Ultrasonic signal acquisition device, method and apparatus for power device component breakdown

Abstract

The application discloses an ultrasonic signal collection device, method and equipment for breakdown of power equipment components. The application can improve the monitoring sensitivity of component breakdown by analyzing the current waveform of a fuse blown, analyzing the spectrum of generated ultrasonic waves, and selecting a proper sensor center frequency based on the spectrum and cost factors. The application adopts a closed sensor, and a specially designed resonance plate resonates at the center frequency of the ultrasonic probe, so that the ultrasonic signal can be efficiently coupled, that is, waterproof and dustproof are realized, and the use of a coupling agent is avoided, so that the application can be used outdoors for a long time.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of power safety, in particular to an ultrasonic signal acquisition device, method and equipment for breakdown of power equipment components. BACKGROUND

[0002] High-voltage capacitor is an important reactive compensation device in power system, and its safety and reliability have important influence on the safety and reliability of power grid. High-voltage capacitor is an energy storage device, and once serious failure occurs, it may cause fire, explosion and other accidents, which seriously threatens the safety of personnel and property in power station. Therefore, the monitoring of capacitor element breakdown has been one of the hotspots of capacitor research.

[0003] After the breakdown of the capacitor element, electric spark will occur near the breakdown point, and the internal fuse of the element will also explode due to the energy release of other elements. Whether it is the electric spark of the breakdown point or the electric explosion of the internal fuse, it will produce rich ultrasonic signals, so the discharge phenomenon in the capacitor can be detected by using an ultrasonic sensor.

[0004] At present, the capacitor internal discharge monitoring or detection technology based on ultrasonic sensor is mainly used in the laboratory. It cannot be used on open outdoor power equipment. SUMMARY

[0005] Therefore, the present application provides an ultrasonic signal acquisition device, method and equipment for breakdown of power equipment components to solve the problem that the ultrasonic signal of the breakdown of the power equipment cannot be used on open outdoor power equipment.

[0006] To solve the above problems, the present application provides an ultrasonic signal acquisition device, method and equipment for breakdown of power equipment components.

[0007] The embodiment of the present application provides an ultrasonic signal acquisition device for breakdown of power equipment components, which comprises:

[0008] The shell of the device has a bottom surface which is adapted to be installed on the surface of the power equipment;

[0009] The resonance plate is installed at the bottom of the shell, and the resonance frequency thereof is coupled with the detection range of the ultrasonic probe;

[0010] The ultrasonic probe is located directly above the resonance plate and is used to acquire the ultrasonic signal of the resonance plate.

[0011] The acquisition device provided by the embodiment of the present application realizes the use of the power equipment in the outdoor scene by packaging the resonance plate in the shell, and has good sealing effect. The alarm of the fuse breakdown of the equipment can be realized.

[0012] Preferably, the resonance plate is integrated with the bottom surface, embedded in the bottom surface, and sealed with sealant between the resonance plate and the bottom surface.

[0013] Alternatively, the resonance plate is designed separately from the bottom surface, and the resonance plate is suspended and connected to the bottom surface of the shell through a mounting component.

[0014] The resonance plate can be installed in two structures, and the suspended mode has better sound transmission effect.

[0015] Preferably, the mounting component is two parallel protrusions with a folded edge.

[0016] The resonance plate has a protruding folded edge that cooperates with the folded edge, and the two are clamped to form a vibrating cavity below the resonance plate.

[0017] The folded edge and the folded edge are used to facilitate installation and fixation, and can be further fixed by screws.

[0018] Preferably, the folded edge of the shell is fixed with a screw component for abutting the bottom surface of the shell to adjust the vibration frequency of the vibration plate.

[0019] By adjusting the external force of the screw component, the tension of the resonance plate is improved.

[0020] Preferably, the parameters of the resonance plate satisfy the following equation:

[0021]

[0022] E is the Young's modulus of the resonance plate; t is the thickness of the resonance plate; a and b are the length and width of the resonance plate, respectively; the center frequency of the ultrasonic probe is f0;

[0023] v is the Poisson's ratio of the resonance plate;

[0024] ρ is the density of the resonance plate.

[0025] Preferably, the resonance plate is made of metal, the Young's modulus is 210GPa, the Poisson's ratio is 0.3, the outer size is 2cm×2cm×0.1cm, and the resonance frequency is 39.36kHz.

[0026] The embodiment also provides an ultrasonic signal acquisition method for breakdown of power equipment components, which adopts the ultrasonic signal acquisition device, and includes the following steps:

[0027] Step 1: According to the breakdown frequency of the power equipment component to be measured, adjust the screw component so that the sensitivity of the ultrasonic probe detection is the highest;

[0028] Step 2: Fix the screw component;

[0029] Step 3: The bottom surface of the ultrasonic signal acquisition device is attached to the surface of the power equipment, fixedly installed, and an alarm is generated when the signal of the ultrasonic probe exceeds a threshold value.

