Method and device for measuring broadband impedance of power distribution network

Abstract

The invention relates to the technical field of electric power, and particularly provides a method and device for measuring broadband impedance of a power distribution network, and the method comprises the steps: obtaining a non-injection type impedance measurement impedance value and an injection type impedance measurement impedance value of the power distribution network; and fusing the non-injection type impedance measurement impedance value and the injection type impedance measurement impedance value to obtain a final impedance measurement value. According to the method, the frequency band integrity and precision of impedance measurement are remarkably improved, the inherent defect of a single method is eliminated, reliable technical support is provided for stable operation and resonance suppression of the power distribution network, and the method is suitable for the application scene of the modern power distribution network containing high-proportion distributed energy.

Description

Technical Field

[0001] This invention relates to the field of power technology, and specifically to a method and apparatus for measuring the wideband impedance of a power distribution network. Background Technology

[0002] With the widespread integration of high proportions of renewable energy, energy storage systems, and various power electronic loads into distribution networks, their structural form and operating characteristics have undergone profound changes. The rapid control response of power electronic devices and their interaction with the power grid have made stability issues such as harmonic resonance and broadband oscillations in distribution networks increasingly prominent. Against this backdrop, broadband impedance characteristics have become a key indicator for analyzing system stability, evaluating the performance of renewable energy grid integration, and locating resonance sources. Accurately obtaining the broadband impedance characteristics of the distribution network is of paramount importance for ensuring the safe, stable, and high-quality operation of the power grid.

[0003] Currently, impedance measurement methods for distribution networks are mainly divided into two categories: non-injection measurement and injection measurement. Non-injection measurement methods utilize inherent disturbance events in the distribution network, such as load switching, as excitation sources. By measuring the voltage and current responses at the point of common coupling, the system impedance is calculated using frequency domain analysis. This method does not require an external excitation device and does not interfere with the operation of the power grid, but it also has limitations: (1) The effective frequency band of impedance measurement depends entirely on the spectral characteristics of natural disturbance events, resulting in a missing frequency band; (2) The signal quality is poor, as the amplitude and frequency of natural disturbance signals are random and uncontrollable, and the signal-to-noise ratio is often low; (3) Measurement requires waiting for specific disturbance events to occur, lacking initiative and making it difficult to meet the needs of real-time or on-demand measurement.

[0004] The injection-based measurement method actively injects a known broadband signal with limited amplitude into the power grid via power electronic devices. Impedance is then calculated using frequency domain analysis by measuring the system's voltage and current responses. This method offers controllable excitation signals, high measurement accuracy, and a continuous frequency band. However, it also has inherent drawbacks: ① Potential interference to the system: Even with a small injected signal amplitude, it can still have unpredictable negative impacts on sensitive loads, relay protection devices, and power quality; ② Model idealization error: The measurement results are based on an idealized injected signal model and linear system assumptions. In practical applications, factors such as the nonlinear characteristics of power electronics, coupling impedance, and background harmonics introduce errors, causing deviations between the measurement results and the actual operating state of the system; ③ Typically requires additional dedicated signal injection equipment, increasing system complexity and implementation costs.

[0005] In summary, existing single measurement techniques all have inherent drawbacks that cannot be overcome: non-injection methods cannot fully grasp the broadband impedance characteristics of the system; while injection methods can grasp broadband characteristics, they may introduce interference to the system and suffer from model distortion. There is a contradiction between the two in terms of bandwidth coverage, measurement accuracy, and impact on the system. Summary of the Invention

[0006] To overcome the above-mentioned defects, this invention proposes a method and device for measuring the wideband impedance of a power distribution network.

[0007] Firstly, a method for measuring the broadband impedance of a distribution network is provided, the method comprising: Obtain the non-injection impedance measurement and injection impedance measurement values ​​of the distribution network; The impedance values ​​of the non-injection impedance measurement and the injection impedance measurement are fused to obtain the final impedance measurement value.

