Partial discharge testing device and testing method for insulating pull rod in force application state

Abstract

The invention relates to a partial discharge testing device and testing method for an insulating pull rod in a force application state. A tank body is filled with insulating gas, and a high-voltage electrode and two ground electrodes are arranged in the tank body; the force application assembly penetrates through the tank body, the first end of the force application assembly is connected with an external force application device, the second end of the force application assembly has a locking state and an unlocking state, the two to-be-tested insulating pull rods are both installed on the force application assembly, and the two ends of the to-be-tested insulating pull rods are connected with the high-voltage electrode and one of the ground electrodes respectively; two detection resistors in the partial discharge test assembly are respectively connected in series into grounding electrode loops of the two to-be-tested insulating pull rods; the test process comprises the steps of feeding the to-be-tested insulation pull rod into the tank body, performing partial discharge measurement and obtaining a test result; partial discharge testing is carried out on the to-be-tested insulation pull rod segment by segment, so that the distance between the high-voltage electrode and the low-voltage electrode is reduced, the partial discharge testing sensitivity of the insulation pull rod is remarkably improved, and meanwhile, the capability of discovering tiny insulation defects of the insulation pull rod through partial discharge detection is improved.

Description

Technical Field

[0001] The invention relates to the technical field of power transmission and transformation equipment testing and detection, and in particular to a partial discharge testing device and a testing method for an insulating pull rod under a force-applied state. Background Art

[0002] At present, insulating rods are important components in high-voltage switchgear and are widely used in circuit breakers and disconnectors to transfer power and energy to the moving mechanism and also play the role of electrical insulation. Due to the dispersion of the production process, there may be tiny local defects inside or on the surface of the insulating rods. These tiny defects may cause the degradation of the insulating material and internal damage to the insulation under the action of mechanical stress and long-term high field strength, greatly reducing its insulation performance and mechanical strength, increasing the risk of switchgear operation, and seriously affecting the stability and reliability of the system. Therefore, it is necessary to effectively detect the tiny defects of the insulating rods.

[0003] The partial discharge test is an effective means of detecting tiny local defects in insulating media; the higher the sensitivity of the partial discharge test, the more effective it is in detecting smaller insulation defects. The current standard requires that the partial discharge of a single insulating component should not exceed 3pC.

[0004] The traditional method for conducting insulation withstand voltage and partial discharge tests on insulating rods is to arrange multiple insulating rods in parallel in a test fixture to improve test efficiency. The two ends of each insulating rod are respectively installed in the high-voltage shielding cover and low-voltage shielding cover of the fixture. During the test, the test voltage is applied between the high and low voltage shielding covers to measure the partial discharge.

[0005] However, when multiple insulating rods are connected in parallel for partial discharge testing, the coupling capacitance between the rods is very large, which affects the sensitivity of partial discharge detection. The sensitivity of partial discharge detection is 1pC, which makes it difficult to detect smaller defects. At the same time, it is impossible to perform partial discharge detection on the insulating rods under force, and studies have shown that mechanical load has an important influence on the detection of partial discharge. Summary of the invention

[0006] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a partial discharge testing device and a testing method for an insulating rod under a force applied state, which has the advantage of being able to perform partial discharge detection on the insulating rod under a force applied state and effectively detect tiny defects; at the same time, the sensitivity of the partial discharge test of the insulating rod is improved.

[0007] The above-mentioned inventive object of the present invention is achieved through the following technical solutions: On the one hand, the present invention provides a partial discharge test device for an insulating pull rod under a force-applying state, comprising a tank body, a high-voltage electrode, two ground electrodes, a force-applying component and a partial discharge test component; the tank body is filled with insulating gas, the high-voltage electrode and the two ground electrodes are both arranged in the tank body, the high-voltage electrode is located between the two ground electrodes, and the high-voltage electrode and the ground electrodes are spaced a preset distance apart; the force-applying component passes through the tank body, the first end of the force-applying component is connected to an external force-applying device, the second end of the force-applying component has two states, locked and unlocked, the two insulating pull rods to be tested are both located in the tank body, and the two insulating pull rods to be tested are both installed in the force-applying component The two ends of the insulating rod to be tested are respectively connected to the high-voltage electrode and one of the ground electrodes; when the second end of the force-applying component is in an unlocked state, the force-applying component can slide relative to the tank body, and the force-applying component can drive the two insulating rods to be tested to slide the insulating rods to be tested; when the insulating rods to be tested are subjected to a partial discharge test, the second end of the force-applying component is in a locked state, and the external force-applying device applies axial pressure or tension to the insulating rod to be tested; the partial discharge test component is arranged on the outer peripheral wall of the tank body, and the two detection resistors in the partial discharge test component are respectively connected in series with the grounding electrode loops of the two insulating rods to be tested, and the two insulating rods to be tested are in a parallel state in the detection loop.

[0008] Preferably, in the partial discharge testing device for an insulating rod under a force-applied state provided by the present invention, the partial discharge testing component comprises two pulse current detection sensors and two ultra-high frequency sensors, the two pulse current detection sensors and the two ultra-high frequency sensors are both arranged on the outer peripheral wall of the tank body, and the two ultra-high frequency sensors are respectively arranged corresponding to the test sections of the two insulating rods to be tested; the detection impedances of the two pulse current detection sensors are respectively connected in series with the grounding electrode loops of the two insulating rods to be tested; the pulse current detection sensors and the ultra-high frequency sensors are both used to detect partial discharge of the insulating rods to be tested.

