Harmonic resonance severity evaluation method and system under uncertain condition of power distribution network

Abstract

The invention provides a harmonic resonance severity evaluation method and system under an uncertain condition of a power distribution network, and belongs to the technical field of harmonic resonance analysis of the power distribution network, and the method comprises the steps: carrying out the frequency scanning of each node of the power distribution network, and obtaining a corresponding harmonic impedance matrix; constructing a harmonic resonance evaluation model by determining a function relationship between a harmonic impedance matrix and a resonant frequency index and a harmonic resonance amplification index; decomposing the variance of the harmonic resonance amplification index into uncertain component combinations; a global sensitivity analysis method is adopted to determine the influence of each uncertain component in the power distribution network on a harmonic resonance amplification index, and then severity evaluation of harmonic resonance under the condition of the uncertain components is obtained. The problem that the propagation mode and the influence area of each frequency resonance cannot be quantified when the harmonic resonance problem of the power distribution system is processed by adopting a modal analysis method in the prior art is solved.

Description

Technical Field

[0001] The present application belongs to the technical field of harmonic resonance analysis of distribution networks, and more specifically, to a method and system for evaluating the severity of harmonic resonance under uncertain conditions of distribution networks. Background Art

[0002] With the extensive use of nonlinear devices in distribution networks, the harmonic and resonance problems in distribution networks are becoming more and more serious. Distribution systems with a large number of nodes, complex component types, and large source-load power fluctuations may have multiple harmonics. Only a small harmonic current source excitation will cause a huge harmonic voltage, causing the harmonic voltage to exceed the limit, affecting the normal operation of the power grid and even destroying equipment. Different resonant frequencies in the system have different propagation modes and influence ranges.

[0003] The problem of harmonic resonance in distribution systems urgently needs further research and control. At present, the main research methods for harmonic resonance in distribution networks are frequency domain analysis and modal analysis. The frequency domain analysis method can obtain the resonant frequency of the system by obtaining the impedance frequency domain information of the system, but cannot obtain more information; the modal analysis method can obtain the information of the resonant frequency and resonance intensity and analyze the observability and excitability of each node through the participation factor, but cannot quantify the propagation mode and affected area of ​​each frequency resonance, and the existing methods have not yet considered the situation of uncertain distribution network parameters. Summary of the invention

[0004] In view of the defects of the prior art, the purpose of this application is to provide a method and system for evaluating the severity of harmonic resonance under uncertain conditions in a distribution network, aiming to solve the problem that when the modal analysis method is currently used to deal with the harmonic resonance problem of the distribution system, the propagation mode and affected area of ​​each frequency resonance cannot be quantified.

[0005] To achieve the above objectives, the present application provides a method for evaluating the severity of harmonic resonance under uncertain conditions of a distribution network, comprising the following steps: Step 1: Perform frequency scanning on each node of the distribution network to obtain the corresponding harmonic impedance matrix; Step 2: Construct a harmonic resonance evaluation model by determining the functional relationship between the harmonic impedance matrix, the resonant frequency index, and the harmonic resonance amplification index; wherein the harmonic resonance amplification index is used to identify the propagation mode and impact range of harmonic resonances of different frequencies; and the resonant frequency index is used to screen out the resonant frequency propagated at each node; Step 3: Based on the resonance frequency index, the propagated resonance frequency at each node is screened out, and the variance of the corresponding harmonic resonance amplification index is decomposed into various uncertain component combinations; Step 4: Input the uncertain components into the harmonic resonance assessment model, and use the global sensitivity analysis method to determine the impact of each uncertain component in the distribution network on the harmonic resonance amplification index, and then obtain the severity assessment of the harmonic resonance under the condition of uncertain components.

[0006] Further preferably, step one specifically includes the following steps: Perform frequency scans on each node of the distribution network to obtain harmonic impedance data; Then, a harmonic impedance matrix is ​​established based on the harmonic impedance data; The harmonic impedance data include: injection frequency, node harmonic voltage phasor, node harmonic current phasor, node mutual impedance value and self-impedance value.

[0007] Further preferably, the harmonic impedance matrix Z The following conditions are met:

[0008] Among them, the harmonic impedance matrix , V j h The frequency is h Node j Harmonic voltage; I j h The frequency is h Node j At harmonic current; when i ≠ j hour, Z ij h The frequency is h Time Node i and nodes j The mutual impedance between i = j hour, Z ij h The frequency is h Time Node j The self-impedance j =1,2…n; n is the total number of nodes in the distribution network.

