A method for simulating the diffusion of characteristic gases in a true-type GIS device failure

Abstract

The present invention discloses a method for simulating the diffusion of fault characteristic gases in a full-scale GIS device, which further includes: on the basis of collecting the gas production data of characteristic components under different fault types simulated in the laboratory and considering the influence of various key factors, optimizing and fitting the data to obtain a gas production rate equation, and importing the equation into FLUENT software to realize the diffusion of fault characteristic gases in the full-scale SF6 device; thereby achieving an effect very close to the diffusion of characteristic gases generated by partial discharge or local overheating in a real device while they are being generated, revealing the diffusion mechanism of SF6 decomposed characteristic gases in the GIS device, and combining with gas component detection technology to improve the level of fault discovery and diagnosis of the GIS device.

Description

Technical Field

[0001] The present invention belongs to the technical field of GIS equipment fault diagnosis, and particularly relates to a method for simulating the diffusion of fault characteristic gases in a true-type GIS equipment. Background Art

[0002] GIS equipment is widely used in the power system due to its small floor area and long operation and maintenance time. However, from the fault statistics data after the wide application of GIS equipment in recent years, the reliability of GIS is still affected by insulation faults and overheating faults: the equipment faults account for more than 12% of the total failure rate of electrical equipment. A large number of literature reports, standards and actual operation data show that when insulation faults and overheating faults occur in GIS equipment, sulfur hexafluoride (SF 6 ) will decompose to generate CF 4 , CO 2 , SOF 4 , SOF 2 , SO 2 F 2， SO 2 and HF and other fault characteristic components.

[0003] The detection technology of SF 6 characteristic gas components has developed rapidly, and latent faults of GIS equipment have been found many times by detecting fault characteristic components. However, in actual operating GIS equipment, the characteristic gas components are greatly affected by the internal gas diffusion characteristics of the equipment and the internal adsorbent. When partial discharge or local overheating occurs in the equipment, a small amount of fault characteristic components such as SO 2 and other gases will be adsorbed during the diffusion to the gas filling port, resulting in the inability to detect in time. Only relying on the characteristic gas component detection technology, there is a situation of missed detection of SF 6 equipment faults. The power outage caused by equipment faults brings huge economic losses. Application No. 202011403631.X proposed an analysis method for the diffusion effect of characteristic component gases in SF 6 electrical equipment. Application No. 202110110103.3 proposed a method for determining the diffusion characteristics of SO 2 in GIS equipment based on CFD technology. Application No. 202110925446.5 proposed a fault location method for gas insulated switchgear equipment. However, on the one hand, the above existing technologies do not consider issues such as the gas production time and gas production rate during internal equipment faults, ignoring the gas production process of characteristic gases and the time to reach the maximum concentration, which has a large difference from the actual situation; on the other hand, it is the diffusion constructed for a simple model, and there are deficiencies in judging the gas diffusion characteristics in real GIS equipment. Summary of the Invention

[0004] Technical problem to be solved by the present invention: To provide a method for simulating the diffusion of characteristic gases in a true-type GIS device, which can simulate the real situation of the simultaneous generation and diffusion of characteristic gases during a GIS chamber failure based on a full-scale model, and can express the process of the generation of characteristic gas components (such as the time when a certain characteristic gas reaches its maximum concentration) in an experiment. This technology complements the gas component detection technology, and through joint analysis, it further improves the level of fault discovery and diagnosis of GIS devices.

[0005] Technical solution of the present invention:

[0006] A method for simulating the diffusion of characteristic gases in a true-type GIS device, which includes: on the basis of collecting the gas production data of characteristic components under different fault types and considering the influence of various key factors in the laboratory, optimizing and fitting the data to obtain a gas production rate equation, and importing the equation into FLUENT software to realize the diffusion of characteristic gases in a true-type SF 6 device during a fault.

[0007] Specifically, it includes the following steps:

[0008] Step 1: Establish a GIS chamber model, mesh it through ICEM, and then import it into the FLUENT main simulation software using workbench;

[0009] Step 2: Input the basic experimental parameters, including pressure, temperature, characteristic gas component parameters, and the gas production rate equation, into the FLUENT software, and then perform a simulation;

[0010] Step 3: Output the simulation results to obtain the diffusion cloud maps of various characteristic gases and the concentration changes at the monitoring points.