[0009] Preferably, the partial discharge testing device for an insulating pull rod under a force-applied state provided by the present invention further includes a pot-type insulator, a voltage-equalizing cover, a high-voltage conductor and a guide cylinder, the top end of the pot-type insulator is connected to the outer wall of the tank body, the bottom end of the pot-type insulator is inserted into the tank body and connected to the voltage-equalizing cover, the guide cylinder is located in the high-voltage electrode, one end of the high-voltage conductor is connected to the pot-type insulator, the other end of the high-voltage conductor is connected to the outer peripheral wall of the guide cylinder through the voltage-equalizing cover, the two ends of the guide cylinder are respectively connected to the two ends of the high-voltage electrode, and the test power supply is connected to the high-voltage electrode through the high-voltage conductor.

[0010] Preferably, in the partial discharge testing device for an insulating pull rod in a force-applied state provided by the present invention, the end of the guide cylinder is connected to the end of the high-voltage electrode through a fixing unit.

[0011] Preferably, in the partial discharge testing device for an insulating pull rod under a force applied state provided by the present invention, the fixing unit includes a connecting plate and at least one supporting sleeve, the connecting plate is located inside the high-voltage electrode, the connecting plate is attached to the end of the guide cylinder, the connecting plate is bolted to the guide cylinder, the supporting sleeve is located between the end plate of the high-voltage electrode and the connecting plate, and the supporting sleeve is connected to the connecting plate via a connecting bolt.

[0012] Preferably, the partial discharge testing device for an insulating pull rod under a force-applied state provided by the present invention further includes two insulating support sleeves, both of which are arranged at opposite ends of the tank body, and the insulating support sleeves and the ground electrodes are arranged in a one-to-one correspondence, and the ground electrode is connected to the end cover of the tank body through the insulating support sleeves.

[0013] Preferably, in the partial discharge testing device for an insulating rod in a force-applying state provided by the present invention, the force-applying assembly includes a force transmission rod, a positioning unit and a slider, the slider is located in the guide cylinder, the slider can slide along the guide cylinder, the two insulating rods to be tested are connected by the slider, one end of the force transmission rod is inserted into one end of the tank body, and is connected to one end of one of the insulating rods to be tested away from the slider, the other end of the force transmission rod extends to the outside along the center line direction of the tank body, and is connected to an external force-applying device, the first end of the positioning unit is inserted into the other end of the tank body, and is connected to one end of the other insulating rod to be tested away from the slider, the second end of the positioning unit extends to the outside along the center line direction of the tank body, and the second end of the positioning unit has two states of locking and unlocking; when the second end of the positioning unit is in the unlocked state, the force-applying assembly is pulled, and the force-applying assembly drives the insulating rod to be tested to move, so that the undetected part of the insulating rod to be tested moves to the detection area.

[0014] Preferably, in the partial discharge testing device for an insulating pull rod under a force-applied state provided by the present invention, the positioning unit includes a positioning transmission rod and a locking assembly, one end of the positioning transmission rod is inserted into the tank body, and the other end of the positioning transmission rod extends to the outside along the center line direction of the tank body and is connected to the locking assembly, and the positioning transmission rod cooperates with the locking assembly so that the positioning transmission rod has two states: locked and unlocked.

[0015] Preferably, in the partial discharge testing device for an insulating pull rod under a force-applied state provided by the present invention, the locking assembly comprises a first fixing plate, a second fixing plate and at least one connecting sleeve, the first fixing plate and the second fixing plate are both located outside the tank body, the first fixing plate and the second fixing plate are spaced apart along the center line direction of the tank body, the first fixing plate is attached to an end of the tank body away from the force-applied transmission rod, the first fixing plate is bolted to the tank body, one end of the connecting sleeve is connected to the first fixing plate by a first fastening bolt, and the other end of the connecting sleeve is connected to the second fixing plate by a second fastening bolt; the first end of the positioning transmission rod passes through the first fixing plate and is inserted into the tank body, an external thread is provided on the outer peripheral wall of the second end of the positioning transmission rod, and the second end of the positioning transmission rod passes through the first nut and is threadedly connected to the second fixing plate and the second nut in sequence.

[0016] On the other hand, the present invention provides a method for testing a partial discharge test device for an insulating pull rod under a force-applied state as described above, comprising the following steps: S101, inserting two insulating pull rods to be tested installed on the force-applying assembly into the tank body, and filling the tank body with the insulating gas until the pressure value in the tank body reaches a set pressure value; S102, applying pressure or tension along the direction of the insulating rod to be tested to the insulating rod to be tested by an external force-applying device according to the specified force-applying requirements, and performing partial discharge measurement on the insulating rod to be tested by a partial discharge test assembly; S103, if the partial discharge detection sensitivity is less than or equal to 0.1pC, unlock the second end of the force-applying component, move the undetected portion of the insulating rod to be tested to the detection area and lock the second end of the force-applying component, continue to detect the undetected portion of the insulating rod to be tested according to S102, if the partial discharge detection sensitivity is less than or equal to 0.1pC, the insulating rod to be tested meets the partial discharge requirements; If the partial discharge detection sensitivity is greater than 0.1pC, and the signal amplitudes of each detection impedance are consistent and have the same polarity, it is power supply interference; If the partial discharge detection sensitivity is greater than 0.1pC, excluding the case where the signal amplitudes of the detection impedances are consistent and the polarities are the same, and the signal amplitude of a certain detection impedance is large and opposite to the signal amplitudes of other detection impedances, then the detected portion of the insulating pull rod to be tested corresponding to the detection impedance has partial discharge; If the partial discharge detection sensitivity is greater than 0.1pC, excluding the cases where the signal amplitudes of the detection impedances are consistent and the polarities are the same, and at the same time excluding the case where the signal amplitude of a certain detection impedance is large and opposite to the signal amplitudes of other detection impedances, it is other interference.