[0009] Further preferably, the harmonic resonance amplification index is:

[0010] in, ARHV For Node i For Node j The degree of harmonic voltage amplification; V i h andV j h Node j When unit current is injected, the frequency is h Node i and nodes j Harmonic voltage; Z ij h The frequency is h Time Node i and nodes j The mutual impedance between Z jj h The frequency is h hour j When the harmonic resonance amplification index is greater than 1, it indicates that the node i The first h Subharmonic voltage distortion is higher than the harmonic source node j Harmonic voltage distortion at h The propagation direction of subharmonic voltage distortion is from node i Propagate to nodes j When the harmonic resonance amplification index is less than 1, it indicates that the node i The first h Subharmonic voltage distortion is lower than the harmonic source node j Harmonic voltage distortion at.

[0011] Further preferably, the resonant frequency index is the resonant frequency corresponding to when the harmonic resonance amplification index is greater than 1.

[0012] In a second aspect, the present application provides a system for evaluating the severity of harmonic resonance under uncertain conditions of a distribution network, comprising: A matrix construction module is used to perform frequency scanning on each node of the distribution network to obtain the corresponding harmonic impedance matrix; A model building module is used to build a harmonic resonance evaluation model by determining the functional relationship between the harmonic impedance matrix and the resonant frequency index and the harmonic resonance amplification index; wherein the harmonic resonance amplification index is used to identify the propagation mode and impact range of harmonic resonances of different frequencies; and the resonant frequency index is used to screen out the resonant frequency propagated at each node; An uncertain component acquisition module is used to decompose the variance of the harmonic resonance amplification index corresponding to the resonance frequency propagated at each node screened out by the resonance frequency index into an uncertain component combination; The severity assessment module is used to input the uncertain components into the harmonic resonance assessment model, and use the global sensitivity analysis method to determine the impact of each uncertain component in the distribution network on the harmonic resonance amplification index, and then obtain the severity assessment of the harmonic resonance under the condition of uncertain components.

[0013] Further preferably, the matrix construction module comprises: a data acquisition unit and a matrix construction unit; The data acquisition unit is used to perform frequency scanning on each node of the distribution network to obtain harmonic impedance data; The matrix building unit is used to build a harmonic impedance matrix according to the harmonic impedance data; The harmonic impedance data include: injection frequency, node harmonic voltage phasor, node harmonic current phasor, node mutual impedance value and self-impedance value.

[0014] Further preferably, the harmonic impedance matrix in the matrix construction unit Z The following conditions are met:

[0015] Among them, the harmonic impedance matrix , V j h The frequency is h Node j Harmonic voltage; I j h The frequency is h Node j At harmonic current; when i ≠ j hour, Z ij h The frequency is h Time Node i and nodes j The mutual impedance between i = j hour, Z ij h The frequency is h Time Node j The self-impedance j =1,2…n; n is the total number of nodes in the distribution network.

[0016] Further preferably, the harmonic resonance amplification index in the model building module is:

[0017] in, ARHV For Node i For Node j The degree of harmonic voltage amplification; V i h and V j hNode j When unit current is injected, the frequency is h Node i and nodes j Harmonic voltage; Z ij h The frequency is h Time Node i and nodes j The mutual impedance between Z jj h The frequency is h hour j When the harmonic resonance amplification index is greater than 1, it indicates that the node i The first h Subharmonic voltage distortion is higher than the harmonic source node j Harmonic voltage distortion at h The propagation direction of subharmonic voltage distortion is from node i Propagate to nodes j When the harmonic resonance amplification index is less than 1, it indicates that the node i The first h Subharmonic voltage distortion is lower than the harmonic source node j Harmonic voltage distortion at.

[0018] Further preferably, the resonant frequency index in the model building module is the resonant frequency corresponding to when the harmonic resonance amplification index is greater than 1.

[0019] In a third aspect, the present application provides an electronic device comprising: at least one memory for storing programs; and at least one processor for executing the programs stored in the memory. When the program stored in the memory is executed, the processor is used to execute the method described in the first aspect or any possible implementation of the first aspect.

[0020] In a fourth aspect, the present application provides a computer-readable storage medium, which stores a computer program. When the computer program runs on a processor, the processor executes the method described in the first aspect or any possible implementation of the first aspect.

[0021] In a fifth aspect, the present application provides a computer program product. When the computer program product runs on a processor, the processor executes the method described in the first aspect or any possible implementation of the first aspect.

