A high temperature arc gas pressure measuring device

Abstract

The present invention provides a high-temperature arc gas pressure measuring device, comprising a high-voltage power supply, two electrodes, an optical fiber connector, a laser transmitter, a beam splitter, an optical fiber coupler, a signal conditioner, a diaphragm displacement structure and a closed cavity, wherein the diaphragm displacement structure is arranged in the inner cavity of the closed cavity, one end of the optical fiber connector is arranged in the inner cavity of the closed cavity and is connected to the diaphragm displacement structure, the other end of the optical fiber connector is arranged outside the closed cavity, and the end of the optical fiber connector located outside the closed cavity comprises a first connecting end and a second connecting end, wherein the beam splitter generates a first light beam and a second light beam, and the first connecting end is connected to the first light beam through a first optical fiber, which can solve the problem that an arc is generated when the existing high-voltage switch equipment is disconnected, and air pressure is generated around the arc, thereby affecting the normal operation of the equipment.

Description

Technical Field

[0001] The invention belongs to the field of circuit breaker arc breaking and optical technology, and in particular relates to a high-temperature arc gas pressure measuring device. Background Art

[0002] Today, China's national economy and comprehensive national strength are constantly increasing. For the planning and construction of high-voltage and ultra-high-voltage power transmission and transformation projects in my country, the power system network for transmitting electric energy must be more reliable. At the same time, the requirements for stable and safe operation of power equipment are also constantly increasing. The development of power transmission and transformation systems and related power equipment is of great significance. In power transmission construction projects, circuit breakers, transformers, grounding switches and other electrical equipment have the function of protecting and allocating transmission lines. As the most important and complex power equipment in the power system, circuit breakers have strict requirements on their breaking and arc extinguishing capabilities.

[0003] When the circuit breaker is in the process of breaking, an arc will be ignited on the short-circuit contact. As a high-temperature plasma, the temperature of the arc is very high, with an upper limit of 20×103K and a lower limit of 6×103K. When the arc burns, the temperature at the center is the highest, reaching 12000K. The edge temperature is only 500K because it is in contact with the surrounding air and other substances, consuming and exchanging heat energy quickly. Due to the temperature relationship of the arc, a temperature gradient will be generated around it, causing the flow of gas, causing the air pressure around the arc to change, and then affecting the working state of the circuit breaker. Therefore, as an important parameter reflecting the state of the arc, a measuring device is urgently needed to measure the area around the arc to measure the air pressure around the arc. Summary of the invention

[0004] Therefore, the technical problem to be solved by the present invention is to provide a high-temperature arc gas pressure measuring device, which can solve the problem that the existing high-voltage switchgear will generate an arc when it is disconnected, and gas pressure will be generated around the arc, affecting the normal operation of the equipment.

[0005] In order to solve the above problems, the present invention provides a high-temperature arc gas pressure measuring device, including a high-voltage power supply, two electrodes, an optical fiber connector, a laser transmitter, a beam splitter, an optical fiber coupler, a signal conditioner, a diaphragm displacement structure and a closed cavity;

[0006] A diaphragm displacement structure is arranged in the inner cavity of the closed cavity, one end of the optical fiber connector is arranged in the inner cavity of the closed cavity and is connected to the diaphragm displacement structure, the other end of the optical fiber connector is arranged on the outside of the closed cavity, and the end of the optical fiber connector located on the outside of the closed cavity includes a first connection end and a second connection end, wherein a beam splitter generates a first light beam and a second light beam, the first connection end is connected to the first light beam through a first optical fiber, one end of the optical fiber coupler is connected to the second light beam through a third optical fiber and to the second connection end through a second optical fiber, the other end of the optical fiber coupler is connected to a signal regulator, a laser transmitter is connected to the beam splitter, two electrodes are arranged in the inner cavity of the closed cavity, and the two electrodes are arranged opposite to each other, and the ends of the two electrodes that are far away from each other are electrically connected to a high-voltage power supply located outside the closed cavity.