[0017] In summary, the beneficial technical effects of the present invention are as follows: the present application provides a partial discharge test device and a test method for an insulating pull rod under a force-applied state, wherein the partial discharge test device comprises a tank body, a high-voltage electrode, two ground electrodes, a force-applying component and a partial discharge test component; the tank body is filled with insulating gas, the high-voltage electrode and the two ground electrodes are both arranged in the tank body, the high-voltage electrode is located between the two ground electrodes, and a preset distance is provided between the high-voltage electrode and the ground electrodes; the force-applying component runs through the tank body, the first end of the force-applying component is connected to an external force-applying device, the second end of the force-applying component has two states, locked and unlocked, the two insulating pull rods to be tested are both located in the tank body, the two insulating pull rods to be tested are both installed on the force-applying component, the two ends of the insulating pull rod to be tested are respectively connected to the high-voltage electrode and one of the ground electrodes, and when the second end of the force-applying component is in an unlocked state, the force-applying component can The insulating rods to be tested can slide relative to the tank body, and the force-applying component can drive the two insulating rods to be tested to slide. When the insulating rods to be tested are subjected to a partial discharge test, the second end of the force-applying component is in a locked state, and the external force-applying device applies axial pressure or tension to the insulating rods to be tested; the partial discharge test component is arranged on the outer peripheral wall of the tank body, and the two detection resistors in the partial discharge test component are respectively connected in series with the grounding electrode loops of the two insulating rods to be tested, and the two insulating rods to be tested are in a parallel state in the detection loop; the test process: sending the insulating rods to be tested into the tank body - partial discharge measurement - test results; by performing partial discharge tests on the insulating rods to be tested section by section, the distance between the high and low voltage electrodes is reduced, the sensitivity of the partial discharge test of the insulating rods is significantly improved, and at the same time, the ability of the partial discharge detection to detect tiny insulation defects of the insulating rods is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the overall structure of a partial discharge testing device for an insulating pull rod under a force-applied state provided by an embodiment of the present invention.

[0019] Figure 2 It is a schematic diagram of the arrangement of a UHF sensor and a pulse current detection sensor in a partial discharge test device for an insulating pull rod under a force-applied state provided by an embodiment of the present invention.

[0020] Figure 3 for Figure 1 Enlarged view of point A in the middle.

[0021] Figure 4 for Figure 1 Enlarged view of point B in the middle.

[0022] Figure 5 It is a flow chart of a testing method of a partial discharge testing device for an insulating pull rod under a force-applied state provided by another embodiment of the present invention.

[0023] Figure 6It is a schematic diagram of the interference signal propagation path in a test method of a partial discharge test device for an insulating pull rod under a force application state provided by another embodiment of the present invention.

[0024] Figure 7 It is a schematic diagram of the propagation path of the partial discharge signal in the test method of the partial discharge test device for the insulating pull rod under the force application state provided by another embodiment of the present invention.

[0025] In the figure, 1. partial discharge test device; 10. tank body; 11. end cover; 20. high voltage electrode; 21. end plate; 30. ground electrode; 40. force application assembly; 41. force application transmission rod; 42. positioning unit; 421. positioning transmission rod; 422. locking assembly; 4221. first fixing plate; 4222. second fixing plate; 4223. connecting sleeve; 4224. first fastening bolt; 4225. second fastening bolt; 4226. first nut; 4227. second nut; 43. slider; 50. partial discharge test assembly; 51. pulse current detection sensor; 511. detection impedance; 52. ultra-high frequency sensor; 60. pot insulator; 70. voltage grading cover; 80. high voltage conductor; 90. guide tube; 100. fixing unit; 101. connecting plate; 102. support sleeve; 110. insulating support sleeve; 2. insulating pull rod to be tested. DETAILED DESCRIPTION

[0026] The present invention is further described in detail below in conjunction with the accompanying drawings.

[0027] Reference Figure 1 and Figure 2 , is a partial discharge test device 1 for an insulating pull rod under a force-applied state disclosed in the present invention, comprising a tank body 10, a high-voltage electrode 20, two ground electrodes 30, a force-applying component 40 and a partial discharge test component 50; the tank body 10 is filled with insulating gas, the high-voltage electrode 20 and the two ground electrodes 30 are both arranged in the tank body 10, the high-voltage electrode 20 is located between the two ground electrodes 30, and the high-voltage electrode 20 and the ground electrode 30 are spaced a preset distance apart.

[0028] The tank body 10 is made of metal and is in a closed shape.

[0029] Specifically, the high voltage electrode 20 is disposed at the geometric center of the tank body 10 , and the two ground electrodes 30 are located at opposite ends of the tank body 10 .

