Relay protection tester based on simulation waveform simulation

Abstract

The invention discloses a relay protection tester based on simulation waveform simulation. The relay protection tester comprises a relay protection tester body, upper computer software and Simulink simulation software, the upper computer software and the Simulink simulation software are both installed on a computer connected with the relay protection tester body; the Simulink simulation software is used for building a power system simulation model required by teaching, performing simulation to generate current and voltage waveforms, and selecting fault phase current and voltage waveforms required by experiment requirements for storage; and the upper computer software is used for reading the stored fault phase current and voltage waveform data required by the experiment requirement and sending the data to the relay protection tester body. Compared with setting of a parameter template, the method has the advantages that rich power system component models in a component library of Simulink simulation software are applied, a power system closer to reality can be built, simulated current and voltage waveform data are more accurate, and the power system is greatly simplified by using template parameters.

Description

Technical Field

[0001] The invention relates to the technical field of relay protection, and in particular to a relay protection tester based on simulation waveform simulation. Background Art

[0002] In the experimental teaching of relay protection, relay protection tester is often used to test relay protection simulation circuit. The simulated output of the power system is formed by setting the template parameters and added to the simulation circuit for experiment. Usually there are a large number of templates stored in the relay protection tester, which lays the foundation for the whole teaching process. However, the long-term problem is that the simplification of the power system brought by the template makes the simulation output accuracy decrease, and the experimental results obtained lack persuasiveness.

[0003] Currently, there are also relay protection testers that use recording files instead of template parameter settings, which makes the experiment more accurate and reasonable. However, for schools, they generally do not have access to recording files and recording files can only reflect specific situations and are not flexible enough. For expanded experimental teaching content, the limitations of recording files are obvious. Summary of the invention

[0004] 1. Technical problems to be solved: The simplification of the power system brought by the template reduces the accuracy of the simulation output, and the experimental results obtained are not convincing. The existing relay protection tester that uses recording files instead of template parameter settings has obvious limitations.

[0005] In view of the above technical problems, the present invention provides a relay protection tester based on simulation waveform simulation.

[0006] 2. Technical solution: A relay protection tester based on simulation waveform simulation comprises a relay protection tester body, a host computer software and a Simulink simulation software; the host computer software and the Simulink simulation software are both installed on a computer connected to the relay protection tester body; The Simulink simulation software is used to build a power system simulation model required for teaching and simulate to generate current and voltage waveforms, and select the fault phase current and voltage waveforms required by the experimental requirements for saving; The host computer software is used to read the stored fault phase current and voltage waveform data required by the experimental requirements and send these data to the relay protection tester body; The relay protection tester body is used to receive the fault phase current and voltage waveform data required by the experimental requirements, and convert it into an analog electrical signal through a digital-to-analog conversion module, and then amplify the electrical signal through its own amplification module and send it to the relay protection simulation circuit for experimental testing.

[0007] Furthermore, the power system simulation model required for the teaching is constructed by using component models in the Power system library in the component library of the Simulink simulation software.

[0008] Furthermore, the current and voltage waveforms are detected by a scope module.

[0009] Furthermore, the experiment requires that the required fault phase current and voltage waveform data be saved in a specified text document (.txt) through the Function module in the component library of the Simulink simulation software.

[0010] Furthermore, the data type stored in the Function module is a single-precision floating point number.

[0011] Furthermore, the host computer software reads the fault phase current and voltage waveform data required by the experimental requirements stored in the specified text document, extracts data features for fault analysis, and sends the fault phase current and voltage waveform data to the relay protection instrument tester body through the optical fiber jumper.

[0012] Furthermore, the relay protection tester body converts the received fault phase current and voltage waveform data into analog electrical signals of voltage and current through its own digital-to-analog conversion module.

[0013] 3. Beneficial effects: (1) Compared with setting parameter templates, the present invention uses the rich power system component models in the component library of Simulink simulation software, which can build a power system closer to the actual one. The simulated current and voltage waveform data will be more accurate, and the use of template parameters itself greatly simplifies the power system.

