Optical fiber ultrasonic wave-ultrahigh frequency composite sensor for GIS partial discharge detection

Abstract

The utility model belongs to the field of GIS partial discharge detection, and particularly relates to an optical fiber ultrasonic-ultrahigh frequency composite sensor for GIS partial discharge detection, which comprises a cover plate, an ultrasonic sensor and an ultrahigh frequency sensor, the ultrasonic sensor comprises an induction optical fiber, an input connector and an output connector, the cover plate is provided with an annular groove, the induction optical fiber is fixed in the annular groove, and the output connector is fixed in the annular groove. Two ends of the sensing optical fiber are respectively connected with the input connector and the output connector, the input connector is used for inputting an external optical signal into the sensing optical fiber, and the output connector is used for outputting the optical signal in the sensing optical fiber to external detection equipment; the ultrahigh frequency sensor comprises an inductive probe, a pressing ring, a base and an N-type connector, the base is fixed on the cover plate, the pressing ring and the inductive probe are installed on the base, the inductive probe is mushroom-shaped and comprises a head part and a connecting part, and the connecting part sequentially penetrates through the pressing ring, the base and the cover plate and is electrically connected with the N-type connector; the problems that an existing composite sensor is low in measurement precision and sensitivity and poor in anti-interference capacity are solved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to GIS partial discharge detection field, concretely relates to the optical fiber ultrasonic wave - ultra high frequency compound sensor for GIS partial discharge detection. BACKGROUND

[0002] The safe operation of power system mainly depends on the safe operation of high-voltage power equipment in the power system. Gas insulated switchgear (GIS) is widely used in power systems due to its high reliability, small footprint, simple maintenance and long maintenance period, but defects such as bubbles, cracks, suspended conductive particles and burrs may occur during manufacturing, transportation, installation and operation of GIS equipment. These defects can cause the electric field intensity in some areas of the GIS equipment to be too high, which can cause partial discharge when it exceeds the breakdown field strength of the insulating medium. Therefore, through the detection of partial discharge, the insulation defects existing in the GIS equipment can be found in time to avoid sudden insulation breakdown accidents of the equipment, which is of great significance to the safe operation of GIS equipment and power grid.

[0003] The commonly used partial discharge detection methods currently include pulse current method, ultrasonic wave method, chemical detection method, ultra high frequency method and optical detection method. Among them, the ultrasonic wave method and the ultra high frequency method are two methods commonly used in the field of GIS equipment. The ultra high frequency method has high sensitivity and wide detection range, and can realize the positioning of the partial discharge source and the identification of the discharge type. However, in the field application, due to the existence of a large amount of electromagnetic interference, the detection results of the ultra high frequency method often occur false judgment. The ultrasonic wave method has strong anti-interference ability and high positioning accuracy because it detects non-electric quantity. However, mechanical vibration interference often has negative impact on the ultrasonic wave method detection in the field.

[0004] In order to improve the reliability and accuracy of the field detection, the utility model with publication number CN207164194U discloses an acoustic-electric composite sensor for GIS partial discharge detection, which integrates ultrasonic sensor and ultra high frequency sensor. It can not only detect partial discharge by ultra high frequency method, but also by ultrasonic wave method, and has the advantages of both methods. However, the non-contact ultrasonic sensor in this composite sensor has low measurement accuracy and sensitivity. In addition, in the GIS equipment, there may be other sound sources (such as conductive particles colliding with metal shell, electromagnetic vibration, etc.). The sound waves generated by these sound sources may interfere with the ultrasonic waves generated by partial discharge, affecting the accuracy of non-contact ultrasonic sensor detection. UTILITY MODEL CONTENTS

[0005] The utility model aims at providing an optical fiber ultrasonic wave-ultra high frequency composite sensor for GIS partial discharge detection to solve the problems of low measurement accuracy and sensitivity and poor anti-interference ability in the prior art.