[0030] Among them, the force-applying component 40 passes through the tank body 10, the first end of the force-applying component 40 is connected to the external force-applying device, the second end of the force-applying component 40 has two states of locking and unlocking, the two insulating pull rods 2 to be tested are both located in the tank body 10, the two insulating pull rods 2 to be tested are both installed on the force-applying component 40, and the two ends of the insulating pull rods 2 to be tested are respectively connected to the high-voltage electrode 20 and one of the ground electrodes 30. When the second end of the force-applying component 40 is in the unlocked state, the force-applying component 40 can slide relative to the tank body 10, and the force-applying component 40 can drive the two insulating pull rods 2 to be tested. The insulating rods 2 to be tested slide to facilitate partial discharge measurement of the insulating rods 2 to be tested section by section. When the partial discharge test is performed on the insulating rods 2 to be tested, the second end of the force-applying assembly 40 is in a locked state, and the external force-applying device applies axial pressure or tension to the insulating rods 2 to be tested. By performing partial discharge tests on the insulating rods 2 to be tested section by section, the distance between the high and low voltage electrodes is reduced, the sensitivity of the partial discharge test on the insulating rods is significantly improved, and at the same time, the ability of partial discharge detection to detect tiny insulation defects in the insulating rods is improved.

[0031] In this embodiment, the partial discharge test assembly 50 is arranged on the outer wall of the tank body 10, and the two detection resistors in the partial discharge test assembly 50 are respectively connected in series with the grounding electrode 30 circuits of the two insulating rods 2 to be tested, and the two insulating rods 2 to be tested are in a parallel state in the detection circuit.

[0032] Furthermore, in the present embodiment, the partial discharge test assembly 50 includes two pulse current detection sensors 51 and two ultra-high frequency sensors 52, and the two pulse current detection sensors 51 and the two ultra-high frequency sensors 52 are both arranged on the outer peripheral wall of the tank body 10, and the two ultra-high frequency sensors 52 are respectively arranged corresponding to the test sections of the two insulating rods 2 to be tested; the detection impedances 511 of the two pulse current detection sensors 51 are respectively connected in series with the grounding electrode 30 loops of the two insulating rods 2 to be tested; the pulse current detection sensors 51 and the ultra-high frequency sensors 52 are both used to detect partial discharge of the insulating rods 2 to be tested.

[0033] Specifically, the detection impedance 511 of the pulse current detection sensor 51 is connected in series to the ground electrode 30 loop of the insulating pull rod, and the partial discharge signal is led out of the tank body 10 and connected to the oscilloscope.

[0034] The detection process of the partial discharge test device 1 for the insulating rod provided in this embodiment adopts a distributed pulse current measurement method to measure the partial discharge of the insulating rod, wherein the pulse current partial discharge signal is measured for the insulating rods 2 to be tested respectively. When a partial discharge occurs in one of the insulating rods 2 to be tested, the signal amplitude of its detection impedance 511 will be much larger than the signal amplitude of another detection impedance 511, and the polarity is opposite; when there is interference in the power supply, since the equivalent capacitance of the detection part of each insulating rod 2 to be tested is similar, the signal amplitude and polarity of each detection impedance 511 are the same; therefore, based on the relationship between the signal amplitude and polarity of each detection impedance 511, interference can be effectively identified, and it can be distinguished which specific insulating rod 2 to be tested has partial discharge; when the partial discharge is less than or equal to 0.1pC, the insulating rod 2 to be tested meets the partial discharge requirements.

[0035] Furthermore, the partial discharge testing device 1 for an insulating pull rod under a force-applied state provided in this embodiment also includes a pot-type insulator 60, a voltage-equalizing cover 70, a high-voltage conductor 80 and a guide tube 90. The top end of the pot-type insulator 60 is connected to the outer wall of the tank body 10, the bottom end of the pot-type insulator 60 is inserted into the tank body 10 and connected to the voltage-equalizing cover 70, the guide tube 90 is located in the high-voltage electrode 20, one end of the high-voltage conductor 80 is connected to the pot-type insulator 60, and the other end of the high-voltage conductor 80 is connected to the outer wall of the guide tube 90 through the voltage-equalizing cover 70, the two ends of the guide tube 90 are respectively connected to the two ends of the high-voltage electrode 20, and the test power supply is connected to the high-voltage electrode 20 through the high-voltage conductor 80.

[0036] Specifically, the center line of the guide cylinder 90 is colinearly arranged with the center line of the tank body 10 , and the insulating rod 2 to be tested is inserted into the guide cylinder 90 , and the insulating rod 2 to be tested can slide relative to the guide cylinder 90 .

[0037] When the partial discharge test is performed on the insulating rod 2 to be tested, the test voltage is applied to the test section of the insulating rod 2 to be tested by the voltage applying device.

[0038] Continue to refer to Figure 3 In this embodiment, the end of the guide cylinder 90 is connected to the end of the high voltage electrode 20 through the fixing unit 100.

[0039] Furthermore, in this embodiment, the fixing unit 100 includes a connecting plate 101 and at least one supporting sleeve 102. The connecting plate 101 is located inside the high-voltage electrode 20. The connecting plate 101 is attached to the end of the guide cylinder 90. The connecting plate 101 is bolted to the guide cylinder 90. The supporting sleeve 102 is located between the end plate 21 of the high-voltage electrode 20 and the connecting plate 101. The supporting sleeve 102 is connected to the connecting plate 101 via connecting bolts.

