Distribution terminal testing method using extended FT3 data frame injection

Abstract

The present invention relates to a distribution terminal testing method using an IEC61850 extended FT3 data frame injection method, comprising: scanning a code to collect nameplate parameters of the distribution terminal and automatically generating a test plan; after both parties establish a link, automatically accessing an algorithm database to drive a device to output an extended FT3 data frame to simulate various types of short-circuit faults, ground faults, circuit breakers, load switches, etc.; simultaneously, a remote simulation master station unit is used to implement data interaction with the distribution terminal through a network port or a serial port, and further collect telemetry and telesignaling sensing data of the distribution terminal; finally, a big data fusion analysis is performed to judge the correctness and automatically generate a test report; and a loop is performed to determine whether the test of all test cases has been completed. If not, the next test case logic test is performed. The present invention implements an injection test of an extended FT3 data frame digital signal, realizes the automated execution of test cases during the test process, improves the efficiency of full or random inspections upon arrival, and reduces the skill level and ability requirements of technical personnel.

Description

Technical Field

[0001] The invention belongs to the field of power distribution terminal testing, and in particular relates to a test method for a power distribution terminal using an extended FT3 data frame injection mode. Background Art

[0002] In recent years, the construction and application of distribution automation has been widely promoted, and certain technical issues have gradually emerged. Among them, the quality level and matching degree of primary and secondary equipment have always been important factors restricting the effectiveness of distribution automation application. With the development of technology, integrated primary and secondary equipment sets have gradually become the most important equipment model for distribution automation. Integrated primary and secondary equipment sets can effectively solve many problems caused by the independent design, assembly, supply, and installation of traditional primary and secondary equipment. However, traditional integrated primary and secondary equipment sets are essentially simple integration of primary and secondary equipment, which makes it difficult to effectively improve the overall accuracy of the equipment, avoid signal interference and attenuation caused by prefabricated cable signal transmission, and achieve overall miniaturization and intensive design of the equipment. In the digital primary and secondary deep integration mode, digital signal interaction is used between switches and distribution terminals, avoiding the influence of prefabricated cables on the transmission signal. At the same time, the use of electronic sensors and digital signal interaction mode can greatly reduce the size of switches and distribution terminals, greatly improve the integration level of equipment, and facilitate the miniaturization and integration of equipment.

[0003] Deep integration is a key development direction for distribution automation equipment technology. However, the changes in the interaction between primary and secondary devices under the conditions of deep integration have also brought new technical challenges to testing and on-site operation and maintenance. With the emergence of deep integration of primary and secondary equipment, the integration between primary and secondary equipment has further increased, and the sampling information exchange has changed from analog to digital. This makes it impossible to use traditional test devices such as digital relays and distribution terminal testers to directly increase the amount of power on the distribution terminal. Traditional transformer testers are also unable to perform accuracy verification on primary equipment. Therefore, it is urgent to propose field testing and operation and maintenance technical solutions for deep integration of primary and secondary equipment. Summary of the Invention

[0004] The purpose of the present invention is to address the above-mentioned problems and provide a distribution terminal testing method using an extended FT3 data frame injection method. The distribution terminal is tested using a test device that outputs digital signals, and data is sampled through the distribution terminal interface to determine whether the performance and function of the distribution terminal are qualified. The test device can simultaneously output multiple independent test signals to achieve concurrent testing of multiple distribution terminals, thereby improving the testing efficiency of the distribution terminals.

[0005] The technical solution of the present invention is a distribution terminal testing method using an extended FT3 data frame injection method. Multiple test cases are used to automatically test various possible failure modes of the distribution terminal. The test signal is sent to the distribution terminal in an extended FT3 message injection method, and is collected back through the distribution terminal to determine whether the terminal function and performance are qualified. The test device used is equipped with a simulation master station, a digital signal generation module, a state quantity simulator, a control execution indicator and a communication interface.