[0008] Preferably, the impedance value of the non-injection impedance measurement is as follows:

[0009] In the above formula, Frequency point Non-injection impedance measurement of impedance values, Frequency point Non-injection impedance measurement voltage value Frequency point Non-injection impedance measurement of current value.

[0010] Preferably, the impedance value of the injection impedance measurement is as follows:

[0011] In the above formula, Frequency point The impedance value is measured by injection impedance measurement. Frequency point The voltage value measured by the injection impedance method. Frequency point The current value is measured by the injection impedance method.

[0012] Preferably, the fusion of the non-injection impedance measurement value and the injection impedance measurement value includes: The non-injection impedance measurement value and the injection impedance measurement value are weighted and fused, and the sum of the weights of the non-injection impedance measurement value and the injection impedance measurement value is 1.

[0013] Furthermore, the final impedance measurement value is as follows:

[0014] In the above formula, This is the final value of the impedance measurement. Frequency point Non-injection impedance measurement of impedance values, Frequency point The impedance value is measured by injection impedance measurement. Frequency point The weighting coefficients.

[0015] Furthermore, the frequency point The process of obtaining the weight coefficients includes: When frequency point The signal-to-noise ratio of non-injected data is higher than the first preset threshold and the frequency point When the signal-to-noise ratio of the injected data is lower than the second preset threshold, the frequency point The weighting coefficient is 1; When frequency point The signal-to-noise ratio of the injected data is higher than the first preset threshold and the frequency point Non-injection data missing or frequency points When the signal-to-noise ratio of non-injected data is lower than the second preset threshold, the frequency point The weighting coefficient is 0; When frequency point Non-injection data signal-to-noise ratio and frequency points When the signal-to-noise ratio of the injected data is higher than the first preset threshold, the initial frequency point The weighting coefficient is 0.5, and for frequency points... The weighting coefficients are dynamically updated.

[0016] Furthermore, the frequency point The signal-to-noise ratio of non-injected data is as follows:

[0017] In the above formula, Frequency point The signal-to-noise ratio of non-injected data, Frequency point Non-injection impedance measurement of impedance values, Frequency point Non-injected impedance measurement noise.

[0018] Furthermore, the frequency point The signal-to-noise ratio of the injected data is as follows:

[0019] In the above formula, Frequency point The signal-to-noise ratio of the injected data, Frequency point The impedance value is measured by injection impedance measurement. Frequency point Noise in the injected impedance measurement.

[0020] Furthermore, the frequency point is determined by the following formula. The weighting coefficients are dynamically updated:

[0021] In the above formula, Frequency point The signal-to-noise ratio of the injected data, Frequency point The signal-to-noise ratio of non-injected data, is the scale factor.

[0022] Secondly, a device for measuring the broadband impedance of a power distribution network is provided, the device comprising: The acquisition module is used to acquire the non-injection impedance measurement impedance value and the injection impedance measurement impedance value of the distribution network. The fusion module is used to fuse the impedance values ​​of the non-injection impedance measurement and the injection impedance measurement to obtain the final impedance measurement value.

[0023] Preferably, the impedance value of the non-injection impedance measurement is as follows:

[0024] In the above formula, Frequency point Non-injection impedance measurement of impedance values, Frequency point Non-injection impedance measurement voltage value Frequency point Non-injection impedance measurement of current value.

[0025] Preferably, the impedance value of the injection impedance measurement is as follows:

[0026] In the above formula, Frequency point The impedance value is measured by injection impedance measurement. Frequency point The voltage value measured by the injection impedance method. Frequency point The current value is measured by the injection impedance method.

[0027] Preferably, the fusion of the non-injection impedance measurement value and the injection impedance measurement value includes: The non-injection impedance measurement value and the injection impedance measurement value are weighted and fused, and the sum of the weights of the non-injection impedance measurement value and the injection impedance measurement value is 1.