[0022] It can be understood that the beneficial effects of the second to fifth aspects mentioned above can be found in the relevant description of the first aspect mentioned above, and will not be repeated here.

[0023] In general, the above technical solutions conceived by this application have the following beneficial effects compared with the prior art: The present application provides a method for evaluating the severity of harmonic resonance under uncertain conditions of a distribution network, wherein a resonant frequency index and a harmonic resonance amplification index are defined, and the propagation mode and impact range of harmonic resonances of different frequencies can be identified through the harmonic resonance amplification index, and a functional relationship is established between the harmonic impedance matrix and the above two indicators, and the severity of harmonic resonance under uncertain component conditions can be evaluated by analyzing the corresponding harmonic resonance amplification index through the input of uncertain components. This solves the problem that the propagation mode and impact area of ​​each frequency resonance cannot be quantified when the modal analysis method is used to deal with the harmonic resonance problem of the distribution system. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a flow chart of a method for evaluating the severity of harmonic resonance under uncertain conditions of a distribution network provided in an embodiment of the present application; Figure 2 This is a circuit diagram of an industrial power distribution system provided in an embodiment of the present application; Figure 3 is an equivalent circuit diagram of a power distribution system provided in an embodiment of the present application; Figure 4 is the harmonic resonance amplification index of the harmonic source located at node 6 provided in the embodiment of the present application; Figure 5 This is a sensitivity analysis result diagram of the 12.8pu node 5 harmonic resonance amplification index provided in an embodiment of the present application. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0026] In the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0027] In the description of the embodiments of the present application, unless otherwise specified, “plurality” means two or more than two.

[0028] The technical solutions provided in the embodiments of the present application are introduced.

[0029] Example 1 like Figure 1 As shown, the present application provides a method for evaluating the severity of harmonic resonance under uncertain conditions of a distribution network, which specifically includes the following steps: Step S1: Perform frequency scanning on each node of the distribution network to obtain the corresponding harmonic impedance matrix; The harmonic impedance data of the distribution network is obtained through frequency scanning; the harmonic impedance data includes: injection frequency, node harmonic voltage phasor, node harmonic current phasor, node mutual impedance value and self-impedance value; according to the harmonic impedance data, the system harmonic impedance matrix is ​​established Z :

[0030] in, V j h ( j =1,2…,n) is the frequency h Node j Harmonic voltage; I j h ( j =1,2…n) is the frequency h Node j Harmonic current; Z ij h ( i ≠ j ) is the frequency h Time Node i and nodes j The mutual impedance between Z ij h ( i = j ) is the frequency h Time Node j The self-impedance of the distribution network; n is the total number of nodes in the distribution network; Step S2: obtaining a functional relationship between the harmonic impedance matrix and the resonant frequency index and the harmonic resonance amplification index as a harmonic resonance evaluation model, wherein the harmonic resonance amplification index is used to identify the propagation mode and influence range of harmonic resonances of different frequencies; and the resonant frequency index is used to screen the harmonic resonance frequency; The harmonic resonance amplification index can be determined by the following formula:

[0031] in, ARHV For Node i For Node j The degree of harmonic voltage amplification; V i h andV j h Node j When unit current is injected, the frequency is h Node i and nodes j Harmonic voltage; Z ij h The frequency is h Time Node i and nodes j The mutual impedance between Z jj h The frequency is h hour j The self-impedance between.

[0032] Furthermore, ARHV Benchmarking:

[0033] in, ARIH For Node i For Node j The frequency is h The harmonic voltage amplification ratio, V i h and V j h Node j When unit current is injected, the frequency is h Node i and nodes j Harmonic voltage; V i 1 and V j 1 Node i and nodes j At the fundamental voltage.

