Temporary overvoltage calculation method and device for new energy alternating current delivery system

Abstract

The invention discloses a temporary overvoltage calculation method and device for a new energy alternating current delivery system. The method comprises the following steps: screening influence parameters of an overvoltage peak value of a new energy alternating current delivery system in electromagnetic transient simulation based on a Morris global sensitivity analysis method, and determining key influence factors; according to the value range of the key influence factor and a preset constraint condition, determining a sample data set composed of multiple groups of sample data of the key influence factor and a temporary overvoltage peak value of each group of data; fitting the sample data set by adopting a QR decomposition least square method to obtain a fitting relationship between the key influence factors and the transient overvoltage peak value; and substituting the simulation key influence factor value of the new energy alternating current delivery system into the fitting relation to calculate the simulation transient overvoltage peak value of the new energy alternating current delivery system.

Description

Technical Field

[0001] The present invention relates to the technical field of power systems, and more specifically, to a method and device for calculating temporary overvoltage of a new energy AC transmission system. Background Art

[0002] In recent years, my country's renewable energy power generation has developed rapidly. The proportion of renewable energy power generation equipment such as photovoltaic and wind power has increased, and the installed capacity is the highest in the world. A large number of power electronic equipment has poured into the power system, which has significantly reduced the voltage support capacity of the renewable energy power grid. Fault disturbances will cause the system to produce large temporary voltage fluctuations, causing the system voltage to rise, which may cause the renewable energy generators to be disconnected from the grid or equipment to be damaged. Therefore, it is very important to accurately characterize overvoltage.

[0003] Electromagnetic transient simulation technology and electromechanical transient simulation technology are currently advantageous tools for judging whether transient stability is within the safety margin. For electromagnetic transient simulation research, the voltage instantaneous value characteristics can be analyzed, and the voltage harmonic components can be more accurately characterized. However, in the calculation of power system mode, it is usually limited by computing resources and computing efficiency, and has the characteristics of high precision and slow simulation speed. For electromechanical transient simulation research, based on the phasor model, some differential equations are simplified into algebraic equations, which can only be used to analyze the power frequency component. However, due to its high computing efficiency, it is widely used in power system mode calculation, and has the characteristics of fast simulation speed and low precision. In order to take into account the advantages of high electromagnetic simulation accuracy and fast electromechanical simulation speed, it is urgent to propose a method for analyzing the electromagnetic-electromechanical mapping relationship of temporary overvoltage in the new energy AC transmission system, which can ensure that the voltage value is quickly obtained while also meeting the accuracy of the results. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a method and device for calculating temporary overvoltage in a new energy AC transmission system.

[0005] According to one aspect of the present invention, a method for calculating temporary overvoltage of a new energy AC transmission system is provided, comprising:

[0006] Based on the Morris global sensitivity analysis method, the influencing parameters of the overvoltage peak of the new energy AC transmission system in the electromagnetic transient simulation are screened to determine the key influencing factors;

[0007] According to the value range of the key influencing factors and the preset constraint conditions, a sample data set consisting of multiple groups of sample data of the key influencing factors and the temporary overvoltage peak value of each group of data is determined;

[0008] The least square method of QR decomposition is used to fit the sample data set to obtain the fitting relationship between the key influencing factors and the transient overvoltage peak value;

[0009] The simulation key influencing factor values ​​of the new energy AC transmission system are substituted into the fitting relationship to calculate the simulation transient overvoltage peak value of the new energy AC transmission system.

[0010] Optionally, based on the Morris global sensitivity analysis method, the influencing parameters of the overvoltage peak of the new energy AC transmission system in the electromagnetic transient simulation are screened to determine the key influencing factors, including:

[0011] Determine the value range of the influencing parameters;

[0012] Map the value range to the preset range, and discretize it to obtain the discretized parameter value;

[0013] Construct a sampling sample according to the discretized parameter value, and randomly draw a base value of the parameter from the sampling sample once;

[0014] Starting from the base value, each influencing parameter is sampled one by one with the increase of the preset difference value, so as to generate multiple groups of sampling sample data;

[0015] Perform simulation calculation on multiple groups of sample data according to the electromagnetic model to determine the temporary overvoltage peak values ​​corresponding to the multiple groups of sample data;

[0016] According to multiple groups of sampling sample data and their corresponding temporary overvoltage peak values, respectively calculate the basic influence of each influencing parameter in each group of sampling sample data;

[0017] According to the basic influence of the influencing parameters, determine the influence degree of each influencing parameter;

[0018] The influence degrees of all influencing parameters are arranged in descending order, and the influencing parameters whose influence degrees exceed the preset threshold are selected as key influencing factors.

[0019] Optionally, the sample is:

[0020] {0,1 / (p-1),2 / (p-1),…,1-1 / (p-1)}

[0021] Where p is the discretization parameter value.