[0040] Specifically, the connecting plate 101 is arranged perpendicular to the center line of the guide cylinder 90, a through hole is opened on the connecting plate 101, the through hole is connected to the guide cylinder 90, the center line of the support sleeve 102 is arranged parallel to the center line of the guide cylinder 90, and during use, one end of the connecting bolt passes through the end plate 21 of the high-voltage electrode 20 in turn and is threadedly connected to the support sleeve 102 and the connecting plate 101.

[0041] like Figure 3 As shown, in this embodiment, the number of the supporting sleeves 102 is three.

[0042] like Figure 1 Taking the shown orientation as an example, the left end of the insulating rod 2 to be tested on the right side is inserted into the guide tube 90 and connected to the right end of the insulating rod 2 to be tested on the left side. Both insulating rods 2 to be tested can slide along the guide tube 90.

[0043] Continue to refer to Figure 1 The partial discharge testing device 1 for the insulating pull rod provided in this embodiment also includes two insulating support sleeves 110, which are arranged at opposite ends of the tank body 10, and the insulating support sleeves 110 are arranged in a one-to-one correspondence with the ground electrode 30, and the ground electrode 30 is connected to the end cover 11 of the tank body 10 through the insulating support sleeves 110.

[0044] Specifically, the center line of the insulating support sleeve 110 is arranged parallel to the center line of the tank body 10 . In some practicable embodiments, the center line of the insulating support sleeve 110 is arranged colinearly with the center line of the tank body 10 .

[0045] Furthermore, in this embodiment, the force-applying assembly 40 includes a force-applying transmission rod 41, a positioning unit 42, and a slider 43. The slider 43 is located in the guide cylinder 90, and the slider 43 can slide along the guide cylinder 90. The two insulating pull rods 2 to be tested are connected by the slider 43. One end of the force-applying transmission rod 41 is inserted into one end of the tank body 10 and is connected to one end of one of the insulating pull rods 2 to be tested away from the slider 43. The other end of the force-applying transmission rod 41 extends to the outside along the center line direction of the tank body 10 and is connected to the external force-applying device 43. The first end of the positioning unit 42 is inserted into the other end of the tank body 10 and is connected to the end of another insulating rod 2 to be tested that is away from the slider 43. The second end of the positioning unit 42 extends to the outside along the center line direction of the tank body 10. The second end of the positioning unit 42 has two states: locked and unlocked. When the second end of the positioning unit 42 is in the unlocked state, the force-applying component 40 is pulled, and the force-applying component 40 drives the insulating rod 2 to be tested to move, so that the undetected part of the insulating rod 2 to be tested moves to the detection area.

[0046] It should be noted that the detection area is the ground electrode.

[0047] Specifically, Figure 1 Taking the shown orientation as an example, the right end of the force transmission rod 41 passes through the left end cover 11 of the tank body 10 and is inserted into the insulating support sleeve 110 on the corresponding side, and is connected to the left end of the insulating rod 2 to be tested on the left side. The left end of the positioning unit 42 passes through the right end cover 11 of the tank body 10 and is inserted into the insulating support sleeve 110 on the corresponding side, and is connected to the right end of the insulating rod 2 to be tested on the right side.

[0048] Continue to refer to Figure 4 In this embodiment, the positioning unit 42 includes a positioning transmission rod 421 and a locking assembly 422. One end of the positioning transmission rod 421 is inserted into the tank body 10, and the other end of the positioning transmission rod 421 extends to the outside along the center line direction of the tank body 10 and is connected to the locking assembly 422. The positioning transmission rod 421 cooperates with the locking assembly 422 so that the positioning transmission rod 421 has two states: locked and unlocked.

[0049] Specifically, one end of the positioning transmission rod 421 passes through the end cover 11 of the tank body 10 and is inserted into the insulating support sleeve 110 on the corresponding side, and is connected to the end of the insulating pull rod 2 to be tested on the corresponding side.

[0050] Furthermore, in this embodiment, the locking assembly 422 includes a first fixing plate 4221, a second fixing plate 4222 and at least one connecting sleeve 4223. The first fixing plate 4221 and the second fixing plate 4222 are both located outside the tank body 10. The first fixing plate 4221 and the second fixing plate 4222 are spaced apart along the center line direction of the tank body 10. The first fixing plate 4221 is attached to the end of the tank body 10 away from the force transmission rod 41. The first fixing plate 4221 is bolted to the tank body 10. The connecting sleeve One end of 4223 is connected to the first fixing plate 4221 through a first fastening bolt 4224, and the other end of the connecting sleeve 4223 is connected to the second fixing plate 4222 through a second fastening bolt 4225; the first end of the positioning transmission rod 421 passes through the first fixing plate 4221 and is inserted into the tank body 10, and an external thread is provided on the outer peripheral wall of the second end of the positioning transmission rod 421, and the second end of the positioning transmission rod 421 passes through the first nut 4226 and is threadedly connected with the second fixing plate 4222 and the second nut 4227 in turn.

[0051] Specifically, the first fixing plate 4221 and the second fixing plate 4222 are arranged in parallel, the first fixing plate 4221 and the second fixing plate 4222 are arranged perpendicular to the center line of the tank body 10 , and the center line of the connecting sleeve 4223 is arranged in parallel to the center line of the tank body 10 .

[0052] like Figure 4 As shown, in this embodiment, the number of connecting sleeves 4223 is two.

