Digital feeder terminal digital quantity transmission protocol self-adaptive analysis system and method

Abstract

The invention belongs to the technical field of feeder terminal communication, and particularly relates to a digital feeder terminal digital quantity transmission protocol self-adaptive analysis system and a digital feeder terminal digital quantity transmission protocol self-adaptive analysis method. The differential signal conversion module is used for converting an input signal into a single-ended level signal; the transmission rate detection module is used for detecting single-end level signal overturning and recording the level holding time between two adjacent overturning; the data transmission rate is judged according to the level holding time, and the serial data and the judged transmission rate are transmitted to the decoding module; the decoding module is used for decoding the serial data based on the transmission rate; retrieving a start character from the decoded data; according to the position of the start character, analyzing the data set length and the data set field in the decoded data, and verifying the correctness of the whole message content; if verification is correct, the type of the corresponding data frame format is judged according to the data set length and the data set field, effective data content extraction is carried out, and message content analysis is completed.

Description

Technical Field

[0001] The present invention belongs to the technical field of feeder terminal communication, and in particular relates to a digital feeder terminal digital quantity transmission protocol adaptive parsing system and method. Background Art

[0002] With the transformation of the global energy structure and the in-depth implementation of the sustainable development strategy, distributed power sources, as a clean and low-carbon energy supply method, are gradually becoming an important part of the power system. The wide access of these distributed power sources not only enriches the power types of the power grid, improves the flexibility and reliability of the power grid, but also effectively promotes the optimization and adjustment of the energy structure and reduces the dependence on fossil fuels.

[0003] In the context of large-scale access of distributed power sources to the distribution network, the intelligence and automation level of the distribution network also needs to be improved accordingly to meet the operation requirements of the new power system. As key equipment for the intelligentization of distribution networks, primary and secondary integrated network source boundary column circuit breakers and distribution automation terminals are increasingly widely used. This type of equipment integrates multiple functions such as protection, measurement, control, and communication. It can monitor the operating status of the distribution network in real time, respond to faults quickly, isolate faults and restore power supply, and improve the power supply reliability and operating efficiency of the distribution network.

[0004] Traditional digital feeder terminals (FTUs) mainly follow the FT3 frame format in the GB / T 20840.8 "Transformer Part 8: Electronic Current Transformer" standard in data transmission. Although this format can meet basic data transmission needs, its data transmission capacity and flexibility are insufficient when facing the complex and changeable operation scenarios of the distribution network after the access of distributed power sources. For this reason, the digital feeder terminal that integrates the network source function adopts a more advanced and complex extended FT3 format protocol for data transmission. This improvement not only significantly improves the capacity and efficiency of data transmission, but also supports more types of data content (such as distributed power status information, power generation data, forecast information, etc.), providing more comprehensive and detailed data support for the intelligent management of the distribution network.

[0005] However, the application of the extended FT3 format protocol also brings challenges to the data receiving end. Due to the increase in data transmission content and the complexity of the format, the traditional data receiving module may not be able to directly be compatible with and parse these new formats of data. Summary of the invention

[0006] In order to overcome the problems in the prior art, the present invention proposes a system and method for adaptively parsing a digital quantity transmission protocol of a digital feeder terminal.

[0007] The technical solution of the present invention to solve the above technical problems is as follows:

[0008] In a first aspect, the present invention provides a digital feeder terminal digital quantity transmission protocol adaptive parsing system, comprising: a differential signal conversion module, a transmission rate detection module and a decoding module;

[0009] The differential signal conversion module is used to convert the input signal into a single-ended level signal;

[0010] The transmission rate detection module is used to detect the flip of the single-ended level signal and record the level holding time between two adjacent flips; determine the data transmission rate according to the length of the level holding time, and pass the serial data and the determined transmission rate to the decoding module;

[0011] A decoding module is used to decode the serial data based on the transmission rate; retrieve the start character from the decoded data; parse the data set length and data set field in the decoded data according to the position of the start character, and verify the decoded data; if the verification is correct, determine the type of the corresponding data frame format according to the data set length and data set field; extract the valid data content according to the determined data frame format type, and complete the message content parsing.

