Distributed harmonic measuring device

Abstract

The utility model relates to the technical field of power grid harmonic measurement, in particular to a distributed harmonic measurement device, which comprises a plurality of measurement sensors, a harmonic measurement device, a local supervision host and a cloud server, the measurement sensors send collected signals to the cloud server through wireless signals, the local supervision host is connected with the cloud server through a local area network, and harmonic measurement data calculated by the cloud server is supplemented to a database of the local supervision host. The local supervision host supplements, verifies and corrects the data processed by the harmonic measurement device. According to the utility model, the accuracy and reliability of harmonic measurement can be improved by comparing and verifying the cloud computing result and the direct connection measurement result, and meanwhile, the cloud server can also realize the storage, management and remote access of data, thereby facilitating the query, monitoring and maintenance of the data.

Description

Technical Field

[0001] The utility model relates to the technical field of power grid harmonic measurement, in particular to a distributed harmonic measurement device. Background Art

[0002] A harmonic measurement device is a device used to detect harmonics in a power system. In a power system, nonlinear loads (such as electronic devices, frequency converters, etc.) will generate harmonics, which may cause instability of the power system and damage to equipment. Through the harmonic measurement device, power system operators can monitor the harmonic level and evaluate its impact on the system.

[0003] Existing distributed harmonic measurement devices (such as Figure 1 shown) include a frequency conversion device 5, a sensor 6, a harmonic measurement device 1, a local supervision host 2, and a background supervision host 7. Each sensor 6 is connected to a frequency conversion device 5. The harmonic measurement device 1 is communicatively connected to multiple sensors 6. The harmonic measurement device 1 transmits the measured data to the local supervision host 2, and the local supervision host 2 is connected to the background supervision host 7 through a local area network.

[0004] However, existing distributed harmonic measurement devices usually require a large number of sensors and data acquisition devices, involving the coordination and communication of multiple devices and nodes. Factors such as device location, communication network, and power supply need to be considered. The deployment and maintenance processes are relatively cumbersome, which will lead to data transmission delays and excessive data processing burdens, affecting real-time monitoring and response capabilities. Moreover, after the harmonic measurement device transmits the measurement results to the local supervision host, the local supervision host cannot compare and verify the measurement results, resulting in the problem of reduced accuracy and reliability of harmonic measurement. Content of the Utility Model

[0005] In view of this, the purpose of the present utility model is to provide a distributed harmonic measurement device to solve the problem that the existing harmonic measurement device cannot compare and verify the measurement results after harmonic measurement, resulting in reduced accuracy and reliability of harmonic measurement.

[0006] Based on the above purpose, the present utility model provides a distributed harmonic measurement device, including multiple measurement sensors, a harmonic measurement device, and a local supervision host. Each measurement sensor is connected to a frequency conversion device. The measurement sensor is used to collect data from the frequency conversion device and transmit the collected data to the harmonic measurement device. The harmonic measurement device transmits the received data to the local supervision host, and it also includes a cloud server.

[0007] The measurement sensor sends the collected signals to the cloud server via wireless signals, and the local supervision host is connected to the cloud server through a local area network. The harmonic measurement data calculated by the cloud server will be supplemented into the database of the local supervision host, and the local supervision host supplements, verifies, and corrects the data processed by the harmonic measurement device.

[0008] Preferably, the measurement sensor includes a data acquisition unit and a signal processing unit. The data acquisition unit is used to collect data information of the frequency conversion equipment for harmonic and spectrum analysis, and transmits the collected data information to the signal processing unit. The signal processing unit amplifies, filters, and converts the analog-to-digital of the original signal into a digital signal, and sends the processed data to the harmonic measurement device.

[0009] Preferably, the harmonic measurement device transmits the measured data to the local supervision host through a 4G or 5G module.

[0010] Preferably, the cloud server includes a data storage unit and a data operation unit. The data operation unit is used to preprocess the original data collected by the data acquisition unit, and the data storage unit is used to store the processed data.

[0011] Preferably, the local supervision host analyzes the harmonic measurement data and the supplemented cloud data using the DFT algorithm, and its basic algorithm formula is as follows:

[0012] [X(k)=\sum_{n=0}^{N-1}x(n)\cdote^{-i2\pi\frac{kn}{N}}]

[0013] Among them, given a discrete-time domain signal sequence (x(n)) of length (N), (n = 0, 1, 2,... N - 1) represents the sampling points of the signal, and the DFT converts this signal into a discrete frequency domain signal sequence (X(k)), where (k = 0, 1, 2,..., N - 1) represents the discrete values of the frequency.

[0014] Preferably, among them: (X(k)) is the complex representation in the frequency domain, containing the amplitude and phase information of the signal at frequency (k);

[0015] (x(n)) is the value of the time-domain signal at the sampling point (n):

[0016] (e^{-i2\pi\frac{kn}{N}}) is the rotation factor, used to represent components of different frequencies in the frequency domain.

