A recording method based on high-precision time synchronization mechanism of power line carrier

Abstract

The present invention discloses a recording method based on a high-precision time synchronization mechanism of a power line carrier, comprising a high-precision clock synchronization mechanism, a network-wide broadcast agreed synchronous recording, starting voltage and current recording based on an agreed synchronous recording timestamp, calculating the characteristics of the recorded data, and determining whether the recorded data has compression characteristics. The present invention is a low-voltage power grid dynamic electric energy recording method based on a carrier high-precision clock synchronization mechanism, which is independent of GPS-type clock synchronization technology and avoids the problem of clock synchronization failure in underground and underground distribution rooms due to the absence of satellite signals. At the same time, it can also make dynamic compression strategies based on the characteristics of the recorded data to avoid a large amount of redundant data occupying the line bandwidth. It can be effectively applied to the power quality analysis of low-voltage power grids, has a good online monitoring effect of power quality when in use, and realizes the value-added application of recorded big data, with good application prospects.

Description

Technical Field

[0001] The present invention relates to the technical field of low-voltage electric energy monitoring, and in particular to a wave recording method based on a high-precision time synchronization mechanism of a power line carrier. Background Art

[0002] Voltage, current, frequency, harmonics, and other data are crucial monitoring indicators for low-voltage distribution networks. Traditional metering devices can only monitor effective values, lacking the ability to monitor transient or sudden changes in power lines and unable to analyze the synchronous transient characteristics of the power grid. Power quality monitoring devices, which rely on GPS-based clock synchronization technology, have monitoring blind spots in locations like underground distribution rooms and those without satellite signals. With the advent of a new era of "dual carbon," improving grid power monitoring and building a new-generation power metering system are particularly pressing. Summary of the Invention

[0003] The technical problem to be solved by the present invention is a recording method based on a high-precision time synchronization mechanism of a power line carrier. It is independent of GPS-type clock synchronization technology, avoiding the problem of monitoring blind spots when there is no satellite signal in scenes such as underground and underground distribution rooms. The value-added application based on recording big data can be effectively applied to the power quality analysis of low-voltage power grids, and to various power branch fields such as topology analysis, impedance analysis, and line loss analysis, and has good application prospects.

[0004] The present invention is implemented by the following technical solution: a recording method based on a high-precision time synchronization mechanism of a power line carrier, specifically comprising the following steps:

[0005] S1. Start power line carrier high-precision clock synchronization, establish a high-precision clock network through power line carrier clock synchronization technology, determine whether the clock is synchronized, and execute the next step;

[0006] S2, based on the high-precision clock network established in S1, broadcasts the agreed recording time to the entire network and executes the next step;

[0007] S3. When the recording time agreed in S2 is reached, the electric energy data recording is started immediately and the next step is executed;

[0008] S4, calculate the data characteristics of the recorded electric energy data, compare the data characteristics of S4 to see whether they reach the compressibility threshold, if the conditions are met, execute S5, if not, execute S6;

[0009] S5, compress the recorded data and mark the compression algorithm and compression parameters in the data structure, and jump to S6;

[0010] S6. Store the recorded data and wait for data recall.

[0011] As a preferred technical solution, the power line carrier clock synchronization method in S1 is:

[0012] When sending data values, the carrier transmitter embeds a high-precision timestamp into the data frame. When the receiver captures the first sampling point of the carrier synchronization data frame, it synchronizes the local time with the timestamp. Based on the maximum power supply radius of 500 meters in a typical low-voltage substation, the propagation delay of electromagnetic waves in copper wires is about several microseconds. Therefore, the clock accuracy of the high-precision clock network established by this method is at the level of tens of microseconds.

[0013] As a preferred technical solution, the method for broadcasting the agreed recording time to the entire network in S2 is:

[0014] The "agreed recording time" is added to the application data frame. The time unit is the timestamp of the high-precision clock network in S1.

[0015] As a preferred technical solution, S4 specifically includes:

[0016] Perform FFT fast Fourier transform on the recorded data and perform frequency domain analysis on the recorded data. If the total harmonic distortion exceeds the threshold, it is determined that the frequency domain compressibility is poor and no compression processing is performed; if the total harmonic distortion is less than the set threshold, it is determined that the data can be losslessly compressed in the frequency domain.

[0017] As a preferred technical solution, the range of the threshold value set in S4 is 10% to 30%.

