Electromagnetic radiation probability analysis method integrating data driving and kernel density estimation

Abstract

According to the electromagnetic radiation probability analysis method fusing data driving and kernel density estimation, harmonic current amplitudes of all frequencies of an electromagnetic radiation source are sampled, a corresponding probability distribution model is constructed, then sampling is carried out from the probability distribution model to obtain harmonic current amplitude samples, and the harmonic current amplitude samples are calculated. The method comprises the following steps: firstly, carrying out power flow calculation to obtain a harmonic voltage amplitude, constructing a mapping relation between the harmonic voltage amplitude and a harmonic current amplitude, then carrying out harmonic current prediction, determining the harmonic voltage amplitude under the predicted harmonic current, and estimating probability distribution, thereby effectively avoiding the problem of insufficient precision in the prior art. And the method can conform to an actual scene, so that accurate data support is provided for subsequent formulation of coordinated dispatching measures of a power grid.

Description

Technical Field

[0001] This invention relates to a method for analyzing power grid parameters, and more particularly to a method for electromagnetic radiation probability analysis that integrates data-driven and kernel density estimation. Background Technology

[0002] With the large-scale integration of distributed power sources, such as photovoltaic power generation and electric vehicle charging stations, and nonlinear power electronic equipment into medium and low voltage distribution networks, electromagnetic radiation pollution within the system is becoming increasingly serious. Electromagnetic interference can not only cause relay protection malfunctions, equipment overheating, and control failures, but also affect power quality assessment and the effectiveness of operation control strategies.

[0003] In existing technologies, electromagnetic radiation power flow analysis involves a one-time static power flow calculation based on fixed electromagnetic radiation source injection parameters. However, in actual operation, the injection characteristics of the electromagnetic radiation source (such as current amplitude and phase angle) are significantly affected by external factors such as illumination, temperature, and load fluctuations, exhibiting high uncertainty and dynamism. Deterministic methods using fixed parameter modeling cannot accurately reflect the electromagnetic radiation response behavior of the system under multiple scenarios and states.

[0004] Therefore, in order to solve the above-mentioned technical problems, it is urgent to propose a new technical approach. Summary of the Invention

[0005] In view of this, the purpose of this invention is to provide an electromagnetic radiation probability analysis method that integrates data-driven and kernel density estimation. This method samples the harmonic current amplitudes at various frequencies of the electromagnetic radiation source and constructs a corresponding probability distribution model. Then, it samples the harmonic current amplitudes from the probability distribution model, performs power flow calculations to obtain the harmonic voltage amplitudes, and establishes a mapping relationship between the harmonic voltage amplitudes and harmonic current amplitudes. Finally, it predicts the harmonic currents and determines the harmonic voltage amplitudes under the predicted harmonic currents, estimating the probability distribution. This effectively avoids the accuracy problems of existing technologies, is consistent with actual scenarios, and thus provides accurate data support for the formulation of subsequent power grid coordination and scheduling measures.

[0006] This invention provides a method for electromagnetic radiation probability analysis that integrates data-driven approaches and kernel density estimation, comprising the following steps:

[0007] S1. Construct an uncertainty model for electromagnetic radiation sources in the power grid;

[0008] S2. The uncertainty model of the electromagnetic radiation source is sampled using the Latin hypersolution method to form a sample, which includes N sample points;

[0009] S3. Perform deterministic power flow simulation calculations on the samples to determine the harmonic voltage injected into the power grid system by the electromagnetic radiation source;

[0010] S4. Construct a mapping model of harmonic current and harmonic voltage injected into the power grid system by electromagnetic radiation source, and determine the current sensitivity coupling matrix based on the mapping model;

[0011] S5. Perform harmonic current flow calculations on the power grid system, predict the harmonic current amplitude of the electromagnetic radiation source at future times, and determine the harmonic voltage amplitude at future times based on the harmonic current amplitude at future times and the current sensitivity coupling matrix.

[0012] The radiation probability distribution of each node in the power grid is obtained by fitting the harmonic voltage amplitude using a Gaussian kernel function.

[0013] Furthermore, in step S1, the uncertainty model of the electromagnetic radiation source is specifically as follows:

[0014] Obtain the amplitude of the harmonic current injected into the power grid by the k-th electromagnetic radiation source at frequency h. ;

[0015] Construct a distribution model of harmonic current amplitude based on the harmonic current amplitude:

[0016] ;

[0017] in: This indicates that the k-th electromagnetic radiation source is at frequency The amplitude of the harmonic current follows a normal distribution. This represents the average value of the harmonic current. It represents the standard deviation of harmonic current.

