Insulator string zero value diagnosis method and system

Abstract

The invention belongs to the technical field of power systems, and discloses an insulator string zero value diagnosis method and system, and the method comprises the steps: analyzing insulator strings of different string types, and determining the voltage distribution conditions of insulators at all positions of the insulator strings under a normal operation condition and a zero value insulator condition; determining the position of the sensitive insulator according to the determined voltage distribution condition; according to the voltage distribution value of the position of the sensitive insulator, determining a luminescence threshold value of an electroluminescent material; and selecting an electroluminescent material according to the luminescence threshold value, carrying out luminescence by using the electroluminescent material according to the voltage change of the sensitive insulator, and determining whether the insulator string to be diagnosed has a zero-value fault according to the luminescence state. According to the invention, the position of the sensitive insulator is searched in the insulator chain of the power transmission line, and the electroluminescent material is applied, so that a single-piece or double-piece insulator alarm function is realized when the insulator chain has a zero-value fault.

Description

Technical Field

[0001] The present invention relates to the technical field of power systems, and in particular to a method and system for diagnosing zero value of an insulator string. Background Art

[0002] Insulators are important equipment components in transmission lines, which play the role of electrical insulation and mechanical support and are widely used in transmission lines of all levels. Insulators can be roughly divided into porcelain insulators, glass insulators and composite insulators according to material classification. Among them, porcelain insulators are widely used in my country's high-voltage transmission lines due to their good electrical insulation performance, good mechanical properties and good chemical stability. Moreover, porcelain insulators are cost-effective, have mature solutions for coordinating with electrical systems, and have rich experience in operation and maintenance technology. They are one of the most widely used types of insulators. However, porcelain insulators may have zero-value problems during operation. The harm lies in the fact that the existence of zero-value insulators makes the voltage distribution in the insulator string uneven, causing some insulators to withstand voltages higher than the design value. When dirty flashover and overvoltage occur, flashover occurs, causing large currents to flow through the insulator. The thermal effect caused by this causes faults such as porcelain head fracture, iron cap cracking or steel foot desheathing. In severe cases, this may cause the insulator to fall off the string, thus causing large-scale power outages.

[0003] The diagnosis technology of zero-value insulators has always been a hot research topic. Traditional methods include direct measurement of insulator resistance and voltage. The insulation resistance measurement method is a power outage detection method. Its advantages are direct detection means and simple methods. Its disadvantages are that it requires high-altitude detection, which brings difficulty and danger to the staff, and the workload of detecting a large number of insulators is huge. Compared with insulation resistance detection, the distributed voltage detection method operated by spark forks can be detected with power on, but there is still a problem of large workload and difficulty in achieving real-time monitoring. Many scholars have proposed diagnostic methods for physical quantities such as insulator string current and heat caused by zero-value insulators. Methods such as leakage current measurement and pulse current measurement can achieve real-time monitoring of insulator status by measuring current, but these methods are easily affected by changes in the operating status of the line itself, resulting in misjudgment and missed judgment, and these influencing factors are difficult to eliminate. Infrared thermal imaging detection, ultrasonic detection, and ultraviolet imaging detection can also achieve online monitoring, but they are easily affected by other environmental factors, and the detection methods used are relatively complex and have low accuracy.

[0004] In general, the physical quantity most directly affected by the appearance of zero-value insulators in the insulator string is the voltage distribution of the insulator string. Using the distributed voltage of the insulator string as the detection quantity is still the most accurate means. Therefore, how to develop a new type of insulator string zero-value diagnosis based on the distributed voltage of the insulator string as the detection quantity is an urgent problem to be solved. Summary of the invention

[0005] An embodiment of the present invention provides a method and system for diagnosing zero value of an insulator string. The method determines the position of a sensitive insulator based on the change law of the voltage distribution of each insulator in the string when zero value insulators appear at various positions in different string types, and uses electroluminescent materials at this position to monitor the voltage increase of the insulator to determine whether a zero value fault occurs in the insulator string.

[0006] In order to have a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. This summary is not intended to be a general review, nor is it intended to identify key / important components or to delineate the scope of protection of these embodiments. Its only purpose is to present some concepts in a simple form as a preface to the detailed description that follows.

[0007] According to a first aspect of an embodiment of the present invention, a method for diagnosing a zero value of an insulator string is provided.

