A Test Device for the Sensitivity Directivity of a Fiber Optic Sensor in Transformer Oil

Abstract

The present invention relates to a testing device for the sensitivity directivity of a Fabry-Perot sensor in transformer oil. The device mainly includes a host computer, a motor control module, an optical demodulator, a Fabry-Perot sensor, a transformer oil tank model, sound-absorbing cotton, a sound source, a sliding table, and a signal generator. Among them, the sliding table mainly includes a Fabry-Perot sensor transverse travel motor, a Fabry-Perot sensor rotation motor, a slider, a turntable, a guide rail, a sound source rotation motor, a sound source transverse travel motor, a sound source connecting rod, a sound source fixing inverted Ω clamp, a slide rail groove, a limit block, a Fabry-Perot sensor connecting rod, a Fabry-Perot sensor fixing L-shaped inverted Ω clamp, and a sliding table card seat. The device has a flexible structural design, enabling the Fabry-Perot sensor and the sound source to be accurately positioned and angle-adjusted in the oil tank, providing important experimental conditions for detecting sensitivity and accuracy, and ensuring the safety and stability of the power system.

Description

Technical Field

[0001] The present invention relates to the technical field of power equipment detection and diagnosis, and particularly to a Fabry-Perot sensor sensitivity directivity test device in transformer oil. Background Art

[0002] In modern power systems, power transformers, as key equipment, may experience potential faults such as partial discharge during long-term operation, threatening the stability and security of the system. Partial discharge is a common fault precursor in power equipment. If not detected and processed in a timely manner, it may lead to insulation damage of the equipment and further cause serious electrical accidents. Therefore, effective detection and diagnosis of internal partial discharge in transformers have become a key means to ensure the safe operation of power systems.

[0003] Traditional partial discharge detection methods, such as the high-frequency current method and the ultrasonic detection method, although they can provide certain fault information, their effects are often not ideal in the complex oil-immersed transformer environment. The high-frequency current method is easily affected by external interference, while the traditional piezoelectric ceramic-based ultrasonic detection method is limited by factors such as signal attenuation and noise interference, and cannot be built-in. The distance from the fault point is relatively far. Therefore, in practical applications, the accuracy and reliability of these methods are affected to a certain extent. The Fabry-Perot sensor measures ultrasonic signals based on the principle of optical interference and is a fully insulated optical component that can be implanted inside the transformer oil tank. It has the advantages of anti-electromagnetic interference, high sensitivity, and adaptability to complex environments, and has gradually been applied in partial discharge detection. However, the sensitivity and detection ability of the Fabry-Perot sensor are closely related to its directivity. Therefore, researching and optimizing the directivity detection of the Fabry-Perot sensor in transformer oil has become the key to improving its performance.

[0004] The patent with the publication number CN203386470U provides a directivity test device that can adjust the angle. However, its distance adjustment is limited, and the directivity parameters of the sensor sensitivity are insufficient. In addition, the signal in transformer oil is related to the propagation distance, so attenuation is involved. Therefore, tests at different distances are required, which brings limitations to the application of this technology. Summary of the Invention

[0005] The present invention provides a test device for the sensitivity directivity of a Fabry - Perot sensor in transformer oil, aiming to solve the problems of the lack of a device capable of accurate directivity calibration in transformer oil and insufficient sensitivity directivity parameters of the sensor at the present stage, so as to overcome the challenges brought by signal attenuation and noise interference in existing partial discharge detection. The device simulates the ultrasonic signals generated by partial discharge by precisely controlling the relative position and angle of the Fabry - Perot sensor and the sound source, and detects the response characteristics of the sensor to sound signals at different angles and distances. In addition, by adjusting the frequency range of the sound source, the propagation characteristics of sound signals with different frequencies in transformer oil are deeply studied, and the influence on the detection effect of the Fabry - Perot sensor is explored. The distance between the sound source and the sensor is also an important factor affecting the propagation of ultrasonic signals. This device can flexibly adjust the distance between the two through a sliding table to study the attenuation and scattering laws of signals under different propagation paths.