[0006] The power distribution terminal testing method using the extended FT3 data frame injection method includes the following steps:

[0007] Step 1: Scan the code to collect the nameplate parameter information of the power distribution terminal;

[0008] Step 2: Generate a test plan based on the nameplate parameters. After establishing a link, both parties access the test case database and drive the digital signal generation module to output extended FT3 data frames to simulate various types of short-circuit faults, ground faults, and switch position signals. The encryption security and effectiveness of the upper and lower data frames are monitored to prevent tampering during transmission. The data frames are stored in the database as a basis for evaluation and analysis.

[0009] Step 3: The remote simulation master station exchanges data with the distribution terminal through the network port or serial port, further collects the telemetry and telesignaling sensing data of the distribution terminal, and classifies and stores the collected telesignaling, telemetry, and remote control data frames in the database. At the same time, the upper and lower data frames are analyzed and context-correlated in real time to check the legitimacy of the messages.

[0010] Step 4: Perform a peer-to-peer evaluation of the FT3 data frames and distribution terminal sampling values ​​output with the set parameters to obtain the conclusions of this round of testing items, and write the data into the database for storage and computation.

[0011] Step 5: Based on the evaluation conclusion, the results are displayed to the user in color for confirmation, and a test report for this test item is generated;

[0012] Step 6: Loop to determine whether all test cases have been tested. If all test cases have been completed, end; otherwise, proceed to the next test case and execute step 2.

[0013] Furthermore, the test method utilizes a simulated master station to control a digital signal generation module, a state quantity simulator, and a control execution indicator to issue test instructions, and compares and verifies the instructions with the data information retrieved through the communication interface, thereby realizing telemetry, telesignaling, remote control, remote parameter retrieval and configuration, alarm management, and timing function testing.

[0014] Preferably, the link layer for communication between the digital signal generation module and the power distribution terminal adopts the FT3 protocol, wherein the idle state of the status word is binary 1, and 70 idle bits are set between two adjacent data frames to facilitate clock synchronization of the power distribution terminal.

[0015] Furthermore, the test device includes a host computer, a DSP processor and a CPLD module. The host computer performs test control and human-computer interaction to realize the simulation master station function; the DSP processor generates a sine waveform and outputs it to the CPLD module; the CPLD module performs Manchester encoding and converts it into an FT3 message.

[0016] Preferably, when testing the power distribution terminal, the test device outputs 8 independent sampling value signals at a rate of 4000 points / second, and the effective value, phase and frequency value of the alternating current corresponding to each sampling value signal are continuously adjusted.

[0017] The voltage, current, and frequency of the sampling signal output by the digital signal generation module of the test device meet the following standards:

[0018] (1) AC voltage:

[0019] The voltage range is 0~300V. The voltage error is no more than 2mV from 0~0.5V and no more than 0.05% from 0.5~300V. The minimum change step is no more than 1mV.

[0020] (2) AC current:

[0021] The current value range is 0~100A, the error is no more than 2mA when 0~0.5A, and no more than 0.05% when 0.5~100A; the minimum change step is no more than 1mA;

[0022] (3) AC frequency:

[0023] The frequency range is 10Hz~1000Hz, the error is no more than 0.001Hz from 10Hz to 100Hz, and the error is no more than 0.001% from 100Hz to 1000Hz; the minimum change step is no more than 0.001Hz.

[0024] Preferably, the phase of the AC sampling signal output by the digital signal generating module of the test device meets the following standards: the phase range is 0-360°, the error is no more than 0.2°, and the minimum adjustment step is no more than 0.1°.

[0025] Preferably, the waveform of the AC sampling signal output by the digital signal generating module of the test device meets the following standards:

[0026] When the AC voltage is greater than 100V and the AC current is greater than 10A, the total harmonic distortion rate shall not exceed 0.1% and the DC component shall not exceed 0.1%.

[0027] Preferably, the delay range of the FT3 message output by the digital signal generation module of the test device is 0-3000 μs, and the minimum change step is 1 μs.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] 1) This invention implements the injection test of FT3 format digital signals for digitally integrated distribution terminals. The test process realizes the automated execution of test cases and can perform concurrent tests on multiple distribution terminals, thereby improving the efficiency of on-site operation and maintenance. The test equipment used is miniaturized and digitized.

