Mutual inductor transformer noise vibration sensor and application thereof

Abstract

The application discloses a mutual inductance transformer noise vibration sensor and application thereof, and relates to the technical field of transformers, which comprises the following steps: the spring, the fixed iron core and the slide rail are rigidly connected on the body shell; the moving iron core is rigidly connected on the spring, and the spring is used for conducting external structure vibration energy to the moving iron core; the moving iron core swings on the slide rail after accepting the conduction; and the magnetic motive force is generated by the excitation winding and the external sine excitation circuit. The transformer is mainly composed of two iron cores and two parts of windings. The external vibration signal is conducted to the inside through the spring and is converted into the change of the relative position of the two iron cores. The application has the characteristics of high sensitivity and wide frequency response range by using the principle of inductance change, and can accurately capture the vibration signal in the range from small to large. Meanwhile, the application has strong anti-interference ability. More importantly, the application is suitable for high-temperature and high-pressure environments.

Description

Technical Field

[0001] This invention relates to the field of transformer technology, specifically to a mutual inductance transformer noise and vibration sensor and its application. Background Technology

[0002] In modern power systems, transformers are considered critical energy conversion devices, and their stable operation is essential for the safety and reliability of the power grid. Transformer failures can lead to power outages, increased losses, and even equipment damage, severely impacting the stability of the power system. Simultaneously, transformer fault detection also significantly affects the operational efficiency and economic benefits of the power system. Timely fault resolution can reduce maintenance costs, minimize outage time, and improve the availability and reliability of the power system. Furthermore, effective fault detection helps improve the energy efficiency of the power system, promoting the application of clean energy and sustainable development. Therefore, timely detection and resolution of transformer faults is of paramount importance.

[0003] In recent years, with the rapid development of computer equipment, sensor acquisition instruments, and intelligent information analysis and processing technologies, significant progress has been made in the condition assessment methods for power transformers. Emerging technologies, such as dissolved gas analysis in oil, partial discharge monitoring, dielectric response technology, winding deformation and hot spot temperature monitoring, furfural content monitoring in insulating oil, and transformer noise detection, have provided more comprehensive, accurate, and reliable means for the monitoring and assessment of power transformers. The widespread application of these technologies not only helps improve the safety, reliability, and operating efficiency of transformers but also makes a positive contribution to the stable operation of the power system and energy supply. However, they all have certain limitations. For example, dissolved gas analysis in oil requires relatively complex operation, has a certain time delay, cannot be monitored in real time, and cannot directly locate specific fault locations; winding deformation and hot spot temperature monitoring require high-precision sensors and monitoring equipment, which are costly and limited to monitoring winding deformation and hot spot temperature, unable to cover other possible fault types; when conducting transformer noise detection, environmental noise may interfere with the accuracy of noise detection technology, leading to misjudgments or omissions. Transformer vibration detection technology, on the other hand, has advantages such as high sensitivity and accuracy, comprehensiveness, and real-time performance. It can monitor minute vibrations of transformers with high sensitivity and accuracy, and can promptly detect minute fault signals inside the transformer. It can comprehensively monitor the vibration of the transformer, including vibration signals of different frequencies and amplitudes, and can provide real-time feedback on the transformer's operating status. It has strong comprehensive performance advantages and can effectively identify and locate transformer faults.

[0004] Common vibration sensor types include piezoelectric sensors, accelerometers, and piezoelectric ceramic sensors. Piezoelectric sensors are known for their simple structure, small size, and high-frequency response. However, their sensitivity is significantly affected by environmental factors such as temperature and humidity, potentially leading to instability under specific operating conditions. Accelerometers, another common vibration sensor, offer high accuracy and the ability to measure both static and dynamic vibrations, but may perform poorly in low-frequency vibration detection. Furthermore, while piezoelectric ceramic sensors possess high sensitivity and fast response, their application is limited by high-temperature and high-pressure environments. Summary of the Invention

[0005] The purpose of this invention is to provide a mutual inductance transformer noise and vibration sensor and its application, so as to solve the problems in the prior art mentioned in the background.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a mutual inductance transformer noise and vibration sensor, comprising: a sensor body shell and a spring, an excitation winding, an induction winding, a fixed iron core, a moving iron core, and a slide rail installed inside the body shell;

[0007] The spring, the fixed iron core, and the slide rail are rigidly connected to the outer shell of the main body. The moving iron core is rigidly connected to the spring. The spring is used to transmit the vibration energy of the external structure to the moving iron core.