[0014] (2) Compared with the recording file, the Simulink simulation software used in the present invention can build the required power system simulation model according to teaching needs by replacing the power system component model or changing the system structure, and can simulate the current and voltage data under various conditions. The data of the recording file is fixed and cannot be changed, and it is difficult for general universities to obtain it. In comparison, the current and voltage data of the present invention are much more convenient to obtain. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural block diagram of the relay protection tester based on simulation waveform simulation of the present invention; Figure 2 A method for using the relay protection tester based on simulation waveform simulation of the present invention; Figure 3 It is a power system simulation model of a single-phase ground short circuit fault of phase A of a 110KV transmission line in embodiment 2 of the present invention; Figure 4 The parameter settings of the Three-Phase Source module in Example 2 of the present invention; Figure 5 The parameter setting of the node in Embodiment 2 of the present invention; Figure 6 The parameter setting of line in Embodiment 2 of the present invention; Figure 7 The load parameter setting in Embodiment 2 of the present invention; Figure 8 The parameter setting of the Three-Phase Fault module in Example 2 of the present invention; Fig. 9 is the waveform change of the three-phase current Iabc at the node 2 side in Embodiment 2 of the present invention, Fig.10 The waveform change of the three-phase voltage Uabc at the node 2 side in Embodiment 2 of the present invention; Fig.11 The data stored in the fcn module in Embodiment 2 of the present invention; Fig.12 When the text_ref.txt file is loaded in Embodiment 2 of the present invention, the host computer displays the fault phase current data; Fig.13 The physical wiring of the relay protection tester of embodiment 2 of the present invention; Fig.14 This is a physical diagram of the IA and IN ports in Example 2 of the present invention; Fig.15 This is a physical diagram of the analog circuit for measuring the quantity in Example 2 of the present invention; Fig.16 This is a physical diagram of a DL-32 type AC current relay in Example 2 of the present invention; Fig.17 This is a physical diagram of the output terminal connection of the experimental result return quantity of the simulation circuit in Example 2 of the present invention; Fig.18 Connecting the input port of the relay protection tester of Embodiment 2 of the present invention; Fig.19 The experimental results of the verification selectivity returned to the host computer software in Example 2 of the present invention; Fig. 20 This is the experimental result of verifying the speediness in Example 2 of the present invention, which is returned to the host computer software. DETAILED DESCRIPTION

[0016] The present invention will be described in detail below with reference to the accompanying drawings. Specific embodiment: like Figure 1As shown, a relay protection tester based on simulation waveform simulation includes a relay protection tester body, a host computer software and a Simulink simulation software; the host computer software and the Simulink simulation software are both installed on a computer connected to the relay protection tester body to facilitate human-computer interaction; Simulink simulation software is used to build the power system simulation model required for teaching and simulate to generate current and voltage waveforms. The fault phase current and voltage waveform data required by the experiment are saved into the specified text document (.txt) through the component library Function module of Simulink simulation software; The upper computer software is used to read the fault phase current and voltage waveform data required by the experimental requirements generated by the power system simulation model stored in the specified text document, extract data features for fault analysis, and send the fault phase current and voltage waveform data to the relay protection instrument tester body through the optical fiber jumper; The relay protection tester body is used to receive the fault phase current and voltage waveform data, convert it into analog quantities of voltage and current through its own digital-to-analog conversion module, and then amplify the electrical signal through its own amplifier module and send it to the relay protection simulation circuit for experimental testing.

[0018] In this embodiment, the host computer software and Simulink simulation software transmit the fault phase current and voltage waveform data obtained by simulation through a text document (.txt), and the general parameter template will be directly integrated into the host computer software or the relay protection tester body, and the recording document will be directly sent to the relay protection tester body via USB.

[0019] Embodiment 2: like Figure 2 As shown, the use method of the relay protection tester of the present invention is demonstrated by testing the single-phase ground short-circuit current relay of phase A of a 110KV transmission line, and includes the following steps: Step 1: Use the Power system library in the Simulink simulation software component library to build the following components according to the requirements of the teaching experiment. Figure 3 The power system simulation model of the 110KV transmission line A phase single-phase ground short circuit fault shown; 110KV transmission line A phase single-phase ground short circuit fault power system simulation model: The leftmost is the three-phase power supply, which is set by the Three-Phase Source module. The parameter settings are as follows Figure 4 As shown, nodes 1, 2, 3, and 4 are transmission line buses, and the parameter settings are as follows: Figure 5 As shown; line1, line2, line3 are the equivalent RL impedances of the transmission line between the two buses, and the parameter settings are as follows Figure 6 As shown; load1, load2, and load3 are the loads of the corresponding buses, and the parameter settings are as follows Figure 7 As shown; a phase A ground short circuit occurs in the line where load1 is located, which is set by the Three-Phase Fault module. The parameter settings are as follows Figure 8 As shown; Node 2 and Node 3 detect the changes of the three-phase current and voltage waveforms on the corresponding bus through the scope module; the required fault phase (phase A) current Ia is saved through the fcn module (function module); The following is the code in the fcn module: function y = fcn(u) %#codegen fileID=fopen('text_ref.txt','a'); fprintf(fileID,'%s','float const data_sampl_Ia[3456000]={'); fprintf(fileID,'%f','%c\n','u',','); fprintf(fileID,'%s','};'); fclose(fileID); y = u; Step 2: After debugging the power system simulation model, click the Run button, the Simulink simulation software enters the simulation, and the current and voltage waveform data are obtained, which can be observed through the scope module; Fig. 9 is the waveform change of the three-phase current Iabc on the node 2 side, Fig.10 The waveform change of the three-phase voltage Uabc on the node 2 side; Step 3: After entering the simulation, the Function function enters the working state and selects the fault data required for the experiment. Figure 7 The first waveform is the fault phase current Ia. When the system simulation is running, the fcn module automatically saves its data to the text_ref.txt file. The data saved in this file is as follows Fig.11 As shown, the data type is a single-precision floating point number, and there are 4001 fault current data in total; Step 4: Open the host computer software and select "Load Data" to load the text_ref.txt file. After loading, the host computer displays the fault phase current data as follows: Fig.12 As shown, click the "Start" button in the host computer software, the experiment starts, and the host computer software transmits the fault phase current data to the relay protection tester through the optical fiber; Step 5: The relay protection tester body converts the data into a small signal analog quantity through the digital-to-analog conversion module, and then uses a power amplifier to amplify the signal and transmit it to the relay protection analog circuit.