[0030] 2) The present invention solves the problem of signal injection failure during the use of digital power distribution terminal equipment by using Manchester coding to sample FT3 data frames and parse the information carried by the FT3 data;

[0031] 3) The present invention provides multiple idle bits between adjacent data frames of the FT3 message sent during the test process to facilitate receiver clock synchronization;

[0032] 4) The present invention uses a simulated master station to control the digital signal generation module, state quantity simulator, and control execution indicator to issue test instructions, and compare and verify the data information collected by the communication interface, thereby realizing remote measurement, remote signaling, remote control, remote parameter access and configuration, alarm management, and time synchronization tests of the distribution terminal;

[0033] 5) The testing method of the present invention realizes rapid detection and closed-loop testing of various fault modes of the distribution terminal, and automatically generates a test report after the test is completed, which can meet the laboratory and on-site debugging and testing requirements of the distribution automation system and terminal equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The present invention will be further described below with reference to the accompanying drawings and examples.

[0035] Figure 1 Schematic diagram of a flow chart of a method for testing a power distribution terminal according to an embodiment of the present invention.

[0036] Figure 2 Schematic diagram of a testing device according to an embodiment of the present invention.

[0037] Figure 3 Schematic diagram of Manchester encoding of FT3 messages according to an embodiment of the present invention. DETAILED DESCRIPTION

[0038] like Figure 2 As shown, the test device of the embodiment includes a simulation master station, a digital signal generation module, a state quantity simulator, a control execution indicator and a communication interface.

[0039] like Figure 1 As shown, the distribution terminal test method using the extended FT3 data frame injection method includes the following steps:

[0040] Step 1: Scan the code to collect the nameplate parameter information of the power distribution terminal;

[0041] Step 2: Generate a test plan based on the nameplate parameters. After establishing a link, both parties access the test case database and drive the digital signal generator module to output extended FT3 data frames to simulate various types of short-circuit faults, ground faults, and circuit breaker and load switch operation signals. Simultaneously, the encryption security and effectiveness of the upstream and downstream data frames are monitored to prevent data tampering during transmission. The data frames are stored in the database as a basis for evaluation and analysis.

[0042] Step 3: The remote simulation master station exchanges data with the distribution terminal through the network port or serial port, further collects the telemetry and telesignaling sensing data of the distribution terminal, and classifies and stores the collected telesignaling, telemetry, and remote control data frames in the database. At the same time, the upper and lower data frames are analyzed and context-correlated in real time to check the legitimacy of the messages.

[0043] Step 4: Perform a peer-to-peer evaluation of the FT3 data frames and distribution terminal sampling values ​​output with the set parameters to obtain the conclusions of this round of testing items, and write the data into the database for storage and computation.

[0044] Step 5: Based on the evaluation conclusion, the results are displayed to the user in color for confirmation, and a test report for this test item is generated;

[0045] Step 6: Loop to determine whether all test cases have been tested. If all test cases have been completed, end; otherwise, proceed to the next test case and execute step 2.

[0046] The test device product includes a host computer, a DSP processor and a CPLD module. The host computer performs test control and human-computer interaction to realize the function of simulating a master station; the DSP processor generates a sine waveform and outputs it to the CPLD module; the CPLD module performs Manchester encoding and converts it into an FT3 message. In the embodiment, the host computer adopts a ZYNQ series embedded processing platform, specifically the AM3352 core board, and the DSP processor is STM32F429. The Core 0 core of the host computer runs the Linux system and the Core 1 core runs BareMate. Core0, Core1 and FPGA communicate and transmit data at high speed through shared DDR memory and AXI bus, synchronously sampling telemetry values ​​and telesignaling data, and the sampling frequency is not less than 8kHz.

[0047] The simulation master station of the test device supports communication protocols such as DL / T 634.5101, DL / T 634.5104, and MQTT, controls the digital signal generation module, state quantity simulator, and control execution indicator to issue test instructions, and compares and verifies the information collected by the communication interface to realize telemetry, telesignaling, remote control, remote parameter retrieval and configuration, alarm management, time synchronization and other test functions.