[0006] According to the technical solution of the present invention, a test device for the sensitivity directivity of a Fabry - Perot sensor in transformer oil is provided. This device mainly consists of the following components:

[0007] The upper computer, as the control center of the whole system, communicates with the motor control module to achieve data processing and analysis;

[0008] The motor control module is responsible for driving the motor on the sliding table, thereby controlling the movement of the Fabry - Perot sensor and the sound source, and returning data to the upper computer;

[0009] The optical demodulator is used to demodulate the sound signals received by the Fabry - Perot sensor and analyze the signal characteristics to obtain measurement data;

[0010] The Fabry - Perot sensor is used to sense external signals. Its sensitive diaphragm can generate vibrations, thereby causing changes in interference signals to help detect partial discharge phenomena in transformer oil;

[0011] The transformer oil tank model simulates the actual transformer oil tank. The transformer oil tank model includes a tank shell and transformer oil inside the tank shell;

[0012] Sound - absorbing cotton is evenly arranged on the inner wall of the oil tank to reduce the reflection of sound signals and avoid interfering with the detection results;

[0013] The sound source can emit sound signals with different frequencies to simulate the ultrasonic signals generated by partial discharge in transformer oil;

[0014] The sliding table is placed above the transformer oil tank model and is clamped by a sliding - table clamp to support precise horizontal and angular adjustment of the Fabry - Perot sensor and the sound source in the oil tank;

[0015] The signal generator generates the required test signals to provide the necessary sound signal input for the whole test device.

[0016] The beneficial effects of the present invention are as follows:

[0017] This device can accurately control the angle and position of the Fabry - Perot sensor, providing reliable experimental conditions for directivity testing. It is applicable to the testing of multi - frequency acoustic signals, especially in the range of 20 - 300 kHz. It can simulate the ultrasonic characteristics of partial discharge, thereby optimizing the response effect of the sensor. In addition, the sliding table system can flexibly adjust the distance and angle between the sensor and the sound source, and study the ultrasonic attenuation and scattering laws under different propagation paths. This not only improves the accuracy and reliability of transformer partial discharge detection, but also provides an important experimental basis for the design of Fabry - Perot sensors and the development of power transformer fault diagnosis technology. Description of the Drawings

[0018] Figure 1 General layout of the Fabry - Perot sensor sensitivity directivity testing device in transformer oil according to the embodiment of the present invention;

[0019] Figure 2 Structural diagram of the sliding table that needs to be protected according to the embodiment of the present invention;

[0020] Figure 3 Schematic diagram of the position of the Fabry - Perot sensor according to the embodiment of the present invention;

[0021] Figure 4 Schematic diagram of the position of the sound source according to the embodiment of the present invention;

[0022] Figure 5 Cross - sectional view of the position of the sensitive diaphragm of the Fabry - Perot sensor according to the embodiment of the present invention;

[0023] Figure 6 Top view of the fuel tank according to the embodiment of the present invention.

[0024] Reference numerals: 1 - host computer; 2 - motor control module; 3 - optical demodulator; 4 - Fabry - Perot sensor; 5 - transformer oil tank model; 6 - sound - absorbing cotton; 7 - sound source; 8 - sliding table; 9 - signal generator; 801 - Fabry - Perot sensor horizontal travel motor; 802 - Fabry - Perot sensor rotation motor; 803 - slider; 804 - turntable; 805 - guide rail; 806 - sound source rotation motor; 807 - sound source horizontal travel motor; 808 - sound source connecting rod; 809 - sound source fixed inverted Ω clip; 810 - slide rail groove; 811 - limit block; 812 - Fabry - Perot sensor connecting rod; 813 - Fabry - Perot sensor fixed inverted L - shaped inverted Ω clip; 814 - sliding table card seat. Detailed Embodiments

[0025] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present disclosure can be more thoroughly understood and the scope of the present disclosure can be fully conveyed to those skilled in the art.