[0007] Optionally, the diaphragm displacement structure includes a protective housing, a reflector, a diaphragm and a micro air tube;

[0008] The protective shell is connected to the bottom of the inner cavity of the closed cavity, the diaphragm is arranged on one side of the protective shell, the reflector is arranged on the diaphragm, the first light beam passes through the optical fiber connector and the reflector in sequence, and after reflection, the first light beam passes through the second connecting end and is connected to the optical fiber coupler, one end of the micro airway is connected to the protective shell, and the other end of the micro airway passes through the outside of the closed cavity and is connected to the atmosphere.

[0009] Optionally, the diaphragm displacement structure further includes a bracket, one end of which is connected to the bottom of the inner cavity of the closed cavity, and the other end of which is connected to the protective shell.

[0010] Optionally, the optical fiber connector is connected to the sealed cavity via a fastener.

[0011] Optionally, the diaphragm displacement structure may measure the displacement of the diaphragm by laser.

[0012] Optionally, the diaphragm displacement structure measures the displacement of the diaphragm by laser:

[0013] After the laser transmitter emits laser, it is divided into a first light beam and a second light beam by a beam splitter. The first light beam is transmitted to the optical fiber connector through the first optical fiber, and then transmitted to the diaphragm displacement structure and then reflected through the second optical fiber to the optical fiber coupler. The second light beam is directly transmitted to the optical fiber coupler through the third optical fiber.

[0014] Optionally, the length of the first optical fiber is set to d1, the length of the second optical fiber is set to d2, the length of the third optical fiber is set to d3, and the distance between the first optical fiber and the reflector is set to d4. When the diaphragm is not under pressure and does not displace, d1+d2+2d4=d3 is preset. When the diaphragm is displaced under pressure, the optical path difference is calculated, and the formula is as follows:

[0015]

[0016] Among them, I is the interference light intensity, I1 is the measurement light intensity, and I2 is the reference light intensity. is the reference light phase, To measure the optical phase.

[0017] Optionally, the phase difference formula between the first light beam and the second light beam is as follows:

[0018]

[0019] Where L is the optical path difference between the measurement light and the reference light, which is twice the distance to be measured d, v is the frequency of light, and c is the speed of light. is the phase difference between the reference light and the measurement light, is the reference light phase, To measure the optical phase;

[0020] When the laser frequency v achieves linear scanning without mode hopping, the interference light intensity I measured by the signal conditioner is a periodic signal with a fixed frequency, and its frequency expression is as follows:

[0021]

[0022] in, is the frequency scanning range, is the frequency scanning time, L is the optical path difference between the measurement light and the reference light, and f is the frequency of the interference light signal.

[0023] Optionally, after obtaining the change in the frequency f of the interference light signal, the change in the optical path difference between the measurement light beam and the reference light beam can be obtained, and the measured distance d can be obtained as follows:

[0024]

[0025] Where f is the frequency of the interference light signal, c is the speed of light, is the frequency scanning range, is the frequency sweep time.

[0026] Optionally, the central disturbance of the diaphragm in the diaphragm is calculated as follows:

[0027]

[0028] Among them, W is the central disturbance of the diaphragm, a is the effective radius of the diaphragm, t is the diaphragm thickness, E is the diaphragm elastic modulus, μ is the diaphragm Poisson's ratio, and p is the pressure.

[0029] Beneficial Effects

[0030] A high-temperature arc pressure measuring device provided in an embodiment of the present invention is provided with electrodes and a diaphragm displacement structure in a closed cavity, and a laser transmitter, a beam splitter, and a fiber coupler are provided outside. The optical fiber emitted by the laser transmitter is divided into a first light beam and a second light beam through the beam splitter. The first light beam passes through the incident optical fiber and the reflector and then is transmitted through the reflecting optical fiber. It interferes with the second light beam after passing through the fiber coupler. The position of the diaphragm will also change when the pressure changes. At the same time, the position of the reflector is changed, so that the interference fringes change. The signal regulator uses a certain calculation formula to analyze the interference fringes to obtain the displacement of the diaphragm, thereby obtaining the magnitude of the pressure. This solves the problem that the existing high-voltage switchgear generates an arc when it is disconnected, and air pressure is generated around the arc, which affects the normal operation of the equipment.

[0031] advantage:

[0032] 1. The experimental device can be applied to various voltage forms, including AC voltage, DC voltage, impulse voltage, etc.