[0022] Optionally, the preset difference is:

[0023] Δ=1 / (p-1)

[0024] Where p is the discretization parameter value.

[0025] Optionally, the basic impact is calculated as:

[0026]

[0027] In the formula, i is the number of the influencing parameter, j represents the number of the sample data, and the preset difference Δ=1 / (p-1). The sensitivity of the i-th influencing parameter of the j-th group of sample data, x i is the i-th influencing parameter.

[0028] Optionally, the influence degree consists of a mean and a standard deviation, where the mean μ of the i-th influence parameter is i and standard deviation σ i for:

[0029]

[0030] In the formula, The basic influence of the i-th influencing parameter of the j-th group of sample data, N is the number of groups of sample data.

[0031] Optionally, the preset constraints are:

[0032]

[0033] Where X / R is the impedance ratio and SCR is the short circuit ratio.

[0034] Optionally, the objective function of the least squares method for QR decomposition is:

[0035]

[0036] In the formula, Q is an orthogonal matrix, Y is the overvoltage peak difference vector, R1 is the upper triangular matrix of the R matrix in the QR decomposition, A is the unknown quantity to be fitted, C1 has the same number of rows as R1, and solving the equation R1A=C can obtain the optimal estimate of the coefficient A. In this case, the minimum variance is ||C2||2 2 .

[0037] Optionally, the fitted relationship is:

[0038] ΔU r =1.473-0.873SCR-1.003X / R-0.002K p_PLL +0.808SCR×X / R

[0039] +0.0005SCR×K p_PLL +0.197(SCR) 2 +0.038(X / R) 2 -0.205(SCR) 2

[0040] ×X / R-0.002(X / R) 3

[0041] In the formula, X / R is the impedance ratio, SCR is the short circuit ratio, K p_PLL is the PLL control parameter, ΔU r Temporary overvoltage peak.

[0042] According to another aspect of the present invention, there is provided a temporary overvoltage calculation device for a new energy AC transmission system, comprising:

[0043] The screening module is used to screen the influencing parameters of the overvoltage peak of the new energy AC transmission system in the electromagnetic transient simulation based on the Morris global sensitivity analysis method to determine the key influencing factors;

[0044] A composition module, used to determine a sample data set consisting of multiple groups of sample data of key influencing factors and a temporary overvoltage peak value of each group of data according to a value range of the key influencing factors and preset constraints;

[0045] A fitting module is used to fit the sample data set using the least square method of QR decomposition to obtain the fitting relationship between the key influencing factors and the transient overvoltage peak value;

[0046] The calculation module is used to bring the simulation key influencing factor values ​​of the new energy AC transmission system into the fitting relationship to calculate the simulation transient overvoltage peak value of the new energy AC transmission system.

[0047] According to another aspect of the present invention, a computer-readable storage medium is provided, wherein the storage medium stores a computer program, and the computer program is used to execute the method described in any one of the above aspects of the present invention.

[0048] According to another aspect of the present invention, an electronic device is provided, comprising: a processor; a memory for storing instructions executable by the processor; the processor is configured to read the executable instructions from the memory and execute the instructions to implement the method described in any one of the above aspects of the present invention.

[0049] Thus, the present invention provides a method for calculating the temporary overvoltage of a new energy AC transmission system. Based on the Morris global sensitivity analysis method, the influencing parameters of the overvoltage peak value of the new energy AC transmission system in the electromagnetic transient simulation are screened to determine the key influencing factors; according to the value range of the key influencing factors and the preset constraints, a sample data set consisting of multiple groups of sample data of the key influencing factors and the temporary overvoltage peak value of each group of data is determined; the sample data set is fitted by the least square method of QR decomposition to obtain the fitting relationship between the key influencing factors and the transient overvoltage peak value; the simulation key influencing factor values ​​of the new energy AC transmission system are brought into the fitting relationship to calculate the simulation transient overvoltage peak value of the new energy AC transmission system. While ensuring that the voltage value is quickly obtained, the accuracy of the result can also be met. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] A more complete understanding of exemplary embodiments of the present invention may be obtained by referring to the following drawings:

[0051] Figure 1 It is a flow chart of a temporary overvoltage calculation method of a new energy AC transmission system provided by an exemplary embodiment of the present invention;

[0052] Figure 2 It is a schematic diagram of the structure of a VSC grid-connected system of a PSCAD electromagnetic model provided by an exemplary embodiment of the present invention;

[0053] Figure 3 is a power outer loop control block diagram provided by an exemplary embodiment of the present invention;

[0054] Figure 4 is a current inner loop control block diagram provided by an exemplary embodiment of the present invention;

[0055] Figure 5 is a PLL control block diagram provided by an exemplary embodiment of the present invention;

[0056] Figure 6 is a block diagram of a building system provided by an exemplary embodiment of the present invention;

[0057] Figure 7 It is a structural schematic diagram of a temporary overvoltage calculation device for a new energy AC transmission system provided by an exemplary embodiment of the present invention;

[0058] Figure 8 This is a structure of an electronic device provided by an exemplary embodiment of the present invention. DETAILED DESCRIPTION

[0059] Below, the exemplary embodiments according to the present invention will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments of the present invention, and it should be understood that the present invention is not limited to the exemplary embodiments described here.

