A method and system for accurately locating a single-end fault of a high-voltage GIL device

Abstract

The embodiment of the present invention provides a method and system for accurately locating a single-end fault of a high-voltage GIL device, and relates to the technical field of electrical equipment. The method proposes to add an ultra-wideband voltage sensor to the outlet end of the high-voltage GIL device, accurately record the transient voltage waveform generated by the fault point, perform continuous wavelet transform on the transient voltage waveform, obtain the cumulative characteristic curve of the wavelet coefficient, and then extract the characteristic moment of the voltage traveling wave, so as to calculate the time length of the transient voltage propagating from the fault point to the outlet end, and finally combine the propagation speed of the electromagnetic wave in the GIL device to obtain the distance between the fault point and the outlet end. The method only requires an ultra-wideband voltage sensor to automatically realize 10-meter-level accurate positioning of the fault point of the GIL device, which is of great significance for shortening the emergency repair time of the insulation fault of the GIL device, improving the efficiency of GIL fault handling, and ensuring the reliability of power supply.

Description

Technical Field

[0001] The present invention relates to the technical field of electrical equipment, and in particular to a method and system for accurately locating a single-end fault of a high-voltage GIL device. Background Art

[0002] Gas-insulated transmission lines (GIL) are high-voltage, high-current power transmission equipment that uses high-pressure gas and conductors in a coaxial arrangement. GIL equipment has large transmission capacity, low unit loss, low environmental impact, and high operational reliability. It is widely used in large hydropower stations, nuclear power stations, and complex transmission channels such as river crossings and mountain crossings.

[0003] During the operation of high-voltage GIL equipment, insulation breakdown failures are often caused by latent internal insulation defects. Once insulation breakdown occurs in high-voltage GIL, the transmission channel will be blocked, which will seriously affect the power output of the power station and threaten the safety and stability of the large power grid. Therefore, after an insulation breakdown occurs in high-voltage GIL equipment, it is necessary to quickly and accurately locate the fault location to facilitate timely designation of emergency repair plans and shorten the power outage time.

[0004] However, since the GIL equipment is fully enclosed, it is difficult to quickly locate the fault location. Since the GIL is long, usually more than 500 meters, and the gas chambers are long and numerous, the conventional gas decomposition product detection method is too time-consuming and costly to locate the faulty gas chamber, and it may not be able to detect the faulty gas chamber.

[0005] Therefore, designing a method and system for quickly and accurately locating faults of high-voltage GIL equipment, which can quickly, conveniently and accurately determine the fault point of the high-voltage GIL equipment, is a technical problem that urgently needs to be solved. Summary of the invention

[0006] The purpose of the present invention includes being able to quickly, conveniently and accurately determine the fault point of a high-voltage GIL device.

[0007] The embodiments of the present invention can be implemented as follows:

[0008] In a first aspect, an embodiment of the present invention provides a method for accurately locating a single-end fault of a high-voltage GIL device. The method for accurately locating a single-end fault of a high-voltage GIL device includes:

[0009] Detect transient voltage generated at the fault point of GIL equipment;

[0010] According to the transient voltage, the time length of the transient voltage propagating from the fault point to the outgoing line terminal is obtained;

[0011] According to the duration, the location of the fault point is obtained.

[0012] In an optional implementation manner, the step of obtaining the time length for the transient voltage to propagate from the fault point to the outgoing line terminal according to the transient voltage includes:

[0013] According to the transient voltage, the transient voltage waveform u(t) is obtained;

[0014] Perform continuous wavelet transformation on the transient voltage waveform u(t) to obtain the wavelet coefficient cumulative characteristic curve p(t), and extract the voltage traveling wave characteristic moment according to the wavelet coefficient cumulative characteristic curve p(t);

[0015] According to the characteristic moment of voltage traveling wave, the time length of transient voltage propagating from the fault point to the outgoing line terminal is obtained.

[0016] In an optional implementation, the transient voltage waveform u(t) is subjected to continuous wavelet transform to obtain the wavelet coefficient cumulative characteristic curve p(t) as follows:

[0017]

[0018] Among them, CWT(f,t) is the continuous wavelet transform coefficient, and F1 is the cutoff frequency.

[0019] In an optional implementation, the calculation formula of the continuous wavelet transform coefficient CWT(f,t) is:

[0020]

[0021] in, is the Haar function.

[0022] In an optional implementation manner, the calculation formula for the time it takes for the transient voltage to propagate from the fault point to the outgoing line terminal is obtained according to the characteristic moment of the voltage traveling wave:

[0023]

[0024] Wherein, T is the duration of transient voltage propagation from the fault point to the outgoing line terminal, t1 is the traveling wave characteristic moment corresponding to the first largest local extreme point P(1) in the wavelet coefficient cumulative characteristic curve p(t), and t3 is the traveling wave characteristic moment corresponding to the third largest local extreme point P(3) in the wavelet coefficient cumulative characteristic curve p(t).