[0030] The embodiments also provide a power equipment having a fuse that can be broken, and the surface of which is attached with the ultrasonic signal acquisition device described above. The power equipment can be a capacitor. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 Structure diagram of capacitor ultrasonic sensor

[0032] Figure 2 Structure diagram of resonant plate and sensor shell

[0033] Figure 3 Working flow diagram of ultrasonic sensor

[0034] Figure 4 Fuse current simulation model

[0035] Figure 5 Fuse resistivity- specific action quantity curve

[0036] Figure 6 Fuse model substituted into capacitor element series section simulation model

[0037] Figure 7 Fuse current simulation result

[0038] Figure 8 Resonant plate ultrasonic sensor effect simulation DETAILED DESCRIPTION

[0039] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0040] The present application provides an ultrasonic signal acquisition device, method and equipment for power equipment component breakdown, which realizes sensitive extraction of ultrasonic signals generated by capacitor component breakdown under long-term outdoor conditions.

[0041] The device embodiment of the present application includes the structure of the ultrasonic acquisition device, which is as follows Figure 1As shown, the structure includes a housing 1, with the bottom surface of the appropriate installation of the surface of the power equipment; the housing has a resonance plate 4, installed in the bottom of the housing; the housing also has an ultrasonic probe 3, located directly above the resonance plate 4, the probe pickup direction directly to the resonance plate, for collecting the resonance plate ultrasonic signal. The resonance frequency of the resonance plate and the detection range of the ultrasonic probe are coupled. The sensor resonance plate 4 is tightly fitted with the bottom surface of the shell, and the bottom of the sensor shell is the bottom surface of the appropriate installation of the surface of the power equipment. In use, the bottom surface of the sensor is pasted on the capacitor shell. As shown. Figure 1

[0042] The resonance plate and the sensor bottom structure have two implementation structures: the resonance plate and the housing bottom are integrated, or the resonance plate and the housing bottom are designed separately.

[0043] In one embodiment, the resonance plate and the housing bottom are integrated, embedded in the housing bottom, and sealed with sealant between the resonance plate and the housing bottom for waterproofing.

[0044] In this embodiment, the resonance plate and the housing bottom are designed separately, and the resonance plate is suspended and connected with the housing through a mounting member.

[0045] The structures in the two embodiments can realize the installation of the resonance plate, and the suspended mode has better sound transmission effect.

[0046] In this embodiment, the mounting member is two parallel protrusions with flanges; the resonance plate has a protruding folded edge that cooperates with the flange, and the two are clamped, forming a vibration cavity below the resonance plate. The use of flanges and folded edges facilitates installation and fixation, and can be further fixed by screws. As shown Figure 2

[0047] The flange of the housing is fixed with a screw member for abutting the vibration plate to adjust the vibration frequency of the vibration plate. By adjusting the external force of the screw member, the tension of the resonance plate is improved.

[0048] In this embodiment, the resonance plate resonates at the center frequency of the probe, and the center frequency of the ultrasonic probe is f0. The useful ultrasonic signal generated in the capacitor can drive the sensor resonance plate to vibrate to the greatest extent, improving the sensitivity of the sensor.

[0049] In this embodiment, in order to make the resonance plate resonate near f0, its size and material properties satisfy the formula:

[0050]

[0051] In the formula,

[0052] E is the modulus of the resonance plate ​​

[0053] t is the thickness of the resonant plate

[0054] a, b are the length and width of the resonant plate, respectively

[0055] v is the Poisson's ratio of the resonant plate

[0056] p is the density of the resonant plate

[0057] In this embodiment, the ultrasonic sensor adopts a fully sealed structure, and the whole is in the shape of a cuboid. The resonant plate is installed at the bottom of the sensor. The resonant plate is suspended and connected with the shell through a mounting component. The screw component is a screw. The screw is used for fine adjustment. The prestress of the resonant plate is adjusted. The resonant frequency of the resonant plate is more effectively consistent.

[0058] According to the above embodiment of the acquisition device, the application describes the method and process of the ultrasonic sensor structure for collecting ultrasonic signals through a method embodiment.

[0059] In one embodiment, the process of collecting ultrasonic signals by the fully sealed ultrasonic sensor is as shown in Figure 3 .

[0060] In this embodiment, step S01 is to adjust the screw component before the acquisition device collects the work, so that the sensitivity of the ultrasonic wave probe detection is the highest according to the breakdown frequency of the power equipment component to be measured.

[0061] In step S01 of this embodiment, a capacitor unit is selected. The parameter setting of the capacitor unit refers to the model BAM11 / √3-334-1W. The element capacitance is 6.59 μF. The parallel number is 12, and the series number is 3. A fuse current simulation model is established, as shown in Figure 4 . The fuse current obtained by simulation is as shown in Figure 7 . The waveform is a wideband signal. The fft calculation shows that the frequency is distributed from 20 kHz to 1 MHz. The peak value appears near 0.8 MHz. Considering the cost of the probe and the acquisition system, a 40 kHz sensor is selected.