[0026] Figure 1 This is the overall diagram of the Fabry-Perot sensor sensitivity directivity test device in transformer oil according to an embodiment of the present invention. As Figure 1 shown, the device mainly consists of the following key parts: a host computer 1, which serves as the control center of the entire system, communicates with the motor control module to achieve data processing and analysis; a motor control module 2, which is responsible for driving the Fabry-Perot sensor lateral travel motor 801, the Fabry-Perot sensor rotation motor 802, the sound source rotation motor 806, and the sound source lateral travel motor 807 on the slide table, controls the movement of the Fabry-Perot sensor and the sound source, and returns data to the host computer; an optical demodulator 3, which is used to demodulate the sound signal received by the Fabry-Perot sensor and analyze the signal characteristics to obtain measurement data; a Fabry-Perot sensor 4, which is used to sense external signals, and its sensitive diaphragm can generate vibrations, thereby causing changes in interference signals to help detect partial discharge phenomena in transformer oil; a transformer oil tank model 5, which simulates an actual transformer oil tank, and the transformer oil tank model 6 includes a tank shell and transformer oil inside the tank shell; sound-absorbing cotton 6, which is evenly arranged on the inner wall of the tank to reduce the reflection of sound signals and avoid interfering with the detection results; a sound source 7, which can emit sound signals of different frequencies, simulates the ultrasonic signals generated by partial discharges in transformer oil, and the frequency range is mainly between 20 - 300 kHz; a slide table 8, which is placed above the transformer oil tank model 5 and is clamped by a slide table clamp 814, includes multiple motors and mechanical structures, and supports precise lateral and angular adjustments of the Fabry-Perot sensor and the sound source in the tank; a signal generator 9, which generates the required test signals and provides the necessary sound signal input for the entire test device. These components work together to ensure that the device can accurately measure the sound signals in transformer oil, thereby improving the detection sensitivity and accuracy and ensuring the safety and stability of the power system.

[0027] Figure 2The structure and function of the slide table part according to an embodiment of the present invention. The slide table 8 is mainly composed of the following components: a Fabry-Perot sensor lateral travel motor 801, driven by the motor control module 2, responsible for driving the Fabry-Perot sensor to move laterally in the oil tank to adjust the distance between the Fabry-Perot sensor 4 and the sound source 7; a Fabry-Perot sensor rotation motor 802, connected to the first slider 803 and the first turntable 804, controlling the angle of the Fabry-Perot sensor in the oil to ensure that the sensor can be precisely adjusted in orientation as needed; the first slider 803, with a diameter smaller than the slide rail groove 810, equipped with an external thread, used to drive the lateral movement of the first turntable 804, with a travel range between the Fabry-Perot sensor lateral travel motor 801 and the limit block 811; the first turntable 804, directly connected to the Fabry-Perot sensor rotation motor 802, controlled by the host computer 1 and the motor control module 2, with scales on the turntable for distinguishing the angle change of the Fabry-Perot sensor 4, and threaded holes on the first turntable 804, connected to the Fabry-Perot sensor 4 through the Fabry-Perot sensor connecting rod 812 and the Fabry-Perot sensor fixing inverted L-shaped inverted Ω clamp 813; the guide rail 805, with an internal thread matching the external thread of the slider 803, used to ensure the smooth movement of the first slider 803 in the slide rail groove 810; a sound source rotation motor 806, having a similar function to the Fabry-Perot sensor rotation motor 802, connected through a second slider and a second turntable (not shown in the figure); the second slider, with a diameter smaller than the slide rail groove 810, equipped with an external thread, used to drive the lateral movement of the second turntable; the second turntable, directly connected to the sound source rotation motor 806, controlled by the host computer 1 and the motor control module 2, with scales on the second turntable for distinguishing the angle change of the sound source, and threaded holes on the second turntable, connected to the sound source 7 through the sound source connecting rod 808, the sound source fixing inverted Ω clamp 809, thereby controlling the angle of the sound source in the transformer oil; a sound source lateral travel motor 807, driven by the motor control module 2, used to control the lateral position movement of the sound source in the oil tank to adjust the distance between the sound source and the Fabry-Perot sensor 4; the Fabry-Perot sensor connecting rod 812, used to connect the first turntable 804 and the Fabry-Perot sensor, the sound source connecting rod 808, used to connect the second turntable and the sound source; the sound source fixing inverted Ω clamp 809, used to clamp the sound source 7 to ensure its stability during the test; the slide rail groove 810, restricting the movement positions of the first slider 803 and the second slider, with a limit block 811 in the middle to further restrict the travel of the slider and prevent it from exceeding the predetermined range; the limit block 811, used to limit the travel of the sound source lateral travel motor 807 and the Fabry-Perot sensor lateral travel motor 801 to ensure that each component is within the normal working range; the Fabry-Perot sensor fixing inverted L-shaped inverted Ω clamp 813, clamping the Fabry-Perot sensor 4 to make the plane of the sensitive film coincide with the axis of the Fabry-Perot sensor connecting rod 812, so as to ensure that when the sensor rotates, the distance between the sensitive area and the sound source remains unchanged; the slide table clamp 814, used to firmly clamp the slide table on the transformer model 5 to ensure the stability of the equipment during the test.

