A waveform recording method for a fault indicator

Abstract

The present invention relates to a waveform recording method for a fault indicator, belonging to the technical field of signal waveform recording, and solves the problems of large storage space occupied by existing waveform recording and low transmission efficiency. The method includes: a three-phase acquisition unit in the fault indicator acquires the current and electric field of an overhead line, and when the waveform recording start condition is satisfied, it notifies the aggregation unit in the fault indicator; the aggregation unit issues a synchronization command, and after receiving the synchronization response from the three-phase acquisition unit, broadcasts the synchronization waveform recording start timestamp; the three-phase acquisition unit respectively extracts multiple cycle waveform data according to the waveform recording start timestamp, performs ultra-wide compression on each cycle waveform data, and constructs corresponding compression indication information to send to the aggregation unit; the aggregation unit performs decompression according to the compression indication information, and further obtains a complete waveform file according to the restored three-phase waveform data. High-efficiency compression and transmission of waveform recording are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of signal recording, and in particular to a recording method for a fault indicator. Background Art

[0002] At present, the power system distribution network overhead line has an increasing demand for transient recording fault indicator transmission data. More sampled data can present higher frequency transient characteristics, which has a deeper meaning for fault analysis and provides the possibility for successfully analyzing higher impedance grounding faults. As the standards for recording fault indicators are gradually improved, the size of waveform files has gradually doubled, and the amount of data is getting larger and larger. More and more attention is paid to how to improve the efficiency of lossless compression to meet the requirements of storage and transmission under the premise of unchanged transmission rate and reliability.

[0003] Due to the periodic change characteristics of the fault waveform and the continuous and relatively slow change characteristics of the sine wave, the waveform data is usually compressed during the recording process using the adjacent cycle mutation difference and single cycle adjacent point difference algorithms.

[0004] However, the difference of adjacent cycle mutations has high compression efficiency for waveforms with stable load signals and no obvious periodic changes; for example, when high-order harmonics are carried but the harmonics are relatively stable. The difference of adjacent points of a single cycle has high compression efficiency for waveforms with small amplitudes and no obvious mutations; for example, when the line load is small, there are many glitches but the amplitude is not large. However, the actual field recorded waveform is affected by different loads and has various distortions without obvious rules. For example, fixed bit width allocation leads to bit width redundancy of high-frequency small-amplitude differences, and the waveform changes under capacitive loads have the situation of gradual shift of the neutral point. The transient part of the actual ground fault mostly shows the characteristic of gradual frequency attenuation. The above-mentioned similar scenarios greatly reduce the compression efficiency of the existing algorithm, and still require a large amount of storage space. At the same time, the transmission time is long, which increases the delay time of data processing and affects the timely response and processing of the master station to the fault. Summary of the invention

[0005] In view of the above analysis, an embodiment of the present invention aims to provide a method for recording a fault indicator, so as to solve the problem that the existing recording method occupies a large storage space and has low transmission efficiency.

[0006] An embodiment of the present invention provides a method for recording a fault indicator, comprising the following steps:

[0007] The three-phase acquisition unit in the fault indicator collects the current and electric field of the overhead line, and notifies the collection unit in the fault indicator when the recording start condition is met;

[0008] The collection unit sends a synchronization command, and after receiving the synchronization response from the three-phase acquisition unit, it broadcasts the synchronization recording start timestamp;

[0009] The three-phase acquisition unit extracts multiple cycle waveform data respectively according to the recording start timestamp, performs super-bit width compression on each cycle waveform data, constructs corresponding compression indication information and sends it to the collection unit;

[0010] The collection unit decompresses the data according to the compression indication information, and then obtains a complete waveform file according to the restored three-phase waveform data.

[0011] Based on the further improvement of the above method, each cycle waveform data is compressed with ultra-bit width, including:

[0012] Obtain the differential array corresponding to each cycle waveform data according to the differential type, and determine the normal bit width and the maximum bit width according to the differential array;

[0013] Compressing the differential array according to the normal bit width and the super bit width identifier to obtain a normal bit width compression sequence;

[0014] The differential values ​​exceeding the normal bit width in the differential array are compressed according to the maximum bit width to obtain an ultra-bit width compressed sequence.

[0015] Based on further improvement of the above method, the compression indication information includes: differential type, normal bit width, maximum bit width, extra bit width points, normal bit width compression sequence and extra bit width compression sequence; the normal bit width compression sequence is spliced ​​with the extra bit width compression sequence to obtain cyclic waveform compression data.