[0006] To solve the above technical problems, the utility model provides the following technical scheme:

[0007] The utility model provides a fiber ultrasonic wave - ultra high frequency composite sensor for GIS partial discharge detection, including cover plate, ultrasonic sensor and ultra high frequency sensor, the cover plate includes first end surface and second end surface, and ultrasonic sensor and ultra high frequency sensor are arranged respectively on the first end surface and the second end surface of cover plate,

[0008] Ultrasonic sensor includes inductive fiber, input connector and output connector, and the first end surface of cover plate is equipped with ring groove, and inductive fiber is fixed in ring groove in ring shape, and the both ends of inductive fiber are connected with input connector and output connector respectively, and input connector is used for inputting external light signal into inductive fiber, and output connector is used for outputting the light signal in inductive fiber to external detection equipment,

[0009] Ultra high frequency sensor includes inductive probe, compression ring, base and N type joint, and the base is fixed on the second end surface of cover plate, and compression ring and inductive probe are installed on the base, and inductive probe is mushroom-shaped, and inductive probe includes head and connecting part, and connecting part penetrates compression ring, base, cover plate and N type joint electrically connected in proper order.

[0010] Further, the ultra high frequency sensor further includes gland, the gland is covered outside compression ring and base, and the gland is connected into a whole with compression ring, base and cover plate by screw, a first sealing groove is arranged on compression ring, a first sealing ring is arranged in the first sealing groove, and the head of inductive probe is connected into a whole with compression ring and first sealing ring by screw.

[0011] Further, a center hole is arranged on the cover plate, the N type joint includes flange, insulating ring, joint core and copper column, the flange is fixed on the first end surface of cover plate, the insulating ring is arranged inside the flange, one end of the joint core penetrates the insulating ring, and the other end of the joint core is located in the center hole and connected with the copper column, a mandrel and a spring are sequentially connected on the connecting part of inductive probe, and the spring is connected with the copper column of N type joint.

[0012] Further, a second sealing groove and a third sealing groove are further arranged on the second end surface of cover plate, a second sealing ring and a third sealing ring are respectively arranged in the second sealing groove and the third sealing groove, a fourth sealing groove is arranged on the end surface of mandrel, and a fourth sealing ring is arranged in the fourth sealing groove.

[0013] Further, the inductive fiber adopts 100 meters bending insensitive common single mode fiber or special multi-core fiber and is arranged in ring shape closely, and the inductive fiber is fixed in the ring groove by epoxy resin pouring.

[0014] Furthermore, a cable outlet box is provided on the first end face of the cover plate, and a mounting bracket is provided inside the cable outlet box. The input connector and output connector of the ultrasonic sensor are both fixed on the mounting bracket. The cover plate has multiple mounting holes evenly distributed around its circumference. The mounting holes, in conjunction with screws, can fix the cover plate to the flange structure of the GIS equipment.

[0015] Compared with the prior art, the present invention has the following beneficial technical effects:

[0016] 1. This utility model uses an inductive optical fiber to detect ultrasonic signals generated by partial discharge in GIS (i.e., an optical fiber ultrasonic sensor). It is superior to the non-contact ultrasonic sensors used in the prior art in terms of accuracy and sensitivity. It can more accurately capture the weak sound wave signals generated by partial discharge inside GIS equipment. Furthermore, since the optical fiber ultrasonic sensor uses optical fiber to transmit signals, it is not affected by electromagnetic interference generated by the operation of GIS equipment and can work stably in the complex environment of strong electromagnetic field of GIS equipment.

[0017] 2. This utility model integrates an ultrasonic sensor and an ultra-high frequency sensor into one unit, which can simultaneously detect ultrasonic signals and ultra-high frequency signals. It combines the advantages of the ultra-high frequency method with the ultrasonic method with its strong anti-interference ability, resulting in high reliability and wide applicability of the detection results.

[0018] 3. This utility model has a simple structure and small size, and is easy to integrate with the flange structure of GIS equipment. It can comprehensively monitor the ultrasonic signals and ultra-high frequency signals generated by partial discharge in real time during the operation of GIS equipment. The detection results are highly reliable and can detect insulation defects of GIS equipment in a timely manner, ensuring the safe operation of GIS equipment. Attached Figure Description

[0019] Figure 1 This is an exploded view of the present invention;

[0020] Figure 2 This is a cross-sectional view of the present invention;

[0021] Figure 3 for Figure 2 Enlarged view of point A in the middle.