[0053] When the positioning transmission rod 421 is in an unlocked state, the first nut 4226 and the second nut 4227 are loosened to allow the positioning transmission rod 421 to slide along the center line of the tank body 10, thereby moving the insulating rod 2 to be tested. When the untested portion of the insulating rod 2 to be tested moves to the test area, the first nut 4226 and the second nut 4227 are rotated to lock the positioning transmission rod 421. When performing a partial discharge test on the insulating rod 2 to be tested, an external force-applying device applies axial pressure or tension to the insulating rod 2 to be tested, and performs partial discharge measurement on the insulating rod 2 to be tested through the partial discharge test assembly 50.

[0054] Continue to refer to Figures 5 to 7 Another embodiment provides a method for testing the partial discharge testing device 1 for an insulating pull rod under a force-applied state as described above, comprising the following steps: S101 , placing two insulating pull rods 2 to be tested installed on the force-applying assembly 40 into the tank body 10 , and filling the tank body 10 with insulating gas until the pressure value in the tank body 10 reaches a set pressure value.

[0055] Before the two insulating rods 2 to be tested installed on the force-applying assembly 40 are sent into the tank body 10 and the insulating gas is filled into the tank body 10, the surfaces of the insulating rods 2 to be tested need to be cleaned to remove static electricity and foreign matter attached to the surface of the insulator.

[0056] Specifically, the two insulating pull rods 2 to be tested installed on the force-applying assembly 40 are sent into the tank body 10, the partial discharge test assembly 50 is connected, and the tank body 10 is filled with insulating gas. When the pressure in the tank body 10 reaches the set pressure value, the filling of insulating gas is stopped, and the test power supply is connected.

[0057] S102 , applying pressure or tension along the direction of the insulating rod 2 to be tested by an external force-applying device according to prescribed force-applying requirements, and performing partial discharge measurement on the insulating rod 2 to be tested by a partial discharge test assembly 50 .

[0058] Specifically, a test voltage for partial discharge measurement is loaded on the tested section of the insulating rod 2 to be tested by a voltage applying device, and an axial pressure or tension is applied to the insulating rod 2 to be tested by an external force applying device according to specified force requirements.

[0059] S103. If the local discharge detection sensitivity is less than or equal to 0.1pC, unlock the second end of the force-applying component 40, move the undetected portion of the insulating rod 2 to be tested to the detection area and lock the second end of the force-applying component 40, and continue to detect the undetected portion of the insulating rod 2 to be tested according to S102. If the local discharge detection sensitivity is less than or equal to 0.1pC, the insulating rod 2 to be tested meets the partial discharge requirements.

[0060] Specifically, if the partial discharge detection sensitivity is lower than the required value (0.1 pC), the partial discharge test passes. If the partial discharge detection sensitivity is still higher than the required value (0.1 pC) after eliminating interference, it should be determined that the insulated pull rod 2 to be tested has partial discharge.

[0061] If the partial discharge detection sensitivity is greater than 0.1pC, the signal amplitudes of the detection impedances 511 are consistent and the polarities are the same, which indicates power supply interference. If the partial discharge detection sensitivity is greater than 0.1pC, excluding the case where the signal amplitudes of the detection impedances 511 are consistent and the polarities are the same, and the signal amplitude of a certain detection impedance 511 is large and opposite to the signal amplitudes of other detection impedances 511, the detected part of the insulating pull rod 2 to be tested corresponding to the detection impedance 511 has partial discharge.

[0062] If the partial discharge detection sensitivity is greater than 0.1pC, it is excluded that the signal amplitudes of the detection impedances 511 are consistent and the polarities are the same, and at the same time, it is excluded that the signal amplitude of a certain detection impedance 511 is large and opposite to the signal amplitude of other detection impedances 511, then it is other interference.

[0063] Specifically, if it is power supply interference or other interference, further inspection is required to eliminate the interference.

[0064] Among them, the distributed pulse current measurement method is used to measure the partial discharge of the insulating rod 2 to be tested. When a partial discharge occurs in one of the insulating rods 2 to be tested, the signal amplitude of its detection impedance 511 will be much larger than the signal amplitude of another detection impedance 511, and the polarity is opposite; when there is interference in the power supply, since the equivalent capacitance of the detection part of each insulating rod 2 to be tested is similar, the signal amplitude and polarity of each detection impedance 511 are the same. Based on the relationship between the signal amplitude and polarity of each detection impedance 511, interference can be effectively identified, and it can be distinguished which specific insulating rod 2 to be tested has partial discharge.

[0065] In this embodiment, due to the presence of the coupling capacitor Ck and the tooling capacitor Ct for conventional partial discharge pulse current detection, most of the interference current can be shunted when interference occurs, thereby effectively suppressing the interference signal flowing through the detection part of the insulating rod 2 to be tested and improving the signal-to-noise ratio; when partial discharge occurs in a certain insulating rod 2 to be tested, the partial discharge current can also be effectively shunted, greatly reducing the partial discharge current flowing through the normal test unit, thereby effectively improving the sensitivity of partial discharge detection.