[0016] Based on a further improvement of the above method, the over-bit width flag is to set each bit to 1 according to the normal bit width.

[0017] Based on the further improvement of the above method, the difference array is compressed according to the normal bit width and the super bit width mark to obtain the normal bit width compression sequence, which is in the order of the difference values ​​in the difference array. If the absolute value of the difference value is less than or equal to , For normal bit width, the differential value is superimposed Then, the unsigned bit is binary-encoded according to the normal bit width. Otherwise, the differential value is binary-encoded using the extra bit width flag.

[0018] Based on the further improvement of the above method, the difference values ​​in the difference array that exceed the conventional bit width are compressed according to the maximum bit width to obtain the super bit width compression sequence, which is to compress the difference values ​​in the difference array whose absolute values ​​are greater than The differential value is encoded in binary format according to the maximum bit width and the highest bit is the sign bit; Normal bit width.

[0019] Based on the further improvement of the above method, determining the normal bit width and the maximum bit width according to the differential array includes:

[0020] Based on the highest bit being the sign bit, calculate the bit width and proportion of each difference value in the difference array, where the largest bit width is the maximum bit width;

[0021] Sort the proportions of non-maximum bit widths from large to small. If the proportion of the first non-maximum bit width exceeds 50%, the bit width is the regular bit width; otherwise, take the bit widths corresponding to the first two proportions as the bit widths to be determined, calculate the lengths of the frequency waveform compressed data after super-bit width compression, and take the bit width to be determined corresponding to the smallest length as the regular bit width.

[0022] Based on the further improvement of the above method, the first cycle waveform data is obtained by calculating the data difference of adjacent sampling points in the cycle to obtain a differential array, and the differential type is the difference between adjacent sampling points in the cycle.

[0023] Based on the further improvement of the above method, the waveform data of non-first cycle are obtained by calculating the data difference of adjacent sampling points within the cycle and the data difference of adjacent cycle interval sampling points to obtain two differential arrays, and the length of the cycle waveform compressed data after the two differential arrays are compressed by super-bit width is calculated respectively, and the compression indication information is constructed according to the differential array corresponding to the minimum length.

[0024] Based on a further improvement of the above method, the aggregation unit decompresses according to the compression indication information, including:

[0025] According to the conventional bit width , take each binary code from the regular bit width compression sequence in turn, if the binary code is not an extra bit width mark, convert the binary code to a decimal value and subtract , get the actual differential value; otherwise, take out the corresponding binary code from the super-bit width compression sequence according to the maximum bit width and convert it into a decimal value to get the actual differential value;

[0026] Based on the length of each cycle waveform data, each cycle waveform data is restored according to the difference type and the actual difference value.

[0027] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0028] 1. Optimize the compression method during the fault indicator recording process and construct the optimal compressed indication information. The conventional compression sequence is represented by the super-bit width mark and the unsigned bit width, and the real differential sequence is represented by the maximum bit width differential value. This improves the compression efficiency and reduces the memory usage, thereby shortening the transmission time, reducing the communication interference and current consumption, and improving the stability and reliability of the fault indicator.

[0029] 2. Support multiple ways of calculating differences, and determine the compression bit width through the majority bit width in combination with the actual bit width, and adaptively select the method with the highest compression efficiency, which improves the flexibility and adaptability of compression and improves the performance of the fault indicator.

[0030] In the present invention, the above-mentioned technical solutions can also be combined with each other to achieve more preferred combination solutions. Other features and advantages of the present invention will be described in the subsequent description, and some advantages can become obvious from the description, or can be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained through the contents particularly pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings are only used for the purpose of illustrating specific embodiments and are not to be considered as limiting the present invention. In the entire drawings, the same reference symbols represent the same components;

[0032] Figure 1 The present invention is a flowchart of a method for recording a fault indicator in an embodiment of the present invention. DETAILED DESCRIPTION

[0033] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0034] A specific embodiment of the present invention discloses a method for recording a fault indicator. Figure 1 As shown, the following steps are included:

[0035] S1. The three-phase acquisition unit in the fault indicator collects the current and electric field of the overhead line, and when the recording start condition is met, it notifies the collection unit in the fault indicator;

[0036] S2, the collection unit sends a synchronization command, and after receiving the synchronization response from the three-phase acquisition unit, broadcasts the synchronous recording start timestamp;

[0037] S3, the three-phase acquisition unit extracts multiple cycle waveform data respectively according to the recording start timestamp, performs super-bit width compression on each cycle waveform data, constructs corresponding compression indication information and sends it to the collection unit;

[0038] S4. The collection unit decompresses according to the compression instruction information, and then obtains a complete waveform file according to the restored three-phase waveform data.