[0018] As the preferred technical solution, the compression algorithm in S5 is a frequency domain lossless compression algorithm. It uses FFT to perform frequency transformation on the data, retains only the Nth harmonic, performs IFFT and compares it with the original data to generate a patch; then a dynamic optional compression algorithm is used to compress the harmonic and patch data.

[0019] As a preferred technical solution, the range of the Nth harmonic is set to 10 to 30 in S4, and the dynamically selectable algorithms are LZMA, LZ4, and ZSTD.

[0020] The beneficial effects of the present invention are as follows: the low-voltage power grid dynamic electric energy recording method based on the power line carrier high-precision time synchronization mechanism described in the present invention is independent of GPS-type clock synchronization technology. Compared with the existing technology, on the one hand, it avoids the problem of monitoring blind spots when there is no satellite signal in scenes such as underground and underground distribution rooms; on the other hand, through the frequency domain lossless compression algorithm, under normal circumstances, it can achieve twice the effect of time domain compression, saving a large amount of bandwidth resources, improving the feasibility of the dynamic electric energy recording method, and can be effectively applied to multiple power branches such as power quality analysis of low-voltage power grids, and has good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0022] Figure 1 The present invention is a flow chart of a method for recording dynamic electric energy in a low-voltage power grid based on a high-precision time synchronization mechanism of a power line carrier. DETAILED DESCRIPTION

[0023] All features disclosed in this specification, or all steps in the disclosed methods or processes, except mutually exclusive features and / or steps, can be combined in any manner.

[0024] Any feature disclosed in this specification (including any appended claims, abstract and drawings), unless otherwise stated, may be replaced by other equivalent or similar features. That is, unless otherwise stated, each feature is only an example of a series of equivalent or similar features.

[0025] In the description of the present invention, it should be understood that the terms "one end", "the other end", "outside", "upper", "inside", "horizontal", "coaxial", "center", "end", "length", "outer end" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they should not be understood as limiting the present invention.

[0026] In addition, in the description of the present invention, “a plurality of” means at least two, for example, two, three, etc., unless otherwise clearly and specifically defined.

[0027] Terms such as "upper", "above", "lower", and "below" used in this invention to indicate spatial relative positions are for the purpose of convenience to describe the relationship of one unit or feature relative to another unit or feature as shown in the accompanying drawings. Terms of spatial relative position may be intended to encompass different orientations of the device in use or operation in addition to the orientation shown in the drawings. For example, if the device in the drawings is turned over, units described as being "below" or "beneath" other units or features will be "above" the other units or features. Thus, the exemplary term "below" may encompass both the above and below orientations. The device may be oriented in other ways (rotated 90 degrees or in other orientations) and the spatially relative descriptive terms used herein interpreted accordingly.

[0028] In the present invention, unless otherwise expressly specified or limited, terms such as "disposed," "socketed," "connected," "through," and "inserted" should be understood in a broad sense. For example, they may refer to fixed or detachable connections, or integration; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components or interaction between two components, unless otherwise expressly specified or limited. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0029] like Figure 1 As shown, a recording method based on a high-precision time synchronization mechanism of a power line carrier of the present invention comprises the following steps:

[0030] S1. Start power line carrier high-precision clock synchronization, establish a high-precision clock network through power line carrier clock synchronization technology, determine whether the clock is synchronized, and execute S2;

[0031] S2, based on the high-precision clock network established in S1, broadcasts the agreed recording time to the entire network and executes S3;

[0032] S3. When the recording time agreed in S2 is reached, the electric energy data recording is immediately started and S4 is executed;

[0033] S4, calculate the data characteristics of the recorded electric energy data, compare the data characteristics of S4 to see whether they reach the compressibility threshold, if the conditions are met, execute S5, if not, execute S6;

[0034] S5, compress the recorded data and mark the compression algorithm and compression parameters in the data structure, and jump to S6;

[0035] S6, storing the recorded data and waiting for data call;

[0036] In this embodiment, the power line carrier clock synchronization method in S1 is as follows: the carrier transmitter embeds a high-precision timestamp in the data frame when transmitting data values. The receiver synchronizes its local time with the timestamp upon capturing the first sampling point of the carrier synchronization data frame. Based on the maximum power supply radius of 500 meters in a typical low-voltage substation, the propagation delay of electromagnetic waves in copper wires is approximately several microseconds. Therefore, the high-precision clock network established by this method has a clock accuracy of tens of microseconds.