[0011] The GIS chamber model adopts a 1:1 full-scale model.

[0012] The method for building the GIS chamber model is as follows: Use the structure diagram of a 110KV-class GIS device, and select the voltage transformer, circuit breaker, disconnector, earthing switch, fast earthing switch, and lightning arrester as the prototype for building a 1:1 model. Use CAD to draw the diagram and build the model according to the actual size.

[0013] The implementation method of the gas production rate equation includes:

[0014] Collect the concentration values of each characteristic gas component changing with time under different conditions and input them into an Excel table;

[0015] Import the data into Origin, judge the applicable function form, and use the corresponding function to fit the data to obtain a fitting curve;

[0016] Determine whether the fitting degree of the fitting curve meets the requirements, and finally output the fitting curve that meets the requirements.

[0017] The characteristic gas components include CO 2 , SO 2 F 2 , SO 2 , CF 4 and H 2 S.

[0018] During the simulation process, pour the gas production time and gas production rate equations of different characteristic gas components into FLUENT and conduct diffusion simulation simultaneously; the gas production time includes the start time and the end time.

[0019] The basic experimental parameters also include moisture, adsorbent, and oxygen content; they are taken into consideration during the simulation, and these parameters are jointly considered with the model and fault type selected during modeling to obtain the parameters closest to reality.

[0020] Advantages of the present invention:

[0021] The present invention simulates the state of characteristic gas generation and diffusion while generating during GIS chamber faults. Referring to the size of GIS equipment under 110 kV in actual engineering, FLUENT is used as the simulation software, and a 1:1 real model is built in the simulation system. Referring to the generation rates of different characteristic gases at different energy levels, corresponding mathematical formulas are obtained through numerical analysis and imported into the FLUENT software. On the basis of considering the gas production time rate, simulate the state of characteristic gas starting from zero and diffusing while generating, so as to obtain the effect of characteristic gas generation and diffusion while generating, which is very close to that of partial discharge or local overheating of real equipment, revealing the diffusion mechanism of SF 6 decomposition characteristic gas of GIS equipment, and combining with gas component detection technology to improve the fault discovery and diagnosis level of GIS equipment. Description of the drawings

[0022] Figure 1 It is a schematic flow chart of the present invention. Detailed implementation manners

[0023] On the basis of collecting the gas production data of characteristic components under different fault types simulated in the laboratory and considering the influence of various key factors, the data is optimized and fitted to obtain the gas production rate equation, and the equation is imported into the FLUENT software to realize the diffusion of fault characteristic gas in the real SF 6 equipment.

[0024] When using the FLUENT software to solve the diffusion process of GIS fault characteristic gas, the steps are as follows:

[0025] ① Establish a GIS compartment model, mesh it using ICEM, and then import it into the FLUENT main simulation software through workbench;

[0026] ② Input the actual basic experimental parameters (pressure, temperature, characteristic gas component parameters, etc.) into the FLUENT software. The most important one is the gas production rate equation, and then conduct the simulation;

[0027] ③ Output the simulation results to obtain the diffusion cloud maps of each characteristic gas and the concentration changes at the monitoring points, and obtain an experimental process that can better fit the situation of generation and diffusion during GIS equipment failures.

[0028] In order to obtain more realistic simulation results, the present invention uses a 1:1 full-scale model to simulate the actual GIS equipment, so that the diffusion of characteristic gases in each internal compartment of the GIS equipment can be observed (such as the diffusion characteristics of different characteristic gases in dead corners and corners), and the diffusion of fault characteristic components in the actual GIS equipment is visualized.

[0029] Select the structure diagram of the widely used 110KV-class GIS equipment, and select the typical interval (including voltage transformer, circuit breaker, disconnecting switch, earthing switch, fast earthing switch, lightning arrester) as the prototype for building the 1:1 model. Use CAD to draw the diagram and build the model according to the actual size. The full-scale model simulation largely solves the situation that does not conform to reality caused by the disconnection between simulation and reality, and provides a more accurate method for actually solving GIS faults.