[0039] During implementation, multiple fault indicators are installed on the overhead lines of the power distribution network for locating faults of the overhead lines of the power distribution network. For example, the fault indicators are high-precision transient waveform recording type fault indicators.

[0040] The fault indicator consists of a three-phase collection unit and a collection unit, wherein the three-phase collection units are respectively suspended on the ABC three-phase lines to collect the current and electric field of the overhead lines; the collection unit obtains the respective waveforms from the three-phase collection units; the collection unit is connected to the three-phase collection unit wirelessly. For example, the three-phase collection unit uses a 433MHz wireless module to exchange data with the collection unit.

[0041] Specifically, in step S1, the three-phase acquisition unit acquires the current and electric field of the overhead line, identifies whether the recording start condition is met, and if any phase acquisition unit or multiple phase acquisition units identify that the recording start condition is met, the wireless module notifies the collection module. Among them, meeting the recording start condition includes: the absolute value of the current change exceeds the current change threshold, or the absolute value of the field strength change exceeds the field strength change threshold. Exemplarily, the current change threshold is 150A, and the field strength change threshold is 10%.

[0042] Furthermore, since the synchronization error of the three-phase waveform must be within the set error range, otherwise it cannot reflect the actual waveform at the same time, and the generated fault waveform is meaningless. Therefore, in step S2, the collection unit sends a synchronization command to the three-phase acquisition unit, and the three-phase acquisition unit feeds back a synchronization response after receiving the synchronization command. When the collection unit receives the synchronization response from the three-phase acquisition unit, the collection unit uses the wireless module to send a broadcast to synchronize the recording start timestamp.

[0043] Exemplarily, the three-phase acquisition unit of the zero-sequence voltage-started high-precision transient waveform recording fault indicator has a GNSS timing device, and the time synchronization error range is in the microsecond level.

[0044] Furthermore, in step S3, the acquisition unit of each phase reads 12 cycles before and after the recording start timestamp from the current and electric field channels respectively, usually 4 cycles before the start timestamp and 8 cycles after the start timestamp. The sampling rate is 12.8KHz, and each cycle waveform data contains 256 sampling points. The data obtained after analog-to-digital conversion of each sampling point is between 0 and 4095.

[0045] Each cycle waveform data is taken as an independent data unit and is subjected to super-bit width compression to obtain corresponding compression indication information.

[0046] It should be noted that the compression indication information includes: differential type, normal bit width, maximum bit width, extra bit width points, normal bit width compression sequence and extra bit width compression sequence.

[0047] Perform ultra-wide compression on each cycle waveform data, including:

[0048] ①According to the differential type, obtain the differential array corresponding to each cycle waveform data, and determine the normal bit width and maximum bit width according to the differential array.

[0049] It should be noted that the difference types include: adjacent sampling point differences within a cycle and adjacent cycle interval differences. Among them, the adjacent sampling point differences within a cycle are to calculate the data difference of adjacent sampling points within a single cycle, that is, the data of the current sampling point is subtracted from the data of the previous sampling point, as the difference value of the current sampling point. At this time, the first difference value in each cycle is the data of the first sampling point itself; the adjacent cycle interval difference is to calculate the data difference of adjacent cycle interval sampling points starting from the second cycle, that is, starting from the second cycle, the data of each sampling point in the current cycle is subtracted from the data of the corresponding sampling point in the previous cycle, and the difference value of each sampling point in the current cycle is obtained.

[0050] In this embodiment, for the first cycle waveform data, only the difference between adjacent sampling points in the cycle is selected as the difference type; for the non-first cycle waveform data, the above two difference types are respectively used to obtain two difference arrays.

[0051] Further, determining the normal bit width and the maximum bit width according to the differential array includes:

[0052] It should be noted that when the bit width is L and the highest bit is the sign bit, the data range based on the original code (that is, without considering the complement code) is: . For example, when the bit width is 3, the data range is [-3, 3]; that is, if the difference value is in the range of [-3, 3], the bit width is 3. After calculating the bit width of each difference value in the difference array, the proportion of each bit width is obtained. The largest bit width is taken as the maximum bit width in the difference indication information.