[0025] In an optional implementation manner, the calculation formula for obtaining the location of the fault point according to the duration is:

[0026] L = T × v;

[0027] Among them, L is the distance between the fault point and the outgoing line terminal, and v is the propagation speed of electromagnetic waves in the GIL equipment.

[0028] In a second aspect, an embodiment of the present invention provides a single-end precise fault location system for a high-voltage GIL device, the single-end precise fault location system for a high-voltage GIL device comprising:

[0029] An ultra-wideband voltage sensor is used to be installed at the outlet of the GIL device and detect the transient voltage generated at the fault point of the GIL device;

[0030] The server is connected to the ultra-wideband voltage sensor and is used to obtain the duration of the transient voltage propagating from the fault point to the output terminal according to the transient voltage, and to obtain the location of the fault point according to the duration.

[0031] Advantageous effects of the method and system for accurately locating a single-end fault of a high-voltage GIL device provided by the embodiments of the present invention:

[0032] By detecting the transient voltage generated at the fault point of the GIL equipment and using waveform feature analysis to obtain the time it takes for the transient voltage to propagate from the fault point to the outgoing line end, and based on the time, the location of the fault point can be determined. This enables the fault point of the high-voltage GIL equipment to be determined quickly, conveniently, and accurately, and can achieve single-end precise positioning of ten-meter-level faults. This is of great significance for shortening the repair time of insulation faults of GIL equipment, improving the efficiency of fault handling of GIL equipment, and ensuring power supply reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0034] Figure 1 A block diagram of a single-end accurate fault location system for high-voltage GIL equipment provided by an embodiment of the present invention;

[0035] Figure 2 A first scenario diagram of the application of the single-end accurate fault location method for high-voltage GIL equipment provided by an embodiment of the present invention;

[0036] Figure 3 A second scenario diagram for the application of the single-end accurate fault location method for high-voltage GIL equipment provided by an embodiment of the present invention;

[0037] Figure 4 A flow chart of a method for accurately locating a single-end fault of a high-voltage GIL device provided by an embodiment of the present invention;

[0038] Figure 5A flow chart for obtaining the time it takes for transient voltage to propagate from the fault point to the outgoing line terminal;

[0039] Figure 6 The transient voltage waveform u(t) is formed by the transient voltage generated at the fault point of the GIL equipment;

[0040] Figure 7 The wavelet coefficient cumulative characteristic curve p(t) is obtained by continuous wavelet transform of the transient voltage waveform u(t).

[0041] Icons: 100- single-end precise fault location system for high-voltage GIL equipment; 110- ultra-wideband voltage sensor; 120- server; 200- GIL equipment; 210- outlet terminal; 220- fault point. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0043] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0045] In the description of the present invention, it should be noted that if the terms "upper", "lower", "inside", "outside", etc. appear to indicate an orientation or position relationship, they are based on the orientation or position relationship shown in the accompanying drawings, or are the orientation or position relationship in which the product of the invention is usually placed when used. They are only for the convenience of describing the present invention 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 operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0046] In addition, the terms “first”, “second”, etc., if used, are merely used to distinguish between the descriptions and should not be understood as indicating or implying relative importance.

[0047] It should be noted that, in the absence of conflict, the features in the embodiments of the present invention may be combined with each other.

[0048] Please refer to Figure 1 This embodiment provides a single-end precise fault location system 100 for high-voltage GIL equipment. The single-end precise fault location system 100 for high-voltage GIL equipment includes an ultra-wideband voltage sensor 110 and a server 120. The ultra-wideband voltage sensor 110 is electrically connected to the server 120.

[0049] See also Figure 2 and Figure 3 The ultra-wideband voltage sensor 110 is used to be installed at the outlet terminal 210 of the GIL device 200. Specifically, the distance between the ultra-wideband voltage sensor 110 and the outlet terminal 210 of the GIL device 200 is preferably less than or equal to 15m. The ultra-wideband voltage sensor 110 is also used to detect the transient voltage generated by the fault point 220 of the GIL device 200.

[0050] The server 120 is used to obtain the duration of the transient voltage propagating from the fault point 220 to the outgoing line terminal 210 according to the transient voltage, and obtain the position of the fault point 220 according to the duration. Figure 3 and Figure 4 The distance between the fault point 220 and the outlet terminal 210 is L. The single-end precise fault positioning system 100 for high-voltage GIL equipment provided in this embodiment can quickly, conveniently and accurately determine the size of L, thereby determining the position of the fault point 220. This is of great significance for shortening the repair time of insulation faults of the GIL equipment 200, improving the fault handling efficiency of the GIL equipment 200, and ensuring power supply reliability.