[0017] The beneficial effects of the present utility model are as follows:

[0018] 1. By adding a cloud server for data processing and discrete Fourier transform (DFT) analysis, cloud computing resources and computing power can be fully utilized. The harmonic measurement data calculated by the cloud server will be supplemented to the local supervision host, used to supplement and verify the directly connected harmonic measurement data. By comparing and verifying the cloud computing results with the directly connected measurement results, the accuracy and reliability of harmonic measurement can be improved. At the same time, the cloud server can also achieve data storage, management, and remote access, facilitating data query, monitoring, and maintenance work.

[0019] 2. Since some data processing and analysis tasks are completed in the cloud, the deployment and maintenance processes of on-site devices can be simplified, reducing the burden on the communication network and the data transmission delay. There is no need to configure complex data processing devices at each monitoring point, reducing the complexity of deployment and maintenance, as well as costs and maintenance difficulties. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0021] Figure 1 It is a schematic diagram of the existing distributed harmonic measurement of the present invention;

[0022] Figure 2 It is a schematic structural diagram of the present invention.

[0023] In the figure: 1. Harmonic measurement device; 2. Local supervision host; 3. Measurement sensor; 4. Cloud server; 5. Frequency conversion device; 6. Sensor; 7. Back-end supervision host. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] To make the purpose, technical solutions, and advantages of the present invention clearer and more understandable, the following will further elaborate on the present invention in detail with reference to specific embodiments and the accompanying drawings.

[0025] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present utility model should have the ordinary meanings understood by those with ordinary skills in the field to which the present utility model belongs. The "first", "second" and similar words used in the present utility model do not denote any order, quantity or importance, but are only used to distinguish different components. Words such as "including" or "comprising" mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connected" or "coupled" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Upper", "lower", "left", "right", etc. are only used to represent relative position relationships. When the absolute position of the object being described changes, the relative position relationship may also change accordingly.

[0026] As Figure 2 shown, a distributed harmonic measurement device includes multiple measurement sensors 3, a harmonic measurement device 1, and a local supervision host 2. Each measurement sensor 3 is connected to a frequency conversion device. The measurement sensor 3 is used to collect data from the frequency conversion device and transmit the collected data to the harmonic measurement device 1. The harmonic measurement device 1 transmits the received data to the local supervision host 2. Moreover, the measurement sensor 3 is internally provided with a wireless signal transmitter, a microcontroller unit MCU, and a data converter. The output end of the data converter is electrically connected to the wireless signal transmitter for transceiver unit communication. It also includes a cloud server 4;

[0027] The measurement sensor 3 transmits the collected signal to the cloud server 4 wirelessly. And the local supervision host 2 is connected to the cloud server 4 through a local area network. The harmonic measurement data calculated by the cloud server 4 will be supplemented to the database of the local supervision host 2. The local supervision host 2 supplements, verifies, and corrects the data processed by the harmonic measurement device 1.

[0028] In a preferred embodiment of the present utility model, the measurement sensor 3 includes a data acquisition unit and a signal processing unit. The data acquisition unit is used to collect data information of the frequency conversion device for harmonic and spectrum analysis, and transmit the collected data information to the signal processing unit. The signal processing unit amplifies, filters, and converts the analog-to-digital of the original signal into a digital signal, and transmits the processed data to the harmonic measurement device 1. The data acquisition unit, signal processing unit, wireless signal transmitter, microcontroller unit MCU, and data converter inside the measurement sensor 3 are all conventional units in the prior art.

[0029] Verify the accuracy of the cloud processing results by comparing them with existing standards or reference data and perform necessary corrections, which may include comparing with test data of known devices or comparing with the results of other harmonic measurement devices.

[0030] In another preferred embodiment of the present utility model, the harmonic measurement device 1 transmits the measured data to the local supervision host 2 through a 4G or 5G module.

[0031] In still another preferred embodiment of the present utility model, the cloud server 4 includes a data storage unit and a data operation unit. The data operation unit is used to preprocess the raw data collected by the data acquisition unit, and the data storage unit is used to store the processed data.

[0032] On the cloud server, preprocess the raw data collected from the sensors, which may include steps such as noise removal, filtering, compensation, etc. to ensure accuracy and reliability. The deployment of the cloud server enables users to access and manage the data remotely without on-site operation, greatly simplifying the process of system maintenance and management.

[0033] It should be noted that the local supervision host 2 uses the DFT algorithm to analyze the harmonic measurement data and the supplemented cloud data. The basic algorithm formula is as follows:

[0034] [X(k)=\sum_{n=0}^{N - 1}x(n)\cdote^{-i2\pi\frac{kn}{N}}]

[0035] Wherein, given a discrete-time domain signal sequence (x(n)) of length (N), (n = 0, 1, 2,... N - 1) represents the sampling points of the signal. The DFT converts this signal into a discrete frequency domain signal sequence (X(k)), where (k = 0, 1, 2,..., N - 1) represents the discrete values of the frequency.