[0008] In one embodiment, the insulator string zero value diagnosis method includes:

[0009] Analyze insulator strings of different string types to determine the voltage distribution of insulators at various positions of the insulator string under normal operating conditions and under zero-value insulator conditions;

[0010] Determine the position of a sensitive insulator according to the determined voltage distribution, wherein the sensitive insulator is the insulator with the largest comprehensive voltage change;

[0011] Determining the light emission threshold of the electroluminescent material according to the voltage distribution value at the position of the sensitive insulator;

[0012] According to the light emission threshold, an electroluminescent material is selected, and the selected electroluminescent material is disposed on a sensitive insulator of an insulator string to be diagnosed;

[0013] Electroluminescent materials are used to emit light according to the voltage change of the sensitive insulator, and it is determined whether a zero-value fault occurs in the insulator string to be diagnosed according to the light emission state.

[0014] In one embodiment, analyzing insulator strings of different string types to determine the voltage distribution of insulators at various positions of the insulator string under normal operating conditions includes:

[0015] Model the insulator strings of different string types to obtain the corresponding insulator string models;

[0016] According to the normal operating condition parameters, the electrostatic field simulation calculation is performed on the insulator string model to obtain the voltage distribution of the insulators at various positions of the insulator string under normal operating conditions.

[0017] In one embodiment, insulator strings of different string types are analyzed to determine the voltage distribution of insulators at various positions of the insulator string when a zero-value insulator working condition occurs, including:

[0018] Model the insulator strings of different string types to obtain the corresponding insulator string models;

[0019] Respectively replace the insulators at each position in the insulator string model with zero-value insulators to obtain a corresponding zero-value insulator string model;

[0020] The electrostatic field simulation calculation is carried out on the zero-value insulator string model respectively, and the voltage distribution of the insulators at various positions of the insulator string under the condition of zero-value insulators is obtained.

[0021] In one embodiment, the number of the sensitive insulator is one, and when the number of the sensitive insulator is one, determining the position of the sensitive insulator according to the determined voltage distribution includes:

[0022] According to the voltage distribution of insulators at various positions of the insulator string under normal operating conditions and the voltage distribution of insulators at various positions of the insulator string under the condition of zero-value insulators, the comprehensive voltage variation of insulators at various positions is calculated;

[0023] The insulator with the largest comprehensive voltage change is taken as the sensitive insulator, and the position of the sensitive insulator is obtained.

[0024] In one embodiment, the number of the sensitive insulators is 2, and when the number of the sensitive insulators is 2, determining the position of the sensitive insulator according to the determined voltage distribution includes:

[0025] According to the voltage distribution of insulators at various positions of the insulator string under normal operating conditions and the voltage distribution of insulators at various positions of the insulator string under the condition of zero-value insulators, the comprehensive voltage variation of insulators at various positions is calculated;

[0026] The insulator with the largest integrated voltage change is taken as the main sensitive insulator to obtain the position of the main sensitive insulator; the insulator with the second largest integrated voltage change is taken as the secondary sensitive insulator to obtain the position of the secondary sensitive insulator;

[0027] The position of the main sensitive insulator and the position of the secondary sensitive insulator are both used as the position of the sensitive insulator.

[0028] In one embodiment, the calculation formula of the comprehensive voltage change is:

[0029]

[0030] In the formula, δij is the comprehensive voltage change of the insulator; u ij is the voltage distribution value of the insulator when the zero-value insulator is present; u i0 is the voltage distribution value of the insulator under normal operating conditions; i is the i-th insulator; j is the j-th zero-value insulator.

[0031] In one embodiment, the maximum integrated voltage variation is calculated as follows:

[0032]

[0033] In the formula, a j is the maximum comprehensive voltage change; i is the i-th insulator; n is the total number of insulators in the insulator string; δ ij is the comprehensive voltage change of the insulator.

[0034] In one embodiment, determining the light emission threshold of the electroluminescent material according to the voltage distribution value of the sensitive insulator includes:

[0035] According to the predetermined voltage distribution of the insulators at various positions, the voltage distribution value under the condition that no zero-value insulator working condition occurs at the sensitive insulator position is obtained;

[0036] The minimum voltage value in the obtained voltage distribution value is set as the light emission threshold value of the electroluminescent material.