[0033] 2. The present invention uses optical fiber for data transmission and places the data processing device outside the experimental cavity, which reduces the space occupied and avoids the influence of the complex internal electromagnetic environment on data acquisition.

[0034] 3. The internal probe bracket adopts polytetrafluoroethylene structure, which has good insulation performance and can reduce the impact on the arc burning experiment itself.

[0035] 4. The bracket of the experimental device can be moved, and the air pressure in different areas can be measured as needed.

[0036] 5. The protective shell is connected to the atmosphere through a micro air pipe to ensure that the air pressure inside the protective shell is constant at atmospheric pressure when the temperature inside the cavity changes. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a schematic diagram of the structure of an experimental device according to an embodiment of the present invention;

[0038] Figure 2 For the embodiment of the present invention Figure 1 The enlarged structural diagram at A in the middle;

[0039] Figure 3 For the embodiment of the present invention Figure 1 The enlarged structural diagram at B in the middle;

[0040] Figure 4 Flow chart of the experimental method of an embodiment of the present invention.

[0041] The reference numerals are as follows:

[0042] 1. High voltage power supply; 2. Electrode; 3. Fiber optic connector; 4. Fastener; 5. Laser emitter; 6. Beam splitter; 7. Signal conditioner; 8. Fiber optic coupler; 9. Protective housing; 10. Reflector; 11. Diaphragm; 12. Sealed cavity; 13. Bracket; 14. Micro air tube. DETAILED DESCRIPTION

[0043] See also Figures 1 to 4 According to an embodiment of the present invention, a high temperature arc pressure measuring device is shown. Figure 1-Figure 3 , including a high-voltage power supply 1, two electrodes 2, an optical fiber connector 3, a laser emitter 5, a beam splitter 6, an optical fiber coupler 8, a signal regulator 7, a diaphragm displacement structure and a closed cavity 12; the diaphragm displacement structure is arranged in the inner cavity of the closed cavity 12, one end of the optical fiber connector 3 is arranged in the inner cavity of the closed cavity 12 and is connected to the diaphragm displacement structure, the other end of the optical fiber connector 3 is arranged on the outside of the closed cavity 12, and the end of the optical fiber connector 3 located on the outside of the closed cavity 12 includes a first connection end and a second connection end, wherein the beam splitter 6 generates a first light beam and a second light beam, the first connection end is connected to the first light beam through a first optical fiber, one end of the optical fiber coupler 8 is connected to the second light beam through a third optical fiber and to the second connection end through a second optical fiber, the other end of the optical fiber coupler 8 is connected to the signal regulator 7, the laser emitter 5 is connected to the beam splitter 6, the electrode 2 is arranged in the inner cavity of the closed cavity 12, and the two ends of the motor 2 are electrically connected to the high-voltage power supply 1 located on the outside of the closed cavity 12. The present invention connects the high-voltage power supply 1 through two electrodes 2, ignites an arc in the gap between the two electrodes 2, and emits the first light beam and the second light beam through the laser emitter 5. The two light beams with different phases will interfere, that is, the first light beam connects to the optical fiber connector 3, is reflected by the diaphragm displacement structure, and then connects to the optical fiber coupler 8 through the third optical fiber. The second light beam directly connects to the optical fiber coupler 8 through the second optical fiber, and is connected to the signal regulator 7 through the optical fiber coupler 8, and then the required pressure information is analyzed. The problem that the existing high-voltage switchgear generates an arc when it is disconnected and generates air pressure around the arc, which affects the normal operation of the equipment is solved.

[0044] Furthermore, the electrode 2 is a spherical finger electrode 2 , the electrode 2 is cylindrical, one end of which is hemispherical, and the spherical surfaces of the two electrodes 2 are opposite to each other and arranged coaxially.

[0045] Furthermore, the optical fiber connector 3 is a dual-port optical fiber connector 3, the optical fiber connector 3 passes through the closed cavity wall 12, the middle of the optical fiber connector is a threaded structure, and the sealing of the cavity is ensured by threaded connection, and both ends of the optical fiber connector 3 are further fixed and sealed by fasteners 4. Among them, the fastener 4 is a nut.

[0046] Furthermore, the fiber coupler 8 is a 3×3 fiber coupler, which combines two incident lights into one light beam, thereby generating interference phenomenon.