[0022] In the diagram: cover plate 1, annular groove 11, outlet box 12, mounting bracket 13, center hole 14, second sealing ring 15, third sealing ring 16, mounting hole 17, ultrasonic sensor 2, sensing fiber optic cable 21, input connector 22, output connector 23, ultra-high frequency sensor 3, sensing probe 31, spindle 311, spring 312, fourth sealing ring 313, pressure ring 32, first sealing ring 321, base 33, N-type connector 34, flange 341, insulating ring 342, connector core 343, copper pillar 344, pressure cap 35. Detailed Implementation

[0023] The following detailed description illustrates the specific implementation method:

[0024] Example

[0025] like Figure 1 As shown, the fiber optic ultrasonic-ultra-high frequency composite sensor for partial discharge detection in GIS includes a cover plate 1, an ultrasonic sensor 2, and an ultra-high frequency sensor 3. The cover plate 1 includes a first end face and a second end face, and the ultrasonic sensor 2 and the ultra-high frequency sensor 3 are respectively disposed on the first end face and the second end face of the cover plate 1.

[0026] like Figure 1 , 2 As shown, an annular groove 11 is formed on the first end face of the cover plate 1, and a terminal box 12 is welded on the first end face. A mounting bracket 13 is welded inside the terminal box 12. The cover plate 1 also has a central hole 14 and multiple mounting holes 17. The multiple mounting holes 17 are evenly distributed on the cover plate 1 in a circumferential direction. By engaging the mounting holes 17 with screws, the cover plate 1 can be integrated with the flange 341 joint of the GIS equipment, so as to facilitate the real-time online monitoring of the partial discharge of the GIS equipment using the composite sensor of this utility model.

[0027] like Figure 1 , 2 As shown, the ultrasonic sensor 2 includes a sensing fiber 21, an input connector 22, and an output connector 23. The sensing fiber 21 is made of 100 meters of ordinary single-mode fiber or special multi-core fiber that is not sensitive to bending and is arranged in a tight ring. The sensing fiber 21 is fixed in the ring groove 11 by epoxy resin casting. The two ends of the sensing fiber 21 are connected to the input connector 22 and the output connector 23, respectively. The input connector 22 is used to input external optical signals into the sensing fiber 21, and the output connector 23 is used to output the optical signals in the sensing fiber 21 to the external detection equipment. Both the input connector 22 and the output connector 23 are fixed on the mounting bracket 13.

[0028] By integrating the ultrasonic sensor 2 on the first end face of the cover plate 1, the external light signal is input into the sensing optical fiber 21 through the input joint 22, when the GIS device generates partial discharge in the operation process, ultrasonic waves are formed, which propagate in the form of elastic waves in the internal and surrounding space of the GIS device, the sensing optical fiber 21 is affected by the ultrasonic waves and deforms or vibrates, and then the transmission characteristics (such as light intensity, phase, etc.) of the light in the sensing optical fiber 21 are changed, the changes of the light signals are detected by the external detection device and converted into electric signals, so that the reception and measurement of the ultrasonic signals are realized, and the characteristic information of the ultrasonic waves is analyzed to determine whether the partial discharge phenomenon exists in the internal of the GIS device; the ultrasonic sensor 2 for detecting the ultrasonic signals generated by the GIS partial discharge (i.e. the optical fiber ultrasonic sensor 2) is adopted, which has good detection precision and sensitivity, can more accurately capture the weak sound wave signals generated by the internal partial discharge of the GIS device, transmits the light signals by the sensing optical fiber 21, is not affected by the electromagnetic interference generated by the operation of the GIS device, and can stably work in the complex environment of the strong electromagnetic field of the GIS device.