[0037] According to a second aspect of an embodiment of the present invention, a zero-value diagnosis system for an insulator string is provided.

[0038] In one embodiment, the insulator string zero value diagnosis system comprises:

[0039] The voltage distribution analysis module is used to analyze insulator strings of different string types and determine the voltage distribution of insulators at various positions of the insulator string under normal operating conditions and under the condition of zero-value insulators;

[0040] A sensitive insulator determination module, used to determine the position of a sensitive insulator according to the determined voltage distribution, wherein the sensitive insulator is the insulator with the largest comprehensive voltage change;

[0041] A light-emitting threshold determination module, used to determine the light-emitting threshold of the electroluminescent material according to the voltage distribution value at the position of the sensitive insulator;

[0042] A luminescent material setting module, used for selecting an electroluminescent material according to the luminescent threshold, and setting the selected electroluminescent material on a sensitive insulator of an insulator string to be diagnosed;

[0043] The zero-value fault diagnosis module is used to utilize electroluminescent materials to emit light according to the voltage change of sensitive insulators, and determine whether a zero-value fault occurs in the insulator string to be diagnosed according to the light emission state.

[0044] In one embodiment, when the voltage distribution analysis module analyzes insulator strings of different string types to determine the voltage distribution of insulators at various positions of the insulator strings under normal operating conditions, the insulator strings of different string types are modeled to obtain corresponding insulator string models; based on normal operating condition parameters, the insulator string model is subjected to electrostatic field simulation calculation to obtain the voltage distribution of insulators at various positions of the insulator string under normal operating conditions.

[0045] In one embodiment, when the voltage distribution analysis module analyzes insulator strings of different string types to determine the voltage distribution of insulators at various positions of the insulator string when a zero-value insulator working condition occurs, the insulator strings of different string types are modeled to obtain corresponding insulator string models; the insulators at various positions in the insulator string model are replaced with zero-value insulators to obtain corresponding zero-value insulator string models; and the zero-value insulator string models are subjected to electrostatic field simulation calculations to obtain the voltage distribution of insulators at various positions of the insulator string when a zero-value insulator working condition occurs.

[0046] In one embodiment, the number of the sensitive insulator is 1, and when the number of the sensitive insulator is 1, when the sensitive insulator determination module determines the position of the sensitive insulator according to the determined voltage distribution, the comprehensive voltage change of the insulators at each position of the insulator string under normal operating conditions and the voltage distribution of the insulators at each position of the insulator string under the condition where a zero-value insulator appears is calculated; the insulator with the largest comprehensive voltage change is taken as the sensitive insulator, and the position of the sensitive insulator is obtained.

[0047] In one embodiment, the number of the sensitive insulators is 2, and when the number of the sensitive insulators is 2, when the sensitive insulator determination module determines the position of the sensitive insulator according to the determined voltage distribution, the comprehensive voltage change of the insulators at each position of the insulator string under normal operating conditions and the voltage distribution of the insulators at each position of the insulator string under the condition where a zero-value insulator appears is calculated; the insulator with the largest comprehensive voltage change is taken as the main sensitive insulator to obtain the position of the main sensitive insulator; the insulator with the second largest comprehensive voltage change is taken as the secondary sensitive insulator to obtain the position of the secondary sensitive insulator; the position of the main sensitive insulator and the position of the secondary sensitive insulator are both taken as the position of the sensitive insulator.

[0048] In one embodiment, the calculation formula of the comprehensive voltage change is:

[0049]

[0050] In the formula, δ ij is the comprehensive voltage change of the insulator; u ij is the voltage distribution value of the insulator when the zero-value insulator is present; u i0 is the voltage distribution value of the insulator under normal operating conditions; i is the i-th insulator; j is the j-th zero-value insulator.

[0051] In one embodiment, the maximum integrated voltage variation is calculated as follows:

[0052]

[0053] In the formula, a j is the maximum comprehensive voltage change; i is the i-th insulator; n is the total number of insulators in the insulator string; δ ij is the comprehensive voltage change of the insulator.