[0012] Furthermore, in the differential signal conversion module, the input signal is an EIA RS-485 differential signal of the digital quantity transmission physical layer.

[0013] Furthermore, in the transmission rate detection module, judging the data transmission rate according to the length of time the level is maintained includes:

[0014] If the level is maintained for time t hold Satisfy 40ns≤t hold ≤60ns, and the level holding time meets the above requirements for 10 consecutive times, the transmission rate is determined to be 10Mbit / s;

[0015] If the level is maintained for time t hold Satisfy 180ns≤t hold ≤220ns, and if the level holding time meets the above requirements for 5 consecutive times, the transmission rate is determined to be 5Mbit / s.

[0016] Furthermore, in the transmission rate detection module, the level holding time continues to be detected after the transmission rate is detected; if it is detected that the level holding time does not meet the level holding time required by the current transmission rate, it is determined that the current data transmission rate detection error is made, and the serial data is stopped from being transmitted to the decoding module, and an error flag is sent to it; at the same time, the detection module restarts the detection of the data transmission rate.

[0017] Furthermore, in the decoding module, if an error flag of the transmission rate detection module is received, the decoding module stops decoding the data until the transmission rate detection module transmits a correct signal.

[0018] Furthermore, in the decoding module, if the verification is correct, determining the length of the data set and the data format type of the data set includes:

[0019] If the decimal data set length is 44 and the data set field is 01, the data format is determined to be the FT3 general data frame format;

[0020] If the length of the decimal data set is 62 and the decimal data set field is 254, the data format is determined to be the FT3 extended data frame format.

[0021] Furthermore, in the decoding module, if the data set length or data set field does not meet the requirements, or a check error occurs, the frame data is discarded.

[0022] In a second aspect, the present invention further provides a method for adaptively parsing a digital quantity transmission protocol of a digital feeder terminal, comprising the following steps:

[0023] Convert the input signal into a single-ended level signal; detect the flip of the single-ended level signal and record the level holding time between two adjacent flips;

[0024] Determine the data transmission rate based on how long the level is maintained;

[0025] Based on the data transmission rate, the serial data is decoded to retrieve a start symbol from the decoded data;

[0026] According to the position of the start character, the data set length and the data set field in the decoded data are parsed, and the correctness of the decoded data is verified; if the verification is correct, the type of the corresponding data frame format is determined according to the data set length and the data set field;

[0027] According to the judged data frame format type, the effective data content is extracted to complete the message content parsing.

[0028] Furthermore, after the transmission rate is detected, the level holding time between two adjacent flips is continued to be detected; if the level holding time between the two adjacent flips detected does not meet the current transmission rate level holding time, the current data transmission rate detection error is determined and an error flag is sent; otherwise, the detected transmission rate is transmitted to the serial data and passed to the decoding module.

[0029] Furthermore, if an error flag of the transmission rate detection module is received, decoding of the data is stopped until the transmission rate detection module transmits a correct signal.

[0030] Compared with the prior art, the present invention has the following technical effects:

[0031] (1) The present invention monitors the reversal of the level signal and the level holding time between adjacent reversals, and can determine the data transmission rate in real time. At the same time, since the length of the level holding time also reflects the stability of the signal, this method not only determines the transmission rate, but also indirectly monitors the quality of signal transmission, providing a strong guarantee for the stable operation of the system.

[0032] (2) The present invention identifies the data frame format type through the data set length and the data set double field, and adds a verification judgment step. This method not only improves the accuracy of data frame format recognition, but also ensures the reliability of the recognition result through the verification mechanism, effectively avoiding misrecognition caused by transmission errors or interference.