[0034] when ARHV When greater than 1, it means at node (node) i The first h Subharmonic voltage distortion is higher than the harmonic source node j The harmonic voltage distortion at h The propagation direction of subharmonic voltage distortion is from node i Propagate to nodes j at ARHV When it is less than 1, at the node i The first h Subharmonic voltage distortion is lower than the harmonic source nodej Harmonic voltage distortion at the node i From Node j No propagation loop is formed; ARHV The frequency greater than 1 is h The node set of can determine the influence range of harmonic resonance. Therefore, the harmonic resonance index indicates the influence range and propagation path of harmonic resonance. The resonant frequency index is ARHV When greater than 1 h value; in practical applications, according to ARHV The meaning of greater than 1 is that each node can be directly considered later. ARHV When greater than 1 h value, no need to consider the ARHV Less than 1 h value; the resonant frequency propagated at each node can be screened out according to the resonant frequency index, and the calculation of the harmonic resonance amplification index at the resonant frequency that cannot be propagated at each node is omitted, which can greatly improve the calculation efficiency of the harmonic resonance evaluation model; Step S3: using a global sensitivity analysis method to determine the impact of each uncertain component of the distribution network on the harmonic resonance amplification index; The Scobol sensitivity analysis algorithm is used. This algorithm is a variance-based sensitivity analysis method. It decomposes the variance of the harmonic resonance amplification index into a combination of a single parameter and a multi-parameter sub-function. The variance of a single parameter or multiple input parameters in the harmonic resonance evaluation model is used to quantify the influence of the parameters and the interaction between the parameters. The sensitivity calculation results characterize the influence of the components on the resonance under uncertain system parameters. Specifically, the calculation process is as follows:

[0035]

[0036] in, is the mathematical expectation function, is the mathematical variance function, is a variable, is the input variable, To remove variables Then the vector formed by all the remaining variables is For the The first-order response index corresponding to the sample data is: For the The total response index corresponding to the sample data.

[0037] In a non-limiting preferred embodiment, the harmonic resonance amplification index under a certain resonant frequency index of the distribution network is used as the output variable, and the harmonic impedance matrix under a certain resonant frequency index is used as the input variable. The Scobol sensitivity analysis method is used to calculate the first-order response index and the total response index corresponding to each sample data as the influence degree of the resonance of the distribution network. The first-order response index The larger the value, the single input variable The more significant the effect on modal impedance, the greater the overall response index. The larger the variable The greater the degree of interaction with other variables, the greater the impact on the modal impedance.

[0038] The method provided by this application is further described below: Figure 2 is the actual circuit diagram of the power distribution system. Figure 3 is the equivalent circuit diagram of the power distribution system, from Figure 4 It can be seen that the harmonic resonance amplification index of the power distribution system harmonic source is located at node 6, and the main resonance frequencies are around 3.6pu and 12.8pu; in this embodiment, the nodes are each bus; Figure 5 This is the result of the sensitivity analysis of the harmonic resonance amplification index of the 12.8pu node 5. For the resonance with a resonance frequency of 12.8pu, the key component is the equivalent reactance of the power grid. X g and capacitive load C p2 .

[0039] Example 2 The present application provides a harmonic resonance severity assessment system under uncertain conditions of a distribution network, comprising: A matrix construction module is used to perform frequency scanning on each node of the distribution network to obtain the corresponding harmonic impedance matrix; A model building module is used to build a harmonic resonance evaluation model by determining the functional relationship between the harmonic impedance matrix and the resonant frequency index and the harmonic resonance amplification index; wherein the harmonic resonance amplification index is used to identify the propagation mode and impact range of harmonic resonances of different frequencies; and the resonant frequency index is used to screen out the resonant frequency propagated at each node; An uncertain component acquisition module is used to decompose the variance of the harmonic resonance amplification index corresponding to the resonance frequency propagated at each node screened out by the resonance frequency index into an uncertain component combination; The severity assessment module is used to input the uncertain components into the harmonic resonance assessment model, and use the global sensitivity analysis method to determine the impact of each uncertain component in the distribution network on the harmonic resonance amplification index, and then obtain the severity assessment of the harmonic resonance under the condition of uncertain components.

[0040] Further preferably, the matrix construction module comprises: a data acquisition unit and a matrix construction unit; The data acquisition unit is used to perform frequency scanning on each node of the distribution network to obtain harmonic impedance data; The matrix building unit is used to build a harmonic impedance matrix according to the harmonic impedance data; The harmonic impedance data include: injection frequency, node harmonic voltage phasor, node harmonic current phasor, node mutual impedance value and self-impedance value.

[0041] Further preferably, the harmonic impedance matrix in the matrix construction unit Z The following conditions are met:

[0042] Among them, the harmonic impedance matrix , V j h The frequency is h Node j Harmonic voltage; I j h The frequency is h Node j At harmonic current; when i ≠ j hour, Z ij h The frequency is h Time Node i and nodes j The mutual impedance between i = j hour, Z ij h The frequency is h Time Node j The self-impedance j =1,2…n; n is the total number of nodes in the distribution network.

