A GIL partial discharge positioning device based on optical fiber timing networking

Abstract

The present invention relates to a GIL partial discharge positioning device based on optical fiber timing networking, comprising a partial discharge detection sensor installed in a GIL cavity and a local collection unit connected thereto, a partial discharge detection sensor is arranged at each end of each local collection unit, and the local collection unit is connected to a background monitoring control unit through a network connection line; a GIL partial discharge positioning device based on optical fiber timing networking is provided, which greatly improves the positioning accuracy and the efficiency of the state maintenance of power equipment; the accurate timing of different local collection units can be realized, and the TOA of the partial discharge signal to the sensor can be accurately calculated to realize the accurate positioning of the partial discharge source. The present invention can effectively improve the effectiveness of online partial discharge monitoring and improve the efficiency of the state maintenance of power equipment.

Description

Technical Field

[0001] The invention relates to the field of GIL partial discharge online monitoring devices, in particular to a GIL partial discharge positioning device based on optical fiber timing networking. Background Art

[0002] Gas-insulated Metal-enclosed Transmission Line (GIL) is a long-distance power transmission equipment that uses SF6 or SF6 mixed with other gases for insulation. It has the outstanding advantages of high voltage, high current, strong power transmission capacity, flexible layout, stable operation, long service life and small impact on the environment. Due to the modular structural design of the GIL system, insulation defects such as metal particles, insulation cracks, and metal spikes are often left inside due to poor component processing technology and poor assembly site environment. Under normal conditions of the GIL, these defects are repeatedly broken down and extinguished locally under the action of external voltage, that is, partial discharge occurs. Although the discharge amount of such discharge is generally not large, and the short-term existence will not cause the entire insulation to break down immediately, under long-term working voltage, partial discharge will cause the insulation defects to gradually expand, and finally cause the entire insulation to break down. Once a GIL fails, the repair workload is large and the power outage time is long. In addition, GIL is generally responsible for the large-capacity power transmission task of important lines, and the economic losses and social impacts caused by failure and shutdown are immeasurable.

[0003] The partial discharge detection of GIL is to install ultrasonic sensors or UHF sensors on its cavity, and judge whether there is partial discharge inside the GIL and the location of the partial discharge source through the characteristics of ultrasonic or UHF signals received by the sensor. At present, there are generally two methods to locate the partial discharge source:

[0004] 1) Based on the positioning of the receiving sensor, that is, if a sensor receives a partial discharge signal, it can be roughly determined that the discharge source is located near this sensor. Although this method is easy to implement, it has low accuracy. In particular, the super-long GIL tube is equivalent to a coaxial waveguide, and the discharge signal will propagate along the tube. Because the sensors along the line all receive the discharge signal, positioning fails.

[0005] 2) First, the discharge source is initially located based on the online monitoring device, and then a second accurate positioning is performed in combination with live detection means. Although this method makes up for the problem of inaccurate positioning of partial discharge online monitoring to a certain extent, it also increases the workload of live detection, especially for GIL lines that are several kilometers or even tens of kilometers long. This method is difficult to operate and has poor feasibility.

[0006] It can be seen that achieving online precise positioning of GIL partial discharge is a technical difficulty that needs to be urgently solved in the field of GIL condition monitoring and diagnosis research technology. Summary of the invention

[0007] The technical problem to be solved by the present invention is to provide a GIL partial discharge positioning device based on optical fiber timing networking to solve the defects existing in the prior art.

[0008] The technical solution of the present invention to solve the above technical problems is as follows:

[0009] A GIL partial discharge positioning device based on optical fiber timing networking comprises a partial discharge detection sensor installed in a GIL cavity and a local collection unit connected thereto, wherein a partial discharge detection sensor is arranged at both ends of each of the local collection units, and the local collection units are connected to a background monitoring control unit via a network connection line; the partial discharge detection sensor is responsible for collecting ultrasonic signals or ultra-high frequency electromagnetic wave signals excited by local discharge inside the GIL, and transmitting them to the local collection unit connected thereto, the local collection unit comprises an amplifier, a filter and an analog-to-digital converter connected in series in sequence, and sends the processed data to the background monitoring control unit; when the background monitoring control unit detects the discharge signal detected by the partial discharge sensor, it sends a timing instruction to the local collection unit via the network transmission line.

[0010] Further, the partial discharge detection sensor is connected to the on-site collection unit via a coaxial cable or an optical fiber;

[0011] Furthermore, the field collection units are connected in series through optical fibers to form a network. When they receive a time synchronization instruction issued by the background monitoring control unit, they use the clock of a field collection unit as a reference to synchronize the time of other field collection units.

[0012] The present invention also provides a GIL partial discharge positioning method based on optical fiber timing networking, which specifically includes the following steps:

[0013] 1) When the background monitoring control unit detects partial discharge inside the GIL, it sends a timing instruction to the on-site acquisition unit through the network transmission line;

[0014] 2) When the local collection unit receives the time synchronization instruction issued by the background monitoring control unit, it uses the clock of a local collection unit as a reference to synchronize the time of other local collection units;

[0015] 3) After the on-site acquisition unit completes the timing, it will trigger the sensor to synchronously collect the partial discharge signal, process and upload the signal, and the background monitoring control unit calculates the location of the partial discharge source by detecting the arrival time of the partial discharge signal to different sensors.