[0048] The test device's digital signal generation module supports FT3 format data injection and outputs eight independent sampling channels at a rate of 4000 points / s. The effective value, phase, and frequency of each output channel can be independently and continuously adjusted, and the AC frequency output range is no less than 10Hz to 1000Hz. During testing, when the AC voltage is greater than 100V and the AC current is greater than 10A, the total harmonic distortion of the AC waveform does not exceed 0.1%.

[0049] When testing the distribution terminal, FT3 data frames are sent to the distribution terminal through the electrical communication interface or optical communication interface. The distribution terminal collects the FT3 data frames in real time according to the high-frequency clock to obtain real-time sampling values; the sampling values ​​of the FT3 data frames are parsed using Manchester coding, such as Figure 3 As shown, the received information is obtained; the actual data is obtained according to the real-time sampling value, the received information and the preset proportional factor; the present invention uses Manchester encoding to sample the FT3 data frame and parses the information carried by the FT3 data frame, thereby solving the problem that the signal cannot be injected during the use of the digital distribution terminal equipment.

[0050] In an embodiment, the communication link layer between the digital signal generation module of the test device and the power distribution terminal uses the FT3 format of IEC60870-5-1, and the idle state of the status word is binary 1. Binary 1s are continuously transmitted between two data frames using Manchester encoding. To facilitate receiver clock synchronization, 70 idle bits are provided between the two frames. In an embodiment, 16 octets of user data are terminated by a 16-bit check sequence. As needed, the data frame is filled with buffer bytes to complete the specified number of bytes. The power distribution terminal verifies the quality of the received signal, the start character, each check sequence, and the frame length. If any of these checks are incorrect, the received data frame is discarded.

[0051] The sampling signal output by the digital signal generation module of the test device meets the following requirements:

[0052] (1) AC voltage meets the following requirements:

[0053] 1) Output range: not less than 0~300V;

[0054] 2) Accuracy: The error is no more than 2mV when 0~0.5V, and no more than 0.05% when 0.5~300V;

[0055] 3) Minimum change step: no more than 1mV.

[0056] (2) AC current meets the following requirements:

[0057] 1) Output range: not less than 0~100A;

[0058] 2) Accuracy: The error is no more than 2mA at 0~0.5A, and no more than 0.05% at 0.5~100A;

[0059] 3) Minimum change step: no more than 1mA.

[0060] (3) Frequency meets:

[0061] 1) Output range: not less than 10Hz~1000Hz;

[0062] 2) Accuracy: The error should not exceed 0.001Hz at 10Hz~100Hz, and the error should not exceed 0.001% at 100Hz~1000Hz;

[0063] 3) Minimum change step: no more than 0.001Hz.

[0064] (IV) Phase satisfaction:

[0065] 1) Accurate output range: 0~360°;

[0066] 2) Accuracy: error is no more than 0.2°;

[0067] 3) Minimum adjustment step: no more than 0.1°.

[0068] (5) Waveform quality meets the following requirements:

[0069] 1) When the AC voltage is greater than 100V and the AC current is greater than 10A, the total harmonic distortion rate does not exceed 0.1%;

[0070] 2) When the AC voltage is greater than 100V and the AC current is greater than 10A, the DC component shall not exceed 0.1%.

[0071] When the FT3 sampling value is output, the discrete value of the time interval between adjacent messages shall not exceed 2μs.

[0072] (6) FT3 delayed output meets:

[0073] 1) Delay range: 0~3000μs;

[0074] 2) Accuracy: no more than 10μs;

[0075] 3) Minimum change step: 1μs.

[0076] The implementation results show that the testing method of the present invention is aimed at digital deep-integrated distribution terminals, realizing the injection test of FT3 format digital signals and the automatic execution of test cases. The testing device is miniaturized and digitized, effectively improving the on-site operation and maintenance efficiency.

