A fusion type series resonance inductance-capacitance dual pressure measurement test equipment

Abstract

The present invention relates to a combined series resonance inductance-capacitance dual pressure measurement test device, which includes a variable frequency power supply, an excitation transformer, a reactance-capacitance fusion device group, a voltage transformer, an inductance pressure measurement meter head, a voltage dividing capacitor, and a capacitance pressure measurement meter head; wherein, the reactance-capacitance fusion device group includes a support base, an insulating support cylinder, one or more sections of reactance-capacitance fusion devices, and a grading ring; each reactance-capacitance fusion device is stacked one above the other from bottom to top, and the reactance-capacitance fusion device includes an insulating cylinder, an inductance coil and a capacitor placed in the insulating cylinder, the two ends of the coil are respectively led out with a first inductance tap and a second inductance tap outside the insulating cylinder, and the two ends of the capacitor are respectively led out with a first capacitor tap and a second capacitor tap outside the insulating cylinder; a third inductance tap is also led out outside the insulating cylinder near the upper side of the first inductance tap of the inductance coil of the reactance-capacitance fusion device located at the bottom; the first inductance tap and the third inductance tap of the reactance-capacitance fusion device located at the bottom are connected to the input end of the voltage transformer, and the first capacitor tap is connected to the input end of the voltage dividing capacitor. Compared with the prior art, the present invention has the advantages of high reliability and self-boosting ability, etc.

Description

Technical Field

[0001] The present invention relates to the field of AC withstand voltage tests, and particularly to a combined series resonance inductance-capacitance dual voltage measurement test device. Background Art

[0002] The AC withstand voltage test applies an AC test voltage to the main insulation of switchgear such as GIS / HGIS. The AC withstand voltage test is a test that most conforms to the actual operating conditions of electrical equipment, an important means to avoid insulation failures of equipment, and a decisive test among various insulation tests of switchgear.

[0003] On-site AC withstand voltage tests of switchgear usually use a frequency conversion series resonance test device. Traditional frequency conversion series resonance test devices mainly include equipment such as a frequency conversion power supply, an excitation transformer, a step-up reactor, and a measuring voltage divider. Among them, the step-up reactor and the measuring voltage divider bear the highest voltage and are relatively large in size. The test principle is as Figure 1 shown.

[0004] When performing a series resonance withstand voltage test, a relatively high AC voltage will be applied to the high-voltage end of the test object, and this voltage cannot be directly measured. Currently, measuring this voltage is achieved through a specially configured high-precision capacitance voltage divider. The voltage divider is usually composed of multiple levels of capacitors in series or resistors and capacitors in parallel and then multiple levels in series, thereby forming the high-voltage arm capacitance (resistance-capacitance) and low-voltage arm capacitance (resistance-capacitance) of the voltage divider. Figure 1 In

[0005] C2 in is the high-voltage arm capacitance, and C3 is the low-voltage arm capacitance. The measuring meter directly measures the low voltage on the low-voltage arm capacitance, and then performs corresponding calculation and amplification according to the voltage division ratio of the high-voltage arm to the low-voltage arm of the voltage divider to obtain the actual high voltage value, that is, the high voltage value applied to the test object C1.

[0006] The purpose of the present invention is to provide a combined series resonance inductance-capacitance dual voltage measurement test device.

[0007] The purpose of the present invention can be achieved through the following technical solutions:

[0008] A combined series resonance inductance-capacitance dual pressure measurement test device, comprising a variable frequency power supply, an excitation transformer, a reactance-capacitance fusion device group, a voltage transformer, an inductance pressure measurement meter head, a voltage dividing capacitor, and a capacitance pressure measurement meter head; the reactance-capacitance fusion device group includes a support base, an insulating support cylinder, one or more reactance-capacitance fusion devices, and a grading ring; the reactance-capacitance fusion devices are stacked on top of each other from bottom to top, and each reactance-capacitance fusion device includes an insulating cylinder, an inductance coil, and a capacitor disposed in the insulating cylinder.