[0047] Furthermore, the laser transmitter 3 is an infrared laser transmitter, and similarly, the optical fiber used is an infrared optical fiber.

[0048] Furthermore, the optical fiber emitted by the laser transmitter 3 is divided into a first light beam and a second light beam by a beam splitter 6. The first light beam is connected to the optical fiber connector 3 through the first optical fiber, and is connected to the pressure sensor through the optical fiber connector 3. The pressure sensor is used to measure the pressure around the arc.

[0049] Furthermore, the second optical fiber is reflected by the reflector 10 and then connected to the optical fiber coupler 8 through the third optical fiber.

[0050] Please refer to Figure 3 The diaphragm displacement structure includes a protective shell 9, a reflector 10, a diaphragm 11 and a micro air tube 14; the protective shell 9 is connected to the bottom of the inner cavity of the closed cavity 12, the diaphragm 11 is arranged on one side of the protective shell 9, and the reflector 10 is arranged on the diaphragm 11. The first light beam passes through the optical fiber connector 3 and the reflector 10 in sequence. After reflection, the first light beam passes through the second connection end and is connected to the optical fiber coupler 8. One end of the micro air tube 14 is connected to the protective shell 9, and the other end of the micro air tube 14 passes through the outside of the closed cavity 12 and is connected to the atmosphere. The first light beam is irradiated onto the reflector 10, and is reflected to the optical fiber coupler 8 by the reflector 10. The pressure is measured by the pressure sensor on the first light beam, thereby changing the position of the diaphragm 11, and then the required pressure information is analyzed by the signal demodulator.

[0051] Furthermore, the protective shell is made of metal and is covered with an insulating coating to avoid affecting the internal electric field of the device. The protective shell 9 is a cylindrical structure.

[0052] Furthermore, the diaphragm 11 is fixed on the protective housing 9 , and the diaphragm 11 is fixedly connected on all sides, so the displacement occurs in the middle of the diaphragm 11 .

[0053] Furthermore, one end of the micro air tube 14 is connected to the protective shell 9, and the other end passes through the cavity wall of the protective shell 9 to connect to the atmosphere. The position where the micro air tube 14 passes through the cavity is sealed by epoxy resin to ensure the airtightness of the device.

[0054] Furthermore, one end of the bracket 13 is connected to the bottom of the inner cavity of the sealed cavity 12 , and the other end of the bracket 13 is connected to the protective shell 9 for adjusting the position of the diaphragm 11 .

[0055] The diaphragm displacement structure can measure the displacement of the diaphragm through laser. The specific principle is as follows:

[0056] The laser transmitter 5 emits a laser of a certain frequency, which is divided into two laser beams after passing through the optical fiber beam splitter 6, namely a first laser beam and a second laser beam. The first laser beam is transmitted to the protective housing 9 through the first optical fiber, and then reflected by the transmitting mirror 10, and then transmitted to the optical fiber coupler 8 through the second optical fiber. The second laser beam is directly transmitted to the optical fiber coupler 8 through the third optical fiber. Assuming that the length of the first optical fiber is d1, the length of the second optical fiber is d2, the length of the third optical fiber is d3, and the distance between the end face of the first optical fiber and the reflector 10 is d4, the optical path experienced by the first laser beam when transmitted to the optical fiber coupler 8 is d1+d2+2d4, and the optical path experienced by the second laser beam when transmitted to the optical fiber coupler 8 is d3.

[0057] When the diaphragm 11 is not displaced by pressure, let d1+d2+2d4=d3, then the optical path of the first light beam and the second light beam before being transmitted to the optical fiber coupler 8 is the same. When the diaphragm 11 is displaced by pressure, the value of d3 changes, and an optical path difference is generated between the first light beam and the second light beam. The diaphragm displacement can be obtained by calculating the optical path difference.

[0058] The first beam is the measuring light, with a light intensity of I1, and the second beam is the reference light, with a light intensity of I2. The intensity of the interference light after passing through the optical fiber coupler 8 is:

[0059]

[0060] Among them, I is the interference light intensity, I1 is the measurement light intensity, and I2 is the reference light intensity. is the reference light phase, To measure the optical phase

[0061] The phase difference between the first beam and the second beam is:

[0062]

[0063] Where L is the optical path difference between the measurement light and the reference light, which is twice the distance to be measured d, v is the frequency of light, and c is the speed of light. is the phase difference between the reference light and the measurement light, is the reference light phase, To measure the optical phase.