[0033] (3) The present invention makes full use of the characteristics of the FT3 general frame format and the extended frame format, and can decode serial data more effectively, and quickly locate the start symbol, parse the data set length and data set field. This process not only improves the speed of data processing, but also ensures the integrity and accuracy of the data, providing a solid foundation for subsequent content analysis and data processing.

[0034] (4) Since the present invention adopts an intelligent and flexible method in detecting the transmission rate and identifying the data frame format, the system can easily adapt to the data transmission requirements of different types and different rates.

[0035] (5) The present invention helps to promptly discover and solve problems that may arise during data transmission by real-time monitoring of signal transmission quality and identifying data frame format types, thereby improving the stability and reliability of the entire system. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present invention or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. 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 creative work.

[0037] Figure 1 It is a schematic diagram of the process of the present invention. DETAILED DESCRIPTION

[0038] In order to further explain the technical means and effects taken by the present invention to achieve the predetermined invention purpose, the specific implementation methods, structures, features and effects of the technical solutions proposed by the present invention are described in detail below in conjunction with the accompanying drawings and preferred embodiments. The specific features, structures or characteristics in one or more embodiments may be combined in any suitable form. Unless otherwise defined, all technical and scientific terms used in the present invention have the same meaning as those commonly understood by technicians in the technical field of the present invention.

[0039] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a digital feeder terminal digital quantity transmission protocol adaptive receiving system and method, which can detect in real time without any human interference, accurately and reliably receive the digital quantity transmission content, realize adaptive reception, eliminate parameter configuration, reduce program versions, and improve the compatibility of the device.

[0040] In one embodiment of the present invention, a digital feeder terminal digital quantity transmission protocol adaptive parsing system is provided, comprising: a differential signal conversion module, a transmission rate detection module and a decoding module;

[0041] The differential signal conversion module is used to convert the input signal into a single-ended level signal;

[0042] The transmission rate detection module is used to detect the flip of the single-ended level signal and record the level holding time between two adjacent flips; determine the data transmission rate according to the length of the level holding time, and pass the serial data and the determined transmission rate to the decoding module;

[0043] The decoding module is used to decode the serial data based on the transmission rate; retrieve the start character from the decoded data; parse the data set length and data set field in the decoded data according to the position of the start character, and verify the correctness of the decoded data, which includes the data set length and data set field; if the verification is correct, determine the type of the corresponding data frame format according to the data set length and data set field; extract the valid data content according to the determined data frame format type, and complete the message content parsing.

[0044] In this embodiment, the differential signal conversion module is used to convert the input signal into a single-ended level signal. Specifically, the EIA RS-485 differential signal used in the digital transmission physical layer is converted into a single-ended level signal via the THVD1450DR chip.

[0045] In this embodiment, the transmission rate detection module is used to detect the flip of the single-ended level signal and record the level holding time between two adjacent flips; the data transmission rate is determined according to the length of the level holding time, and the serial data and the determined transmission rate are passed to the decoding module.

[0046] Serial data transmission uses Manchester code encoding to detect the flip of single-ended level signal and record the level holding time between two adjacent flips. Specifically, the single-ended level signal is tapped inside the FPGA (i.e. delayed by one clock cycle), generally two or three times, and the D flip-flop or register inside the FPGA can be used to tap the input signal; to detect whether the single-ended level signal flips, the current signal can be compared with the previous beat signal. If they are different, it means that the level flips, and the level holding time is counted using the FPGA internal clock when the level flips, and the level holding time between two adjacent flips is recorded.

[0047] The data transmission rate is determined based on the level holding time, and the serial data and the determined transmission rate are passed to the decoding module. Specifically, according to the Manchester encoding rule, binary numbers are transmitted using the rising edge or the falling edge, so the level holding time can only be the length of half a code element or the length of one code element; because the length of half a code element of 5Mbit / s is equal to the length of one code element of 10Mbit / s, the length of one code element of 5Mbit / s and the length of half a code element of 10Mbit / s are used when determining the level time.