[0054] In one embodiment, when the luminescence threshold determination module confirms the luminescence threshold of the electroluminescent material based on the voltage distribution value of the sensitive insulator, the voltage distribution value under the condition that no zero-value insulator appears at the sensitive insulator position is obtained based on the voltage distribution of the insulators at each predetermined position; and the minimum voltage value in the obtained voltage distribution value is set as the luminescence threshold of the electroluminescent material.

[0055] The technical solution provided by the embodiment of the present invention may have the following beneficial effects:

[0056] The present invention realizes the alarm function of a single or double insulator when a zero-value fault occurs in the insulator string by finding the position of a sensitive insulator in the insulator string of the transmission line and combining the application of electroluminescent materials. The present invention realizes the self-display function of the zero-value insulator string by defining the position of a single or double sensitive insulator in the insulator string, thereby realizing real-time monitoring of the zero-value situation in the insulator, avoiding the work of measuring the voltage of each insulator string in the original. At the same time, since the sensitive insulator position only emits light and displays itself when a zero value occurs in the string, the service life of the electroluminescent material in this application is effectively extended.

[0057] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0059] Figure 1 is a flow chart of a method for diagnosing a zero value of an insulator string according to an exemplary embodiment;

[0060] Figure 2 The invention is a structural block diagram of an insulator string zero value diagnosis system according to an exemplary embodiment. DETAILED DESCRIPTION

[0061] The following description and accompanying drawings fully illustrate the specific embodiments of this article so that those skilled in the art can practice them. Parts and features of some embodiments may be included in or replace parts and features of other embodiments. The scope of the embodiments of this article includes the entire scope of the claims, as well as all available equivalents of the claims. Herein, the terms "first", "second", etc. are only used to distinguish one element from another, without requiring or implying any actual relationship or order between these elements. In fact, the first element can also be called the second element, and vice versa. Moreover, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that the structure, device or equipment including a series of elements includes not only those elements, but also other elements that are not explicitly listed, or also include elements inherent to such structure, device or equipment. In the absence of more restrictions, the elements defined by the sentence "including one..." do not exclude the existence of other identical elements in the structure, device or equipment including the elements. Each embodiment is described in a progressive manner herein, and each embodiment focuses on the differences from other embodiments, and the same and similar parts between the embodiments can be referred to each other.

[0062] The terms "longitudinal", "lateral", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. in this document indicate the orientation or position relationship based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing this document and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In the description of this document, unless otherwise specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a mechanical connection or an electrical connection, it can also be the internal communication of two elements, it can be a direct connection, or it can be an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0063] As used herein, the term "plurality" means two or more than two, unless otherwise specified.

[0064] In this document, the character " / " indicates that the preceding and following objects are in an "or" relationship. For example, A / B means: A or B.

[0065] In this article, the term "and / or" is a description of the association relationship between objects, indicating that three relationships may exist. For example, A and / or B means: A or B, or, A and B.

[0066] It should be understood that, although the various steps in the flow chart are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear description in this article, the execution of these steps is not strictly limited in order, and these steps can be executed in other orders. Moreover, at least a portion of the steps in the figure may include multiple sub-steps or multiple stages, and these sub-steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these sub-steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a portion of the sub-steps or stages of other steps.

[0067] Each module in the device or system of the present application can be implemented in whole or in part by software, hardware, or a combination thereof. The above modules can be embedded in or independent of a processor in a computer device in the form of hardware, or can be stored in a memory in a computer device in the form of software, so that the processor can call and execute operations corresponding to the above modules.

[0068] In the absence of conflict, the embodiments of the present invention and the features of the embodiments may be combined with each other.

[0069] Figure 1 An embodiment of an insulator string zero value diagnosis method of the present invention is shown.

[0070] In this optional embodiment, the insulator string zero value diagnosis method includes:

[0071] Step S101, analyzing insulator strings of different string types to determine the voltage distribution of insulators at various positions of the insulator string under normal operating conditions and under the condition of zero-value insulators;

[0072] Step S103, determining the position of a sensitive insulator according to the determined voltage distribution, wherein the sensitive insulator is the insulator with the largest comprehensive voltage change;

[0073] Step S105, confirming the light emission threshold of the electroluminescent material according to the voltage distribution value at the position of the sensitive insulator;

[0074] Step S107, selecting an electroluminescent material according to the luminescence threshold, and placing the selected electroluminescent material on a sensitive insulator of the insulator string to be diagnosed;

[0075] Step S109, utilizing the electroluminescent material to emit light according to the voltage change of the sensitive insulator, and determining whether a zero-value fault occurs in the insulator string to be diagnosed according to the light emission state.