[0029] As shown in Figures 1-3 The ultrasonic sensor 2 is integrated on the first end face of the cover plate 1, the external light signal is input into the sensing optical fiber 21 through the input joint 22, when the GIS device generates partial discharge in the operation process, ultrasonic waves are formed, which propagate in the form of elastic waves in the internal and surrounding space of the GIS device, the sensing optical fiber 21 is affected by the ultrasonic waves and deforms or vibrates, and then the transmission characteristics (such as light intensity, phase, etc.) of the light in the sensing optical fiber 21 are changed, the changes of the light signals are detected by the external detection device and converted into electric signals, so that the reception and measurement of the ultrasonic signals are realized, and the characteristic information of the ultrasonic waves is analyzed to determine whether the partial discharge phenomenon exists in the internal of the GIS device; the ultrasonic sensor 2 for detecting the ultrasonic signals generated by the GIS partial discharge (i.e. the optical fiber ultrasonic sensor 2) is adopted, which has good detection precision and sensitivity, can more accurately capture the weak sound wave signals generated by the internal partial discharge of the GIS device, transmits the light signals by the sensing optical fiber 21, is not affected by the electromagnetic interference generated by the operation of the GIS device, and can stably work in the complex environment of the strong electromagnetic field of the GIS device.

[0030] By integrating the ultrasonic sensor 2 on the first end face of the cover plate 1, the external light signal is input into the sensing optical fiber 21 through the input joint 22, when the GIS device generates partial discharge in the operation process, ultrasonic waves are formed, which propagate in the form of elastic waves in the internal and surrounding space of the GIS device, the sensing optical fiber 21 is affected by the ultrasonic waves and deforms or vibrates, and then the transmission characteristics (such as light intensity, phase, etc.) of the light in the sensing optical fiber 21 are changed, the changes of the light signals are detected by the external detection device and converted into electric signals, so that the reception and measurement of the ultrasonic signals are realized, and the characteristic information of the ultrasonic waves is analyzed to determine whether the partial discharge phenomenon exists in the internal of the GIS device; the ultrasonic sensor 2 for detecting the ultrasonic signals generated by the GIS partial discharge (i.e. the optical fiber ultrasonic sensor 2) is adopted, which has good detection precision and sensitivity, can more accurately capture the weak sound wave signals generated by the internal partial discharge of the GIS device, transmits the light signals by the sensing optical fiber 21, is not affected by the electromagnetic interference generated by the operation of the GIS device, and can stably work in the complex environment of the strong electromagnetic field of the GIS device.

[0031] AsFigure 2 As shown, the second end face of the cover plate 1 is provided with a second sealing groove and a third sealing groove, and the second sealing groove and the third sealing groove are respectively provided with a second sealing ring 15 and a second sealing ring 15; the end face of the mandrel 311 is provided with a fourth sealing groove, and the fourth sealing groove is provided with a fourth sealing ring 313; by arranging the first sealing ring 321, the second sealing ring 15, the third sealing ring 16 and the fourth sealing ring 313, the sealing property of the equipment can be effectively guaranteed, and the SF6 gas in the GIS equipment can be prevented from leaking out.

[0032] The ultrasonic sensor 2 and the UHF sensor 3 are integrated, so that the ultrasonic signal and the UHF signal can be detected at the same time, the advantages of wide detection range of the UHF method and strong anti-interference ability of the ultrasonic method are combined, the reliability of the detection result is high, and the applicability is wide; moreover, the overall structure of the sensor is simple and small in size, and the sensor is easy to be integrated with the flange 341 structure of the GIS equipment, so that the ultrasonic signal and the UHF signal generated by partial discharge can be comprehensively and real-timely monitored during the operation of the GIS equipment, the reliability of the detection result is high, the insulation defects of the GIS equipment can be found in time, and the safe operation of the GIS equipment is guaranteed.

[0033] The above-mentioned is only an embodiment of the utility model, and the well-known specific technical solutions and / or common knowledge in the scheme are not described in detail. It should be noted that, for those skilled in the art, without departing from the technical scheme of the utility model, a plurality of deformations and improvements can be made, which should also be regarded as the protection scope of the utility model, and these will not affect the effect and practicality of the utility model. The protection scope of the present application should be subject to the content of its claims, and the specific implementation mode and the like in the specification can be used to explain the content of the claims.