[0009] Two ends of the inductance coil in the reactance-capacitance fusion device are respectively led out with a first inductance tap and a second inductance tap outside the insulating cylinder, and two ends of the capacitor in the reactance-capacitance fusion device are respectively led out with a first capacitor tap and a second capacitor tap outside the insulating cylinder; the first inductance tap and the first capacitor tap are located near the lower part of the insulating cylinder, and the second inductance tap and the second capacitor tap are located near the upper part of the insulating cylinder; a third inductance tap is also led out from the inductance coil of the reactance-capacitance fusion device stacked at the bottommost to outside the insulating cylinder.

[0010] The output end of the variable frequency power supply is connected to the input end of the excitation transformer, the first pole of the output end of the excitation transformer is grounded, the second pole is connected to the first inductance tap of the lowermost reactance-capacitance fusion device, and the first inductance tap and the third inductance tap of the lowermost reactance-capacitance fusion device are connected to the input end of the voltage transformer, the output end of the voltage transformer is connected to the inductance pressure measurement meter head, the first capacitor tap of the lowermost reactance-capacitance fusion device is connected to the input end of the voltage dividing capacitor, the other end of the voltage dividing capacitor is grounded, and the capacitance pressure measurement meter head is connected to the voltage dividing capacitor.

[0011] Except for the lowermost and uppermost reactance-capacitance fusion devices, the first inductance tap of any reactance-capacitance fusion device is connected to the second inductance tap of the reactance-capacitance fusion device below it, the second inductance tap is connected to the first inductance tap of the reactance-capacitance fusion device above it, the first capacitor tap is connected to the second capacitor tap of the reactance-capacitance fusion device below it, and the second capacitor tap is connected to the first capacitor tap of the reactance-capacitance fusion device above it;

[0012] The second inductance tap and the second capacitor tap of the uppermost reactance-capacitance fusion device are commonly connected to the grading ring at the top of the reactance-capacitance fusion device group.

[0013] The grading ring of the reactance-capacitance fusion device group is located above the uppermost reactance-capacitance fusion device, and the second inductance tap and the second capacitor tap of the uppermost reactance-capacitance fusion device, as well as the high-voltage end of the test sample capacitor, are all connected to the grading ring.

[0014] The extraction position of the third inductance tap on the inductance coil is near the upper part of the first inductance tap, and the part between the third inductance tap and the first inductance tap belongs to a small part of the inductance coil.

[0015] The capacitor in the reactance-capacitance fusion device is composed of multiple single capacitors connected in series and parallel. The inductance coil in the reactance-capacitance fusion device is a wound circular coil, which is located in the center of the insulating cylinder, and each single capacitor is arranged around the outside of the inductance coil.

[0016] The insulating support cylinder is placed on the support base, and the lowermost reactance-capacitance fusion device is placed on the insulating support cylinder.

[0017] The inside of the reactance-capacitance fusion device is filled with dry air, dry nitrogen or insulating oil.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. Due to the adoption of the dual pressure measurement methods of inductance pressure measurement and capacitance pressure measurement, there is no longer a need for the measurement voltage divider configured in the traditional test device, nor is there a need for the test site for placing the measurement voltage divider, thus saving the test site, reducing the requirements for the test safety distance and test risks. At the same time, it also greatly reduces the amount of labor required for hoisting the measurement voltage divider, reducing the test working time and investment cost.

[0020] 2. Due to the adoption of the dual pressure measurement methods of inductance pressure measurement and capacitance pressure measurement, the two methods are different in source, work independently, and compare with each other, improving the reliability of voltage measurement, preventing the uncertain safety factors caused by the unreliability of a single pressure measurement method, and improving the safety of on-site tests. This is especially significant for the withstand voltage partial discharge tests of ultra-high and extra-high voltage GIS equipment, which require a duration of about 1 hour.