[0030] Part for obtaining the gas production rate equation:

[0031] Use the Origin data processing computer software. When using Origin to solve the gas production rate equations of each component, the specific steps are as follows:

[0032] ① First, collect the concentration values of each characteristic gas component changing with time under different conditions and input them into a table (Excel);

[0033] ② Import the data into Origin, preliminarily judge the applicable function form, and apply the corresponding function to fit the data to obtain a fitting curve;

[0034] ③ Judge whether the fitting degree of the fitting curve meets the expectation, and finally output an ideal fitting curve.

[0035] Meeting the expectation means a fitting curve with a fitting degree above 0.95; it shows that the fitting curve coincides highly with the original data and meets the expected requirements.

[0036] Taking SOF 2 As an example:

[0037]

[0038]

[0039] Note: In the formula, y is the concentration (μL / L) and x is the time (h).

[0040] Basically, the gas generation rate equations for other characteristic gas components (CO 2 , SO 2 F 2 , SO 2 , CF 4 , H 2 S) can also be fitted to obtain their respective gas generation rate equations.

[0041] During the simulation process, the gas generation times (start time, end time) and gas generation rate equations of different characteristic gas components can be imported into FLUENT and diffusion simulations can be carried out simultaneously.

[0042] This is because the various parameters or modules of the GIS compartment are not all the same. Among the more critical parameters or factors that can affect the characteristic gas components during a fault, those that are more common in current inventions and research are: temperature, pressure, moisture, adsorbent, oxygen content. These parameters and modules should be taken into account during experiments or simulations. These conditions should be considered jointly with the model selected during modeling, the fault type, etc. for analysis to obtain parameters that are close to reality.

Claims

1. A method for simulating the diffusion of characteristic gases in a true-type GIS device, characterized in that: It includes: Based on the gas production data of characteristic components collected in the laboratory under different simulated fault types and considering the influence of various key factors, after optimizing and fitting the data, a gas production rate equation is obtained. The equation is imported into the FLUENT software to realize the diffusion of fault characteristic gases in the prototype SF 6 equipment; Specifically, it includes the following steps: Step 1: Establish a GIS chamber model, mesh it through ICEM, and then import it into the FLUENT main simulation software using workbench; the method for building the GIS chamber model is as follows: adopt the structure diagram of a 110KV-class GIS device, and select the voltage transformer, circuit breaker, disconnector, earthing switch, fast earthing switch, and lightning arrester as the prototype for building a 1:1 model. Use CAD to draw the diagram and build the model according to the actual size; Step 2: Input the basic experimental parameters, including pressure, temperature, characteristic gas component parameters, and gas production rate equation, into the FLUENT software, and then perform the simulation; The implementation method of the gas production rate equation includes: Collect the concentration values of each characteristic gas component changing with time under different conditions and input them into an Excel table; Import the data into Origin, judge the applicable function form, and use the corresponding function to fit the data to obtain a fitting curve; Judge whether the fitting degree of the fitting curve meets the requirements, and finally output the fitting curve that meets the requirements; Step 3: Output the simulation results to obtain the diffusion cloud map of each characteristic gas and the concentration change of the monitoring points; During the simulation process, pour the gas production time and gas production rate equation of different characteristic gas components into FLUENT and perform the diffusion simulation simultaneously; the gas production time includes the start time and the end time; the basic experimental parameters also include moisture, adsorbent, and oxygen content; these parameters are taken into consideration during the simulation, and these parameters are jointly considered with the model selected during modeling and the fault type to obtain the parameters closest to reality.

2. A method for simulating the diffusion of characteristic gases in a true-type GIS device according to claim 1, characterized in that: The GIS chamber model adopts a 1:1 full-scale model.

3. A method for simulating the diffusion of characteristic gases in a true-type GIS device according to claim 1, characterized in that: The characteristic gas components include CO 2 , SO 2 F 2 , SO 2 , CF 4 and H 2 S.

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