[0076] Figure 2 An embodiment of an insulator string zero value diagnosis system of the present invention is shown.

[0077] In this optional embodiment, the insulator string zero value diagnosis system includes:

[0078] The voltage distribution analysis module 201 is used to analyze insulator strings of different string types to determine the voltage distribution of insulators at various positions of the insulator string under normal operating conditions and under the condition of zero-value insulators;

[0079] A sensitive insulator determination module 203 is used to determine the position of a sensitive insulator according to the determined voltage distribution, wherein the sensitive insulator is the insulator with the largest comprehensive voltage change;

[0080] A light emitting threshold determination module 205, configured to determine the light emitting threshold of the electroluminescent material according to the voltage distribution value at the position of the sensitive insulator;

[0081] A luminescent material setting module 207, configured to select an electroluminescent material according to the luminescent threshold, and set the selected electroluminescent material on a sensitive insulator of the insulator string to be diagnosed;

[0082] The zero-value fault diagnosis module 209 is used to utilize the electroluminescent material to emit light according to the voltage change of the sensitive insulator, and determine whether the insulator string to be diagnosed has a zero-value fault according to the light emission state.

[0083] In the above optional embodiments, when analyzing insulator strings of different string types to determine the voltage distribution of insulators at various positions of the insulator string under normal operating conditions, the insulator strings of different string types can be modeled to obtain a corresponding insulator string model; according to the normal operating condition parameters, boundary conditions such as voltage in the simulation and material properties such as dielectric constants and resistance of components such as insulator porcelain parts, hardware, and equipment such as towers and conductors are set; and the insulator string model is subjected to electrostatic field simulation calculation using physical field finite elements to obtain the voltage distribution of insulators at various positions of the insulator string under normal operating conditions.

[0084] Correspondingly, when analyzing insulator strings of different string types to determine the voltage distribution of insulators at various positions of the insulator string when the zero-value insulator working condition occurs, the insulator strings of different string types can be modeled to obtain the corresponding insulator string model; the insulators at various positions in the insulator string model are replaced with zero-value insulators to obtain the corresponding zero-value insulator string model; then the boundary conditions such as voltage in the simulation and the material properties such as dielectric constants and resistance of components such as insulator porcelain parts, hardware, and equipment such as towers and conductors are set, and electrostatic field simulation calculations are performed on the zero-value insulator string model to obtain the voltage distribution of insulators at various positions of the insulator string when the zero-value insulator working condition occurs.

[0085] In practical applications, when a zero-value insulator appears in a string of insulators, the voltage distribution of the entire string of insulators will change, in which the distributed voltage on the zero-value insulator will become lower, while the distributed voltage on other insulators will be different from the standard situation. This is because the total voltage borne by the entire string of insulators remains unchanged, while the pressure-bearing capacity of the zero-value insulator becomes smaller, and the voltage it should bear is transferred to other insulators, and the size of the difference varies with the position of the zero value. When zero-value insulators appear at different positions in the insulator string, it is difficult to find an insulator at a fixed position whose voltage change amplitude is always the maximum value, but an insulator at a fixed position can be found in the insulator string. When zero-value insulators appear at different positions in the insulator string, the voltage change amplitude borne by the insulator at this fixed position is not always the largest, but it always maintains a large level, which can reach the luminescence threshold of the electroluminescent material and realize the self-display effect. The insulator at this position is defined as a sensitive insulator.

[0086] When a zero-value problem occurs in an insulator string, the voltage withstood by the insulator at the zero-value position will be significantly lower than the voltage value under standard conditions, while the voltage withstood by the insulator at the sensitive insulator position will increase significantly. By means of display means such as electroluminescence, an observable phenomenon will occur when the voltage withstood by the sensitive insulator increases, thereby determining that there is a zero-value problem on the insulator string, and then by inspecting the insulators of the string piece by piece, the zero-value insulator can be accurately located.