Claims

1. A fiber-optic ultrasonic-high frequency composite sensor for GIS partial discharge detection, comprising a cover plate (1), an ultrasonic sensor (2) and a high frequency sensor (3), characterized in that: The cover plate (1) comprises a first end face and a second end face, and the ultrasonic sensor (2) and the ultra-high frequency sensor (3) are arranged on the first end face and the second end face of the cover plate (1) respectively; The ultrasonic sensor (2) comprises a sensing optical fiber (21), an input connector (22) and an output connector (23), the first end face of the cover plate (1) is provided with a ring groove (11), the sensing optical fiber (21) is fixed in the ring groove (11) in a ring shape, the two ends of the sensing optical fiber (21) are connected with the input connector (22) and the output connector (23) respectively, the input connector (22) is used for inputting an external optical signal into the sensing optical fiber (21), and the output connector (23) is used for outputting an optical signal in the sensing optical fiber (21) to an external detection device. The ultra-high frequency sensor (3) comprises a sensing probe (31), a compression ring (32), a base (33) and an N-shaped connector (34), the base (33) is fixed on the second end face of the cover plate (1), the compression ring (32) and the sensing probe (31) are installed on the base (33), the sensing probe (31) is in a mushroom shape, the sensing probe (31) comprises a head part and a connecting part, and the connecting part penetrates the compression ring (32), the base (33), the cover plate (1) and the N-shaped connector (34) in sequence and is electrically connected with the N-shaped connector (34).

2. The optical fiber ultrasonic-hyperfrequency composite sensor for GIS partial discharge detection according to claim 1, characterized in that: The ultra-high frequency sensor (3) further comprises a compression cover (35), the compression cover (35) is arranged outside the compression ring (32) and the base (33), and the compression cover (35) is connected with the compression ring (32), the base (33) and the cover plate (1) into an integral whole through screws; the compression ring (32) is provided with a first sealing groove, the first sealing groove is provided with a first sealing ring (321), and the head part of the sensing probe (31) is connected with the compression ring (32) and the first sealing ring (321) into an integral whole through screws.

3. The optical fiber ultrasonic-hyperfrequency composite sensor for GIS partial discharge detection according to claim 2, characterized in that: The cover plate (1) is provided with a center hole (14), the N-shaped connector (34) comprises a flange (341), an insulating ring (342), a connector core (343) and a copper column (344), the flange (341) is fixed on the first end face of the cover plate (1), the insulating ring (342) is arranged inside the flange (341), one end of the connector core (343) penetrates the insulating ring (342), the other end of the connector core (343) is located in the center hole (14) and is connected with the copper column (344), and the connecting part of the sensing probe (31) is sequentially connected with a core shaft (311) and a plug spring (312), and the plug spring (312) is connected with the copper column (344) of the N-shaped connector (34).

4. The optical fiber ultrasonic-very high frequency composite sensor for GIS partial discharge detection according to claim 3, characterized in that: The second end face of the cover plate (1) is further provided with a second sealing groove and a third sealing groove, the second sealing groove and the third sealing groove are respectively provided with a second sealing ring (15) and a third sealing ring (16), the end face of the core shaft (311) is provided with a fourth sealing groove, and the fourth sealing groove is provided with a fourth sealing ring (313).

5. The optical fiber ultrasonic-hyperfrequency composite sensor for GIS partial discharge detection according to claim 1, characterized in that: The sensing optical fiber (21) adopts a 100-meter bending-insensitive common single-mode optical fiber or a special multi-core optical fiber arranged in a ring shape, and the sensing optical fiber (21) is fixed in the ring groove (11) through epoxy resin pouring. 6.The optical fiber ultrasonic-High Frequency composite sensor for partial discharge detection of GIS according to claim 1, characterized in that: The first end surface of the cover plate (1) is provided with an outlet box (12), the outlet box (12) is provided with a mounting rack (13), the input connector (22) and the output connector (23) of the ultrasonic sensor (2) are fixed on the mounting rack (13); the cover plate (1) is circumferentially provided with a plurality of mounting holes (17), the mounting holes (17) are matched with screws and can fix the cover plate (1) on the flange (341) structure of the GIS equipment.

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