[0064] It can be seen from the above formula that when the laser frequency v achieves linear scanning without mode hopping, the interference light intensity I measured by the signal demodulator is a periodic signal with a fixed frequency, and its frequency expression is as follows:

[0065]

[0066] in, is the frequency scanning range, is the frequency scanning time, L is the optical path difference between the measurement light and the reference light, and f is the frequency of the interference light signal.

[0067] From the above formula, we can know that after obtaining the change of the frequency f of the interference light signal, we can get the change of the optical path difference between the measurement beam and the reference beam, and thus the measured distance d can be obtained as:

[0068]

[0069] Where f is the frequency of the interference light signal, c is the speed of light, is the frequency scanning range, is the frequency sweep time.

[0070] The demodulation method of the signal regulator 7 adopts the Fourier transform method. This algorithm converts the interference spectrum signal from the wavelength domain to the frequency domain, and analyzes the interference signal in the frequency domain. After the signal regulator 7 performs Fourier transform on the interference spectrum signal, the waveform obtained is a peak-shaped waveform. The maximum point of the waveform is the desired frequency of the interference light signal, and the diaphragm displacement distance can be calculated from this frequency.

[0071] In the above device, the diaphragm 11 will bend and deform after being subjected to pressure. The diaphragm deformation causes the reflector 10 fixed on the diaphragm 11 to be displaced. The displacement distance is the above-mentioned distance to be measured d. Since the diaphragm 11 is fixed on all sides and its disturbance is small W≤0.5t, the central disturbance of the diaphragm is calculated as follows:

[0072]

[0073] Among them, W is the central disturbance of the diaphragm, a is the effective radius of the diaphragm, t is the diaphragm thickness, E is the diaphragm elastic modulus, μ is the diaphragm Poisson's ratio, and p is the pressure.

[0074] It can be seen from the above formula that the displacement of the diaphragm is proportional to the pressure it is subjected to, so the pressure on the diaphragm can be measured by measuring the displacement of the diaphragm.

[0075] In the above formula, the elastic modulus and Poisson's ratio of the diaphragm are fixed values ​​after the diaphragm material is determined, and the sensitivity of the diaphragm to compressive deformation can be changed by changing the size and thickness of the diaphragm.

[0076] Please refer to Figure 4 Another aspect of the present invention provides an experimental method for measuring a device, comprising the following steps:

[0077] Step 1: Check whether all parts of the experimental device are intact and airtight, and install the test equipment.

[0078] Step 2: Select the area where you want to measure the pressure and adjust the bracket and sensor position.

[0079] Step 3: Fill the closed air chamber with gas under a certain pressure.

[0080] Step 4: Set the pressure before the experiment starts as the pressure 0 point.

[0081] Step 5: Power on the experimental device, conduct an arc burning experiment, and use the internal pressure sensor probe to collect experimental data.

[0082] Step 6: Turn off the power and discharge the experimental platform.

[0083] Step 7: Use the signal demodulator to process the information collected by the sensor to obtain the expected experimental data.

[0084] It is easy for those skilled in the art to understand that, under the premise of no conflict, the above-mentioned advantageous methods can be freely combined and superimposed.