[0087] Taking the 110kV voltage level transmission line as an example, the insulator string of this voltage level transmission line considers the situation that each string consists of 9 insulators (the one closest to the high-voltage end is defined as No. 9, and the one closest to the ground end is defined as No. 1). Electric field simulation is performed on this situation, and it is found that the voltage of No. 4 insulator differs from the standard value by 6%, which meets the definition of sensitive insulators. Insulator strings with zero value insulators can be found more accurately.

[0088] Generally, in a 110kV voltage level transmission line, there will be only one zero value in a string of insulators. During detection, in order to avoid misjudgment caused by the zero value insulator appearing at the defined sensitive insulator position, a double sensitive insulator can be defined in the insulator string, that is, when a zero value appears at any position in the insulator string, the two positions with the largest voltage change difference and the second largest voltage change difference are found, and jointly judge whether there is a zero value insulator in the insulator string. Therefore, the number of the sensitive insulators can be 1 or 2.

[0089] Specifically, when the number of the sensitive insulator is one, when determining the position of the sensitive insulator according to the determined voltage distribution, the comprehensive voltage change of the insulator at each position of the insulator string under normal operating conditions and the voltage distribution of the insulator at each position of the insulator string under the condition where a zero-value insulator appears can be calculated; the insulator with the largest comprehensive voltage change is taken as the sensitive insulator, and the position of the sensitive insulator is obtained.

[0090] When the number of the sensitive insulators is 2, when determining the position of the sensitive insulator according to the determined voltage distribution, the comprehensive voltage variation of the insulators at each position of the insulator string under normal operating conditions and the voltage distribution of the insulators at each position of the insulator string under the condition where a zero-value insulator appears can be calculated; the insulator with the largest comprehensive voltage variation is taken as the main sensitive insulator to obtain the position of the main sensitive insulator; the insulator with the second largest comprehensive voltage variation is taken as the secondary sensitive insulator to obtain the position of the secondary sensitive insulator; the position of the main sensitive insulator and the position of the secondary sensitive insulator are both taken as the position of the sensitive insulator.

[0091] In the above optional embodiment, the calculation formula of the comprehensive voltage change is:

[0092]

[0093] In the formula, δ ij is the comprehensive voltage change of the insulator; u ij is the voltage distribution value of the insulator when the zero-value insulator is present; u i0 is the voltage distribution value of the insulator under normal operating conditions; i is the i-th insulator; j is the j-th zero-value insulator.

[0094] The calculation formula for the maximum comprehensive voltage change is:

[0095]

[0096] In the formula, a jis the maximum comprehensive voltage change; i is the i-th insulator; n is the total number of insulators in the insulator string; δ ij is the comprehensive voltage change of the insulator.

[0097] In addition, in the above optional embodiment, when confirming the luminous threshold of the electroluminescent material based on the voltage distribution value of the sensitive insulator, the voltage distribution value under the condition that no zero-value insulator appears at the sensitive insulator position is obtained based on the voltage distribution of the insulators at each position determined in advance; the minimum voltage value in the obtained voltage distribution value is set as the luminous threshold of the electroluminescent material, and when the distributed voltage at the sensitive insulator position exceeds this value, the sensitive insulator position emits light, indicating that zero-value insulators appear in the string of insulators and need to be repaired.

[0098] In summary, the present invention realizes the alarm function of a single or double insulator when a zero-value fault occurs in an insulator string by finding the position of a sensitive insulator in a transmission line insulator string and combining the application of electroluminescent materials. The present invention realizes the self-display function of a zero-value insulator string by defining the position of a single or double sensitive insulator in an insulator string, thereby realizing real-time monitoring of the zero-value situation in the insulator, avoiding the work of measuring the voltage of each insulator string in the original insulator string. At the same time, since the sensitive insulator position only emits light and displays itself when a zero value occurs in the string, the service life of the electroluminescent material in this application is effectively extended.

[0099] The present invention is not limited to the structures which have been described above and shown in the drawings, and various modifications and changes may be made without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

Claims

1. A method for diagnosing zero value of an insulator string, characterized in that: include: Analyze insulator strings of different string types to determine the voltage distribution of insulators at various positions of the insulator string under normal operating conditions and under zero-value insulator conditions; Determine the position of a sensitive insulator according to the determined voltage distribution, wherein the sensitive insulator is the insulator with the largest comprehensive voltage change; Determining the light emission threshold of the electroluminescent material according to the voltage distribution value at the position of the sensitive insulator; According to the light emission threshold, an electroluminescent material is selected, and the selected electroluminescent material is disposed on a sensitive insulator of an insulator string to be diagnosed; Electroluminescent materials are used to emit light according to the voltage change of the sensitive insulator, and it is determined whether a zero-value fault occurs in the insulator string to be diagnosed according to the light emission state.