[0060] It should be noted that the relative arrangement of components and steps, the numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise.

[0061] Those skilled in the art can understand that the terms "first" and "second" in the embodiments of the present invention are only used to distinguish different steps, devices or modules, etc., and neither represent any specific technical meaning nor indicate the necessary logical order between them.

[0062] It should also be understood that, in the embodiments of the present invention, “plurality” may refer to two or more than two, and “at least one” may refer to one, two or more than two.

[0063] It should also be understood that any component, data or structure mentioned in the embodiments of the present invention can generally be understood as one or more, unless explicitly limited or otherwise indicated in the context.

[0064] In addition, the term "and / or" in the present invention is only a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in the present invention generally indicates that the associated objects before and after are in an "or" relationship.

[0065] It should also be understood that the description of the various embodiments of the present invention focuses on the differences between the various embodiments, and the same or similar aspects thereof can be referenced to each other, and for the sake of brevity, they will not be described one by one.

[0066] At the same time, it should be understood that for the convenience of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship.

[0067] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

[0068] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.

[0069] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0070] Embodiments of the present invention can be applied to electronic devices such as terminal devices, computer systems, servers, etc., which can operate with many other general or special computing system environments or configurations. Examples of well-known terminal devices, computing systems, environments and / or configurations suitable for use with electronic devices such as terminal devices, computer systems, servers, etc. include, but are not limited to: personal computer systems, server computer systems, thin clients, thick clients, handheld or laptop devices, microprocessor-based systems, set-top boxes, programmable consumer electronics, network personal computers, small computer systems, large computer systems, and distributed cloud computing technology environments including any of the above systems, etc.

[0071] Electronic devices such as terminal devices, computer systems, servers, etc. can be described in the general context of computer system executable instructions (such as program modules) executed by computer systems. Generally, program modules can include routines, programs, object programs, components, logic, data structures, etc., which perform specific tasks or implement specific abstract data types. Computer systems / servers can be implemented in a distributed cloud computing environment, where tasks are performed by remote processing devices linked through a communication network. In a distributed cloud computing environment, program modules can be located on local or remote computing system storage media including storage devices.

[0072] Exemplary Methods

[0073] Figure 1 FIG. 1 is a flow chart of a method for calculating a temporary overvoltage of a new energy AC transmission system provided by an exemplary embodiment of the present invention. This embodiment can be applied to electronic devices, such as Figure 1 As shown, the temporary overvoltage calculation method 100 of the new energy AC transmission system includes the following steps:

[0074] Step 101, screening the influencing parameters of the overvoltage peak of the new energy AC transmission system in the electromagnetic transient simulation based on the Morris global sensitivity analysis method, and determining the key influencing factors;

[0075] Step 102, determining a sample data set consisting of multiple groups of sample data of the key influencing factors and a temporary overvoltage peak value of each group of data according to the value range of the key influencing factors and preset constraints;

[0076] Step 103, using the least square method of QR decomposition to fit the sample data set, to obtain the fitting relationship between the key influencing factors and the transient overvoltage peak value;

[0077] Step 104 , the simulation key influencing factor values ​​of the new energy AC transmission system are brought into the fitting relationship to calculate the simulation transient overvoltage peak value of the new energy AC transmission system.

[0078] Specifically, the present invention proposes a method for analyzing the electromagnetic-electromechanical mapping relationship of temporary overvoltage in a new energy AC transmission system, which can be used to analyze the safety of the power grid and ensure the stable operation of the new energy AC transmission system. The method includes three steps: 1. Screening out the key influencing factors of the overvoltage peak of the new energy AC transmission system in electromagnetic transient simulation based on the Morris global sensitivity analysis method; 2. Obtaining a fitting method based on the least squares method of QR decomposition; 3. Generate samples according to the constraint conditions to establish a mapping relationship between electromagnetic-electromechanical temporary overvoltage peaks;

[0079] Step 1: Screen out the key influencing factors of the overvoltage peak of the new energy AC transmission system in electromagnetic transient simulation based on the Morris global sensitivity analysis method

[0080] (1) Select influencing parameters and determine the value range;

[0081] (2) Select the indicators to be evaluated and analyzed, and perform sampling according to the Morris test principle. Map the value range of n parameters to [0,1] and discretize it to p. Randomly sample once from {0,1 / (p-1),2 / (p-1),…,1-1 / (p-1)} as the base value of the parameter X*=(x1 * ,x2 * ,…,x n * ), starting from the base value, each time a parameter is increased by Δ=1 / (p-1) to complete a sampling, repeat n times, ensure that only one parameter changes in two consecutive samplings, and n parameters change once, n samplings and the base value, a total of n+1 groups of samples form a track. Repeat the above steps to form multiple tracks, that is, multiple groups of sample data;