[0021] 3. Due to the adoption of the reactance-capacitance fusion device group, the series resonance self-boosting can be realized by using the reactor and capacitor of the test device itself, achieving the function of detecting the state of the test equipment and avoiding the adverse effects on the test sample equipment caused by the abnormality of the test equipment itself. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is the schematic diagram of the principle of the traditional frequency conversion series resonance test equipment;

[0023] Figure 2 is the schematic diagram of the principle and structure of the present invention;

[0024] Figure 3 is the schematic diagram of the structure of the main part of the present invention;

[0025] Figure 4 is the schematic diagram of the structure of a single reactance-capacitance fusion device of the present invention;

[0026] Wherein: 1. Variable-frequency power supply; 2. Excitation transformer; 3. Reactor-capacitor fusion device group; 4. Voltage transformer; 5. Inductive pressure measuring head; 6. Voltage-dividing capacitor; 7. Capacitive pressure measuring head; 8. Specimen capacitor; 301. Support base; 302. Insulating support cylinder; 303. Reactor-capacitor fusion device; 304. Grading ring; 305. Inductive coil; 306. Capacitor; 307. First inductive tap; 308. Second inductive tap; 309. First capacitive tap; 310. Second capacitive tap; 311. Third inductive tap; 312. Insulating cylinder. Detailed implementation mode

[0027] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. This embodiment is implemented on the premise of the technical solution of the present invention, and the detailed implementation mode and specific operation process are given, but the protection scope of the present invention is not limited to the following embodiments.

[0028] A fusion type series resonance inductance-capacitance dual pressure measurement test device, as Figures 2 to 4 shown, includes a variable-frequency power supply 1, an excitation transformer 2, a reactor-capacitor fusion device group 3, a voltage transformer 4, an inductive pressure measuring head 5, a voltage-dividing capacitor 6, and a capacitive pressure measuring head 7; the reactor-capacitor fusion device group 3 includes a support base 301, an insulating support cylinder 302, one or more reactor-capacitor fusion devices 303, and a grading ring 304; each reactor-capacitor fusion device 303 is stacked in sequence from bottom to top, and the reactor-capacitor fusion device 303 includes an insulating cylinder 312, and an inductive coil 305 and a capacitor 306 placed in the insulating cylinder 312.

[0029] Both ends of the inductive coil 305 are respectively led out with a first inductive tap 307 and a second inductive tap 308 outside the insulating cylinder 312, both ends of the capacitor 306 are respectively led out with a first capacitive tap 309 and a second capacitive tap 310 outside the insulating cylinder 312, the first inductive tap 307 and the first capacitive tap 309 are located near the lower part of the insulating cylinder 312, the second inductive tap 308 and the second capacitive tap 310 are located near the upper part of the insulating cylinder 312, and the inductive coil 305 of the reactor-capacitor fusion device 303 stacked at the bottommost also leads out a third inductive tap 311 outside the insulating cylinder 312.

[0030] The output terminal of the variable-frequency power supply 1 is connected to the input terminal of the excitation transformer 2. The first pole of the output terminal of the excitation transformer 2 is grounded, and the second pole is connected to the first inductance tap 307 of the lowermost reactance-capacitance fusion device 303. Moreover, the first inductance tap 307 and the second inductance tap 308 of the lowermost reactance-capacitance fusion device 303 are connected to the input terminal of the voltage transformer 4. The output terminal of the voltage transformer 4 is connected to the inductance pressure gauge head 5. The first capacitance tap 309 of the lowermost reactance-capacitance fusion device 303 is connected to the input terminal of the voltage-dividing capacitor 6, and the other end of the voltage-dividing capacitor 6 is grounded. The capacitance pressure gauge head 7 is connected to the voltage-dividing capacitor 6.

[0031] The variable-frequency power supply 1 can change the frequency of the input low-voltage power supply to make the system reach the resonance state. The excitation transformer 2 can appropriately boost the low-voltage power supply to provide energy for the reactance-capacitance fusion device group 3 and the test capacitor 8 to achieve high-voltage resonance. The inductance coil in the reactance-capacitance fusion device group 3 serves as the resonance inductance and the high-voltage end of the inductance measurement. The capacitors therein and the test capacitor 8 are connected in parallel as the resonance capacitance and simultaneously as the high-voltage arm of the capacitance measurement. The voltage transformer 4 converts the high voltage between the first inductance tap 307 and the third inductance tap 311 led out from the bottom of the lowermost reactance-capacitance fusion device 303 into a low voltage, and calculates the high voltage at the top of the reactance-capacitance fusion device group 3 on the inductance pressure gauge head 5. The voltage-dividing capacitor 6 obtains the high voltage at the top of the reactance-capacitance fusion device group 3 through the principle of capacitance voltage division and displays it on the capacitance pressure gauge head 7. The present invention uses the reactors and capacitors inherent in the test device for dual inductance-capacitance pressure measurement, cancels the measuring voltage divider configured in the conventional variable-frequency series resonance test system, reduces the requirements for the test site and the hoisting workload, reduces the test time, and saves the investment cost and operation cost; meanwhile, the two high-voltage measurement functions with different principles and independent operations greatly improve the reliability of the voltage measurement of the test device, which is particularly significant for the withstand voltage partial discharge test of ultra-high and extra-high voltage GIS equipment that needs to be carried out for about 1 hour.

