CN111369874A

CN111369874A - Line protection experiment platform based on model design

Info

Publication number: CN111369874A
Application number: CN202010269967.5A
Authority: CN
Inventors: 刘德武; 梁喆; 尤艺; 陈潇; 孙朝鹏
Original assignee: Anhui University of Science and Technology
Current assignee: Anhui University of Science and Technology
Priority date: 2020-04-08
Filing date: 2020-04-08
Publication date: 2020-07-03

Abstract

The invention describes a line protection experiment platform based on model design, which comprises a software platform and a hardware platform, wherein the software platform is an upper computer consisting of a computer, MATLAB software and CCS software, and the hardware platform comprises a DSP control panel, a voltage and current transformer measuring unit and an analog unit (line model). And a microcomputer protection model is set up on the software platform for simulation verification. The line model simulates an actual power transmission line, and the measuring unit collects fault signals generated by the power transmission line model. And the DSP control unit controls the on and off of the circuit breaker. The student can study the protection action behavior that takes place under different faults, and the simulation effect is good. And the circuit model is adopted to replace the actual power transmission line, so that the simulation safety performance is high and the cost is low.

Description

Line protection experiment platform based on model design

Technical Field

The invention relates to the field of relay protection semi-physical simulation experiment teaching of a power system. The simulation platform can be used for truly and efficiently simulating the running state and the relay protection action condition of the circuit, so that a user can master the relay protection principle, and meanwhile, the potential safety hazard of an experiment is reduced.

Background

The traditional protection experiment contents focus on the relay characteristic test, so that the specific function of the relay in the whole protection system cannot be known in the experiment process. The experiment table can only carry out single experiment operation, cannot fully mobilize and play the subjective initiative of student learning, and cannot meet the requirements of course development on experiments.

The main problems existing at present are as follows:

(1) the protection experiment is mainly based on a single verification experiment, the experiment content and the process are relatively simple, only the experiment data are simply recorded, the action phenomenon is observed, the principle introduced in the verification book is adopted, and the requirement of the experiment on the analysis capability of students is not high.

(2) Most of traditional relay protection experimental equipment is divided into physical models of which the hardware is reduced according to the actual power transmission line proportion, is fixed in operation, is visual and easy to use, but is single in operation, and cannot provide a platform for cultivating the practical ability and the innovation ability of students;

(2) the experimental equipment is single, large in size and high in price, and is not suitable for large-scale popularization.

(3) The operation of connecting the student with the power grid on site has certain danger, and personal safety accidents are easy to happen;

(4) the relay protection experiment platform in the traditional school is fixed in line structure, power transmission parameters can not be changed, only a single experiment can be carried out, and various protection experiments are inconvenient to expand.

Disclosure of Invention

In order to solve various problems of relay protection experiments in traditional teaching, the invention designs a set of experiment platform based on model design with complete functions and strong practicability, the platform adopts a mode of combining software and hardware, a software simulation platform (1) comprises an upper computer (through a GUI interface established in MATLAB, a plurality of relay protection experiments can be selected, experiment models can be converted into programs which can be identified and used by DSP), relay protection simulation experiments can be carried out in the upper computer, a hardware experiment platform (2) establishes a transmission line physical model (10) by using the idea of simulating 'high voltage and high current' by low voltage and small current, and a voltage transformer (6) and a current transformer (7) are used for acquiring voltage, current and voltage of the transmission line model (10) during normal and fault occurrence, A current signal; the collected signals are input into the DSP control panel (5), programs in the DSP control panel (5) are achieved under the upper computer, the DSP control panel (5) can process the signals, and finally the opening and closing of a circuit breaker (11) in the circuit protection device (8) are controlled through the processing result, so that the power transmission line can be rapidly connected or disconnected, and the purpose of fault protection is achieved. Just so can carry out operation and experiment safe relatively, this utility model has compensatied the not enough of traditional experiment, not only can be directly perceived lively show teaching content, can provide a platform that lets the student initiatively practice study in addition, and the student can realize on this platform that it knows its so purpose of knowing it so also to the data acquisition and the modification of protection action algorithm of transmission line trouble, can effectively improve its professional level.

The apparatus of the above problem solved by the present invention comprises:

1. physical model of transmission line (10): is the core of the hardware part of the experimental platform. The line model device includes: motor simulated load, three-phase reactor simulated transmission line. The method simulates the high voltage and large current of the actual power transmission line by using the low voltage and small current, and builds a power transmission line model (10) in a laboratory. The power transmission line can simulate relay protection experiments such as three-section current protection, directional current protection, distance protection and the like. The experimental device is isolated from the power grid through the isolation transformer, and the normal operation of the power grid cannot be influenced.

2. An upper computer: consists of a computer, MATLAB software and CCS software. The part is mainly to establish a simulation model of a relay protection experiment in a computer, combine simulation with a power transmission line which is actually built, and the experiment carried out in the simulation can be actually displayed on the power transmission line.

3. GUI interface in the upper computer: through a GUI interface established in MATLAB, a plurality of relay protection experiments can be selected, and an algorithm is selected.