2. The insulator string zero value diagnosis method according to claim 1, characterized in that: Analyze insulator strings of different string types to determine the voltage distribution of insulators at various positions of the insulator string under normal operating conditions, including: Model the insulator strings of different string types to obtain the corresponding insulator string models; According to the normal operating condition parameters, the electrostatic field simulation calculation is performed on the insulator string model to obtain the voltage distribution of the insulators at various positions of the insulator string under normal operating conditions.

3. The insulator string zero value diagnosis method according to claim 1, characterized in that: The insulator strings of different string types are analyzed to determine the voltage distribution of insulators at various positions of the insulator string under the condition of zero-value insulators, including: Model the insulator strings of different string types to obtain the corresponding insulator string models; Respectively replace the insulators at each position in the insulator string model with zero-value insulators to obtain a corresponding zero-value insulator string model; The electrostatic field simulation calculation is carried out on the zero-value insulator string model respectively, and the voltage distribution of the insulators at various positions of the insulator string under the condition of zero-value insulators is obtained.

4. The insulator string zero value diagnosis method according to claim 1, characterized in that: The number of the sensitive insulator is one, and when the number of the sensitive insulator is one, determining the position of the sensitive insulator according to the determined voltage distribution includes: According to the voltage distribution of insulators at various positions of the insulator string under normal operating conditions and the voltage distribution of insulators at various positions of the insulator string under the condition of zero-value insulators, the comprehensive voltage variation of insulators at various positions is calculated; The insulator with the largest comprehensive voltage change is taken as the sensitive insulator, and the position of the sensitive insulator is obtained.

5. The insulator string zero value diagnosis method according to claim 1, characterized in that: The number of the sensitive insulators is 2, and when the number of the sensitive insulators is 2, determining the position of the sensitive insulator according to the determined voltage distribution includes: According to the voltage distribution of insulators at various positions of the insulator string under normal operating conditions and the voltage distribution of insulators at various positions of the insulator string under the condition of zero-value insulators, the comprehensive voltage variation of insulators at various positions is calculated; The insulator with the largest integrated voltage change is taken as the main sensitive insulator to obtain the position of the main sensitive insulator; the insulator with the second largest integrated voltage change is taken as the secondary sensitive insulator to obtain the position of the secondary sensitive insulator; The position of the main sensitive insulator and the position of the secondary sensitive insulator are both used as the position of the sensitive insulator.

6. The insulator string zero value diagnosis method according to claim 4 or 5, characterized in that: The calculation formula of the comprehensive voltage change is: In the formula, δ ij is the comprehensive voltage change of the insulator; u ij is the voltage distribution value of the insulator when the zero-value insulator is present; u i0 is the voltage distribution value of the insulator under normal operating conditions; i is the i-th insulator; j is the j-th zero-value insulator.

7. The insulator string zero value diagnosis method according to claim 6, characterized in that: The calculation formula for the maximum comprehensive voltage change is: In the formula, a j is the maximum comprehensive voltage change; i is the i-th insulator; n is the total number of insulators in the insulator string; δ ij is the relative comprehensive voltage change of the insulator.

8. The insulator string zero value diagnosis method according to claim 1, characterized in that: According to the voltage distribution value at the sensitive insulator position, confirming the light emission threshold of the electroluminescent material includes: According to the predetermined voltage distribution of the insulators at various positions, the voltage distribution value under the condition that no zero-value insulator working condition occurs at the sensitive insulator position is obtained; The minimum voltage value in the obtained voltage distribution value is set as the light emission threshold value of the electroluminescent material.