[0036] Where: (X(k)) is the complex representation in the frequency domain, containing the amplitude and phase information of the signal at frequency (k);

[0037] (x(n)) is the value of the time-domain signal at the sampling point (n):

[0038] (e^{-i2\pi\frac{kn}{N}}) is the rotation factor, used to represent different frequency components in the frequency domain.

[0039] Applying the discrete Fourier transform (DFT) algorithm to the preprocessed data for frequency-domain analysis can convert the time-domain signal (x(n)) into a frequency-domain signal (X(k)), obtain the energy distribution of the signal at different frequencies, and by analyzing (X(k)), the main frequency components in the signal, i.e., harmonic components, can be identified, and their amplitudes and phases can be calculated.

[0040] In the frequency domain, by analyzing the results of the DFT, the main frequency components in the signal, i.e., harmonic components, can be identified. According to the characteristics of the harmonics, such as frequency, amplitude, and phase information, the harmonics can be detected and identified.

[0041] The harmonic measurement data calculated by the cloud server, including information such as harmonic frequency, amplitude, and phase, will be supplemented to the local supervision host for supplementing, perfecting, and verifying the directly connected harmonic measurement data. By comparing and verifying the cloud computing results with the directly connected measurement results, the accuracy and reliability of harmonic measurement can be improved.

[0042] And since some data processing and analysis tasks are completed in the cloud, the deployment and maintenance processes of on-site devices can be simplified, the burden on the communication network can be reduced, the data transmission delay can be decreased, complex data processing devices do not need to be configured at each monitoring point, the cumbersome degree of deployment and maintenance is reduced, and the cost and maintenance difficulty are lowered.

[0043] Those of ordinary skill in the art should understand that the discussion of any of the above embodiments is only exemplary and is not intended to imply that the scope of the present invention is limited to these examples; under the concept of the present invention, the technical features in the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations in different aspects of the present invention as described above, which are not provided in detail for the sake of brevity.

[0044] The embodiments of the present invention are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A distributed harmonic measurement device, comprising a plurality of measurement sensors (3), a harmonic measurement device (1), and a local supervision host (2). Each measurement sensor (3) is connected to a frequency conversion device. The measurement sensor (3) is used to collect data from the frequency conversion device and transmit the collected data to the harmonic measurement device (1). The harmonic measurement device (1) transmits the received data to the local supervision host (2), characterized in that, It further includes a cloud server (4); The measurement sensor (3) sends the collected signals to the cloud server (4) via wireless signals, and the local supervision host (2) is connected to the cloud server (4) through a local area network. The harmonic measurement data calculated by the cloud server (4) will be supplemented into the database of the local supervision host (2), and the local supervision host (2) supplements, verifies, and corrects the data processed by the harmonic measurement device (1).

2. The distributed harmonic measurement device according to claim 1, characterized in that, The measurement sensor (3) includes a data acquisition unit and a signal processing unit. The data acquisition unit is used to collect the data information of the frequency conversion equipment for harmonic and spectrum analysis, and transmits the collected data information to the signal processing unit. The signal processing unit amplifies, filters, and converts the analog-to-digital of the original signal into a digital signal, and sends the processed data to the harmonic measurement device (1).

3. The distributed harmonic measurement device according to claim 2, wherein The harmonic measurement device (1) transmits the measured data to the local supervision host (2) through a 4G or 5G module.

4. A distributed harmonic measurement device according to claim 2, characterized in that, The cloud server (4) includes a data storage unit and a data operation unit. The data operation unit is used to preprocess the original data collected by the data acquisition unit, and the data storage unit is used to store the processed data.

5. The distributed harmonic measurement device according to claim 4, characterized in that, The local supervision host (2) analyzes the harmonic measurement data and the supplemented cloud data using the DFT algorithm. The basic algorithm formula is as follows: [X(k)=\sum_{n=0}^{N-1}x(n)\cdote^{-i2\pi\frac{kn}{N}}] Among them, given a discrete-time domain signal sequence (x(n)) of length (N), (n = 0, 1, 2,... N - 1) represents the sampling points of the signal. The DFT converts this signal into a discrete frequency domain signal sequence (X(k)), where (k = 0, 1, 2,..., N - 1) represents the discrete values of the frequency.

6. A distributed harmonic measurement device according to claim 5, characterized in that Where: (X(k)) is the complex representation in the frequency domain, containing the amplitude and phase information of the signal at frequency (k); (x(n)) is the value of the time-domain signal at the sampling point (n): (e^{-i2\pi\frac{kn}{N}}) is the rotation factor, used to represent different frequency components in the frequency domain.

Images