[0048] Considering the error factor, a certain margin of error is reserved when judging the level time. The transmission rate is judged based on the level holding time and the number of level holding times. Specifically, if the level holding time t hold Satisfy 40ns≤t hold ≤60ns, and the level meets the hold time requirement for 10 consecutive times, the transmission rate is determined to be 10Mbit / s; if the level hold time t hold Satisfy 180ns≤t hold ≤220ns, and if the level meets the hold time requirement for 5 consecutive times, the transmission rate is determined to be 5Mbit / s.

[0049] In some embodiments, the transmission rate detection module is also used to continue detecting the level holding time between two adjacent flips after the transmission rate is detected; if it is detected that the level holding time between two adjacent flips does not meet the level holding time required by the current transmission rate, it is determined that the current data transmission rate detection error is made, and the serial data is stopped from being transmitted to the decoding module, and an error flag is sent to it; at the same time, the data transmission rate detection is restarted.

[0050] In this embodiment, the decoding module is used to receive the data transmission rate and serial data, decode the Manchester code, and convert the Manchester code into binary data; retrieve the start character that meets the definition of the FT3 application layer from the binary data; parse the data set length and data set field in the serial data according to the start character position, and verify the data set length and data set field; if the verification is correct, judge the data frame format type of the data set length and data set; according to the judged data frame format type, extract the valid data content in the serial data frame to complete the message content parsing. Among them, the valid content refers to the sampling values ​​of electrical quantities such as voltage and current, the switch state quantity, the state flag of the data, and other data.

[0051] According to the known transmission rate and serial data, the Manchester code is decoded and converted into binary data.

[0052] Retrieve the start character that complies with the FT3 application layer definition from the binary data. The start character length is 2 bytes and its value is fixed to 0564 (hexadecimal); when the decoding module finds the start character, it parses the data set length (Length) and data set (DataSetName) fields from the binary data in turn according to the start character position, and performs CRC (Cyclic Redundancy Check) check on the data frame content;

[0053] When the data is verified to be correct, if Length=44 (decimal) and DataSetName=01, the data format is determined to be the FT3 general data frame format; if Length=62 (decimal) and DataSetName=FEH (decimal 254), the data format is determined to be the FT3 extended data frame format;

[0054] If the data set length or data set does not meet the requirements, or the CRC check is wrong, the frame data is discarded. The data set length only recognizes 44 or 62. As long as neither of these two contents is considered to be inconsistent with the requirements, the data set is the same.

[0055] In some embodiments, the decoding module is further used to receive an error flag from the transmission rate detection module, and after receiving the error flag from the transmission rate detection module, stop decoding the data until the transmission rate detection module transmits a correct signal.

[0056] Based on the same inventive concept, an embodiment of the present invention also provides a method for implementing a digital feeder terminal digital quantity transmission protocol adaptive receiving system for implementing the above-mentioned digital feeder terminal digital quantity transmission protocol adaptive receiving system. The implementation scheme for solving the problem provided by the system is similar to the implementation scheme recorded in the above-mentioned method, so the specific limitations in one or more system embodiments provided below can refer to the above-mentioned limitations on a digital feeder terminal digital quantity transmission protocol adaptive receiving system, and will not be repeated here.

[0057] In one embodiment, referring to Figure 1 , provides a digital feeder terminal digital quantity transmission protocol adaptive receiving method, comprising the following steps: converting an input signal into a single-ended level signal; detecting the flip of the single-ended level signal, and recording the level holding time between two adjacent flips; judging the data transmission rate according to the length of the level holding time; decoding the serial data; retrieving the start symbol from the decoded data; parsing the data set length and data set field in the decoded data according to the position of the start symbol, and verifying the data set length and data set field; if the verification is correct, judging the type of the corresponding data frame format according to the data set length and data set field; extracting the valid data content according to the judged data frame format type, and completing the message content parsing.

[0058] The following is a detailed explanation of each of the above steps:

[0059] Step 1: Convert the input signal into a single-ended level signal;

[0060] The THVD1450DR chip is used to convert the input RS-485 differential data into a single-ended level signal.