[0053] Since there are 256 differential values ​​in the differential array corresponding to each cycle waveform data, there may be multiple different bit widths except the maximum bit width. In the prior art, the maximum bit width is usually selected to compress the differential value, which will cause bit width waste and reduce the overall compression efficiency. Therefore, this embodiment sorts the proportion of non-maximum bit widths from large to small. If the proportion of the first non-maximum bit width exceeds 50%, the bit width is the regular bit width; otherwise, the bit widths corresponding to the first two proportions are taken as the bit widths to be determined, and the lengths of the cycle waveform compressed data after super-bit width compression are calculated respectively, and the bit width to be determined corresponding to the minimum length is taken as the regular bit width.

[0054] Exemplarily, if the differential values ​​in the differential array are: 1, -2, 10, 3, -3; the bit widths of each differential value are: 2, 3, 5, 3, 3. Then the maximum bit width is 5, the regular bit width is 3, and only the bit width of 10 exceeds the regular bit width, then the number of excess bit width points is 1. If the differential values ​​in the differential array are: 1, -2, 3, -1, 10; the bit widths of each differential value are: 2, 3, 3, 2, 5. Then the maximum bit width is 5, and the bit widths to be determined are 2 and 3. Subsequent compression operations need to be further performed to calculate the lengths of the corresponding cyclic waveform compression data, respectively, take the bit width to be determined corresponding to the minimum length as the regular bit width, and construct compression indication information.

[0055] ② Compress the differential array according to the regular bit width and super bit width identifier to obtain a regular bit width compression sequence.

[0056] It should be noted that the extra bit width flag is to set each bit to 1 according to the normal bit width, and has no specific numerical meaning. For example, when the normal bit width is 3, the extra bit width flag is 111; when the normal bit width is 4, the extra bit width flag is 1111.

[0057] Furthermore, the difference array is compressed according to the normal bit width and the super bit width flag to obtain a normal bit width compression sequence, which is in the order of the difference values ​​in the difference array. If the absolute value of the difference value is less than or equal to , For normal bit width, the differential value is superimposed Then, the unsigned bit is binary-encoded according to the normal bit width. Otherwise, the differential value is binary-encoded using the extra bit width flag.

[0058] It should be noted that the difference values ​​in the difference array have positive and negative data. Therefore, when calculating the bit width of the actual difference value in the previous step, it is considered that the highest bit is the sign bit. When the highest bit is 1, it indicates a negative number, and when it is 0, it indicates a positive number. So when the bit width is L, it can represent data, but it includes ±0, so only For example, when the bit width is 3, 100 represents -0 instead of 4, and can represent 7 valid data: -3, -2, -1, 0, 1, 2, 3. Therefore, in order to realize the super-bit width identification and not change the differential value range represented by the same bit width during compression, this embodiment does not use the representation method in which the highest bit is the sign bit.

[0059] Specifically, the absolute value of the difference is less than or equal to This means that the bit width of the differential value is less than or equal to the normal bit width. In this case, the differential value is superimposed That is, the difference value is converted to a non-negative number, and then the unsigned bit is encoded in binary according to the normal bit width. Otherwise, the absolute value of the difference value is greater than This means that the bit width of the differential value is greater than the normal bit width. The number of these differential values ​​is the number of extra-bit-width points, which are encoded in binary using the extra-bit-width identifier.

[0060] For example, the actual differential values ​​in the differential array are: 1, -2, 10, 3, -3, the maximum bit width is 5, and the normal bit width is 3; the actual differential values ​​1, -2, 3, -3 less than or equal to the normal bit width are superimposed with 3 to convert to: 4, 1, 6, 0 and then encoded to: 100, 001, 110, 000; the actual differential value 10 greater than the normal bit width is encoded as 111 using the super bit width identifier; finally, the normal bit width compression sequence obtained according to the order of the differential values ​​in the differential array is: 100, 001, 111, 110, 000. The length of the normal bit width compression sequence is obtained by multiplying the number of differential values ​​in the differential array by the normal bit width.

[0061] ③ Compress the differential values ​​in the differential array that exceed the normal bit width according to the maximum bit width to obtain an ultra-bit width compressed sequence.