[0082] (3) Simulation of the maximum voltage of the electromagnetic model: Substituting the sample parameters into the electromagnetic transient model for simulation, the temporary overvoltage peak value of the new energy AC transmission system under each set of sample parameters is obtained;

[0083] (4) Sensitivity calculation: the basic influence of each parameter on the evaluation index is:

[0084]

[0085] Where: i is the parameter number, j represents the track number;

[0086] The mean μ of the basic influence of the i-th parameter i and standard deviation σ i for:

[0087]

[0088] The mean μ of the i-th parameter i The larger the value, the greater the influence of the parameter on the evaluation index; the standard deviation σ i The larger the value is, the stronger the nonlinear effect of the parameter on the model output is or the greater the mutual influence with other parameters is.

[0089] By judging the degree of influence, the key parameters that affect the temporary overvoltage peak of the new energy AC transmission system can be determined;

[0090] Step 2: Get the fitting method based on the least squares method of QR decomposition

[0091] The peak difference vector of overvoltage between electromagnetic transient simulation and electromechanical transient simulation is Y n×1 , where n is the number of samples used for fitting. For the i-th and j-th key factors k i , k j , the constant term, power term, and cross term total m terms, expressed as X n×m . Polynomial coefficient A m×1 is the unknown quantity to be fitted. Then for n groups of samples, we have: n×1 =X n×m A m×1

[0092] Perform QR decomposition on X, and we have X = QR, where Q is an orthogonal matrix and R is an upper triangular matrix. The original least squares problem can be transformed into: By solving the equation R1A=C, we can get the optimal estimate of the coefficient A. In this case, the minimum variance is ||C2||2 2 .

[0093] Then the coefficient of determination R 2 (also known as goodness of fit) to evaluate the fitting effect, R 2 The expression is:

[0094]

[0095] Among them, SST is the total sum of squares, SSR is the regression sum of squares, and SSE is the residual sum of squares. The expression is as follows:

[0096]

[0097] Where: y i is the experimental value, is the average value of the experimental values, is the regression value.

[0098] Step 3: Generate samples based on constraint conditions to establish a mapping relationship between electromagnetic and electromechanical overvoltage peaks

[0099] The analysis obtains the constraints of the key influencing factors of the new energy overvoltage peak in the electromagnetic transient simulation in step 1, and determines the range of key parameters. Samples are uniformly taken according to the constraints and the value range, and then the functional relationship formula is obtained by fitting these samples.

[0100] The coefficient of determination in the goodness of fit describes the variation in the response variable of the model. The fitting effect is judged based on the coefficient of determination.

[0101] In one embodiment of the present invention, the specific examples are as follows:

[0102] Step 1: Screen out the key influencing factors of the temporary overvoltage peak of the new energy AC transmission system in electromagnetic transient simulation based on the Morris global sensitivity analysis method

[0103] The parameters affecting the overvoltage peak of new energy sources include: grid strength SCR, impedance ratio X / R, outer loop PI control parameter K p_P , K i_P , inner loop PI control parameter K p_I , K i_I 、PLL control parameter K p_PLL , K i_PLL , determine the value range as shown in Table 1;

[0104] Table 1 Value ranges of various influencing parameters

[0105]

[0106] In the embodiment of the present invention, the schematic diagram of the electromagnetic transient model structure of the VSC grid-connected system is as follows: Figure 2 As shown, the system consists of a main circuit and a control loop, wherein the main circuit includes a converter and a DC side capacitor, etc., and the control circuit includes an outer loop control link, an inner loop control link and a PLL.

[0107] (1) Power outer loop control link

[0108] The power outer loop control block diagram is as follows: Figure 3 As shown, the power outer loop control equation is:

[0109]

[0110] Where: K p_P and K i_P They are the proportional coefficient and integral coefficient of the active loop PI control respectively.

[0111] (2) Current inner loop control link

[0112] The current loop control block diagram is as follows: Figure 4 As shown, the current loop control equation is:

[0113]

[0114] Where: K p_I and K i_I They are the proportional coefficient and integral coefficient of the current loop PI control respectively.