The circuit relay protection experimental platform based on model design provided by the invention has the following advantages:

1. a physical power transmission line model is established by the idea of simulating high voltage and large current of an actual power transmission line of a power grid by low voltage and small current, so that the normal operation of the power grid is not influenced. For students, the relay protection of the power transmission line is known, and the safety of the students is protected.

2. The establishment of the human-computer interaction interface can intuitively display the protection processes of three-section current protection, directional current protection and distance protection.

3. Compared with the traditional physical model experiment table, the invention is safer and more reliable, has more complete and standard operation steps and can save a great deal of experiment teaching cost.

Drawings

FIG. 1 is a block diagram of an experiment platform system according to the present invention.

Detailed Description

The following detailed description will be provided to further explain the present invention in conjunction with the accompanying drawings, but the present invention is not limited thereto, and all similar methods and similar variations using the present invention shall fall within the protection scope of the present invention.

The invention relates to a relay protection teaching experiment platform device, which has the overall structure shown in figure 1, wherein a software part is an MATLAB simulation platform (1) and is used for establishing simulation models of various relay protection experiments of a power grid transmission line, then generating DSP codes from the simulation models and transmitting the DSP codes to a DSP controller (5) through communication between an upper computer and the DSP controller. In the upper computer, simulation of different relay protection can be carried out, data changes of all parts when faults occur are observed, and modification and setting of an algorithm can be carried out, so that students can learn the relay protection principle conveniently. The hardware experiment platform has two parts, one is DSP control panel (5), and its effect is voltage, the electric current data in gathering simulation transmission line (10) are handled (have voltage, the current signal when transmission line is normal, also have voltage, the current signal when breaking down), and the result of handling controls the shutoff and the switching on of circuit breaker (11) in simulation transmission line (10), and then can carry out syllogic current protection, direction current protection, distance protection effectively. And the other part is a simulated power transmission line (10) (a module line protection device), the part is equivalent processing of the actual power transmission line of the power grid, a physical model (10) of the power transmission line is established by the thought of simulating high voltage and large current by low voltage and small current, fault simulation can be carried out in the simulated power transmission line (10) in the experimental process, and the collection and processing of voltage and current during fault are carried out by the DSP control panel (5) to remove the fault in the power transmission line, thereby completing the experimental process of relay protection.

Claims

1. The utility model provides a line protection experiment platform based on model design, the experiment platform includes software platform (1) and hardware platform (2), wherein the software platform is exactly the host computer that comprises computer, MATLAB software, CCS software, and the hardware platform includes DSP the control unit (5), voltage, current transformer measuring unit (6) (7), step-up transformer (10), analog unit (line model) (11), circuit breaker (12).

2. The line protection experiment platform of claim 1, wherein: during the experiment, different types of experiment items can be entered through a GUI interface of MATLAB, Simulink simulation environment is linked, a simulation model of the experiment items is opened, the structure of the model is observed, simulation parameters are set and adjusted in corresponding sub-interfaces to perform simulation test, after the simulation is finished, a corresponding simulation model with a DSP module is opened, DSP engineering file codes are automatically generated through (Real Time word shop, RTW) provided by the MATLAB, debugging software of the DSP is started, a DSP executable file (out) is generated after the DSP is compiled correctly, the DSP executable file is downloaded into a DSP chip of a hardware system and operates in cooperation with a line model to verify the line protection principle.

3. The control unit (5) according to claim 1, characterized in that: the processor with the model number of DSPTMS320F28335 is adopted, the algorithm realization of microcomputer protection and the processing of measured data can be completed, the on and off of the relay are controlled through the output voltage signal, the on and off of the breaker (12) are further controlled by the relay, and the relay adopts 3 1-path relay modules with the model number of SRD-12 VDC-SL-C.

4. A voltage-current transformer measuring unit (6) (7) according to claim 1, characterized in that: the fault signals of the model lines are collected through voltage transformers and current transformers, the fault signals are transmitted to a DSP control board (5) through conditioning circuits (8) and (9), 6 voltage transformers adopt JDZ (X)10-3 and JSZ (X)10-3, and 9 current transformers adopt LMZC-1.

5. The step-up transformer (10) of claim 1, wherein: and isolating the simulation power transmission line from the power grid, and boosting the voltage of the power grid to 380V from 220V. The booster transformer adopts a SG-25kVA three-phase isolation type transformer.

6. Line model (11) according to claim 1, characterized in that: the low-voltage low-current power transmission line of the actual power grid is simulated by the low-voltage low-current power transmission line. And (3) constructing a power transmission line model with a certain length by using three-phase reactors with different reactance values.

7. The circuit breaker (12) of claim 1 wherein: when the line model (11) needs to break the line, the quick action can be performed to break the line. The circuit breaker (12) adopts 3 air-break circuit breakers with models of NXM-125S.

8. The GUI interface in MATLAB of the software platform of claim 2, wherein: the GUI provides complete user interface development tools, including a local editor, a menu editor, a property editor, an object browser, a geometric arrangement tool, and the like, and the GUI interface of the invention comprises: the computer protection algorithm options, the three-section current protection, the directional current protection and the distance protection options are clicked, and the corresponding simulation experiment can be carried out.