[0018] Furthermore, the specific steps in constructing the mapping relationship model between harmonic current and harmonic voltage injected into the power grid system by electromagnetic radiation sources include:

[0019] Construct a load node current sensitivity model:

[0020] ;

[0021] in: Let be the admittance of branch ij under h electromagnetic radiation; For the branch line's ground admission; These are the elements of the nodal impedance matrix; Let be the current sensitivity of the k-th electromagnetic radiation source to branch ij; This represents the harmonic current in branch ij at frequency h. This represents the harmonic current generated by the i-th electromagnetic radiation source at frequency k;

[0022] Based on current sensitivity Constructing the sensitivity matrix ;

[0023] Construct the overall sensitivity coupling matrix:

[0024] ;

[0025] in: This represents the weight of the k-th electromagnetic radiation source at frequency h;

[0026] Construct a mapping model between harmonic currents and harmonic voltages injected into the power grid system by an electromagnetic radiation source:

[0027] ;

[0028] in: This indicates random fluctuation error.

[0029] Furthermore, step S5 specifically includes:

[0030] The harmonic voltage amplitude at future time moments is determined based on the harmonic current amplitude at future time moments and the current sensitivity coupling matrix:

[0031] ;

[0032] By fitting the harmonic voltage amplitude using a Gaussian kernel function, the radiation probability distribution of each node in the power grid is obtained as follows:

[0033] ;in, For probability density estimation of harmonic voltage; is the Gaussian kernel function; h is the bandwidth parameter used to control the smoothness of the kernel function; v is the harmonic voltage value point where the probability density needs to be estimated. Represents the set of harmonic voltage amplitudes The i-th sample point in the middle.

[0034] The beneficial effects of this invention are as follows: By sampling the harmonic current amplitudes of various frequencies of the electromagnetic radiation source and constructing corresponding probability distribution models, and then sampling the harmonic current amplitude samples from the probability distribution models, power flow calculations are performed to obtain the harmonic voltage amplitudes, and a mapping relationship between the harmonic voltage amplitudes and harmonic current amplitudes is constructed. Then, the harmonic currents are predicted, and the harmonic voltage amplitudes under the predicted harmonic currents are determined, and the probability distribution is estimated. This effectively avoids the problem of insufficient accuracy in the prior art, and can match the actual scenario, thereby providing accurate data support for the formulation of subsequent power grid coordination and dispatch measures. Attached Figure Description

[0035] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0036] Figure 1This is a schematic diagram of the process of the present invention. Detailed Implementation

[0037] The present invention will be further described in detail below:

[0038] This invention provides a method for electromagnetic radiation probability analysis that integrates data-driven approaches and kernel density estimation, comprising the following steps:

[0039] S1. Construct an uncertainty model for electromagnetic radiation sources in the power grid; where electromagnetic radiation sources include existing photovoltaic power generation, electric vehicle charging piles, etc.

[0040] S2. The uncertainty model of the electromagnetic radiation source is sampled using the Latin hypersolution method to form a sample, which includes N sample points;

[0041] S3. Perform deterministic power flow simulation calculations on the samples to determine the harmonic voltage injected into the power grid system by the electromagnetic radiation source;

[0042] S4. Construct a mapping model of harmonic current and harmonic voltage injected into the power grid system by electromagnetic radiation source, and determine the current sensitivity coupling matrix based on the mapping model;

[0043] S5. Perform harmonic current flow calculations on the power grid system, predict the harmonic current amplitude of the electromagnetic radiation source at future times, and determine the harmonic voltage amplitude at future times based on the harmonic current amplitude at future times and the current sensitivity coupling matrix.

[0044] The harmonic voltage amplitude is fitted using a Gaussian kernel function to obtain the radiation probability distribution of each node in the power grid. This method samples the harmonic current amplitudes at various frequencies of the electromagnetic radiation source and constructs corresponding probability distribution models. Harmonic current amplitude samples are then obtained from these models, and power flow calculations are performed to obtain the harmonic voltage amplitudes. A mapping relationship between harmonic voltage amplitudes and harmonic current amplitudes is established, followed by harmonic current prediction and determination of the harmonic voltage amplitude under the predicted harmonic current. The probability distribution is then estimated, effectively avoiding the accuracy issues of existing technologies and ensuring consistency with real-world scenarios. This provides accurate data support for the formulation of subsequent power grid coordination and dispatch measures.

[0045] In this embodiment, the uncertainty model of the electromagnetic radiation source in step S1 is specifically as follows:

[0046] Obtain the amplitude of the harmonic current injected into the power grid by the k-th electromagnetic radiation source at frequency h. ;

[0047] Construct a distribution model of harmonic current amplitude based on the harmonic current amplitude:

[0048] ;

[0049] in: This indicates that the k-th electromagnetic radiation source is at frequency The amplitude of the harmonic current follows a normal distribution. This represents the average value of the harmonic current. It represents the standard deviation of harmonic current.