[0115] (3)PLL

[0116] PLL control block diagram Figure 5 As shown, the PLL control equation is:

[0117]

[0118] Where: K p_PLL is the proportional coefficient of the PLL, K i_PLL is the integral coefficient of the PLL

[0119] The new energy overvoltage peak value obtained by electromagnetic transient simulation after the three-phase short-circuit fault is cleared is selected as the evaluation index Y. The value range of the eight parameters is mapped to [0,1] and discretized to p. The eight parameters are randomly sampled from {0,1 / (p-1),2 / (p-1),…,1-1 / (p-1)} as the base value of the parameter X*=(x1 * ,x2 * ,…,x8 * ), starting from the base value, each time a parameter is increased by Δ=1 / (p-1) to complete a sampling, repeat 8 times, ensure that only one parameter changes in two consecutive samplings, and all 8 parameters change once, 8 samplings and the base value, a total of 9 groups of samples form a track. Repeat the above steps to form multiple tracks;

[0120] Sensitivity calculation, the basic influence of each parameter on the evaluation index is:

[0121]

[0122] The mean μ of the basic influence of the i-th parameter i and standard deviation σ i for:

[0123]

[0124] Determine K p_PLL , X / R, SCR are the key parameters that affect the temporary overvoltage peak of new energy, and then according to the constraints

[0125] The constraint condition is: when the power transmission limit is 1p.u., the maximum X / R corresponding to different SCRs that can maintain static stability is In the common short-circuit ratio and impedance ratio range SCR∈[1.2,2], X / R∈[1,10] of new energy machines, the maximum X / R corresponding to different SCRs that can maintain static stability can be obtained by uniformly selecting the value of SCR, and the value range of X / R can also be obtained according to K p_PLL The value range of is used to obtain the final sample for the following function fitting.

[0126] Step 2: The fitting method of electromagnetic-electromechanical mapping is obtained based on the least squares method of QR decomposition.

[0127] The peak difference vector of overvoltage in electromagnetic transient simulation and electromechanical transient simulation is Yn×1, where n is the number of samples used for fitting. i , k j , the constant term, power term, and cross term total m terms, expressed as X n×m . Polynomial coefficient A m×1 is the unknown quantity to be fitted. Then for n groups of samples, we have: n×1 =X n×m A m×1

[0128] Perform QR decomposition on X, and we have X = QR, where Q is an orthogonal matrix and R is an upper triangular matrix. The original least squares problem can be transformed into: By solving the equation R1A=C, we can get the optimal estimate of the coefficient A. In this case, the minimum variance is ||C2||2 2 .

[0129] For SCR, X / R, K p_PLL Uniformly take values ​​and obtain the functional relationship formula based on these samples:

[0130]

[0131] Then the coefficient of determination R 2 (also known as goodness of fit) to evaluate the fitting effect, R 2 The expression is

[0132] Among them, SST is the total sum of squares, SSR is the regression sum of squares, and SSE is the residual sum of squares. The expression is as follows:

[0133]

[0134] Where: y i is the experimental value, is the average value of the experimental values, is the regression value.

[0135] Coefficient of determination R in goodness of fit 2 It is 0.95, which means that the model explains about 95% of the variation in the response variable and the fitting effect is ideal.

[0136] As built system Figure 6 The parameters are shown in Table 2. It is known that SCR = 2, X / R = 2 and K p_PLL =41rad / (kV·s), and these parameters are substituted into formula (10) to fit the difference between electromechanical and electromagnetic simulation ΔU r1 =0.1960pu, and the system simulates and finds that the difference between electromechanical and electromagnetic is ΔU r2=0.2pu, which is close to and lower than the calculated result, and meets the requirement of conservatism of the calculated result.

[0137] Table 2 System control parameters

[0138]

[0139] Thus, the present invention provides a method for calculating the temporary overvoltage of a new energy AC transmission system. Based on the Morris global sensitivity analysis method, the influencing parameters of the overvoltage peak value of the new energy AC transmission system in the electromagnetic transient simulation are screened to determine the key influencing factors; according to the value range of the key influencing factors and the preset constraints, a sample data set consisting of multiple groups of sample data of the key influencing factors and the temporary overvoltage peak value of each group of data is determined; the sample data set is fitted by the least square method of QR decomposition to obtain the fitting relationship between the key influencing factors and the transient overvoltage peak value; the simulation key influencing factor values ​​of the new energy AC transmission system are brought into the fitting relationship to calculate the simulation transient overvoltage peak value of the new energy AC transmission system. While ensuring that the voltage value is quickly obtained, the accuracy of the result can also be met.

[0140] Exemplary Devices

[0141] Figure 7 FIG. 1 is a schematic diagram of a temporary overvoltage calculation device for a new energy AC transmission system provided by an exemplary embodiment of the present invention. Figure 7 As shown, the apparatus 700 includes:

[0142] A screening module 710 is used to screen the influencing parameters of the overvoltage peak of the new energy AC transmission system in the electromagnetic transient simulation based on the Morris global sensitivity analysis method to determine the key influencing factors;

[0143] The forming module 720 is used to determine a sample data set consisting of multiple groups of sample data of key influencing factors and a temporary overvoltage peak value of each group of data according to the value range of the key influencing factors and preset constraints;

[0144] A fitting module 730 is used to fit the sample data set using the least square method of QR decomposition to obtain a fitting relationship between key influencing factors and transient overvoltage peak values;

[0145] The calculation module 740 is used to bring the simulation key influencing factor values ​​of the new energy AC transmission system into the fitting relationship to calculate the simulation transient overvoltage peak value of the new energy AC transmission system.