[0016] Furthermore, in the above step 3), the specific method for calculating the local discharge source is as follows:

[0017] The double-end positioning method is used to calculate the location of the local discharge source. The device collects the time T1 and T2 when the discharge source signal reaches the sensors at both ends. Assuming that the distance between the two sensors is L and the signal transmission speed is V, L1 can be calculated by the following formula:

[0018] Furthermore, in the above step 3), the specific method for calculating the local discharge source is as follows:

[0019] The single-ended positioning method is used to calculate the location of the local discharge source. The device collects the time T1 when the discharge source signal reaches the sensor, the time T2 when the signal reaches the sensor after being reflected by the insulator, and the time T3 when the signal reaches the sensor after being reflected again by the discharge source. Assuming that the distance from the sensor to the insulator is L0, L can be calculated by the following formula:

[0020] The beneficial effects of the present invention are: providing a GIL partial discharge positioning device based on optical fiber timing networking, greatly improving positioning accuracy and improving the efficiency of power equipment status maintenance; it can achieve accurate timing of different on-site acquisition units, and accurately calculate the TOA of partial discharge signals to sensors to achieve accurate positioning of partial discharge sources. The present invention can effectively improve the effectiveness of partial discharge online monitoring and improve the efficiency of power equipment status maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the structure of the present invention;

[0022] Figure 2 This is a schematic diagram of optical fiber timing of the present invention;

[0023] Figure 3a , Figure 3b It is a schematic diagram of the positioning principle of the present invention. DETAILED DESCRIPTION

[0024] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0025] like Figure 1As shown, a GIL partial discharge positioning device based on optical fiber timing networking includes a partial discharge detection sensor installed in the GIL cavity and an on-site collection unit connected thereto, a partial discharge detection sensor is arranged at both ends of each of the on-site collection units, and the on-site collection units are connected to a background monitoring control unit through a network connection line; the partial discharge detection sensor is responsible for collecting ultrasonic signals or ultra-high frequency electromagnetic wave signals excited by the partial discharge inside the GIL, and transmitting them to the on-site collection unit connected thereto, the on-site collection unit includes an amplifier, a filter and an analog-to-digital converter connected in series in sequence, and sends the processed data to the background monitoring control unit; when the background monitoring control unit detects the discharge signal detected by the partial discharge sensor, it sends a timing instruction to the on-site collection unit through the network transmission line.

[0026] In a specific implementation, the partial discharge detection sensor is connected to an on-site collection unit via a coaxial cable or an optical fiber;

[0027] Specific working principle:

[0028] The on-site acquisition unit of the device is responsible for amplifying, filtering and analog-to-digital conversion of the local discharge signal collected and uploaded by the sensor, and transmitting the processed data to the background monitoring control unit, which is connected to the background monitoring control unit through a network transmission line.

[0029] The background monitoring control unit of the device analyzes and processes the data uploaded by the on-site collection unit and performs positioning calculations. When it detects that there is partial discharge inside the GIL, it sends a timing instruction to the on-site collection unit through the network transmission line.

[0030] In a specific embodiment, the field collection units are networked in series via optical fibers. When they receive a time synchronization instruction from a background monitoring control unit, they use the clock of a field collection unit as a reference to synchronize time with other field collection units.

[0031] After the different on-site acquisition units of the device complete the time synchronization, the sensors will be triggered to synchronously collect the partial discharge signals, and the signals will be processed and uploaded. The background monitoring control unit calculates the location of the partial discharge source by detecting the arrival time difference of the partial discharge signals to different sensors. The device locates the partial discharge source by detecting the arrival time difference of the partial discharge signals to different sensors through the time of arrival (TOA) technology.

[0032] The positioning error of the device caused by the different lengths of the coaxial cables or optical fibers from each sensor to the on-site collection unit is corrected by the background monitoring control unit through addition and subtraction.

[0033] The present invention can realize accurate timing of different on-site acquisition units and accurately calculate the TOA of the partial discharge signal to the sensor to realize accurate positioning of the partial discharge source. The present invention can effectively improve the effectiveness of partial discharge online monitoring and improve the efficiency of power equipment status maintenance.