[0051] Specifically, the effective frequency band of the ultra-wideband voltage sensor 110 is in the range of 2 Hz to 200 MHz, the sampling rate of the ultra-wideband voltage sensor 110 is greater than or equal to 250 MS / s, and the sampling analog bandwidth of the ultra-wideband voltage sensor 110 is greater than or equal to 100 MHz. The recording length of the ultra-wideband voltage sensor 110 for a single trigger is not less than 150 us.

[0052] The server 120 is used to obtain a transient voltage waveform u(t) based on the transient voltage, and then perform continuous wavelet transform on the transient voltage waveform u(t) to obtain a wavelet coefficient cumulative characteristic curve p(t), and then extract the voltage traveling wave characteristic moment based on the wavelet coefficient cumulative characteristic curve p(t), and then obtain the duration of the transient voltage propagation from the fault point 220 to the output terminal 210 based on the voltage traveling wave characteristic moment, and obtain the position of the fault point 220 based on the duration.

[0053] That is, the server 120 stores a program corresponding to the single-end accurate positioning method for high-voltage GIL equipment faults, and the server 120 extracts the program to execute the single-end accurate positioning method for high-voltage GIL equipment faults. Figure 4 The single-end accurate fault location method for high-voltage GIL equipment specifically includes the following steps:

[0054] S1: Detect the transient voltage generated at the fault point of the GIL equipment.

[0055] Specifically, the ultra-wideband voltage sensor 110 is used to detect the transient voltage generated at the fault point 220 of the GIL device 200 and send the transient voltage to the server 120 .

[0056] S2: Please refer to Figure 5 , according to the transient voltage, the time length for the transient voltage to propagate from the fault point to the outgoing line terminal is obtained, which specifically includes the following steps:

[0057] S21: Obtaining a transient voltage waveform u(t) according to the transient voltage.

[0058] Specifically, the ultra-wideband voltage sensor 110 is used to detect the transient voltage generated at the fault point 220 of the GIL device 200, and the server 120 is used to obtain the transient voltage waveform u(t) according to the transient voltage. The general form of the transient voltage waveform u(t) formed by the transient voltage generated at the fault point 220 of the GIL device 200 is as follows: Figure 6 shown.

[0059] S22: Perform continuous wavelet transformation on the transient voltage waveform u(t) to obtain a wavelet coefficient cumulative characteristic curve p(t).

[0060] Among them, the calculation formula for the wavelet coefficient cumulative characteristic curve p(t) obtained by continuous wavelet transform of the transient voltage waveform u(t) is:

[0061]

[0062] Among them, CWT(f,t) is the continuous wavelet transform coefficient, and F1 is the cutoff frequency.

[0063] In the above formula, the calculation formula of the continuous wavelet transform coefficient CWT(f,t) is:

[0064]

[0065] in, is the Haar function.

[0066] The wavelet coefficient cumulative characteristic curve p(t) obtained after S22 is as follows Figure 7 shown.

[0067] S23: Extracting the voltage traveling wave characteristic moment according to the wavelet coefficient cumulative characteristic curve p(t).

[0068] See also Figure 7First, according to the wavelet coefficient cumulative characteristic curve p(t), determine the first largest local extreme point P(1), the second largest local extreme point P(2) and the third largest local extreme point P(3) in the wavelet coefficient cumulative characteristic curve p(t);

[0069] Then, P(1), P(2) and P(3) are extracted, and the traveling wave characteristic moment t1, traveling wave characteristic moment t2 and traveling wave characteristic moment t3 corresponding to P(1), P(2) and P(3) are determined.

[0070] S24: Calculate the time it takes for the transient voltage to propagate from the fault point to the outgoing line terminal according to the characteristic moment of the voltage traveling wave.

[0071] The calculation formula for the duration of the transient voltage propagating from the fault point 220 to the outgoing line terminal 210 is obtained according to the characteristic moment of the voltage traveling wave:

[0072]

[0073] In the above formula, T is the time length of the transient voltage propagating from the fault point 220 to the outgoing line terminal 210, t1 is the traveling wave characteristic moment corresponding to the first largest local extreme point P(1) in the wavelet coefficient cumulative characteristic curve p(t), and t3 is the traveling wave characteristic moment corresponding to the third largest local extreme point P(3) in the wavelet coefficient cumulative characteristic curve p(t).

[0074] S3: According to the duration, the location of the fault point is obtained.

[0075] According to the duration, the calculation formula for obtaining the position of the fault point 220 is:

[0076] L = T × v;

[0077] Wherein, L is the distance between the fault point 220 and the outgoing line terminal 210, and v is the propagation speed of electromagnetic waves in the GIL device 200. Combined with the propagation speed of electromagnetic waves in the GIL, in this embodiment, the value of v can be 294 m / us.