Claims

1. A high temperature arc pressure measuring device, characterized in that: It includes a high voltage power supply (1), two electrodes (2), an optical fiber connector (3), a laser transmitter (5), a beam splitter (6), an optical fiber coupler (8), a signal conditioner (7), a diaphragm displacement structure and a closed cavity (12); The diaphragm displacement structure is arranged in the inner cavity of the sealed cavity (12), one end of the optical fiber connector (3) is arranged in the inner cavity of the sealed cavity (12) and is connected to the diaphragm displacement structure, the other end of the optical fiber connector (3) is arranged outside the sealed cavity (12), and the end of the optical fiber connector (3) located outside the sealed cavity (12) includes a first connection end and a second connection end, wherein the beam splitter (6) generates a first light beam and a second light beam, the first connection end is connected to the first light beam through a first optical fiber, one end of the optical fiber coupler (8) is connected to the second light beam through a third optical fiber and to the second connection end through a second optical fiber, the other end of the optical fiber coupler (8) is connected to the signal regulator (7), the laser transmitter (5) is connected to the beam splitter (6), two electrodes (2) are arranged in the inner cavity of the sealed cavity (12), and the two electrodes (2) are arranged opposite to each other, and the ends of the two electrodes (2) that are far away from each other are both electrically connected to a high-voltage power supply (1) located outside the sealed cavity (12); The diaphragm displacement structure comprises a protective housing (9), a reflector (10), a diaphragm (11) and a micro air tube (14); The protective shell (9) is connected to the bottom of the inner cavity of the sealed cavity (12), the diaphragm (11) is arranged on one side of the protective shell (9), the reflector (10) is arranged on the diaphragm (11), the first light beam passes through the optical fiber connector (3) and the reflector (10) in sequence, and after reflection, the first light beam passes through the second connection end and is connected to the optical fiber coupler (8), one end of the micro air tube (14) is connected to the protective shell (9), and the other end of the micro air tube (14) passes through the outside of the sealed cavity (12) and is connected to the atmosphere; The diaphragm displacement structure detects the air pressure by measuring the displacement of the diaphragm with laser; Specifically, after the laser emitter (5) emits laser light, the laser light is split into a first light beam and a second light beam by a beam splitter (6). The first light beam is transmitted to the optical fiber connector (3) through a first optical fiber, and then transmitted to the diaphragm displacement structure and then transmitted to the optical fiber coupler (8) through a second optical fiber after reflection. The second light beam is directly transmitted to the optical fiber coupler (8) through a third optical fiber.

2. The high temperature arc gas pressure measuring device according to claim 1, characterized in that: The diaphragm displacement structure also includes a bracket (13), one end of the bracket (13) is connected to the bottom of the inner cavity of the sealed cavity (12), and the other end of the bracket (13) is connected to the protective shell (9).

3. The high temperature arc gas pressure measuring device according to claim 1, characterized in that: The optical fiber connector (3) and the sealed cavity (12) are connected via a fastener (4).

4. The high temperature arc gas pressure measuring device according to claim 1, characterized in that: The length of the first optical fiber is set to d1, the length of the second optical fiber is set to d2, the length of the third optical fiber is set to d3, and the distance between the first optical fiber and the reflector (10) is set to d4. When the diaphragm (11) is not under pressure and does not displace, d1+d2+2d4=d3 is preset. When the diaphragm (11) is displaced under pressure, the optical path difference is calculated, and the formula is as follows: Among them, I is the interference light intensity, I1 is the measurement light intensity, and I2 is the reference light intensity. is the reference light phase, To measure the optical phase.

5. The high temperature arc gas pressure measuring device according to claim 4, characterized in that: The phase difference formula between the first beam and the second beam is as follows: Where L is the optical path difference between the measurement light and the reference light, which is twice the distance to be measured d, v is the frequency of light, and c is the speed of light. is the phase difference between the reference light and the measurement light, is the reference light phase, To measure the optical phase; When the laser frequency v realizes linear scanning without mode hopping, the interference light intensity I measured by the signal conditioner (7) is a periodic signal with a fixed frequency, and its frequency expression is as follows: in, is the frequency scanning range, is the frequency scanning time, L is the optical path difference between the measurement light and the reference light, and f is the frequency of the interference light signal.

6. The high temperature arc gas pressure measuring device according to claim 5, characterized in that: After obtaining the change of the frequency f of the interference light signal, the change of the optical path difference between the measurement beam and the reference beam can be obtained. The measured distance d can be obtained by combining the frequency f formula of the interference light signal: Where f is the frequency of the interference light signal, c is the speed of light, is the frequency scanning range, is the frequency sweep time.

7. The high temperature arc gas pressure measuring device according to claim 1, characterized in that: The central disturbance of the diaphragm in the diaphragm (11) is calculated as follows: Among them, W is the central disturbance of the diaphragm, a is the effective radius of the diaphragm, t is the diaphragm thickness, E is the diaphragm elastic modulus, μ is the diaphragm Poisson's ratio, and p is the pressure.

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