Method for determining electric flushing parameters of safety belt of composite insulation part

Abstract

The invention provides a method for determining electric flushing parameters of a safety belt of a composite insulation part, which comprises the following steps of: constructing a relation model between the operating age limit and the altitude of the composite insulation part and the aging characteristic quantity of the composite insulation part, and acquiring the operating age limit and the altitude of the current composite insulation part to be flushed, solving the aging characteristic quantity of the to-be-washed composite insulating part; constructing an aging characteristic quantity and material strength threshold prediction model, and substituting the aging characteristic quantity into the aging characteristic quantity and material strength threshold prediction model to obtain a material strength threshold; determining the voltage grade of the current to-be-washed composite insulation part; a water flow impact pressure prediction model is constructed based on flushing parameters, and the flushing parameters comprise the jet flow safety distance, the water pressure, the nozzle diameter and the jet flow angle; constructing constraint conditions, wherein the constraint conditions comprise a leakage current constraint condition and a mechanical property constraint condition; solving is carried out under the constraint condition, and the optimal flushing parameter is obtained.

Description

Technical Field

[0001] The present invention relates to a method for operation and maintenance of power equipment, and particularly to a method for determining safe live flushing parameters of composite insulation components. Background Art

[0002] Silicone rubber composite insulation components are widely used in power systems due to their good hydrophobicity, anti-pollution performance and low cost. Since the insulation components of transmission lines are exposed to nature for a long time, especially in high-altitude and heavy-industry saline-alkali areas, dirt accumulation will form on their surfaces. These dirt containing salt, acid and alkaline components will form electrolytes after dissolving in water, which have strong conductivity. When encountering special weather such as fog and dew or in a long-term humid seasonal climate, the surface of the insulation components is extremely prone to flashover discharge, thus triggering catastrophic pollution flashover accidents such as tripping and grid system disconnection.

[0003] Although the composite insulation material initially has excellent hydrophobic migration characteristics, after being exposed to the combined action of industrial pollution and climate for a long time, the siloxane chain segments on its surface degrade and age, resulting in an exponential decay of the anti-pollution performance. It is extremely prone to pollution flashover along its surface, causing large-scale power outages. Therefore, how to efficiently remove dirt and maintain the composite insulation components after several years of operation has become the key.

[0004] In the prior art, the live flushing guidelines formulate technical specifications based on the mechanical properties and surface topography of porcelain and glass insulation components, and fail to fully consider the vulnerability of the unique silicone rubber umbrella skirt structure of composite insulation materials. Especially for the aged composite insulation components under strong ultraviolet and long operation years, the mechanical property threshold is greatly reduced. Therefore, the lag of this current technical standard leads to the easy occurrence of mechanical damage to the aged umbrella skirts when using traditional flushing parameters, resulting in surface cracks or even tearing of the umbrella skirts, thus posing a great safety hazard.

[0005] Therefore, in order to solve the above technical problems, it is urgent to propose a new technical means. Summary of the Invention

[0006] In view of this, the purpose of the present invention is to provide a method for determining safe live flushing parameters of composite insulation components, which determines their aging characteristics based on the operation years and altitude of the composite insulation components, then determines the mechanical strength of the composite insulation components based on the aging characteristics, and constructs a flushing parameter solution model by combining its leakage current as a constraint, so as to obtain the pressure, jet angle, flushing safety distance, etc. during the flushing process, reduce the safety hazards during the flushing process, and reduce the damage to the composite insulation components during flushing, ensuring the safe operation of the power system.

[0007] A method for determining safe live flushing parameters of composite insulation components provided by the present invention includes the following steps:

[0008] S1. Build a relationship model between the operation years and altitude of the composite insulation component and the aging characteristic quantity of the composite insulation component, obtain the operation years and altitude of the composite insulation component to be flushed currently, and calculate the aging characteristic quantity of the composite insulation component to be flushed.

[0009] S2. Build a prediction model for the aging characteristic quantity and the material strength threshold, and substitute the aging characteristic quantity into the prediction model for the aging characteristic quantity and the material strength threshold to obtain the material strength threshold.

[0010] S3. Determine the voltage level and the diameter of the flushing nozzle of the composite insulation component to be flushed currently; and build a prediction model for the water flow impact pressure based on the flushing parameters, where the flushing parameters include the jet safety distance, water pressure, nozzle diameter, and jet angle.