[0062] Since the differential values ​​of the extra bit width are only marked with extra bit width marks in the conventional compression sequence, the real differential values ​​need to be saved through the extra bit width compression sequence. The difference value is encoded in binary format according to the maximum bit width and the highest bit is the sign bit; The length of the super-bit width compression sequence is obtained by multiplying the number of super-bit width points by the super-bit width.

[0063] The 10 in the above example is recorded in the super-bit width compressed sequence as: 01010, where the highest bit represents the sign bit.

[0064] Furthermore, the conventional bit width compression sequence is spliced ​​with the super bit width compression sequence to obtain the cyclic waveform compression data; and the length of the cyclic waveform compression data is obtained according to the length of the conventional bit width compression sequence and the length of the super bit width compression sequence.

[0065] In the above example, the bit widths of the differential values ​​in the differential arrays 1, -2, 3, -1, 10 are 2, 3, 3, 2, 5 respectively; the maximum bit width is 5, and the bit widths to be set are 2 and 3. When 2 is used as the normal bit width, the number of super-bit width points is 3, and the cycle waveform compression data is: 10, 11, 11, 00, 11, 10010, 00011, 01010; the length of the cycle waveform compression data is: 5×2+3×5=25; when 3 is used as the normal bit width, the number of super-bit width points is 1, and the cycle waveform compression data is: 100, 001, 110, 010, 111, 01010; the length of the cycle waveform compression data is: 5×3+1×5=20; therefore, the compression efficiency is higher when the differential array is compressed according to the normal bit width of 3 and the maximum bit width of 5.

[0066] Actually, there are 256 differential values ​​in the differential array of each cycle waveform data. If the maximum bit width is 10, the data length after compression according to the existing method is 256×10=2560; according to this embodiment, if the regular bit width is 5 and the number of super bit width points is 56, the length of the cycle waveform compressed data is: 256×5+56×10=1840, the occupied space is reduced by 28%, and the compression efficiency is higher.

[0067] It should be noted that two types of differentials are used to obtain differential arrays for waveform data other than the first cycle, that is, two differential arrays are obtained by calculating the data differences between adjacent sampling points within a cycle and the data differences between adjacent cycle interval sampling points, and super-bit-width compression is performed separately according to the above method. The lengths of the cycle waveform compressed data after super-bit-width compression of the two differential arrays are calculated separately, and compression indication information is constructed according to the differential array corresponding to the minimum length.

[0068] After the compression indication information corresponding to each cycle waveform data is constructed in step S3, it is sent to the collection unit via wireless.

[0069] In step S4, the aggregation unit performs decompression according to the compression indication information, including:

[0070] According to the conventional bit width , take each binary code from the regular bit width compression sequence in turn, if the binary code is not an extra bit width mark, convert the binary code to a decimal value and subtract , get the actual differential value; otherwise, take out the corresponding binary code from the super-bit width compression sequence according to the maximum bit width and convert it into a decimal value to get the actual differential value;

[0071] Based on the length of each cycle waveform data, each cycle waveform data is restored according to the difference type and the actual difference value.

[0072] Furthermore, the collection unit splices the restored waveform data of each cycle by phase and channel to obtain the waveform data of the three-phase current channel and the waveform data of the electric field channel. Then, the waveform data of the three-phase current channel is synthesized into zero-sequence current; the waveform data of the three-phase electric field channel is synthesized into equivalent zero-sequence voltage by electric field normalization, and finally integrated into a complete 8-channel waveform file.

[0073] Furthermore, the collection unit saves the waveform file. That is, the waveform analysis algorithm can be used to screen the non-grounding false start waveform, and the normal start waveform can be short-circuited and grounded to draw a conclusion. It can also wait for the background master station to call the waveform file of the specified time period, and the background master station will conduct a comprehensive judgment.

[0074] Compared with the prior art, the recording method of a fault indicator provided in this embodiment optimizes the compression method during the recording process, constructs the optimal compression indication information, uses the super-width mark and unsigned bit width to represent the conventional compression sequence, and uses the maximum bit width difference value to represent the real difference sequence, thereby improving the compression efficiency, reducing the memory usage, thereby shortening the transmission time, reducing communication interference and current consumption, and improving the stability and reliability of the fault indicator. It supports multiple ways of calculating differences, and determines the compression bit width through the majority bit width in combination with the actual bit width, and adaptively selects the method with the highest compression efficiency, thereby improving the flexibility and adaptability of compression and improving the performance of the fault indicator.