[0028] Furthermore, the final impedance measurement value is as follows:

[0029] In the above formula, This is the final value of the impedance measurement. Frequency point Non-injection impedance measurement of impedance values, Frequency point The impedance value is measured by injection impedance measurement. Frequency point The weighting coefficients.

[0030] Furthermore, the frequency point The process of obtaining the weight coefficients includes: When frequency point The signal-to-noise ratio of non-injected data is higher than the first preset threshold and the frequency point When the signal-to-noise ratio of the injected data is lower than the second preset threshold, the frequency point The weighting coefficient is 1; When frequency point The signal-to-noise ratio of the injected data is higher than the first preset threshold and the frequency point Non-injection data missing or frequency points When the signal-to-noise ratio of non-injected data is lower than the second preset threshold, the frequency point The weighting coefficient is 0; When frequency point Non-injection data signal-to-noise ratio and frequency points When the signal-to-noise ratio of the injected data is higher than the first preset threshold, the initial frequency point The weighting coefficient is 0.5, and for frequency points... The weighting coefficients are dynamically updated.

[0031] Furthermore, the frequency point The signal-to-noise ratio of non-injected data is as follows:

[0032] In the above formula, Frequency point The signal-to-noise ratio of non-injected data, Frequency point Non-injection impedance measurement of impedance values, Frequency point Non-injected impedance measurement noise.

[0033] Furthermore, the frequency point The signal-to-noise ratio of the injected data is as follows:

[0034] In the above formula, Frequency point The signal-to-noise ratio of the injected data, Frequency point The impedance value is measured by injection impedance measurement. Frequency point Noise in the injected impedance measurement.

[0035] Furthermore, the frequency point is determined by the following formula. The weighting coefficients are dynamically updated:

[0036] In the above formula, Frequency point The signal-to-noise ratio of the injected data, Frequency point The signal-to-noise ratio of non-injected data, is the scale factor.

[0037] Thirdly, a computer device is provided, comprising: one or more processors; The processor is used to store one or more programs; When the one or more programs are executed by the one or more processors, the method for measuring the wideband impedance of the distribution network is implemented.

[0038] Fourthly, a computer-readable storage device is provided, on which a computer program is stored, wherein when the computer program is executed, the method for measuring the broadband impedance of the power distribution network is implemented.

[0039] The above-described technical solutions of the present invention have at least one or more of the following beneficial effects: This invention relates to the field of power technology, specifically providing a method and apparatus for measuring broadband impedance in distribution networks. The method includes: acquiring non-injected impedance measurement values ​​and injected impedance measurement values ​​of the distribution network; fusing the non-injected and injected impedance measurement values ​​to obtain the final impedance measurement value. This invention utilizes the high signal-to-noise ratio of injected data to effectively supplement the impedance information of non-injected data in the absence of natural disturbance frequency bands, obtaining a more complete broadband impedance characteristic. By utilizing the characteristic that non-injected data originates from real power grid disturbances, the injected measurement results are calibrated, eliminating the errors caused by model idealization in the pure injected method, making the results closer to the actual operating state of the system. The data mutual correction process can adaptively evaluate the quality of the two types of data at different frequency points and output the optimal result. This significantly improves the frequency band integrity and accuracy of impedance measurement, eliminates the inherent defects of single methods, and provides reliable technical support for stable operation and resonance suppression of distribution networks. It is suitable for modern distribution network application scenarios with a high proportion of distributed energy resources. Attached Figure Description

[0040] Figure 1 This is a schematic flowchart of the main steps of the method for measuring the broadband impedance of a distribution network according to an embodiment of the present invention; Figure 2 This is a schematic diagram of data recording according to an embodiment of the present invention; Figure 3 This is a comparison diagram of the injection and non-injection impedance curves of an embodiment of the present invention; Figure 4 This is a fused broadband impedance curve diagram of an embodiment of the present invention. Detailed Implementation

[0041] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0042] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0043] Example 1 See appendix Figure 1 , Figure 1 This is a schematic flowchart illustrating the main steps of a method for measuring the broadband impedance of a distribution network according to an embodiment of the present invention. Figure 1 As shown, the method for measuring the broadband impedance of a distribution network in this embodiment of the invention mainly includes the following steps: Step S101: Obtain the non-injection impedance measurement value and the injection impedance measurement value of the distribution network; Step S102: Combine the non-injection impedance measurement value and the injection impedance measurement value to obtain the final impedance measurement value.