[0011] S4. Build constraint conditions, including the leakage current constraint condition and the mechanical property constraint condition; solve under the constraint conditions to obtain the optimal flushing parameters.

[0012] Furthermore, the relationship model between the operation years and altitude of the composite insulation component and the aging characteristic quantity of the composite insulation component is specifically:

[0013] Q = 0.1exp(1.62T + 0.9H);

[0014] Where: T represents the normalized operation years, H represents the normalized altitude, and Q represents the aging characteristic quantity of the composite insulation component.

[0015] Furthermore, the prediction model for the aging characteristic quantity and the material strength threshold is specifically:

[0016] x = ln(Q / 1.5) / (-0.55);

[0017] Where: x represents the mean value of the material strength.

[0018] Furthermore, the prediction model for the water flow impact pressure is specifically:

[0019]

[0020] Where: T p represents the water flow impact pressure; θ represents the jet angle, L represents the jet safety distance, P represents the water flow outlet pressure, and A, B1, C1, D1, B2, C2, D2, B3, C3, D3 are all constant coefficients.

[0021] Furthermore, the mechanical property constraint condition is specifically:

[0022] T p < k·x; where: k represents the safety margin, and x represents the mean value of the mechanical strength.

[0023] Further, the leakage current constraint condition is as follows:

[0024] I < 1 mA;

[0025] Where: L nor represents the normalized value of the jet safety distance, P nor represents the normalized value of the water flow outlet pressure, and ρ is the water conductivity.

[0026] Advantages of the present invention: Through the present invention, based on the operation years and altitude of the composite insulation component, its aging characteristics are determined, then based on the aging characteristics, the mechanical strength of the composite insulation component is determined, and combined with its leakage current as a constraint, a flushing parameter solution model is constructed, so as to obtain the pressure, jet angle, flushing safety distance, etc. during the flushing process, reduce the potential safety hazards during the flushing process, and reduce the damage to the composite insulation component during flushing, ensuring the operation safety of the power system. Description of the Drawings

[0027] The present invention will be further described below in conjunction with the drawings and embodiments:

[0028] Figure 1 is the flow chart of the present invention. Detailed Embodiments

[0029] The following further elaborates on the present invention in detail:

[0030] A method for determining the safe live flushing parameters of a composite insulation component provided by the present invention includes the following steps:

[0031] S1. Construct a relationship model between the operation years and altitude of the composite insulation component and the aging characteristic quantity of the composite insulation component, obtain the operation years and altitude of the composite insulation component to be flushed currently, and calculate the aging characteristic quantity of the composite insulation component to be flushed;

[0032] S2. Construct a prediction model of the aging characteristic quantity and the material strength threshold, and substitute the aging characteristic quantity into the prediction model of the aging characteristic quantity and the material strength threshold to obtain the material strength threshold;

[0033] S3. Determine the voltage level of the composite insulation component to be flushed currently; and construct a water flow impact pressure prediction model based on the flushing parameters, where the flushing parameters include jet safety distance, water pressure, nozzle diameter, and jet angle;

[0034] S4. Construct constraint conditions, which include leakage current constraint conditions and mechanical property constraint conditions; solve under the constraint conditions to obtain the optimal flushing parameters; through the present invention, the aging characteristics are determined based on the operation years and altitude of the composite insulation component, then the mechanical strength of the composite insulation component is determined based on the aging characteristics, and combined with its leakage current as a constraint, a flushing parameter solution model is constructed, so as to calculate the pressure, jet angle, flushing safety distance, etc. during the flushing process, reduce the potential safety hazards during the flushing process, and reduce the damage to the composite insulation component during flushing, ensuring the operation safety of the power system.

[0035] In this embodiment, the relationship model between the operation years and altitude of the composite insulation component and the aging characteristic quantity of the composite insulation component is specifically:

[0036] Q = 0.1exp(1.62T + 0.9H);

[0037] Where: T represents the normalized operation years, H represents the normalized altitude, and Q represents the aging characteristic quantity of the composite insulation component.

[0038] The construction of the prediction model for the aging characteristic quantity and the material strength threshold is specifically:

[0039] x = ln(Q / 1.5) / (-0.55);

[0040] Where: x represents the mean value of the material strength.