[0061] Step 2: Detect the flip of the single-ended level signal and record the level holding time between two adjacent flips;

[0062] To beat the single-ended level signal inside the FPGA (i.e., delay one clock cycle), the D flip-flop or register inside the FPGA can be used to beat the input signal; to detect whether the single-ended level signal is flipped, the current signal can be compared with the previous beat signal. If they are different, it means that a level flip has occurred. When the level flips, the internal clock of the FPGA is used to count the level holding time, and the level holding time between two adjacent flips is recorded.

[0063] Step 3: Determine the data transmission rate based on the level holding time;

[0064] According to the Manchester coding rule, binary numbers are transmitted using the rising edge or the falling edge, so the level holding time can only be the length of half a code element or the length of one code element; because the length of half a code element of 5Mbit / s is equal to the length of one code element of 10Mbit / s, the length of one code element of 5Mbit / s and the length of half a code element of 10Mbit / s are used to determine the level time;

[0065] Taking into account the error factor, a certain error margin is left when judging the level time;

[0066] If the level is maintained for time t hold Satisfy 40ns≤t hold ≤60ns, and the level holding time meets the above requirements for 10 consecutive times, the transmission rate is determined to be 10Mbit / s;

[0067] If the level is maintained for time t hold Satisfy 180ns≤t hold ≤220ns, and if the level holding time meets the above requirements for 5 consecutive times, the transmission rate is determined to be 5Mbit / s.

[0068] After step 3, the method further includes: after detecting the transmission rate, continuing to detect the level holding time between two adjacent flips; if the level holding time between the two adjacent flips detected does not meet the level holding time required by the current transmission rate, determining that the current data transmission rate detection error occurs, and sending an error flag; otherwise, the transmission rate is detected and transmitted to the serial data;

[0069] When the transmission rate is known, the level holding time between two adjacent flips is determined, which can only be the duration of half a code element or one code element; if it is detected that the level holding time between two adjacent flips does not meet the current transmission rate characteristics, the transmission rate may have changed and needs to be re-monitored; at the same time, the transmission of serial data is stopped and an error flag is sent.

[0070] Step 4: Decode the Manchester code into binary data according to the known transmission rate and serial data.

[0071] Step 5: Retrieve the start symbol that complies with the FT3 application layer definition from the binary data;

[0072] In the FT3 common frame format and the extended frame format, the start character of the data frame is 0564 (hexadecimal).

[0073] Step 6: According to the start character position, the data set length and data set field in the serial data are parsed, and the data set length and data set field are verified; if the verification is correct, the data frame format type of the data set length and data set is determined;

[0074] Parse the data set length (Length) and data set (DataSetName) fields: According to the provisions of the FT3 common / extended frame format, parse the data set length and the data set field values ​​from the data frame, and perform a CRC check on the data frame content. Only when the check is correct can the data set length and data set be judged;

[0075] If Length=44 (decimal) and DataSetName=01, the data format is determined to be the FT3 general data frame format; if Length=62 (decimal) and DataSetName=FEH (decimal 254), the data format is determined to be the FT3 extended data frame format;

[0076] If the data set length or data set does not meet the requirements, or the CRC check is wrong, the frame data will be discarded;

[0077] If the decoding module receives an error flag from the transmission rate detection module, it stops decoding the data until the transmission rate detection module transmits a correct signal;

[0078] Step 7: Based on the determined data frame format type, extract the valid data content in the serial data frame to complete the message content parsing.

[0079] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the protection scope of the present invention.