[0044] In this embodiment, the impedance value measured by the non-injection impedance method is as follows:

[0045] In the above formula, Frequency point Non-injection impedance measurement of impedance values, Frequency point Non-injection impedance measurement voltage value, Frequency point Non-injection impedance measurement of current value.

[0046] In this embodiment, the impedance value measured by the injection impedance measurement is as follows:

[0047] In the above formula, Frequency point The impedance value is measured by injection impedance measurement. Frequency point The voltage value measured by the injection impedance method. Frequency point The current value is measured by the injection impedance method.

[0048] Optionally, in one embodiment, fusing the non-injection impedance measurement value and the injection impedance measurement value includes: weighting the non-injection impedance measurement value and the injection impedance measurement value, wherein the sum of the weights of the non-injection impedance measurement value and the injection impedance measurement value is 1.

[0049] In one implementation, the final impedance measurement value is as follows:

[0050] In the above formula, This is the final value of the impedance measurement. Frequency point Non-injection impedance measurement of impedance values, Frequency point The impedance value is measured by injection impedance measurement. Frequency point The weighting coefficients.

[0051] In one implementation, the frequency point The process of obtaining the weight coefficients includes: When frequency point The signal-to-noise ratio of non-injected data is higher than the first preset threshold and the frequency point When the signal-to-noise ratio of the injected data is lower than the second preset threshold, the frequency point The weighting coefficient is 1; When frequency point The signal-to-noise ratio of the injected data is higher than the first preset threshold and the frequency point Non-injection data missing or frequency points When the signal-to-noise ratio of non-injected data is lower than the second preset threshold, the frequency point The weighting coefficient is 0; When frequency point Non-injection data signal-to-noise ratio and frequency points When the signal-to-noise ratio of the injected data is higher than the first preset threshold, the initial frequency point The weighting coefficient is 0.5, and for frequency points... The weighting coefficients are dynamically updated.

[0052] In one implementation, the frequency point The signal-to-noise ratio of non-injected data is as follows:

[0053] In the above formula, Frequency point The signal-to-noise ratio of non-injected data, Frequency point Non-injection impedance measurement of impedance values, Frequency point Non-injected impedance measurement noise.

[0054] In one implementation, the frequency point The signal-to-noise ratio of the injected data is as follows:

[0055] In the above formula, Frequency point The signal-to-noise ratio of the injected data, Frequency point The impedance value is measured by injection impedance measurement. Frequency point Noise in the injected impedance measurement.

[0056] In one implementation, the frequency point is determined by the following formula. The weighting coefficients are dynamically updated:

[0057] In the above formula, Frequency point The signal-to-noise ratio of the injected data, Frequency point The signal-to-noise ratio of non-injected data, is the scale factor.

[0058] In one specific embodiment, to demonstrate the feasibility of the broadband impedance measurement method for distribution networks provided by this invention, a 10kV distribution network with large-scale distributed photovoltaic power generation is used as the application scenario, and the invention is implemented at the point of common coupling (PCC). The system rated voltage is 10kV and the rated frequency is 50Hz. The algorithm detects fluctuations in the output power of the photovoltaic power station and collects the instantaneous values ​​of three-phase voltage and current at the PCC point for a total of 10 cycles and 200ms before and after the event, with a sampling rate of 50kHz. After detecting the above event, a control command triggers an impedance measurement device with a rated capacity of 100kVA to inject a signal with an amplitude of 5A and a bandwidth of 1Hz-2kHz into the grid for a duration of 5 cycles. A synchronous acquisition device records the voltage and current data during the injection period at the same 50kHz sampling rate.