[0008] The moving iron core, which receives the conduction, swings on the slide rail;

[0009] The external sinusoidal excitation circuit connected to the excitation winding generates a magnetomotive force.

[0010] The induction winding is connected to an external output circuit;

[0011] The fixed iron core and the moving iron core correspond to form a magnetic circuit, which is used to aggregate the magnetic field generated by the excitation winding and convert the magnetic energy into the induction winding, so as to generate an induced electromotive force in the induction winding.

[0012] Preferably, a waterproof aviation connector is used when the excitation winding and / or the induction winding are connected to the external circuit.

[0013] Preferably, the outer shell of the main body is made of metal.

[0014] Preferably, the outer shell of the body is made of stainless steel.

[0015] Preferably, the outer casing of the main body is connected to the shielding layer of the signal cable.

[0016] The aforementioned mutual inductance transformer noise and vibration sensor is applied to transformers to detect vibration signals.

[0017] Preferably, the outer shell of the main body is connected to the shielding layer of the signal cable during application.

[0018] Compared with the prior art, the beneficial effects of the present invention are:

[0019] The transformer of this invention mainly consists of two iron cores and two windings. External vibration signals are transmitted to the interior through springs, transforming them into changes in the relative positions of the two iron cores. Utilizing the principle of inductance change, it features high sensitivity and a wide frequency response range, accurately capturing vibration signals ranging from minute to large. Simultaneously, it possesses strong anti-interference capabilities, enabling stable operation in complex working environments. More importantly, it is suitable for high-temperature and high-pressure environments, offering broader application prospects. Attached Figure Description

[0020] The accompanying drawings, as part of this invention, are provided to further illustrate the invention. The illustrative embodiments and descriptions of the invention are used to explain the invention, but do not constitute an undue limitation thereof. Clearly, the drawings described below are merely some embodiments, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0021] Figure 1 This is a schematic diagram of a mutual inductance transformer noise and vibration sensor and its application structure according to the present invention.

[0022] Figure 2 This is a schematic diagram of the equivalent circuit of a mutual inductance transformer noise and vibration sensor and its application according to the present invention.

[0023] Figure 3 This is a schematic diagram of the spatial relationship of the core of a mutual inductance transformer noise and vibration sensor and its application, according to the present invention.

[0024] In the diagram: 1. Body shell; 2. Spring; 3. Excitation winding; 4. Induction winding; 5. Stable iron core; 6. Moving iron core; 7. Slide rail. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] Please see Figures 1-3The present invention provides a mutual inductance transformer noise and vibration sensor, including a sensor body housing 1 and a spring 2, an excitation winding 3, an induction winding 4, a fixed iron core 5, a moving iron core 6 and a slide rail 7 installed inside the sensor body housing 1.

[0027] The outer casing 1 is made of stainless steel. One end of the guide rail 7, the fixed iron core 5, and the spring 2 is directly and rigidly connected to the outer casing 1. The spring 2 primarily transfers the vibration energy of the external structure to the moving iron core 6, allowing it to oscillate proportionally with the external vibration frequency and amplitude. The guide rail 7 is connected to the moving iron core 6, ensuring it can only oscillate in one degree of freedom. The excitation winding 3 is externally connected to a sinusoidal excitation circuit to generate magnetomotive force. The induction winding 4 is externally connected to an output circuit. Both the fixed iron core 5 and the moving iron core 6 contribute to constructing magnetic circuits, converging the magnetic field generated by the excitation winding 3 and converting the magnetic energy into the induction winding 4, thus generating an induced electromotive force in the induction winding 4.

[0028] The aforementioned mutual inductance transformer noise and vibration sensor is used to detect vibration signals on transformers.

[0029] Due to the complex environmental conditions within the transformer, waterproof aviation connectors are required for the excitation winding 3 and the induction winding 4 when connecting them to the external circuit. The main body housing 1 is made of stainless steel, which protects the internal structure of the sensor while also providing some interference shielding. Because the electromagnetic environment inside the transformer is complex, and the sensor also uses electromagnetic fields for signal exchange, in practical applications, the sensor's metal housing 1 should be connected to the shielding layer of the signal cable and properly grounded at one end.