[0043] Further preferably, the harmonic resonance amplification index in the model building module is:

[0044] in, ARHV For Node i For Node j The degree of harmonic voltage amplification; V i h and V j h Node jWhen unit current is injected, the frequency is h Node i and nodes j Harmonic voltage; Z ij h The frequency is h Time Node i and nodes j The mutual impedance between Z jj h The frequency is h hour j When the harmonic resonance amplification index is greater than 1, it indicates that the node i The first h Subharmonic voltage distortion is higher than the harmonic source node j Harmonic voltage distortion at h The propagation direction of subharmonic voltage distortion is from node i Propagate to nodes j When the harmonic resonance amplification index is less than 1, it indicates that the node i The first h Subharmonic voltage distortion is lower than the harmonic source node j Harmonic voltage distortion at.

[0045] Further preferably, the resonant frequency index in the model building module is the resonant frequency corresponding to when the harmonic resonance amplification index is greater than 1.

[0046] It should be understood that the above-mentioned system is used to execute the methods in the above-mentioned embodiments. The implementation principles and technical effects of the corresponding program modules in the system are similar to those described in the above-mentioned methods. The working process of the system can refer to the corresponding process in the above-mentioned method and will not be repeated here.

[0047] Based on the method in the above embodiment, an embodiment of the present application provides an electronic device. The device may include: at least one memory for storing programs and at least one processor for executing the programs stored in the memory. When the program stored in the memory is executed, the processor is used to execute the method described in the above embodiment.

[0048] Based on the method in the above embodiment, an embodiment of the present application provides a computer-readable storage medium, which stores a computer program. When the computer program runs on a processor, the processor executes the method in the above embodiment.

[0049] Based on the method in the above embodiment, an embodiment of the present application provides a computer program product. When the computer program product runs on a processor, the processor executes the method in the above embodiment.

[0050] It is understood that the processor in the embodiments of the present application may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application specific integrated circuits (ASIC), field programmable gate arrays (FPGA) or other programmable logic devices, transistor logic devices, hardware components or any combination thereof. The general-purpose processor may be a microprocessor or any conventional processor.

[0051] The method steps in the embodiments of the present application can be implemented by hardware or by a processor executing software instructions. The software instructions can be composed of corresponding software modules, and the software modules can be stored in random access memory (RAM), flash memory, read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), registers, hard disks, mobile hard disks, CD-ROMs, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor so that the processor can read information from the storage medium and write information to the storage medium. Of course, the storage medium can also be a component of the processor. The processor and the storage medium can be located in an ASIC.

[0052] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium or transmitted through the computer-readable storage medium. The computer instructions may be transmitted from a website site, computer, server or data center to another website site, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium may be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more available media integrated. The available medium may be a magnetic medium (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid state disk (SSD)), etc.

[0053] It should be understood that the various numerical numbers involved in the embodiments of the present application are only used for the convenience of description and are not used to limit the scope of the embodiments of the present application.

[0054] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A method for evaluating the severity of harmonic resonance under uncertain conditions of a distribution network, characterized in that: The following steps are involved: Step 1: Perform frequency scanning on each node of the distribution network to obtain the corresponding harmonic impedance matrix; Step 2: Construct a harmonic resonance evaluation model by determining the functional relationship between the harmonic impedance matrix, the resonant frequency index, and the harmonic resonance amplification index; wherein the harmonic resonance amplification index is used to identify the propagation mode and impact range of harmonic resonances of different frequencies; and the resonant frequency index is used to screen out the resonant frequency propagated at each node; Step 3: Based on the resonance frequency index, the propagated resonance frequency at each node is screened out, and the variance of the corresponding harmonic resonance amplification index is decomposed into a combination of uncertain components; Step 4: Input the uncertain components into the harmonic resonance assessment model, and use the global sensitivity analysis method to determine the impact of each uncertain component in the distribution network on the harmonic resonance amplification index, and then obtain the severity assessment of the harmonic resonance under the condition of uncertain components.

2. The harmonic resonance severity assessment method according to claim 1, characterized in that: Step 1 specifically includes the following steps: Perform frequency scans on each node of the distribution network to obtain harmonic impedance data; Then, a harmonic impedance matrix is ​​established based on the harmonic impedance data; The harmonic impedance data include: injection frequency, node harmonic voltage phasor, node harmonic current phasor, node mutual impedance value and self-impedance value.