[0059] Data records such as Figure 2 As shown, the left vertical axis represents active power in kW; the right vertical axis represents current amplitude in 10mA; and the horizontal axis represents time in seconds.

[0060] Comparison of impedance curves for injected and non-injected methods, such as... Figure 3 As shown.

[0061] The final broadband impedance curve after fusion is as follows: Figure 4 As shown.

[0062] Example 2 Based on the same inventive concept, the present invention also provides a measuring device for broadband impedance of a distribution network, the measuring device comprising: The acquisition module is used to acquire the non-injection impedance measurement impedance value and the injection impedance measurement impedance value of the distribution network. The fusion module is used to fuse the impedance values ​​of the non-injection impedance measurement and the injection impedance measurement to obtain the final impedance measurement value.

[0063] Preferably, the impedance value of the non-injection impedance measurement is as follows:

[0064] In the above formula, Frequency point Non-injection impedance measurement of impedance values, Frequency point Non-injection impedance measurement voltage value, Frequency point Non-injection impedance measurement of current value.

[0065] Preferably, the impedance value of the injection impedance measurement is as follows:

[0066] In the above formula, Frequency point The impedance value is measured by injection impedance measurement. Frequency point The voltage value measured by the injection impedance method. Frequency point The current value is measured by the injection impedance method.

[0067] Optionally, in one embodiment, fusing the non-injection impedance measurement value and the injection impedance measurement value includes: weighting the non-injection impedance measurement value and the injection impedance measurement value, wherein the sum of the weights of the non-injection impedance measurement value and the injection impedance measurement value is 1.

[0068] Preferably, the final value of the impedance measurement is as follows:

[0069] In the above formula, This is the final value of the impedance measurement. Frequency point Non-injection impedance measurement of impedance values, Frequency point The impedance value is measured by injection impedance measurement. Frequency point The weighting coefficients.

[0070] Furthermore, the frequency point The process of obtaining the weight coefficients includes: When frequency point The signal-to-noise ratio of non-injected data is higher than the first preset threshold and the frequency point When the signal-to-noise ratio of the injected data is lower than the second preset threshold, the frequency point The weighting coefficient is 1; When frequency point The signal-to-noise ratio of the injected data is higher than the first preset threshold and the frequency point Non-injection data missing or frequency points When the signal-to-noise ratio of non-injected data is lower than the second preset threshold, the frequency point The weighting coefficient is 0; When frequency point Non-injection data signal-to-noise ratio and frequency points When the signal-to-noise ratio of the injected data is higher than the first preset threshold, the initial frequency point The weighting coefficient is 0.5, and for frequency points... The weighting coefficients are dynamically updated.

[0071] Furthermore, the frequency point The signal-to-noise ratio of non-injected data is as follows:

[0072] In the above formula, Frequency point The signal-to-noise ratio of non-injected data, Frequency point Non-injection impedance measurement of impedance values, Frequency point Non-injected impedance measurement noise.

[0073] Furthermore, the frequency point The signal-to-noise ratio of the injected data is as follows:

[0074] In the above formula, Frequency point The signal-to-noise ratio of the injected data, Frequency point The impedance value is measured by injection impedance measurement. Frequency point Noise in the injected impedance measurement.

[0075] Furthermore, the frequency point is determined by the following formula. The weighting coefficients are dynamically updated:

[0076] In the above formula, Frequency point The signal-to-noise ratio of the injected data, Frequency point The signal-to-noise ratio of non-injected data, is the scale factor.