[0146] Optionally, the screening module 710 includes:

[0147] A first determination submodule is used to determine the value range of the influencing parameter;

[0148] The discretization submodule is used to map the value range to a preset range, and discretize it to obtain the discretized parameter value;

[0149] A construction submodule is used to construct a sampling sample according to the discretized parameter value, and randomly select a base value of the parameter from the sampling sample;

[0150] The sampling submodule is used to sample each influencing parameter one by one with a preset difference starting from the base value, and generate multiple groups of sampling sample data;

[0151] A simulation submodule is used to perform simulation calculations on multiple groups of sample data according to an electromagnetic model to determine temporary overvoltage peak values ​​corresponding to the multiple groups of sample data;

[0152] A calculation submodule, for calculating the basic influence of each influencing parameter in each group of sample data according to multiple groups of sample data and their corresponding temporary overvoltage peak values;

[0153] The second determination submodule is used to determine the influence degree of each influencing parameter according to the basic influence of the influencing parameter;

[0154] The submodule is selected to arrange the influence degrees of all influencing parameters in descending order, and select the influencing parameters whose influence degrees exceed a preset threshold as key influencing factors.

[0155] Optionally, the sample is:

[0156] {0,1 / (p-1),2 / (p-1),…,1-1 / (p-1)}

[0157] Where p is the discretization parameter value.

[0158] Optionally, the preset difference is:

[0159] Δ=1 / (p-1)

[0160] Where p is the discretization parameter value.

[0161] Optionally, the basic impact is calculated as:

[0162]

[0163] In the formula, i is the number of the influencing parameter, j represents the number of the sample data, and the preset difference Δ=1 / (p-1). The sensitivity of the i-th influencing parameter of the j-th group of sample data, x i is the i-th influencing parameter.

[0164] Optionally, the influence degree consists of a mean and a standard deviation, where the mean μ of the i-th influence parameter is i and standard deviation σ i for:

[0165]

[0166] In the formula, The basic influence of the i-th influencing parameter of the j-th group of sample data, N is the number of groups of sample data.

[0167] Optionally, the preset constraints are:

[0168]

[0169] Where X / R is the impedance ratio and SCR is the short circuit ratio.

[0170] Optionally, the objective function of the least squares method for QR decomposition is:

[0171]

[0172] In the formula, Q is an orthogonal matrix, Y is the overvoltage peak difference vector, R1 is the upper triangular matrix of the R matrix in the QR decomposition, A is the unknown quantity to be fitted, C1 has the same number of rows as R1, and solving the equation R1A=C can obtain the optimal estimate of the coefficient A. In this case, the minimum variance is ||C2||2 2 .

[0173] Optionally, the fitted relationship is:

[0174] ΔU r =1.473-0.873SCR-1.003X / R-0.002K p_PLL +0.808SCR×X / R+0.0005SCR×K p_PLL +0.197(SCR) 2 +0.038(X / R) 2 -0.205(SCR) 2 ×X / R-0.002(X / R) 3

[0175] In the formula, X / R is the impedance ratio, SCR is the short circuit ratio, K p_PLL is the PLL control parameter, ΔU r Temporary overvoltage peak.

[0176] Exemplary Electronic Devices

[0177] Figure 8 This is a structure of an electronic device provided by an exemplary embodiment of the present invention. Figure 8 As shown, the electronic device 80 includes one or more processors 81 and a memory 82 .

[0178] The processor 81 may be a central processing unit (CPU) or other forms of processing units having data processing capabilities and / or instruction execution capabilities, and may control other components in the electronic device to perform desired functions.

[0179] The memory 82 may include one or more computer program products, which may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may include, for example, random access memory (RAM) and / or cache memory (cache), etc. The non-volatile memory may include, for example, read-only memory (ROM), hard disk, flash memory, etc. One or more computer program instructions may be stored on the computer-readable storage medium, and the processor 81 may run the program instructions to implement the methods of the software programs of the various embodiments of the present invention described above and / or other desired functions. In one example, the electronic device may also include: an input device 83 and an output device 84, which are interconnected via a bus system and / or other forms of connection mechanisms (not shown).

[0180] In addition, the input device 83 may also include, for example, a keyboard, a mouse, etc.

[0181] The output device 84 can output various information to the outside, and can include, for example, a display, a speaker, a printer, a communication network and a remote output device connected thereto.

[0182] Of course, to simplify, Figure 8 Only some of the components related to the present invention in the electronic device are shown, and components such as a bus, an input / output interface, etc. are omitted. In addition, according to specific application conditions, the electronic device may also include any other appropriate components.