[0028] The key lies in how to fix, rotate and adjust the distance to ensure accurate directivity testing in transformer oil. First, the Fabry-Perot sensor 4 is firmly installed on the sliding table 8 through a dedicated fixing structure, such as the Fabry-Perot sensor fixing inverted L-shaped inverted Ω clamp 813. This structure ensures that the plane of the sensor's sensitive diaphragm always coincides with the axis of the Fabry-Perot sensor connecting rod 812, thus maintaining the consistency of sensitivity and avoiding errors caused by position deviation during the test. Secondly, the rotation of the Fabry-Perot sensor 4 is controlled by the Fabry-Perot sensor rotation motor 802. The rotation motor is connected to the turntable 804 through the slider 803, and the turntable is provided with scales to accurately adjust the angle of the sensor. This design enables the sensor to accurately align with the sound source 7, ensuring the maximum reception of signals during detection and improving the accuracy of fault detection. Finally, the distance between the sensor and the sound source is adjusted by the Fabry-Perot sensor lateral travel motor 801. This motor drives the slider 803 to move on the guide rail 805, thereby changing the distance between the Fabry-Perot sensor 4 and the sound source 7 and optimizing the signal reception effect. Through this structural design, the Fabry-Perot sensor can perform high-sensitivity and high-directivity signal detection in a complex transformer oil environment.

[0029] Figure 3 It is a schematic diagram of the position of the Fabry-Perot sensor according to an embodiment of the present invention. This figure mainly includes the Fabry-Perot sensor 4, the Fabry-Perot sensor connecting rod 812, and the Fabry-Perot sensor fixing inverted L-shaped inverted Ω clamp 813. The Fabry-Perot sensor 4 is the core component of this device. Its sensitive diaphragm can sense external sound signals and generate vibrations, thereby causing changes in interference signals. The Fabry-Perot sensor connecting rod 812 is used to connect the Fabry-Perot sensor 4 to other parts of the sliding table, ensuring that the sensor can stably cooperate with the sliding table and the sound source during adjustment. The Fabry-Perot sensor fixing inverted L-shaped inverted Ω clamp 813 is responsible for clamping the Fabry-Perot sensor 4. The design makes the plane of the sensor's sensitive diaphragm always coincide with the axis of the Fabry-Perot sensor connecting rod 812, so that the distance between the response sensitive area and the sound source remains unchanged when the sensor rotates, ensuring the accuracy and stability of the measurement.

[0030] The Fabry-Perot sensor 4 includes a sensitive diaphragm, a Fabry-Perot cavity, a protective sleeve, and a pigtail. The sensitive diaphragm senses external signals, generates vibrations, and the vibrations cause changes in interference signals, which further enables subsequent phase or intensity demodulation to obtain signal characteristics.