[0077] Example 3 Based on the same inventive concept, this invention also provides a computer device, which includes a processor and a memory. The memory stores a computer program, which includes program instructions. The processor executes the program instructions stored in the computer storage medium. The processor may be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. It is the computing and control core of the terminal, and is suitable for implementing one or more instructions. Specifically, it is suitable for loading and executing one or more instructions from the computer storage medium to implement the corresponding method flow or corresponding function, thereby realizing the steps of the method for measuring the broadband impedance of a power distribution network in the above embodiments.

[0078] Example 4 Based on the same inventive concept, this invention also provides a storage medium, specifically a computer-readable storage device (Memory), which is a memory device in a computer device used to store programs and data. It is understood that the computer-readable storage device here can include both the built-in storage medium in the computer device and extended storage media supported by the computer device. The computer-readable storage device provides storage space that stores the terminal's operating system. Furthermore, this storage space also stores one or more instructions suitable for loading and execution by a processor. These instructions can be one or more computer programs (including program code). It should be noted that the computer-readable storage device here can be high-speed RAM or non-volatile memory, such as at least one disk storage device. The processor can load and execute one or more instructions stored in the computer-readable storage device to implement the steps of the method for measuring the broadband impedance of a power distribution network in the above embodiments.

[0079] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0080] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0081] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0082] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0083] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for measuring broadband impedance in a power distribution network, characterized in that, The method includes: Obtain the non-injection impedance measurement and injection impedance measurement values ​​of the distribution network; The impedance values ​​of the non-injection impedance measurement and the injection impedance measurement are fused to obtain the final impedance measurement value.

2. The method as described in claim 1, characterized in that, The impedance value measured by the non-injection impedance method is as follows: In the above formula, Frequency point Non-injection impedance measurement of impedance values, Frequency point Non-injection impedance measurement voltage value, Frequency point Non-injection impedance measurement of current value.

3. The method as described in claim 1, characterized in that, The impedance value measured by the injection impedance method is as follows: In the above formula, Frequency point The impedance value is measured by injection impedance measurement. Frequency point The voltage value measured by the injection impedance method. Frequency point The current value is measured by the injection impedance method.

4. The method as described in claim 1, characterized in that, The fusion of the non-injection impedance measurement value and the injection impedance measurement value includes: The non-injection impedance measurement value and the injection impedance measurement value are weighted and fused, and the sum of the weights of the non-injection impedance measurement value and the injection impedance measurement value is 1.

5. The method as described in claim 4, characterized in that, The final impedance measurement value is as follows: In the above formula, This is the final value of the impedance measurement. Frequency point Non-injection impedance measurement of impedance values, Frequency point The impedance value is measured by injection impedance measurement. Frequency point The weighting coefficients.

6. The method as described in claim 5, characterized in that, The process of obtaining the weighting coefficients for the frequency points includes: When frequency point The signal-to-noise ratio of non-injected data is higher than the first preset threshold and the frequency point When the signal-to-noise ratio of the injected data is lower than the second preset threshold, the frequency point The weighting coefficient is 1; When frequency point The signal-to-noise ratio of the injected data is higher than the first preset threshold and the frequency point Non-injection data missing or frequency points When the signal-to-noise ratio of non-injected data is lower than the second preset threshold, the frequency point The weighting coefficient is 0; When frequency point Non-injection data signal-to-noise ratio and frequency points When the signal-to-noise ratio of the injected data is higher than the first preset threshold, the initial frequency point The weighting coefficient is 0.5, and for frequency points... The weighting coefficients are dynamically updated.

7. The method as described in claim 6, characterized in that, The signal-to-noise ratio of the non-injected data at the specified frequency points is as follows: In the above formula, Frequency point The signal-to-noise ratio of non-injected data, Frequency point Non-injection impedance measurement of impedance values, Frequency point Non-injected impedance measurement noise.

8. The method as described in claim 6, characterized in that, The signal-to-noise ratio of the injected data at the specified frequency points is as follows: In the above formula, Frequency point The signal-to-noise ratio of the injected data, Frequency point The impedance value is measured by injection impedance measurement. Frequency point Noise in the injected impedance measurement.