[0183] Exemplary computer program products and computer-readable storage media

[0184] In addition to the above-mentioned methods and devices, an embodiment of the present invention may also be a computer program product, which includes computer program instructions, which, when executed by a processor, enable the processor to execute the steps of the method according to various embodiments of the present invention described in the above-mentioned "Exemplary Method" section of this specification.

[0185] The computer program product may be written in any combination of one or more programming languages ​​to write program code for performing the operations of the embodiments of the present invention, including object-oriented programming languages ​​such as Java, C++, etc., and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the user computing device, partially on the user device, as a separate software package, partially on the user computing device and partially on a remote computing device, or entirely on a remote computing device or server.

[0186] In addition, an embodiment of the present invention may also be a computer-readable storage medium having computer program instructions stored thereon, which, when executed by a processor, enable the processor to execute the steps of the method according to various embodiments of the present invention described in the above “Exemplary Method” section of this specification.

[0187] The computer readable storage medium can adopt any combination of one or more readable media. The readable medium can be a readable signal medium or a readable storage medium. The readable storage medium can include, for example, but is not limited to, a system, system or device of electricity, magnetism, light, electromagnetic, infrared, or semiconductor, or any combination of the above. More specific examples (non-exhaustive list) of readable storage media include: an electrical connection with one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above.

[0188] The basic principle of the present invention is described above in conjunction with specific embodiments. However, it should be pointed out that the advantages, strengths, effects, etc. mentioned in the present invention are only examples and not limitations, and it cannot be considered that these advantages, strengths, effects, etc. must be possessed by each embodiment of the present invention. In addition, the specific details disclosed above are only for the purpose of illustration and facilitation of understanding, rather than limitation, and the above details do not limit the present invention to being implemented by adopting the above specific details.

[0189] Each embodiment in this specification is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the system embodiment, since it basically corresponds to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0190] The block diagrams of the devices, systems, equipment, and systems involved in the present invention are only illustrative examples and are not intended to require or imply that they must be connected, arranged, and configured in the manner shown in the block diagram. As will be appreciated by those skilled in the art, these devices, systems, equipment, and systems can be connected, arranged, and configured in any manner. Words such as "including", "comprising", "having", etc. are open words, referring to "including but not limited to", and can be used interchangeably with them. The words "or" and "and" used here refer to the words "and / or" and can be used interchangeably with them, unless the context clearly indicates otherwise. The word "such as" used here refers to the phrase "such as but not limited to", and can be used interchangeably with it.

[0191] The method and system of the present invention may be implemented in many ways. For example, the method and system of the present invention may be implemented by software, hardware, firmware or any combination of software, hardware, firmware. The above order of steps for the method is only for illustration, and the steps of the method of the present invention are not limited to the order specifically described above, unless otherwise specifically stated. In addition, in some embodiments, the present invention may also be implemented as a program recorded in a recording medium, which includes machine-readable instructions for implementing the method according to the present invention. Thus, the present invention also covers a recording medium storing a program for executing the method according to the present invention.

[0192] It should also be noted that in the system, device and method of the present invention, each component or each step can be decomposed and / or recombined. These decompositions and / or recombinations should be regarded as equivalent schemes of the present invention. The above description of the disclosed aspects is provided to enable any technician in the field to make or use the present invention. Various modifications to these aspects are very obvious to those skilled in the art, and the general principles defined here can be applied to other aspects without departing from the scope of the present invention. Therefore, the present invention is not intended to be limited to the aspects shown here, but in accordance with the widest range consistent with the principles and novel features disclosed here.

[0193] The above description has been given for the purpose of illustration and description. In addition, this description is not intended to limit the embodiments of the present invention to the forms disclosed herein. Although a number of example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, changes, additions and sub-combinations thereof.

Claims

1. A method for calculating temporary overvoltage of a new energy AC transmission system, characterized in that: include: Based on the Morris global sensitivity analysis method, the influencing parameters of the overvoltage peak of the new energy AC transmission system in the electromagnetic transient simulation are screened to determine the key influencing factors; According to the value range of the key influencing factor and the preset constraint conditions, determine a sample data set consisting of multiple groups of sample data of the key influencing factor and the temporary overvoltage peak value of each group of data; The sample data set is fitted using the least square method of QR decomposition to obtain a fitting relationship between the key influencing factors and the transient overvoltage peak value; The simulation key influencing factor values ​​of the new energy AC transmission system are brought into the fitting relationship to calculate the simulation transient overvoltage peak value of the new energy AC transmission system.