[0020] The actual wiring of the relay protection tester is as follows Fig.13 As shown. Fig.13 The right side of the relay protection tester is connected to the computer through a blue optical fiber line. The digital value of the fault phase current Ia is sent from the computer to the relay protection tester. The red and black wires are respectively drawn from the IA and IN output ports on the left side to connect to the analog circuit. The actual picture of the IA and IN output ports is as follows: Fig.14 The IA and IN output ports are connected to the beginning and end of the analog circuit respectively, the red end is the beginning and the black end is the end. Fig.15 In the simulation circuit, since the experiment tests the action of the A-phase single-phase ground short-circuit current relay of the 110KV transmission line, including whether the action can meet the selectivity and speed, the DL-32 AC current relay is used as the simulation circuit. Fig.16 This is a real DL-32 AC current relay. In the simulation circuit, the connections are as follows: Fig.17 The two terminals shown are used as the return value of the experimental results. The returned results are connected to the input port of the relay protection tester. After the relay protection tester analyzes, the results are displayed to the host computer software through optical fiber. The wiring of the input port of the relay protection tester is as follows: Fig.18 shown. Fig.19 and Fig. 20 The experimental results are returned to the host computer software. Fig.19 Verified selectivity, Fig. 20 Verified the speed.

[0021] Although the present invention has been disclosed as above in terms of preferred embodiments, they are not intended to limit the present invention. Anyone skilled in the art can make various changes or modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection defined by the claims of this application.

Claims

1. A relay protection tester based on simulation waveform simulation, characterized in that: It includes a relay protection tester body, a host computer software and a Simulink simulation software; the host computer software and the Simulink simulation software are both installed on a computer connected to the relay protection tester body; The Simulink simulation software is used to build a power system simulation model required for teaching and simulate to generate current and voltage waveforms, and select the fault phase current and voltage waveforms required by the experimental requirements for saving; The host computer software is used to read the stored fault phase current and voltage waveform data required by the experimental requirements and send these data to the relay protection tester body; The relay protection tester body is used to receive the fault phase current and voltage waveform data required by the experimental requirements, and convert it into analog electrical signals through the digital-to-analog conversion module, and then amplify the electrical signals through its own amplification module and send them to the relay protection simulation circuit for experimental testing.

2. A relay protection tester based on simulation waveform simulation according to claim 1, characterized in that: The power system simulation model required for the teaching is built through the component models in the Power system library in the Simulink simulation software component library.

3. A relay protection tester based on simulation waveform simulation according to claim 1, characterized in that: The current and voltage waveforms are detected by a scope module.

4. A relay protection tester based on simulation waveform simulation according to claim 1, characterized in that: The experiment requires that the required fault phase current and voltage waveform data be saved in a specified text document (.txt) through the Function function module in the component library of the Simulink simulation software.

5. A relay protection tester based on simulation waveform simulation according to claim 4, characterized in that: The data type stored in the Function module is a single-precision floating point number.

6. A relay protection tester based on simulation waveform simulation according to claim 4 or 5, characterized in that: The host computer software reads the fault phase current and voltage waveform data required by the experimental requirements stored in the specified text document, extracts data features for fault analysis, and sends the fault phase current and voltage waveform data to the relay protection instrument tester body through the optical fiber jumper.

7. A relay protection tester based on simulation waveform simulation according to claim 6, characterized in that: The relay protection tester body converts the received fault phase current and voltage waveform data into analog electrical signals of voltage and current through its own digital-to-analog conversion module.

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