3. The harmonic resonance severity assessment method according to claim 2, characterized in that: Harmonic Impedance Matrix Z The following conditions are met: Among them, the harmonic impedance matrix , V j h The frequency is h Node j Harmonic voltage; I j h The frequency is h Node j At harmonic current; when i ≠ j hour, Z ij h The frequency is h Time Node i and nodes j The mutual impedance between i = j hour, Z ij h The frequency is h Time Node j The self-impedance j =1,2…n; n is the total number of nodes in the distribution network.

4. The harmonic resonance severity assessment method according to claim 1 or 3, characterized in that: The harmonic resonance amplification index is: in, ARHV For Node i For Node j The degree of harmonic voltage amplification; V i h and V j h Node j When unit current is injected, the frequency is h Node i and nodes j Harmonic voltage; Z ij h The frequency is h Time Node i and nodes j The mutual impedance between Z jj h The frequency is h hour j When the harmonic resonance amplification index is greater than 1, it indicates that the node i The first h Subharmonic voltage distortion is higher than the harmonic source node j Harmonic voltage distortion at h The propagation direction of subharmonic voltage distortion is from node i Propagate to nodes j When the harmonic resonance amplification index is less than 1, it indicates that the node i The first h Subharmonic voltage distortion is lower than the harmonic source node j Harmonic voltage distortion at.

5. The harmonic resonance severity assessment method according to claim 4, characterized in that: The resonant frequency index is the resonant frequency corresponding to when the harmonic resonance amplification index is greater than 1.

6. A harmonic resonance severity assessment system under uncertain conditions of distribution network, characterized in that: include: A matrix construction module is used to perform frequency scanning on each node of the distribution network to obtain the corresponding harmonic impedance matrix; A model building module is used to build a harmonic resonance evaluation model by determining the functional relationship between the harmonic impedance matrix and the resonant frequency index and the harmonic resonance amplification index; wherein the harmonic resonance amplification index is used to identify the propagation mode and impact range of harmonic resonances of different frequencies; and the resonant frequency index is used to screen out the resonant frequency propagated at each node; An uncertain component acquisition module is used to decompose the variance of the harmonic resonance amplification index corresponding to the resonance frequency propagated at each node screened out by the resonance frequency index into an uncertain component combination; The severity assessment module is used to input the uncertain components into the harmonic resonance assessment model, and use the global sensitivity analysis method to determine the impact of each uncertain component in the distribution network on the harmonic resonance amplification index, and then obtain the severity assessment of the harmonic resonance under the condition of uncertain components.

7. The harmonic resonance severity assessment system according to claim 6, characterized in that: The matrix construction module includes: a data acquisition unit and a matrix construction unit; The data acquisition unit is used to perform frequency scanning on each node of the distribution network to obtain harmonic impedance data; The matrix building unit is used to build a harmonic impedance matrix according to the harmonic impedance data; The harmonic impedance data include: injection frequency, node harmonic voltage phasor, node harmonic current phasor, node mutual impedance value and self-impedance value.

8. The harmonic resonance severity assessment system according to claim 7, characterized in that: Harmonic impedance matrix in matrix building unit Z The following conditions are met:. Among them, the harmonic impedance matrix , V j h The frequency is h Node j Harmonic voltage; I j h The frequency is h Node j At harmonic current; when i ≠ j hour, Z ij h The frequency is h Time Node i and nodes j The mutual impedance between i = j hour, Z ij h The frequency is h Time Node j The self-impedance j =1,2…n; n is the total number of nodes in the distribution network.

9. The harmonic resonance severity assessment system according to claim 6 or 8, characterized in that: The harmonic resonance amplification index in the model building module is: in, ARHV For Node i For Node j The degree of harmonic voltage amplification; V i h and V j h Node j When unit current is injected, the frequency is h Node i and nodes j Harmonic voltage; Z ij h The frequency is h Time Node i and nodes j The mutual impedance between Z jj h The frequency is h hour j When the harmonic resonance amplification index is greater than 1, it indicates that the node i The first h Subharmonic voltage distortion is higher than the harmonic source node j Harmonic voltage distortion at h The propagation direction of subharmonic voltage distortion is from node i Propagate to nodes j When the harmonic resonance amplification index is less than 1, it indicates that the node i The first h Subharmonic voltage distortion is lower than the harmonic source node j Harmonic voltage distortion at.

10. The harmonic resonance severity assessment system according to claim 9, characterized in that: The resonant frequency index in the model building module is the resonant frequency corresponding to when the harmonic resonance amplification index is greater than 1.

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