2. The method according to claim 1, characterized in that Based on the Morris global sensitivity analysis method, the influencing parameters of the overvoltage peak of the new energy AC transmission system in the electromagnetic transient simulation are screened and the key influencing factors are determined, including: Determining a value range of the influencing parameter; Mapping the value range to a preset range and discretizing it to obtain a discretized parameter value; Construct a sampling sample according to the discretized parameter value, and randomly extract a base value of the parameter from the sampling sample once; Starting from the base value, each influencing parameter is sampled one by one with an increase in a preset difference value, to generate multiple groups of sampling sample data; Perform simulation calculation on multiple groups of sample data according to the electromagnetic model to determine the temporary overvoltage peak values ​​corresponding to the multiple groups of sample data; According to multiple groups of sampling sample data and their corresponding temporary overvoltage peak values, respectively calculate the basic influence of each influencing parameter in each group of sampling sample data; Determining the influence degree of each influencing parameter according to the basic influence of the influencing parameter; The influence degrees of all influencing parameters are arranged in descending order, and the influencing parameters whose influence degrees exceed a preset threshold are selected as the key influencing factors.

3. The method according to claim 2, characterized in that The sampling samples are: {0,1 / (p-1),2 / (p-1),…,1-1 / (p-1)} Where p is the discretization parameter value.

4. The method according to claim 2, characterized in that: The preset difference is: Δ=1 / (p-1) Where p is the discretization parameter value.

5. The method according to claim 2, characterized in that: The basic impact calculation formula is: In the formula, i is the number of the influencing parameter, j represents the number of the sample data, and the preset difference Δ=1 / (p-1). The sensitivity of the i-th influencing parameter of the j-th group of sample data, x i is the i-th influencing parameter.

6. The method according to claim 2, characterized in that The influence degree is composed of mean and standard deviation, where the mean value of the i-th influence parameter μ i and standard deviation σ i for: In the formula, The basic influence of the i-th influencing parameter of the j-th group of sample data, N is the number of groups of sample data.

7. The method according to claim 1, characterized in that The preset constraints are: Where X / R is the impedance ratio and SCR is the short circuit ratio.

8. The method according to claim 1, characterized in that The objective function of the least squares method of QR decomposition is: In the formula, Q is an orthogonal matrix, Y is the overvoltage peak difference vector, R1 is the upper triangular matrix of the R matrix in the QR decomposition, A is the unknown quantity to be fitted, C1 has the same number of rows as R1, and solving the equation R1A=C can obtain the optimal estimate of the coefficient A. In this case, the minimum variance is ||C2||2 2 .

9. The method according to claim 1, characterized in that: The fitting relationship is: ΔU r =1.473-0.873SCR-1.003X / R-0.002K p_PLL +0.808SCR×X / R+0.0005SCR×K p_PLL +0.197(SCR) 2 +0.038(X / R) 2 -0.205(SCR) 2 ×X / R-0.002(X / R) 3 In the formula, X / R is the impedance ratio, SCR is the short circuit ratio, K p_PLL is the PLL control parameter, ΔU r Temporary overvoltage peak.

10. A temporary overvoltage calculation device for a new energy AC transmission system, characterized in that: include: The screening module is used to screen the influencing parameters of the overvoltage peak of the new energy AC transmission system in the electromagnetic transient simulation based on the Morris global sensitivity analysis method to determine the key influencing factors; A construction module, used to determine a sample data set consisting of a plurality of groups of sample data of the key influencing factors and a temporary overvoltage peak value of each group of data according to a value range of the key influencing factors and preset constraints; A fitting module, used for fitting the sample data set by using the least square method of QR decomposition to obtain a fitting relationship between the key influencing factors and the transient overvoltage peak value; The calculation module is used to bring the simulation key influencing factor values ​​of the new energy AC transmission system into the fitting relationship to calculate the simulation transient overvoltage peak value of the new energy AC transmission system.

11. The device according to claim 10, characterized in that Screening modules include: A first determination submodule is used to determine the value range of the influencing parameter; A discretization submodule is used to map the value range to a preset range, and discretize it to obtain a discretized parameter value; A construction submodule, used for constructing a sampling sample according to the discretized parameter value, and randomly extracting a base value of the parameter from the sampling sample once; A sampling submodule, used to sample each influencing parameter one by one with a preset difference starting from the base value, to generate multiple groups of sampling sample data; A simulation submodule is used to perform simulation calculations on multiple groups of sample data according to an electromagnetic model to determine temporary overvoltage peak values ​​corresponding to the multiple groups of sample data; A calculation submodule, for calculating the basic influence of each influencing parameter in each group of sample data according to multiple groups of sample data and their corresponding temporary overvoltage peak values; A second determination submodule is used to determine the influence degree of each influencing parameter according to the basic influence of the influencing parameter; The selection submodule is used to arrange the influence degrees of all influencing parameters in descending order, and select the influencing parameters whose influence degrees exceed a preset threshold as the key influencing factors.

12. A computer-readable storage medium, characterized in that: The storage medium stores a computer program, and the computer program is used to execute the method according to any one of claims 1 to 9.

13. An electronic device, characterized in that: The electronic device comprises: processor; a memory for storing instructions executable by the processor; The processor is used to read the executable instructions from the memory and execute the instructions to implement the method described in any one of claims 1 to 9.

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