[0031] Figure 4Schematic diagram of the sound source position according to an embodiment of the present invention. This figure mainly includes a sound source 7, a sound source connecting rod 808, and a sound source fixing inverted Ω clip 809. The sound source 7 can emit sound signals of different frequencies, simulating the sound source in the ultrasonic wave band for partial discharge in transformer oil, and the frequency range is usually between 20 - 300 kHz. When this device is used in other scenarios, such as underwater testing, gas environment testing, etc., the frequency band is determined by the actual test values, including but not limited to the above range. The sound source connecting rod 808 is used to connect the sound source 7 to other parts of the sliding table to ensure the stability and adjustability of the sound source. The sound source fixing inverted Ω clip 809 is responsible for clamping the sound source 7 to keep it stable during the test and avoid position changes caused by vibration or other external interferences. Through the coordinated work of these components, the device can effectively control the position and angle of the sound source.

[0032] Figure 5 Cross-sectional view of the position of the Fabry - Perot sensor sensitive diaphragm according to an embodiment of the present invention. This figure includes key components such as a Fabry - Perot sensor rotation motor 802, a slider 803, a first turntable 804, a guide rail 805, a slide rail groove 810, a Fabry - Perot sensor connecting rod 812, and a Fabry - Perot sensor fixing inverted L - shaped inverted Ω clip 813. The Fabry - Perot sensor rotation motor 802 is connected to the turntable 804 through the slider 803 to control the angular change of the Fabry - Perot sensor in the transformer oil, thereby precisely adjusting the position of the sensitive diaphragm. The guide rail 805 provides support and guidance to ensure the smooth movement of the slider 803 in the slide rail groove 810. The Fabry - Perot sensor connecting rod 812 and the Fabry - Perot sensor fixing inverted L - shaped inverted Ω clip 813 are used to firmly install the Fabry - Perot sensor 4.

[0033] Appendix Figure 6 Top view of the fuel tank according to an embodiment of the present invention. In this figure, the overall layout of the fuel tank can be clearly seen. The outer shell of the fuel tank is designed compactly, providing strong protection. At the same time, it is filled with transformer oil inside, providing a necessary working environment for the testing of the Fabry - Perot sensor and the sound source. The sound - absorbing cotton inside the fuel tank is evenly arranged, effectively reducing the reflection of sound signals on the inner wall of the fuel tank and reducing potential interference, thereby ensuring the accuracy of the detection results. Through this top view, the design layout of the fuel tank can be intuitively understood, providing a convenient reference for subsequent experimental operations.

[0034] Obviously, the above - mentioned embodiments are only examples clearly illustrated and are not limitations on the embodiments. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description, and the changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims

1. A test device for the sensitivity directivity of a Fabry-Perot sensor in transformer oil, characterized in that, The device mainly consists of the following components: The host computer (1), serving as the control center of the entire system, communicates with the motor control module to achieve data processing and analysis; The motor control module (2), responsible for driving the motor on the slide table, thereby controlling the movement of the Fabry-Perot sensor and the sound source, and returning data to the host computer; The optical demodulator (3), used to demodulate the sound signal received by the Fabry-Perot sensor and analyze the signal characteristics to obtain measurement data; The Fabry-Perot sensor (4), used to sense external signals, whose sensitive diaphragm can generate vibrations, thereby causing changes in the interference signal, helping to detect partial discharge phenomena in transformer oil; The transformer oil tank model (5), simulating the actual transformer oil tank, the transformer oil tank model (5) includes an oil tank shell and transformer oil inside the oil tank shell; The sound-absorbing cotton (6), evenly arranged on the inner wall of the oil tank to reduce the reflection of sound signals and avoid interfering with the detection results; The sound source (7), capable of emitting sound signals of different frequencies, simulating the ultrasonic signals generated by partial discharges in transformer oil; The slide table (8), placed above the transformer oil tank model (5), clamped by the slide table clamp seat (814), supporting precise lateral and angular adjustments of the Fabry-Perot sensor and the sound source inside the oil tank; The signal generator (9), generating the required test signals and providing the necessary sound signal input for the entire test device.