[0066] For details, please refer to Figure 6 and Figure 7, detection impedances Z1 and Z2 are set on the ground wires of each insulating pull rod 2 to be tested, and the apparent discharge quantity of each insulating pull rod 2 to be tested is measured. Since the capacitance of the insulating pull rod 2 to be tested (assumed as Cx1) is very small, the partial discharge in Cx1 can generate a large signal on Z1; and because Cx1 << Ck, the power supply noise of the Z1 signal is very small. Thus, the signal-to-noise ratio and sensitivity of partial discharge measurement are improved.

[0067] By comparing the signal amplitudes and pulse polarities of the detection impedances Z1 and Z2, the partial discharge of the insulating pull rod and external pulse interference can be distinguished, and it can be identified which insulating pull rod 2 to be tested has a partial discharge.

[0068] The partial discharge test device 1 and test method for an insulating pull rod under a force application state provided by the present application, wherein the partial discharge test device 1 includes a tank body 10, a high-voltage electrode 20, two ground electrodes 30, a force application component 40, and a partial discharge test component 50; the tank body 10 is filled with an insulating gas, the high-voltage electrode 20 and the two ground electrodes 30 are both arranged in the tank body 10, the high-voltage electrode 20 is located between the two ground electrodes 30, and a preset distance is provided between the high-voltage electrode 20 and the ground electrode 30; the force application component 40 penetrates through the tank body 10, the first end of the force application component 40 is connected to an external force application device, the second end of the force application component 40 has two states of locking and unlocking, both insulating pull rods 2 to be tested are located in the tank body 10, both insulating pull rods 2 to be tested are installed on the force application component 40, and the two ends of the insulating pull rod 2 to be tested are respectively connected to the high-voltage electrode 20 and one of the ground electrodes 30. When the second end of the force application component 40 is in the unlocked state, the force application component 40 can slide relative to the tank body 10, and the force application component 40 can drive the two insulating pull rods 2 to be tested to slide. When performing a partial discharge test on the insulating pull rod 2 to be tested, the second end of the force application component 40 is in the locked state, and the external force application device applies an axial pressure or tension to the insulating pull rod 2 to be tested; the partial discharge test component 50 is arranged on the outer peripheral wall of the tank body 10, and two detection resistances in the partial discharge test component 50 are respectively connected in series into the grounding electrode 30 circuits of the two insulating pull rods 2 to be tested, and the two insulating pull rods 2 to be tested are in a parallel state in the detection circuit; the test process: sending the insulating pull rod 2 to be tested into the tank body 10 - partial discharge measurement - test result; by performing partial discharge tests on the insulating pull rod 2 to be tested section by section, thus, the distance between the high-voltage and low-voltage electrodes is reduced, the sensitivity of the partial discharge test of the insulating pull rod is significantly improved, and at the same time, the ability of partial discharge detection to discover tiny insulation defects of the insulating pull rod is improved.

[0069] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0070] Finally, it should be noted that: Obviously, the above embodiments are only examples for clearly explaining the present invention, and are not intended to limit the implementation methods. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from this are still within the scope of protection of the present invention.

Claims

1. A partial discharge test device for an insulating pull rod under a force-applied state, characterized in that: It includes a tank body, a high voltage electrode, two ground electrodes, a force application component and a partial discharge test component; The tank body is filled with insulating gas, the high-voltage electrode and the two ground electrodes are both arranged in the tank body, the high-voltage electrode is located between the two ground electrodes, and the high-voltage electrode and the ground electrode are spaced by a preset distance; The force-applying component passes through the tank body, the first end of the force-applying component is connected to an external force-applying device, the second end of the force-applying component has two states, locked and unlocked, two insulating rods to be tested are both located in the tank body, the two insulating rods to be tested are both installed on the force-applying component, the two ends of the insulating rods to be tested are respectively connected to the high-voltage electrode and one of the ground electrodes, when the second end of the force-applying component is in an unlocked state, the force-applying component can slide relative to the tank body, the force-applying component can drive the two insulating rods to be tested to slide the insulating rods to be tested, when a partial discharge test is performed on the insulating rods to be tested, the second end of the force-applying component is in a locked state, and the external force-applying device applies axial pressure or tension to the insulating rods to be tested; The partial discharge test assembly is arranged on the outer peripheral wall of the tank body, and two detection resistors in the partial discharge test assembly are respectively connected in series to the grounding electrode loops of the two insulating rods to be tested, and the two insulating rods to be tested are in parallel in the detection loop.

2. The partial discharge testing device for an insulating pull rod under a force-applied state according to claim 1, characterized in that: The partial discharge test assembly includes two pulse current detection sensors and two ultra-high frequency sensors, the two pulse current detection sensors and the two ultra-high frequency sensors are both arranged on the outer peripheral wall of the tank body, and the two ultra-high frequency sensors are respectively arranged corresponding to the test sections of the two insulating pull rods to be tested; The detection impedances of the two pulse current detection sensors are respectively connected in series to the grounding electrode loops of the two insulating pull rods to be tested; The pulse current detection sensor and the ultra-high frequency sensor are both used to detect partial discharge of the insulating pull rod to be tested.

3. The partial discharge testing device for an insulating pull rod under a force-applied state according to claim 1, characterized in that: It also includes a pot-type insulator, a voltage-equalizing cover, a high-voltage conductor and a guide cylinder, wherein the top end of the pot-type insulator is connected to the outer wall of the tank body, the bottom end of the pot-type insulator is inserted into the tank body and connected to the voltage-equalizing cover, the guide cylinder is located in the high-voltage electrode, one end of the high-voltage conductor is connected to the pot-type insulator, the other end of the high-voltage conductor is connected to the outer wall of the guide cylinder through the voltage-equalizing cover, the two ends of the guide cylinder are respectively connected to the two ends of the high-voltage electrode, and the test power supply is connected to the high-voltage electrode through the high-voltage conductor.