[0062] In step S01 of the embodiment, the calculation steps of the center frequency of the ultrasonic probe are as follows:

[0063] Step one, referring to the electric explosion wire theory, the specific action amount model of the thin metal wire is used. The fuse breaking current waveform is simulated by introducing the capacitor series-parallel structure. The simulation model is as shown in Figure 4 .

[0064] The specific action amount calculation formula is as follows:

[0065]

[0066] In the formula,

[0067] g is the specific action quantity,

[0068] j is the current density of the fuse, i.e. the ratio of the current to the cross-sectional area of the fuse,

[0069] t is the energizing time.

[0070] Step two: the resistance of the fuse is calculated as:

[0071] The change of the resistivity of the fuse with the specific action quantity is shown in Figure 5 .

[0072]

[0073] In the formula,

[0074] R is the resistance of the fuse;

[0075] p is the resistivity of the fuse obtained from a table;

[0076] d is the length of the fuse

[0077] S is the cross-sectional area of the fuse

[0078] Step three: the circuit model of the fuse is substituted into the model of the series section of the capacitor element, as shown in Figure 6 , and a switch is used to simulate the breakdown of the element.

[0079] Step four: the current waveform of the internal fuse can be obtained through simulation, and the frequency spectrum distribution of the fuse current can be obtained by performing a fast Fourier transform (fft transform) on the waveform. The frequency spectrum of the ultrasonic signal can be evaluated according to the frequency spectrum, and the center frequency of the ultrasonic probe can be selected according to the cost and other factors.

[0080] In this embodiment, step S02 is: when the breakdown frequency is consistent with the vibration frequency of the resonance plate of the acquisition device, the spiral component is fixed.

[0081] In step S02 of the embodiment, the resonance plate of the ultrasonic acquisition device is made of stainless steel, the Young's modulus thereof is 210 GPa, the Poisson's ratio thereof is 0.3, and the outer dimensions thereof are 2 cm x 2 cm x 0.1 cm. The resonance frequency of the acquisition device is adjusted to 39.36 kHz by adjusting the spiral component thereof, and the spiral component is fixed.

[0082] In this embodiment, step S03 is: the bottom surface of the ultrasonic signal acquisition device is attached to the surface of the capacitor unit, and is fixedly installed. The capacitor generates a breakdown signal through the simulation model, and an alarm is generated if the signal detected by the ultrasonic probe exceeds a threshold value.

[0083] The simulation results of step S03 of this embodiment are shown in Figure 8are shown.

[0084] Through the above-mentioned embodiments, the frequency of the resonance plate and the fixed position of the screw component can be determined in an experimental environment. Various types of power equipment that can be monitored by ultrasound can be installed and adapted, and faults that can be warned by ultrasound can be detected.

[0085] For the solutions described in the various embodiments of the present application, any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. An ultrasonic signal acquisition device for the breakdown of electrical equipment components, characterized in that, include: The housing of the device has a bottom surface that is adapted to be attached to the surface of the electrical equipment; A resonant plate is installed at the bottom inside the housing; Its resonant frequency is coupled with the detection range of the ultrasonic probe; The ultrasonic probe is located directly above the resonant plate and is used to collect ultrasonic signals from the resonant plate. The resonant plate is integrated with the bottom surface and embedded in the bottom surface, with sealant applied between the resonant plate and the bottom surface. Alternatively, the resonant plate and the bottom surface can be designed separately, with the resonant plate suspended and connected to the bottom surface of the housing via mounting components; The parameters of the resonant plate conform to the following equation: E is the Young's modulus of the resonant plate; t is the thickness of the resonant plate; a and b are the length and width of the resonant plate, respectively; the center frequency of the ultrasonic probe is f0. v is the Poisson's ratio of the resonant plate; ρ is the density of the resonant plate.

2. The ultrasonic signal acquisition device according to claim 1, characterized in that, The mounting component consists of two parallel protrusions with flanges; The resonant plate has a raised folded edge that engages with the flange, and the two are snapped together to form a vibrating cavity below the resonant plate.

3. The ultrasonic signal acquisition device according to claim 2, characterized in that, The flange of the housing is fixed with a spiral component, which is used to abut against the bottom surface of the housing to adjust the vibration frequency of the resonant plate.

4. The ultrasonic signal acquisition device according to claim 1, characterized in that, The resonant plate is made of metal with a Young's modulus of 210 GPa, a Poisson's ratio of 0.3, dimensions of 2 cm × 2 cm × 0.1 cm, and a resonant frequency of 39.36 kHz.

5. A method for acquiring ultrasonic signals of component breakdown in power equipment, using the ultrasonic signal acquisition device described in claim 3, comprising: Adjust the spiral component according to the breakdown frequency of the components of the power equipment under test to maximize the detection sensitivity of the ultrasonic probe. Fix the spiral component; The bottom surface of the ultrasonic signal acquisition device is attached to the surface of the power equipment and fixedly installed. When the signal of the ultrasonic probe exceeds the threshold, an alarm is generated.

6. An electrical device having a puncturable fuse and having the ultrasonic signal acquisition device of claim 1 attached to its surface.

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