[0032] The capacitance of the voltage-dividing capacitor 6 is larger than the capacitance in the reactance-capacitance fusion device group 3, so as to play the role of sharing a lower voltage.

[0033] Except for the lowermost and uppermost reactance-capacitance fusion devices 303, the first inductance tap 307 of any reactance-capacitance fusion device 303 is connected to the second inductance tap 308 of the reactance-capacitance fusion device 303 below it, the second inductance tap 308 is connected to the first inductance tap 307 of the reactance-capacitance fusion device 303 above it, the first capacitance tap 309 is connected to the second capacitance tap 310 of the reactance-capacitance fusion device 303 below it, and the second capacitance tap 310 is connected to the first capacitance tap 309 of the reactance-capacitance fusion device 303 above it;

[0034] The second inductance tap 308 and the second capacitance tap 310 of the uppermost reactance-capacitance fusion device 303 are commonly connected to the voltage equalizing ring 304.

[0035] The voltage equalizing ring 304 is located above the uppermost reactance-capacitance fusion device 303. The second inductance tap 308 and the second capacitance tap 310 of the uppermost reactance-capacitance fusion device 303, and the high-voltage end of the test capacitor 8 are all connected to the voltage equalizing ring 304.

[0036] The leading-out position of the third inductance tap 311 of the lowermost reactance-capacitance fusion device 303 on the inductance coil 305 is near the upper part of the first inductance tap 307. The part between the third inductance tap 311 and the first inductance tap 307 belongs to a small part of the inductance coil 305.

[0037] The capacitor 306 in the reactance-capacitance fusion device 303 is composed of multiple single capacitors. The tops and bottoms of the single capacitors are respectively connected by wires to form an equipotential. The inductance coil 305 in the reactance-capacitance fusion device 303 is located at the center of the insulating cylinder 312, and the single capacitors are arranged around the outside of the inductance coil 305. The single capacitors are distributed at equal intervals or unequal intervals outside the inductance coil 305. There is a certain gap between the inductance coil 305 and the capacitor to maintain a certain insulation distance.

[0038] In this embodiment, the inductance coil 305 and the insulating cylinder 312 are coaxially arranged.

[0039] In this embodiment, the insulating support cylinder 302 is placed on the support base 301, and the lowermost reactance-capacitance fusion device 303 is placed on the insulating support cylinder 302.

[0040] In this embodiment, the inside of the reactance-capacitance fusion device 303 is filled with dry air, dry nitrogen or insulating oil.

[0041] In this embodiment, the insulating cylinder 312 is made of insulating materials such as epoxy resin and forms a sealed cylinder.

[0042] This application utilizes the principle of variable-frequency series resonance, uses the excitation transformer 2 to excite the series resonance circuit, adjusts the output frequency of the variable-frequency power supply 1, so that the reactor, capacitor and test capacitor 8 in the system circuit are in series resonance, and the resonance voltage is the voltage applied to the test sample.

[0043] The test device uses the voltage division principle between a partial inductance L2 between the first inductance tap 307 and the third inductance tap 311 at the bottom of the reactor in the reactance-capacitance fusion device group 3 and the total inductance L1 of the reactor to form an inductive voltage divider. Then, through a specially customized voltage transformer 4, a low-voltage signal directly reflecting the high voltage across the total inductance L1 of the reactor is obtained at the output end. Finally, a turns ratio compensation calculation is performed on the inductive voltage measuring meter head 5 to obtain the actual high voltage at the top of the reactance-capacitance fusion device group 3.