2. The method for testing the sensitivity directivity of the fiber optic Fabry - Perot sensor in transformer oil according to claim 1, wherein, The said slide table (8) consists of the following components: The Fabry-Perot sensor lateral travel motor (801), driven by the motor control module (2), responsible for driving the lateral movement of the Fabry-Perot sensor inside the oil tank to adjust the distance between the Fabry-Perot sensor (4) and the sound source (7); The Fabry-Perot sensor rotation motor (802), connected to the first slider (803) and the first turntable (804), controlling the angle of the Fabry-Perot sensor in the oil; The first slider (803), whose diameter is smaller than the slide rail groove (810), is equipped with external threads, used to drive the lateral movement of the first turntable (804), and the travel is between the Fabry-Perot sensor lateral travel motor (801) and the limit block (811); The first turntable (804), directly connected to the Fabry-Perot sensor rotation motor (802), controlled by the host computer (1) and the motor control module (2), has scales on the first turntable (804) for distinguishing the angle change of the Fabry-Perot sensor (4), and has threaded holes on the first turntable (804), and is connected to the Fabry-Perot sensor (4) through the Fabry-Perot sensor connecting rod (812) and the Fabry-Perot sensor fixing inverted L-shaped inverted Ω clamp (813); The guide rail (805), whose internal threads cooperate with the external threads of the first slider (803), used to ensure the smooth movement of the first slider (803) in the slide rail groove (810); The sound source rotation motor (806), connected through the second slider and the second turntable; The second slider, whose diameter is smaller than the slide rail groove (810), is equipped with external threads, used to drive the lateral movement of the second turntable; The second turntable is directly connected to the sound source rotation motor (806) and is controlled by the host computer (1) and the motor control module (2). There are scales on the second turntable for distinguishing the angular change of the sound source. There are threaded holes on the second turntable, which are connected to the sound source (7) through the sound source connecting rod (808), the sound source fixing inverted Ω clamp (809), so as to control the angle of the sound source in the transformer oil; The sound source lateral travel motor (807) is driven by the motor control module (2) and is used to control the lateral position movement of the sound source in the oil tank to adjust the distance between the sound source and the Fabry-Perot sensor (4); The Fabry-Perot sensor connecting rod (812) is used to connect the first turntable (804) and the Fabry-Perot sensor; The sound source connecting rod (808) is used to connect the second turntable and the sound source; The sound source fixing inverted Ω clamp (809) is used to clamp the sound source (7); The slide rail groove (810) limits the moving positions of the first slider (803) and the second slider. There is a limit block (811) in the middle, which is used to limit the stroke of the sound source lateral travel motor (807) and the Fabry-Perot sensor lateral travel motor (801); The Fabry-Perot sensor fixing inverted L-shaped inverted Ω clamp (813) clamps the Fabry-Perot sensor (4) to make the plane of its sensitive diaphragm coincide with the axis of the Fabry-Perot sensor connecting rod (812), so as to ensure that when the sensor rotates, the distance between the response sensitive area and the sound source remains unchanged; The slide table clamping seat (814) is used to firmly clamp the slide table on the transformer model (5) to ensure the stability of the equipment during the test.

3. The method for testing the sensitivity directivity of the Fabry-Perot sensor in transformer oil according to claim 1, characterized in that The Fabry-Perot sensor (4) includes a sensitive diaphragm, a Fabry-Perot cavity, a protective sleeve and a pigtail. The sensitive diaphragm senses external signals and generates vibrations, and the vibrations cause changes in interference signals, so that subsequent signal characteristics can be obtained through phase or intensity demodulation.

4. The method for testing the sensitivity directivity of the Fabry - Perot sensor in transformer oil according to claim 1, wherein, The sound source (7) can emit sound signals of different frequencies, and the frequency range is between 20 - 300 kHz.

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