[0041] The prediction model for the water flow impact pressure is specifically:

[0042]

[0043] Where: T p represents the water flow impact pressure; θ represents the jet angle, L represents the jet safety distance, P represents the water flow outlet pressure, and A, B1, C1, D1, B2, C2, D2, B3, C3, D3 are all constant coefficients, and these constant coefficients are determined by existing methods, such as being given by the empirical method or being fitted through simulation tests.

[0044] In this embodiment, the mechanical property constraint condition is specifically:

[0045] T p < k·x; Where: k represents the safety margin, x represents the mean value of the mechanical strength, and this mean value of the mechanical strength is the mean value of the shear strength, puncture strength, and tensile strength.

[0046] The leakage current constraint condition is:

[0047] I < 1 mA;

[0048] Where: Lnor represents the normalized value of the jet safety distance, P nor represents the normalized value of the water outlet pressure, ρ is the water conductivity, α1 to α 10 all represent constant coefficients, which are determined by existing methods, such as the empirical method, and different values are given at different operating altitudes. Another example is the fitting method. The composite insulation components are simulated and flushed under different water pressures and jet safety distances, and then the leakage current is judged after flushing, and then the fitting is obtained. By solving the mechanical constraint and the leakage current constraint (for the inequality solution, the existing method is adopted and will not be elaborated here), the jet angle, the water outlet pressure and the jet safety distance. Of course, for the diameter of the nozzle, it can be selected according to the water pressure. For example: which nozzle diameter can meet the pressure requirement.

[0049] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the purpose and scope of the technical solutions of the present invention, and they should all be covered by the scope of the claims of the present invention.

Claims

1. A method for determining the safe live flushing parameters of a composite insulation component, characterized in that: It includes the following steps: S1. Construct a relationship model between the operation years and altitude of the composite insulation component and the aging characteristic quantity of the composite insulation component, obtain the operation years and altitude of the composite insulation component to be flushed currently, and calculate the aging characteristic quantity of the composite insulation component to be flushed; S2. Construct a prediction model for the aging characteristic quantity and the material strength threshold, and substitute the aging characteristic quantity into the prediction model for the aging characteristic quantity and the material strength threshold to obtain the material strength threshold; S3. Determine the voltage level of the composite insulation component to be flushed currently; and construct a water flow impact pressure prediction model based on the flushing parameters, where the flushing parameters include the jet safety distance, water pressure, nozzle diameter, and jet angle; S4. Construct constraint conditions, including leakage current constraint conditions and mechanical property constraint conditions; solve under the constraint conditions to obtain the optimal flushing parameters.

2. The method for determining the safe live flushing parameters of the composite insulation component according to claim 1, characterized in that: The relationship model between the operation years and altitude of the composite insulation component and the aging characteristic quantity of the composite insulation component is specifically: Q = 0.1exp(1.62T + 0.9H); Where: T represents the normalized operation years, H represents the normalized altitude, and Q represents the aging characteristic quantity of the composite insulation component.

3. The method for determining the safe live flushing parameters of the composite insulation component according to claim 1, characterized in that: The construction of the prediction model for the aging characteristic quantity and the material strength threshold is specifically: x = ln(Q / 1.5) / (-0.55); Where: x represents the mean value of the material strength.

4. The method for determining the safe live flushing parameters of the composite insulation component according to claim 1, wherein: The water flow impact pressure prediction model is specifically: Where: T p represents the impact pressure of the water flow; θ represents the jet angle, L represents the safe distance of the jet, P represents the outlet pressure of the water flow, and A, B1, C1, D1, B2, C2, D2, B3, C3, D3 are all constant coefficients.

5. The method for determining the safe live washing parameters of the composite insulation component according to claim 1, characterized in that: The mechanical property constraint condition is specifically: T p <k·x; where: k represents the safety margin and x represents the mean mechanical strength.

6. The method for determining the safe live flushing parameters of the composite insulation component according to claim 1, characterized in that: The leakage current constraint condition is: I < 1 mA; Wherein: L nor represents the normalized value of the jet safety distance, P nor represents the normalized value of the water flow outlet pressure, and ρ is the water conductivity.

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