9. The method as described in claim 6, characterized in that, The weighting coefficients of the frequency points are dynamically updated using the following formula: In the above formula, Frequency point The signal-to-noise ratio of the injected data, Frequency point The signal-to-noise ratio of non-injected data, is the scale factor.

10. A device for measuring the wideband impedance of a power distribution network, characterized in that, The device includes: The acquisition module is used to acquire the non-injection impedance measurement impedance value and the injection impedance measurement impedance value of the distribution network. The fusion module is used to fuse the impedance values ​​of the non-injection impedance measurement and the injection impedance measurement to obtain the final impedance measurement value.

11. The apparatus as claimed in claim 10, characterized in that, The impedance value measured by the non-injection impedance method is as follows: In the above formula, Frequency point Non-injection impedance measurement of impedance values, Frequency point Non-injection impedance measurement voltage value, Frequency point Non-injection impedance measurement of current value.

12. The apparatus as claimed in claim 10, characterized in that, The impedance value measured by the injection impedance method is as follows: In the above formula, Frequency point The impedance value is measured by injection impedance measurement. Frequency point The voltage value measured by the injection impedance method. Frequency point The current value is measured by the injection impedance method.

13. The apparatus as claimed in claim 10, characterized in that, The fusion of the non-injection impedance measurement value and the injection impedance measurement value includes: The non-injection impedance measurement value and the injection impedance measurement value are weighted and fused, and the sum of the weights of the non-injection impedance measurement value and the injection impedance measurement value is 1.

14. The apparatus as claimed in claim 3, characterized in that, The final impedance measurement value is as follows: In the above formula, This is the final value of the impedance measurement. Frequency point Non-injection impedance measurement of impedance values, Frequency point The impedance value is measured by injection impedance measurement. Frequency point The weighting coefficients.

15. The apparatus as claimed in claim 14, characterized in that, The process of obtaining the weighting coefficients for the frequency points includes: When frequency point The signal-to-noise ratio of non-injected data is higher than the first preset threshold and the frequency point When the signal-to-noise ratio of the injected data is lower than the second preset threshold, the frequency point The weighting coefficient is 1; When frequency point The signal-to-noise ratio of the injected data is higher than the first preset threshold and the frequency point Non-injection data missing or frequency points When the signal-to-noise ratio of non-injected data is lower than the second preset threshold, the frequency point The weighting coefficient is 0; When frequency point Non-injection data signal-to-noise ratio and frequency points When the signal-to-noise ratio of the injected data is higher than the first preset threshold, the initial frequency point The weighting coefficient is 0.5, and for frequency points... The weighting coefficients are dynamically updated.

16. The apparatus as claimed in claim 15, characterized in that, The signal-to-noise ratio of the non-injected data at the specified frequency points is as follows: In the above formula, Frequency point The signal-to-noise ratio of non-injected data, Frequency point Non-injection impedance measurement of impedance values, Frequency point Non-injected impedance measurement noise.

17. The apparatus as claimed in claim 14, characterized in that, The signal-to-noise ratio of the injected data at the specified frequency points is as follows: In the above formula, Frequency point The signal-to-noise ratio of the injected data, Frequency point The impedance value is measured by injection impedance measurement. Frequency point Noise in the injected impedance measurement.

18. The apparatus as claimed in claim 14, characterized in that, The weighting coefficients of the frequency points are dynamically updated using the following formula: In the above formula, Frequency point The signal-to-noise ratio of the injected data, Frequency point The signal-to-noise ratio of non-injected data, is the scale factor.

19. A computer device, characterized in that, include: One or more processors; The processor is used to execute one or more programs; When the one or more programs are executed by the one or more processors, the method for measuring the broadband impedance of a distribution network as described in any one of claims 1 to 9 is implemented.

20. A computer-readable storage device, characterized in that, It contains a computer program, which, when executed, implements the method for measuring the broadband impedance of the distribution network as described in any one of claims 1 to 9.

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