[0078] The beneficial effects of the single-end accurate fault location system 100 and method for high-voltage GIL equipment provided in this embodiment are as follows:

[0079] By detecting the transient voltage generated by the fault point 220 of the GIL device 200, using waveform feature analysis to obtain the time length for the transient voltage to propagate from the fault point 220 to the outgoing line terminal 210, and obtaining the position of the fault point 220 based on the time length, the fault point 220 of the high-voltage GIL device 200 can be determined quickly, conveniently and accurately, and single-end precise positioning of ten-meter-level faults can be achieved, which is of great significance for shortening the repair time of insulation faults of the GIL device 200, improving the fault handling efficiency of the GIL device 200, and ensuring power supply reliability.

[0080] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A single-end accurate fault location method for high-voltage GIL equipment, characterized in that: The single-end accurate fault location method for high-voltage GIL equipment comprises: Detecting a transient voltage generated at a fault point (220) of a GIL device (200); According to the transient voltage, the duration of the transient voltage propagating from the fault point (220) to the outgoing line terminal (210) is obtained, comprising: obtaining a transient voltage waveform u(t) according to the transient voltage; performing continuous wavelet transform on the transient voltage waveform u(t) to obtain a wavelet coefficient cumulative characteristic curve p(t); extracting a voltage traveling wave characteristic moment according to the wavelet coefficient cumulative characteristic curve p(t); obtaining the duration of the transient voltage propagating from the fault point (220) to the outgoing line terminal (210) according to the voltage traveling wave characteristic moment, performing continuous wavelet transform on the transient voltage waveform u(t) to obtain a wavelet coefficient cumulative characteristic curve p(t) whose calculation formula is: Where CWT(f,t) is the continuous wavelet transform coefficient, F1 is the cutoff frequency; The calculation formula of continuous wavelet transform coefficient CWT(f,t) is: in, is the haar function; The calculation formula for obtaining the time length of the transient voltage propagating from the fault point (220) to the outgoing line terminal (210) according to the voltage traveling wave characteristic moment is: Wherein, T is the duration of the transient voltage propagating from the fault point (220) to the outgoing line terminal (210), t1 is the traveling wave characteristic moment corresponding to the first largest local extreme point P(1) in the wavelet coefficient cumulative characteristic curve p(t), and t3 is the traveling wave characteristic moment corresponding to the third largest local extreme point P(3) in the wavelet coefficient cumulative characteristic curve p(t); According to the duration, the position of the fault point (220) is obtained.

2. The single-end accurate fault location method for high-voltage GIL equipment according to claim 1, characterized in that: According to the duration, the calculation formula for obtaining the position of the fault point (220) is: L = T × v; Wherein, L is the distance between the fault point (220) and the outlet terminal (210), and v is the propagation speed of electromagnetic waves in the GIL device (200).

3. A single-end accurate fault location system for high-voltage GIL equipment, characterized in that: The single-end accurate fault location system for high-voltage GIL equipment comprises: An ultra-wideband voltage sensor (110) is used to be installed at an outlet terminal (210) of a GIL device (200) and detect a transient voltage generated at a fault point (220) of the GIL device (200); The server (120) is connected to the ultra-wideband voltage sensor (110) and is used to obtain the duration of the transient voltage propagating from the fault point (220) to the outlet terminal (210) according to the transient voltage, and obtain the position of the fault point (220) according to the duration, including: obtaining a transient voltage waveform u(t) according to the transient voltage; performing continuous wavelet transform on the transient voltage waveform u(t) to obtain a wavelet coefficient cumulative characteristic curve p(t), and extracting a voltage traveling wave characteristic moment according to the wavelet coefficient cumulative characteristic curve p(t); obtaining the duration of the transient voltage propagating from the fault point (220) to the outlet terminal (210) according to the voltage traveling wave characteristic moment, and performing continuous wavelet transform on the transient voltage waveform u(t) to obtain a calculation formula of the wavelet coefficient cumulative characteristic curve p(t): Where CWT(f,t) is the continuous wavelet transform coefficient, F1 is the cutoff frequency; The calculation formula of continuous wavelet transform coefficient CWT(f,t) is: in, is the haar function; The calculation formula for obtaining the time length of the transient voltage propagating from the fault point (220) to the outgoing line terminal (210) according to the voltage traveling wave characteristic moment is: Wherein, T is the duration of the transient voltage propagating from the fault point (220) to the outgoing line terminal (210), t1 is the traveling wave characteristic moment corresponding to the first largest local extreme point P(1) in the wavelet coefficient cumulative characteristic curve p(t), and t3 is the traveling wave characteristic moment corresponding to the third largest local extreme point P(3) in the wavelet coefficient cumulative characteristic curve p(t).

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