Claims

1. A distribution terminal test method using an extended FT3 data frame injection method is characterized in that: The test device used is equipped with a simulation master station, a digital signal generation module, a state quantity simulator, a control execution indicator and a communication interface; The test method comprises the following steps: Step 1: Scan the code to collect the nameplate parameter information of the power distribution terminal; Step 2: Generate a test plan based on the nameplate parameters. After establishing a link, both parties access the test case database and drive the digital signal generation module to output extended FT3 data frames to simulate various types of short-circuit faults, ground faults, and switch position signals. The encryption security and effectiveness of the upper and lower data frames are monitored to prevent tampering during transmission. The data frames are stored in the database as a basis for evaluation and analysis. Step 3: The remote simulation master station exchanges data with the distribution terminal through the network port or serial port, collects the telemetry and telesignaling sensing data of the distribution terminal, and classifies and stores the collected telesignaling, telemetry, and remote control data frames in the database. At the same time, the upper and lower data frames are analyzed and context-correlated in real time to check the legitimacy of the messages. Step 4: Perform a peer-to-peer evaluation of the FT3 data frames and distribution terminal sampling values ​​output with the set parameters to obtain the conclusions of this round of testing items, and write the data into the database for storage and computation. Step 5: Based on the evaluation conclusion, the results are displayed to the user in color for confirmation, and a test report for this test item is generated; Step 6: Loop to determine whether all test cases have been tested. If all test cases have been completed, end; otherwise, proceed to the next test case and execute step 2.

2. The power distribution terminal testing method according to claim 1, characterized in that: The test method utilizes a single-chip microcomputer to drive a digital signal generation module, a state quantity simulator, and control execution instructions, and compares and verifies the data information collected through the simulated master station unit interface to achieve telemetry, telesignaling, remote control, remote parameter access and configuration, alarm management, protection logic verification, and timing function testing.

3. The power distribution terminal testing method according to claim 1, characterized in that: The data exchange between the digital signal generation module and the distribution terminal adopts the extended FT3 format frame, in which the idle state of the status word is specified as binary 1, and 70 idle bits are set between two adjacent data frames to facilitate clock synchronization of the distribution terminal.

4. The power distribution terminal testing method according to claim 1, characterized in that: The test device includes a host computer, a DSP processor and a CPLD module. The host computer controls the test and human-computer interaction to realize the effective output function of the data frame; the DSP processor generates a sine waveform and outputs it to the CPLD module; the CPLD module performs Manchester encoding and converts it into an extended FT3 data frame for output through an electrical interface or an optical interface.

5. The power distribution terminal testing method according to claim 4, characterized in that: When simulating a power distribution terminal failure, the test device outputs 8 independent sampling values ​​at a rate of 4000 points / second. The effective value, phase and frequency of the AC power corresponding to each sampling value can be adjusted independently and continuously.

6. The power distribution terminal testing method according to claim 5, characterized in that: The voltage, current, and frequency of the sampling signal output by the digital signal generation module of the test device meet the following standards: (1) AC voltage: The voltage range is 0~300V. The voltage error is no more than 2mV from 0~0.5V and no more than 0.05% from 0.5~300V. The minimum change step is no more than 1mV. (2) AC current: The current value range is 0~100A, the error is no more than 2mA when 0~0.5A, and no more than 0.05% when 0.5~100A; the minimum change step is no more than 1mA; (3) AC frequency: The frequency range is 10Hz~1000Hz, the error is no more than 0.001Hz from 10Hz to 100Hz, and the error is no more than 0.001% from 100Hz to 1000Hz; the minimum change step is no more than 0.001Hz.

7. The power distribution terminal testing method according to claim 5, characterized in that: The phase range of the AC sampling signal output by the digital signal generation module of the test device is 0~360°, the error is no more than 0.2°, and the minimum adjustment step is no more than 0.1°.

8. The power distribution terminal testing method according to claim 5, characterized in that: When the AC voltage of the AC sampling signal output by the digital signal generating module of the test device is greater than 100V and the AC current is greater than 10A, the total harmonic distortion rate does not exceed 0.1% and the DC component does not exceed 0.1%.

9. The power distribution terminal testing method according to claim 5, characterized in that: The delay range of the FT3 message output by the digital signal generation module of the test device is 0~3000μs, and the minimum change step is 1μs.

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