fault equivalent model of the new energy grid connection point of the power system includes an equivalent circuit at the time of the fault and an equivalent circuit after the fault; The algorithm model construction unit is specifically used to linearly superimpose the grid-side equivalent parameters, predicted fault point parameters and load-side equivalent parameters according to the equivalent circuit at the time of fault through the superposition theorem to generate a voltage quantity model at the time of fault; linearly superimpose the grid-side equivalent parameters and load-side equivalent parameters according to the equivalent circuit after the fault to generate a voltage quantity model after the fault; and generate the algorithm model for predicting voltage changes before and after the fault based on the voltage quantity model at the time of fault and the voltage quantity model after the fault.

9. The device for predicting fault point jump of a new energy grid connection point in a power system according to claim 7, characterized in that: The jump prediction unit is specifically used to simplify and calculate the voltage change algorithm model before and after the predicted fault according to the grid-side equivalent parameters if the grid-side impedance ratio and the load-side impedance ratio are the same, to generate a first voltage amplitude jump and a first phase jump of the predicted fault point; determine the first voltage amplitude jump and the first phase jump as the predicted jump result; if the grid-side impedance ratio and the load-side impedance ratio are different, simplify and calculate the voltage change algorithm model before and after the predicted fault according to the grid-side equivalent parameters, the grid-side impedance ratio and the load-side equivalent parameters, to generate a second voltage amplitude jump and a second phase jump of the predicted fault point; determine the second voltage amplitude jump and the second phase jump as the predicted jump result.

10. The device for predicting fault point jump of a new energy grid connection point in a power system according to claim 9, characterized in that: The jump prediction unit is specifically used to take the modulus length of the voltage change algorithm model before and after the predicted fault to generate a first voltage amplitude jump formula for predicting the fault point; calculate the equivalent parameters on the grid side through the first voltage amplitude jump formula to generate a first voltage amplitude jump; perform complex number processing and inverse tangent function processing on the voltage change algorithm model before and after the predicted fault to generate a first phase jump formula for predicting the fault point; calculate the equivalent parameters on the grid side through the first phase jump formula to generate a first phase jump.

11. The device for predicting fault point jump of a new energy grid connection point in a power system according to claim 9, characterized in that: The jump prediction unit is specifically configured to take the module length of the voltage change algorithm model before and after the predicted fault according to the grid-side impedance ratio, and generate a second voltage amplitude jump formula for predicting the fault point; The grid-side equivalent parameters and the grid-side impedance ratio are calculated using the second voltage amplitude jump formula to generate a second voltage amplitude jump; based on the grid-side impedance ratio, the voltage change algorithm model for predicting the voltage change before and after the fault is subjected to complex number processing and inverse tangent function processing to generate a second phase jump formula for predicting the fault point; The grid-side equivalent parameter and the grid-side impedance ratio are calculated using the second phase jump formula to generate a second phase jump.

12. The device for predicting fault point jump of a new energy grid connection point in a power system according to claim 7, characterized in that: The device further comprises: a judgment unit, configured to judge whether the voltage amplitude jump at the predicted fault point is greater than a preset voltage jump threshold, and whether the phase jump is greater than a preset phase jump threshold; An early warning unit is used to optimize the new energy grid connection point of the power system according to a preset early warning strategy if the voltage amplitude jump is greater than a preset voltage jump threshold, or the phase jump is greater than a preset phase jump threshold, and repeatedly execute the steps of obtaining the grid-side equivalent parameters of the new energy grid connection point of the power system, predicting the fault point parameters and the load-side equivalent parameters.

13. A computer-readable medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the method for predicting the fault point jump of a new energy grid-connected point in a power system as described in any one of claims 1 to 6 is implemented.

14. A computer device comprising a memory and a processor, wherein the memory is used to store information including program instructions, and the processor is used to control the execution of the program instructions, wherein: When the program instructions are loaded and executed by the processor, the fault point jump prediction method of the new energy grid connection point of the power system according to any one of claims 1 to 6 is implemented.

15. A computer program product comprising a computer program / instructions, characterized in that When the computer program / instructions are executed by a processor, the method for predicting the fault point jump of a new energy grid-connected point in a power system according to any one of claims 1 to 6 is implemented.

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