[0030] Measurement principle:

[0031] The sensor equivalent circuit is Figure 2 As shown, the excitation winding 3 acts as the power source, and the output side is the induction winding 4. M is the mutual inductance between the two windings, which changes with the displacement of the moving iron core. The spatial correspondence between the fixed iron core 5 and the moving iron core 6 at different positions is as follows: Figure 3 As shown.

[0032] The formula for air gap reluctance Zm can be simplified as follows:

[0033]

[0034] Where L is the magnetic circuit length, μ is the magnetic permeability, and S is the cross-sectional area of ​​the air gap magnetic circuit.

[0035] It is evident that magnetic reluctance is inversely proportional to the corresponding area, and inductance is also inversely proportional to magnetic reluctance. Therefore, when the two iron cores are aligned, M is at its maximum, and the output voltage U... o The amplitude is at its maximum; when the two parts of the iron core shift due to vibration, M decreases, and the output voltage U... oThe amplitude decreases. U o The amplitude variation frequency is twice the vibration frequency, U o The magnitude of the amplitude change is directly proportional to the vibration intensity within a certain range.

[0036] External circuit:

[0037] The external circuits mainly include a DC regulated power supply circuit, an oscillation and filtering circuit, an excitation signal amplification circuit, a secondary AC amplification circuit, a phase-sensitive detector circuit, an active low-pass filter circuit, and a DC amplification circuit.

[0038] A linear voltage regulator circuit must be added to the DC power supply section because the proposed sensor has high requirements for power supply stability. This part can be implemented using a mature integrated voltage regulator circuit.

[0039] The sensor's excitation winding (primary) requires a sinusoidal excitation signal. This function needs to be achieved by an oscillation circuit, commonly using an RC circuit and an operational amplifier, or an RC NAND gate. An active filter is needed to filter the signal and obtain a smooth sine wave. Since the amplitude of the filtered sinusoidal excitation signal is relatively small, an external excitation signal amplification circuit is also required.

[0040] The secondary winding has relatively poor load-carrying capacity and high output impedance, requiring an external resistor with a large resistance value to prevent the secondary winding from affecting the primary winding.

[0041] When the secondary signal needs to be followed by a detector circuit after the amplifier circuit to convert the AC signal into a pulsating DC signal, a phase-sensitive detector circuit can be used.

[0042] The pulsating DC signal output after detection needs to be converted into a smooth DC signal using a filtering circuit, typically an active filter circuit. The filtered signal can then be externally amplified according to requirements.

[0043] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A mutual inductor transformer noise vibration sensor, characterized by, include: The sensor body housing (1) and the spring (2), excitation winding (3), induction winding (4), fixed iron core (5), moving iron core (6) and slide rail (7) installed inside the body housing (1); The spring (2), the fixed iron core (5) and the slide rail (7) are rigidly connected to the outer shell (1). The moving iron core (6) is rigidly connected to the spring (2). The spring (2) is used to transmit the vibration energy of the external structure to the moving iron core (6). The moving iron core (6) that receives the conduction swings on the slide rail (7); The excitation winding (3) is connected to an external sinusoidal excitation circuit to generate magnetomotive force; The induction winding (4) is connected to an external output circuit; The fixed iron core (5) and the moving iron core (6) form a magnetic circuit to aggregate the magnetic field generated by the excitation winding (3) and convert the magnetic energy into the induction winding (4) so ​​that an induced electromotive force is generated in the induction winding (4).

2. The mutual inductor transformer noise and vibration sensor of claim 1, wherein: Waterproof aviation plugs are used when the excitation winding (3) and / or the induction winding (4) are connected to the external circuit.

3. The mutual inductor transformer noise and vibration sensor of claim 1, wherein: The outer shell (1) of the main body is made of metal.

4. The mutual inductor transformer noise and vibration sensor of claim 3, wherein: The outer shell (1) of the main body is made of stainless steel.

5. A mutual inductor transformer noise and vibration sensor according to claim 3 or 4, characterised in that: The outer shell (1) of the main body is connected to the shielding layer of the signal cable.

6. The mutual inductance transformer noise and vibration sensor according to any one of claims 1-5 is used to detect vibration signals on a transformer.

7. Use according to claim 6, characterized in that: When in use, the outer shell (1) of the main body is connected to the shielding layer of the signal cable.

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