[0034] Figure 1 The system connection diagram of the GIL partial discharge locating device is shown. In the figure, the partial discharge detection sensor installed in the GIL cavity is connected to the on-site collection unit via a coaxial cable or optical fiber, and the on-site collection unit is connected to the background monitoring control unit via a network connection line; the partial discharge detection sensor is responsible for collecting ultrasonic signals or ultra-high frequency electromagnetic wave signals excited by the local discharge inside the GIL; the on-site collection unit amplifies, filters, and performs analog-to-digital conversion on the partial discharge signals collected and uploaded by the sensor. The background monitoring control unit analyzes and processes the data uploaded by the on-site collection unit, performs positioning calculations, and sends timing instructions to the on-site collection unit;

[0035] Attached Figure 2 Schematic diagram of optical fiber timing network of the device

[0036] Figure 2 The figure is a schematic diagram of the optical fiber timing network. In the figure, the field acquisition unit is connected to the background monitoring control unit through a network connection line, and different field acquisition units are connected in series through optical fiber. When the background monitoring control unit detects the presence of partial discharge inside the GIL, it sends a timing instruction to the field acquisition unit through the network transmission line. When the field acquisition unit receives the timing instruction sent by the background monitoring control unit, it uses the clock of a certain field acquisition unit as a reference to synchronize the time with other field acquisition units. After the field acquisition unit completes the timing, it will trigger the sensor to synchronously collect the partial discharge signal, and process and upload the signal. The background monitoring control unit calculates the location of the partial discharge source by detecting the arrival time of the partial discharge signal to different sensors.

[0037] Figure 3 Schematic diagram of device positioning principle

[0038] Figure 3 is a schematic diagram of the positioning principle of the device. The device calculates the location of the local discharge source by detecting the arrival time of the local discharge signal to the sensor using a double-end positioning method or a single-end positioning method.

[0039] When using the attached Figure 3a In the double-end positioning method, the device collects the time T1 and T2 when the discharge source signal reaches the sensors at both ends. Assuming that the distance between the two sensors is L and the signal transmission speed is V, L1 can be calculated by the following formula (1):

[0040]

[0041] When using the attached Figure 3bIn the single-end positioning method, the device collects the time T1 when the discharge source signal reaches the sensor, the time T2 when the signal is reflected by the insulator and reaches the sensor, and the time T3 when the signal is reflected again by the discharge source and reaches the sensor. Assuming that the distance from the sensor to the insulator is L0, L can be calculated by the following formula (2):

[0042]

[0043] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A GIL partial discharge locating device based on optical fiber timing networking, characterized in that: It includes a local discharge detection sensor installed in the GIL cavity and a local collection unit connected thereto, wherein a local discharge detection sensor is respectively arranged at both ends of each local collection unit, and the local collection unit is connected to a background monitoring control unit via a network connection line; the local discharge detection sensor is responsible for collecting ultrasonic signals or ultra-high frequency electromagnetic wave signals excited by local discharge inside the GIL, and transmitting them to the local collection unit connected thereto, the local collection unit includes an amplifier, a filter and an analog-to-digital converter connected in series in sequence, and sends the processed data to the background monitoring control unit; when the background monitoring control unit detects the discharge signal detected by the local discharge sensor, it sends a timing instruction to the local collection unit via the network transmission line; The field collection units are connected in series through optical fibers to form a network. When they receive a time synchronization instruction issued by the background monitoring control unit, they use the clock of a field collection unit as a reference to synchronize the time of other field collection units. After the on-site acquisition unit completes the timing, it will trigger the sensor to synchronously collect the partial discharge signal, and process and upload the signal. The background monitoring control unit calculates the location of the partial discharge source by detecting the arrival time of the partial discharge signal to different sensors.

2. A GIL partial discharge locating device based on optical fiber timing networking according to claim 1, characterized in that: The partial discharge detection sensor is connected to the on-site collection unit via a coaxial cable or an optical fiber.

3. A GIL partial discharge locating method using the GIL partial discharge locating device based on optical fiber timing networking as claimed in claim 1, characterized in that: The method comprises the following steps: 1) when the background monitoring control unit detects the existence of partial discharge inside the GIL, it sends a time synchronization instruction to the local acquisition unit through the network transmission line; 2) when the local acquisition unit receives the time synchronization instruction sent by the background monitoring control unit, it uses the clock of a certain local acquisition unit as a reference to synchronize the time of other local acquisition units; 3) after the local acquisition unit completes the time synchronization, it triggers the sensor to synchronously collect the partial discharge signal, processes and uploads the signal, and the background monitoring control unit calculates the location of the partial discharge source by detecting the arrival time of the partial discharge signal to different sensors.

4. A GIL partial discharge location method based on optical fiber timing networking according to claim 3, characterized in that: The double-end positioning method is used to calculate the location of the local discharge source. The device collects the time T1 and T2 when the discharge source signal reaches the sensors at both ends. Assuming that the distance between the two sensors is L and the signal transmission speed is V, L1 can be calculated by the following formula:

5. The GIL partial discharge location method based on optical fiber timing networking according to claim 3 is characterized by: The single-ended positioning method is used to calculate the location of the local discharge source. The device collects the time T1 when the discharge source signal reaches the sensor, the time T2 when the signal reaches the sensor after being reflected by the insulator, and the time T3 when the signal reaches the sensor after being reflected again by the discharge source. Assuming that the distance from the sensor to the insulator is L0, L can be calculated by the following formula:

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