4. The partial discharge testing device for an insulating pull rod under a force-applied state according to claim 3, characterized in that: The end of the guide cylinder is connected to the end of the high voltage electrode through a fixing unit.

5. The partial discharge testing device for an insulating pull rod under a force-applied state according to claim 4, characterized in that: The fixing unit includes a connecting plate and at least one supporting sleeve, wherein the connecting plate is located inside the high-voltage electrode, the connecting plate is attached to the end of the guide cylinder, the connecting plate is bolted to the guide cylinder, the supporting sleeve is located between the end plate of the high-voltage electrode and the connecting plate, and the supporting sleeve is connected to the connecting plate via connecting bolts.

6. The partial discharge testing device for an insulating pull rod under a force-applied state according to claim 1, characterized in that: It also includes two insulating support sleeves, which are both arranged at opposite ends of the tank body. The insulating support sleeves are arranged in a one-to-one correspondence with the ground electrode, and the ground electrode is connected to the end cover of the tank body through the insulating support sleeves.

7. The partial discharge testing device for an insulating pull rod under a force-applied state according to claim 3, characterized in that: The force-applying assembly includes a force transmission rod, a positioning unit and a slider, wherein the slider is located in the guide cylinder, the slider can slide along the guide cylinder, the two insulating pull rods to be tested are connected by the slider, one end of the force transmission rod is inserted into one end of the tank body, and is connected to one end of one of the insulating pull rods to be tested away from the slider, the other end of the force transmission rod extends to the outside along the center line direction of the tank body, and is connected to an external force-applying device, the first end of the positioning unit is inserted into the other end of the tank body, and is connected to one end of the other insulating pull rod to be tested away from the slider, the second end of the positioning unit extends to the outside along the center line direction of the tank body, and the second end of the positioning unit has two states: locked and unlocked; When the second end of the positioning unit is in an unlocked state, the force-applying assembly is pulled, and the force-applying assembly drives the insulating rod to be tested to move, so that the undetected portion of the insulating rod to be tested moves to the detection area.

8. The partial discharge testing device for an insulating pull rod under a force-applied state according to claim 7, characterized in that: The positioning unit includes a positioning transmission rod and a locking assembly. One end of the positioning transmission rod is inserted into the tank body, and the other end of the positioning transmission rod extends to the outside along the center line direction of the tank body and is connected to the locking assembly. The positioning transmission rod cooperates with the locking assembly so that the positioning transmission rod has two states: locked and unlocked.

9. The partial discharge testing device for an insulating pull rod under a force-applied state according to claim 8, characterized in that: The locking assembly includes a first fixing plate, a second fixing plate and at least one connecting sleeve, the first fixing plate and the second fixing plate are both located outside the tank body, the first fixing plate and the second fixing plate are spaced apart along the center line direction of the tank body, the first fixing plate is attached to an end of the tank body away from the force transmission rod, the first fixing plate is bolted to the tank body, one end of the connecting sleeve is connected to the first fixing plate by a first fastening bolt, and the other end of the connecting sleeve is connected to the second fixing plate by a second fastening bolt; The first end of the positioning transmission rod passes through the first fixing plate and is inserted into the tank body. The outer peripheral wall of the second end of the positioning transmission rod is provided with an external thread. The second end of the positioning transmission rod passes through the first nut and is threadedly connected with the second fixing plate and the second nut in sequence.

10. A method for testing a partial discharge testing device for an insulating pull rod under a force-applied state according to any one of claims 1 to 9, characterized in that: The steps include: S101, inserting two insulating pull rods to be tested installed on the force-applying assembly into the tank body, and filling the tank body with the insulating gas until the pressure value in the tank body reaches a set pressure value; S102, applying pressure or tension along the direction of the insulating rod to be tested to the insulating rod to be tested by an external force-applying device according to the specified force-applying requirements, and performing partial discharge measurement on the insulating rod to be tested by a partial discharge test assembly; S103, if the partial discharge detection sensitivity is less than or equal to 0.1pC, unlock the second end of the force-applying component, move the undetected portion of the insulating rod to be tested to the detection area and lock the second end of the force-applying component, continue to detect the undetected portion of the insulating rod to be tested according to S102, if the partial discharge detection sensitivity is less than or equal to 0.1pC, the insulating rod to be tested meets the partial discharge requirements; If the partial discharge detection sensitivity is greater than 0.1pC, and the signal amplitudes of each detection impedance are consistent and have the same polarity, it is power supply interference; If the partial discharge detection sensitivity is greater than 0.1pC, excluding the case where the signal amplitudes of the detection impedances are consistent and the polarities are the same, and the signal amplitude of a certain detection impedance is large and opposite to the signal amplitudes of other detection impedances, then the detected portion of the insulating pull rod to be tested corresponding to the detection impedance has partial discharge; If the partial discharge detection sensitivity is greater than 0.1pC, excluding the cases where the signal amplitudes of the detection impedances are consistent and the polarities are the same, and at the same time excluding the case where the signal amplitude of a certain detection impedance is large and opposite to the signal amplitudes of other detection impedances, it is other interference.

Images