[0050] In this embodiment, the specific steps for constructing the mapping relationship model between harmonic current and harmonic voltage injected into the power grid system by the electromagnetic radiation source include:

[0051] Construct a load node current sensitivity model:

[0052] ;

[0053] in: Let be the admittance of branch ij under h electromagnetic radiation; For the branch line's ground admission; These are the elements of the nodal impedance matrix; Let be the current sensitivity of the k-th electromagnetic radiation source to branch ij; This represents the harmonic current in branch ij at frequency h. This represents the harmonic current generated by the i-th electromagnetic radiation source at frequency k;

[0054] Based on current sensitivity Constructing the sensitivity matrix ;

[0055] Construct the overall sensitivity coupling matrix:

[0056] ;

[0057] in: This represents the weight of the k-th electromagnetic radiation source at frequency h;

[0058] Construct a mapping model between harmonic currents and harmonic voltages injected into the power grid system by an electromagnetic radiation source:

[0059] ;

[0060] in: This indicates random fluctuation error.

[0061] This represents the collection of harmonic voltages; similarly: It also represents the collection of time harmonic currents.

[0062] In this embodiment, step S5 specifically includes:

[0063] The harmonic voltage amplitude at future time moments is determined based on the harmonic current amplitude at future time moments and the current sensitivity coupling matrix:

[0064] ;

[0065] By fitting the harmonic voltage amplitude using a Gaussian kernel function, the radiation probability distribution of each node in the power grid is obtained as follows:

[0066] ;in, For probability density estimation of harmonic voltage; The Gaussian kernel function; is the bandwidth parameter used to control the smoothness of the kernel function; v is the harmonic voltage value point where the probability density needs to be estimated. Represents the set of harmonic voltage amplitudes The i-th sample point in the middle.

[0067] in: ;in: Let be the local bandwidth of the i-th sample point; The estimated density value at this point.

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for probabilistic analysis of electromagnetic radiation that integrates data-driven approaches and kernel density estimation, characterized in that: Includes the following steps: S1. Construct an uncertainty model for electromagnetic radiation sources in the power grid; S2. The uncertainty model of the electromagnetic radiation source is sampled using the Latin hypersolution method to form a sample, which includes N sample points; S3. Perform deterministic power flow simulation calculations on the samples to determine the harmonic voltage injected into the power grid system by the electromagnetic radiation source; S4. Construct a mapping model of harmonic current and harmonic voltage injected into the power grid system by electromagnetic radiation source, and determine the current sensitivity coupling matrix based on the mapping model; S5. Perform harmonic current flow calculations on the power grid system, predict the harmonic current amplitude of the electromagnetic radiation source at future times, and determine the harmonic voltage amplitude at future times based on the harmonic current amplitude at future times and the current sensitivity coupling matrix. The radiation probability distribution of each node in the power grid is obtained by fitting the harmonic voltage amplitude using a Gaussian kernel function.

2. The electromagnetic radiation probability analysis method integrating data-driven and kernel density estimation according to claim 1, characterized in that: In step S1, the uncertainty model of the electromagnetic radiation source is specifically as follows: Obtain the amplitude of the harmonic current injected into the power grid by the k-th electromagnetic radiation source at frequency h. ; Construct a distribution model of harmonic current amplitude based on the harmonic current amplitude: ； in: This indicates that the k-th electromagnetic radiation source is at frequency The amplitude of the harmonic current follows a normal distribution. This represents the average value of the harmonic current. It represents the standard deviation of harmonic current.

3. The electromagnetic radiation probability analysis method integrating data-driven and kernel density estimation according to claim 2, characterized in that: The specific steps in constructing the mapping relationship model between harmonic currents and harmonic voltages injected into the power grid system by electromagnetic radiation sources include: Construct a load node current sensitivity model: ； in: Let be the admittance of branch ij under h electromagnetic radiation; For branch line ground admission; These are the elements of the nodal impedance matrix; Let be the current sensitivity of the k-th electromagnetic radiation source to branch ij; This represents the harmonic current in branch ij at frequency h. This represents the harmonic current generated by the i-th electromagnetic radiation source at frequency k; Based on current sensitivity Constructing the sensitivity matrix ; Construct the overall sensitivity coupling matrix: ； in: This represents the weight of the k-th electromagnetic radiation source at frequency h; Construct a mapping model between harmonic currents and harmonic voltages injected into the power grid system by an electromagnetic radiation source: ； in: This indicates random fluctuation error.

4. The electromagnetic radiation probability analysis method integrating data-driven and kernel density estimation according to claim 3, characterized in that: Step S5 specifically includes: The harmonic voltage amplitude at future time moments is determined based on the harmonic current amplitude at future time moments and the current sensitivity coupling matrix: ； By fitting the harmonic voltage amplitude using a Gaussian kernel function, the radiation probability distribution of each node in the power grid is obtained as follows: ;in, For probability density estimation of harmonic voltage; is the Gaussian kernel function; h is the bandwidth parameter used to control the smoothness of the kernel function; v is the harmonic voltage value point where the probability density needs to be estimated. Represents the set of harmonic voltage amplitudes The i-th sample point in the middle.

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