[0037] In this embodiment, the method for broadcasting the agreed recording time to the entire network in S2 is: adding "agreed recording time" to the application data frame, and the time unit is the timestamp of the high-precision clock network in S1.

[0038] In this embodiment, S4 specifically includes performing a fast Fourier transform (FFT) on the recorded data and performing frequency domain analysis on the recorded data. If the total harmonic distortion (THD) exceeds a threshold, the data is determined to be poorly compressible in the frequency domain and no compression is performed. If the THD is less than a set threshold, the data is determined to be suitable for lossless frequency domain compression.

[0039] In this embodiment, the range of the threshold value set in S4 is 10% to 30%.

[0040] In this embodiment, the compression algorithm described in S5 is a frequency domain lossless compression algorithm. The data is frequency-transformed using FFT, retaining only the Nth harmonics, and then subjected to IFFT and compared with the original data to generate a patch. A dynamically selectable compression algorithm is then used to compress the harmonics and patch data.

[0041] In this embodiment, the range of setting the Nth harmonic in S4 is 10 to 30; the dynamically selectable algorithms are LZMA, LZ4, and ZSTD.

[0042] The beneficial effects of the present invention are as follows: Compared with the prior art, the present invention's low-voltage power grid dynamic electric energy recording method based on the carrier high-precision clock synchronization mechanism is not only independent of GPS-type clock synchronization technology, avoiding the problem of clock synchronization failure in underground and underground distribution rooms due to the lack of satellite signals; it can also implement dynamic compression strategies based on the characteristics of the recorded data to avoid large amounts of redundant data occupying the line bandwidth. Deepening applications based on recorded data can be effectively applied to power quality analysis of low-voltage power grids, and can be applied to various power branch fields such as topology analysis, impedance analysis, and line loss analysis. When used, it has good online power quality monitoring effects, realizes value-added applications of recorded big data, and has good application prospects.

[0043] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that are not conceived through creative work should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection defined in the claims.

Claims

1. A recording method based on a high-precision time synchronization mechanism of a power line carrier, characterized in that: Specifically, it includes the following steps: S1. Start the power line carrier high-precision clock synchronization, establish a high-precision clock network through the power line carrier clock synchronization technology, determine whether the clock is synchronized, and execute the next step; S2. According to the high-precision clock network established by S1, broadcast the agreed recording time to the entire network, and execute the next step; S3. When the recording time agreed in S2 is reached, start the electric energy data recording immediately, and execute the next step; S4. Calculate the data characteristics of the recorded electric energy data, compare whether the data characteristics of S4 reach the compressible threshold, if the conditions are met, execute S5, if the conditions are not met, execute S6; S5, compress the recorded data and mark the compression algorithm and compression parameters in the data structure, and jump to S6; S6, store the recorded data and wait for data call; The power line carrier clock synchronization method in S1 is as follows: The carrier transmitter embeds a high-precision timestamp in the data frame while sending the data value. The receiver synchronizes the local time with the timestamp while capturing the first sampling point of the carrier synchronization data frame. Based on the maximum power supply radius of 500 meters in a typical low-voltage substation, the propagation delay of electromagnetic waves in copper wires is several microseconds. Therefore, the clock accuracy of the high-precision clock network established by this method is at the level of tens of microseconds. The method for broadcasting the agreed recording time to the entire network in S2 is: Add "agreed recording time" to the application data frame, and the time unit is the timestamp of the high-precision clock network in S1; S4 specifically includes: performing FFT fast Fourier transform on the recorded data, performing frequency domain analysis on the recorded data, and if the total harmonic distortion exceeds a threshold, it is determined that the frequency domain compressibility is poor and no compression processing is performed; if the total harmonic distortion is less than a set threshold, it is determined that the data can be losslessly compressed in the frequency domain; The threshold value set in S4 ranges from 10% to 30%; The compression algorithm in S5 is a frequency-domain lossless compression algorithm, which uses FFT to perform frequency transformation on the data, retains only the Nth harmonic, performs IFFT, and compares it with the original data to generate a patch; then a dynamically selectable compression algorithm is used to compress the harmonics and patch data; in S4, the range of the Nth harmonic is set to 10 to 30, and the dynamically selectable algorithms are LZMA, LZ4, and ZSTD.

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