Claims

1. A digital feeder terminal digital quantity transmission protocol adaptive analysis system, characterized in that: include: Differential signal conversion module, transmission rate detection module and decoding module; The differential signal conversion module is used to convert the input signal into a single-ended level signal; The transmission rate detection module is used to detect the flip of the single-ended level signal and record the level holding time between two adjacent flips; Determine the data transmission rate according to the length of the level holding time, and pass the serial data and the determined transmission rate to the decoding module; A decoding module, configured to decode the serial data based on the transmission rate; Retrieving a start character from the decoded data; parsing a data set length and a data set field in the decoded data according to the position of the start character, and verifying the correctness of the decoded data content; If the verification is correct, the type of the corresponding data frame format is determined based on the data set length and data set fields; According to the determined data frame format type, the effective data content is extracted to complete the message content analysis.

2. According to claim 1, a digital feeder terminal digital quantity transmission protocol adaptive parsing system is characterized in that: In the differential signal conversion module, the input signal is an EIA RS-485 differential signal of the digital quantity transmission physical layer.

3. The digital feeder terminal digital quantity transmission protocol adaptive parsing system according to claim 1, characterized in that: In the transmission rate detection module, judging the data transmission rate according to the length of time the level is maintained includes: If the level is maintained for time t hold Satisfy 40ns≤t hold ≤60ns, and the level holding time meets the above requirements for 10 consecutive times, the transmission rate is determined to be 10Mbit / s; If the level is maintained for time t hold Satisfy 180ns≤t hold ≤220ns, and if the level holding time meets the above requirements for 5 consecutive times, the transmission rate is determined to be 5Mbit / s.

4. A digital feeder terminal digital quantity transmission protocol adaptive parsing system according to claim 3, characterized in that: In the transmission rate detection module, after the transmission rate is detected, the level holding time continues to be detected; if it is detected that the level holding time does not meet the level holding time required by the current transmission rate, it is determined that the current data transmission rate detection error is stopped, and the serial data is stopped from being transmitted to the decoding module, and an error flag is sent to it; at the same time, the data transmission rate detection is restarted.

5. A digital feeder terminal digital quantity transmission protocol adaptive parsing system according to claim 4, characterized in that: In the decoding module, if an error flag of the transmission rate detection module is received, the decoding of the data is stopped until the transmission rate detection module transmits a correct signal.

6. The digital feeder terminal digital quantity transmission protocol adaptive parsing system according to claim 1, characterized in that: In the decoding module, if the verification is correct, determining the length of the data set and the data format type of the data set includes: If the decimal data set length is 44 and the data set field is 01, the data format is determined to be the FT3 general data frame format; If the length of the decimal data set is 62 and the decimal data set field is 254, the data format is determined to be the FT3 extended data frame format.

7. The digital feeder terminal digital quantity transmission protocol adaptive parsing system according to claim 1, characterized in that: In the decoding module, if the data set length or data set field does not meet the preset requirements, or if a check error occurs, the frame data is discarded.

8. A method for adaptively parsing a digital quantity transmission protocol of a digital feeder terminal, characterized in that: The following steps are involved: Convert the input signal into a single-ended level signal; Detect the flip of single-ended level signal and record the level holding time between two adjacent flips; Determine the data transmission rate based on how long the level is maintained; Based on the transmission rate, decoding the serial data; Retrieve the start symbol from the decoded data; According to the position of the start character, parsing the data set length and data set field in the decoded data, and verifying the correctness of the decoded data content; If the verification is correct, the type of the corresponding data frame format is determined based on the data set length and data set fields; According to the judged data frame format type, the effective data content is extracted to complete the message content parsing.

9. A method for adaptively parsing a digital quantity transmission protocol of a digital feeder terminal according to claim 8, characterized in that: After the transmission rate is detected, the level holding time between two adjacent flips is continued to be detected; if the level holding time between the two adjacent flips detected does not meet the current transmission rate level holding time, it is determined that the current data transmission rate detection error is sent, and an error flag is sent; Otherwise, the transmission rate and serial data will be detected and passed to the decoding module.

10. A digital feeder terminal digital quantity transmission protocol adaptive parsing method according to claim 9, characterized in that: If an error flag is received from the transmission rate detection module, the decoding of the data is stopped until the transmission rate detection module transmits a correct signal.

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