[0075] Those skilled in the art will appreciate that all or part of the processes of the above-mentioned embodiments can be implemented by instructing related hardware through a computer program, and the program can be stored in a computer-readable storage medium, wherein the computer-readable storage medium is a disk, an optical disk, a read-only storage memory, or a random access memory, etc.

[0076] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for recording a fault indicator, characterized in that: The following steps are involved: The three-phase acquisition unit in the fault indicator collects the current and electric field of the overhead line, and notifies the collection unit in the fault indicator when the recording start condition is met; The collection unit issues a synchronization command, and after receiving a synchronization response from the three-phase acquisition unit, broadcasts a synchronization recording start timestamp; The three-phase acquisition unit extracts a plurality of cycle waveform data respectively according to the recording start timestamp, performs super-bit width compression on each cycle waveform data, constructs corresponding compression indication information and sends it to the collection unit; The collection unit decompresses according to the compression indication information, and then obtains a complete waveform file according to the restored three-phase waveform data; The super-bit-width compression of each cycle waveform data comprises: obtaining a differential array corresponding to each cycle waveform data according to a differential type, and determining a normal bit width and a maximum bit width according to the differential array; compressing the differential array according to the normal bit width and the super-bit-width identifier to obtain a normal bit-width compression sequence; and compressing the differential values ​​exceeding the normal bit width in the differential array according to the maximum bit width to obtain an super-bit-width compression sequence; The compression indication information includes: difference type, normal bit width, maximum bit width, number of extra bit width points, normal bit width compression sequence and extra bit width compression sequence; the normal bit width compression sequence is spliced ​​with the extra bit width compression sequence to obtain the cycle waveform compression data; The method of determining the regular bit width and the maximum bit width based on the differential array includes: based on the highest bit being the sign bit, calculating the bit width and proportion of each differential value in the differential array, wherein the largest bit width is the maximum bit width; sorting the proportions of the non-maximum bit widths from large to small, and if the proportion of the first non-maximum bit width exceeds 50%, then the bit width is the regular bit width; otherwise, taking the bit widths corresponding to the first two proportions as the bit widths to be determined, respectively calculating the lengths of the frequency waveform compressed data after super-bit width compression, and taking the bit width to be determined corresponding to the smallest length as the regular bit width.

2. The recording method of the fault indicator according to claim 1, characterized in that: The extra bit width flag is set to 1 for each bit according to the normal bit width.

3. The recording method of the fault indicator according to claim 2, characterized in that: The method of compressing the difference array according to the normal bit width and the super bit width flag to obtain a normal bit width compression sequence is to compress the difference array according to the order of the difference values ​​in the difference array. If the absolute value of the difference value is less than or equal to , For normal bit width, the differential value is superimposed Then, the unsigned bit is binary-encoded according to the normal bit width. Otherwise, the differential value is binary-encoded using the extra bit width flag.

4. The recording method of the fault indicator according to claim 1, characterized in that: The method of compressing the difference values ​​exceeding the normal bit width in the difference array according to the maximum bit width to obtain the super bit width compression sequence is to compress the difference values ​​exceeding the normal bit width in the difference array in turn. The differential value is encoded in binary format according to the maximum bit width and the highest bit is the sign bit; Normal bit width.

5. The recording method of the fault indicator according to claim 1, characterized in that: The first cycle waveform data is obtained by calculating the data difference of adjacent sampling points within the cycle to obtain a differential array, and the differential type is the difference between adjacent sampling points within the cycle.

6. The recording method of the fault indicator according to claim 1, characterized in that: The waveform data other than the first cycle are obtained by calculating the data difference between adjacent sampling points within the cycle and the data difference between adjacent cycle interval sampling points to obtain two differential arrays, and the length of the cycle waveform compressed data after the two differential arrays are compressed over the bit width is calculated respectively, and the compression indication information is constructed according to the differential array corresponding to the minimum length.

7. The method for recording a fault indicator according to claim 1, characterized in that: The aggregation unit decompresses according to the compression indication information, including: According to the conventional bit width , take each binary code from the regular bit width compression sequence in turn, if the binary code is not an extra bit width mark, convert the binary code to a decimal value and subtract , get the actual differential value; otherwise, take out the corresponding binary code from the super-bit width compression sequence according to the maximum bit width and convert it into a decimal value to get the actual differential value; Based on the length of each cycle waveform data, each cycle waveform data is restored according to the difference type and the actual difference value.

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