9. An insulator string zero value diagnosis system, characterized in that: include: The voltage distribution analysis module is used to analyze insulator strings of different string types and determine the voltage distribution of insulators at various positions of the insulator string under normal operating conditions and under the condition of zero-value insulators; A sensitive insulator determination module, used to determine the position of a sensitive insulator according to the determined voltage distribution, wherein the sensitive insulator is the insulator with the largest comprehensive voltage change; A light-emitting threshold determination module, used to determine the light-emitting threshold of the electroluminescent material according to the voltage distribution value at the position of the sensitive insulator; A luminescent material setting module, used for selecting an electroluminescent material according to the luminescent threshold, and setting the selected electroluminescent material on a sensitive insulator of an insulator string to be diagnosed; The zero-value fault diagnosis module is used to utilize electroluminescent materials to emit light according to the voltage change of sensitive insulators, and determine whether a zero-value fault occurs in the insulator string to be diagnosed according to the light emission state.

10. The insulator string zero value diagnosis system according to claim 9, characterized in that: When analyzing insulator strings of different string types and determining the voltage distribution of insulators at various positions of the insulator strings under normal operating conditions, the voltage distribution analysis module models the insulator strings of different string types to obtain corresponding insulator string models; and performs electrostatic field simulation calculation on the insulator string model according to normal operating condition parameters to obtain the voltage distribution of insulators at various positions of the insulator string under normal operating conditions.

11. The insulator string zero value diagnosis system according to claim 9, characterized in that: When the voltage distribution analysis module analyzes insulator strings of different string types and determines the voltage distribution of insulators at various positions of the insulator string under the condition of zero-value insulators, the insulator strings of different string types are modeled to obtain corresponding insulator string models; the insulators at various positions in the insulator string model are replaced with zero-value insulators to obtain corresponding zero-value insulator string models; and the zero-value insulator string models are subjected to electrostatic field simulation calculations to obtain the voltage distribution of insulators at various positions of the insulator string under the condition of zero-value insulators.

12. The insulator string zero value diagnosis system according to claim 9, characterized in that: The number of the sensitive insulators is 1, and when the number of the sensitive insulators is 1, when the sensitive insulator determination module determines the position of the sensitive insulator according to the determined voltage distribution, the comprehensive voltage change of the insulators at each position of the insulator string is calculated according to the voltage distribution of the insulators at each position of the insulator string under normal operating conditions and the voltage distribution of the insulators at each position of the insulator string under the condition where a zero-value insulator appears; the insulator with the largest comprehensive voltage change is taken as the sensitive insulator, and the position of the sensitive insulator is obtained.

13. The insulator string zero value diagnosis system according to claim 9, characterized in that: When the number of the sensitive insulators is 2 and the number of the sensitive insulators is 2, the sensitive insulator determination module determines the position of the sensitive insulator according to the determined voltage distribution, and calculates the comprehensive voltage variation of the insulators at each position according to the voltage distribution of the insulators at each position of the insulator string under normal operating conditions and the voltage distribution of the insulators at each position of the insulator string under the condition where a zero-value insulator appears; takes the insulator with the largest comprehensive voltage variation as the main sensitive insulator to obtain the position of the main sensitive insulator; takes the insulator with the second largest comprehensive voltage variation as the secondary sensitive insulator to obtain the position of the secondary sensitive insulator; The position of the main sensitive insulator and the position of the secondary sensitive insulator are both used as the position of the sensitive insulator.

14. The insulator string zero value diagnosis system according to claim 12 or 13, characterized in that: The calculation formula of the comprehensive voltage change is: In the formula, δ ij is the comprehensive voltage change of the insulator; u ij is the voltage distribution value of the insulator when the zero-value insulator is present; u i0 is the voltage distribution value of the insulator under normal operating conditions; i is the i-th insulator; j is the j-th zero-value insulator.

15. The insulator string zero value diagnosis system according to claim 14, characterized in that: The calculation formula for the maximum comprehensive voltage change is: In the formula, a j is the maximum comprehensive voltage change; i is the i-th insulator; n is the total number of insulators in the insulator string; δ ij is the comprehensive voltage change of the insulator.

16. The insulator string zero value diagnosis system according to claim 9, characterized in that: When the luminescence threshold value determination module confirms the luminescence threshold value of the electroluminescent material according to the voltage distribution value of the sensitive insulator, the voltage distribution value under the condition that no zero-value insulator appears at the sensitive insulator position is obtained according to the voltage distribution of the insulators at various positions determined in advance; and the minimum voltage value in the obtained voltage distribution value is set as the luminescence threshold value of the electroluminescent material.

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