[0044] The test device also uses the voltage division principle between the capacitor C1 in the reactance-capacitance fusion device group 3 and the external voltage dividing capacitor 6C2 to form a capacitive voltage divider. A low-voltage signal directly reflecting the high voltage of the reactance-capacitance fusion device group 3 is obtained across the voltage dividing capacitor 6C2. Finally, a turns ratio calculation is performed on the capacitive voltage measuring meter head 7 to obtain the actual high voltage at the top of the reactance-capacitance fusion device group 3.

[0045] In addition, before the test equipment is connected to the test specimen, it is usually necessary to perform self-boosting on the test equipment to verify the state of the test equipment itself and avoid adverse effects on the test specimen. At this time, since there is no test specimen capacitor 8, the reactor and capacitor in the reactance-capacitance fusion device group 3 can be used to achieve series resonance self-boosting, serving the purpose of detecting the state of the test equipment itself.

Claims

1. A fusion type series resonance inductance-capacitance dual pressure measurement test equipment, including a variable frequency power supply, an excitation transformer, a reactance-capacitance fusion device group, a voltage transformer, an inductance pressure measurement meter head, a voltage dividing capacitor, and a capacitance pressure measurement meter head; the reactance-capacitance fusion device group includes a support base, an insulating support cylinder, one or more sections of reactance-capacitance fusion devices, and a grading ring; each reactance-capacitance fusion device is stacked one above the other from bottom to top, and the reactance-capacitance fusion device includes an insulating cylinder, and an inductance coil and a capacitor placed in the insulating cylinder; The two ends of the inductance coil in the reactance-capacitance fusion device are respectively led out with a first inductance tap and a second inductance tap outside the insulating cylinder, and the two ends of the capacitor in the reactance-capacitance fusion device are respectively led out with a first capacitor tap and a second capacitor tap outside the insulating cylinder; the first inductance tap and the first capacitor tap are located near the lower part of the insulating cylinder, and the second inductance tap and the second capacitor tap are located near the upper part of the insulating cylinder; the inductance coil of the reactance-capacitance fusion device stacked at the bottom also leads out a third inductance tap outside the insulating cylinder; The output end of the variable frequency power supply is connected to the input end of the excitation transformer, the first pole of the output end of the excitation transformer is grounded, the second pole is connected to the first inductance tap of the lowermost reactance-capacitance fusion device, and the first inductance tap and the third inductance tap of the lowermost reactance-capacitance fusion device are connected to the input end of the voltage transformer, the output end of the voltage transformer is connected to the inductance pressure measurement meter head, the first capacitor tap of the lowermost reactance-capacitance fusion device is connected to the input end of the voltage dividing capacitor, the other end of the voltage dividing capacitor is grounded, and the capacitance pressure measurement meter head is connected to the voltage dividing capacitor; Except for the lowermost and uppermost reactance-capacitance fusion devices, the first inductance tap of any reactance-capacitance fusion device is connected to the second inductance tap of the reactance-capacitance fusion device below it, the second inductance tap is connected to the first inductance tap of the reactance-capacitance fusion device above it, the first capacitor tap is connected to the second capacitor tap of the reactance-capacitance fusion device below it, and the second capacitor tap is connected to the first capacitor tap of the reactance-capacitance fusion device above it; The second inductance tap and the second capacitor tap of the uppermost reactance-capacitance fusion device are jointly connected to the grading ring at the top of the reactance-capacitance fusion device group.

2. The integrated series resonance inductance-capacitance dual pressure measurement test equipment according to claim 1, wherein The grading ring of the reactance-capacitance fusion device group is located above the uppermost reactance-capacitance fusion device, and the second inductance tap and the second capacitor tap of the uppermost reactance-capacitance fusion device, and the high-voltage end of the test sample capacitor are all connected to the grading ring.

3. The integrated series resonance inductance-capacitance dual pressure measurement test equipment according to claim 1, wherein, The leading-out position of the third inductance tap on the inductance coil is near the upper part of the first inductance tap, and the part between the third inductance tap and the first inductance tap belongs to a small part of the inductance coil.

4. A combined series resonance inductance-capacitance dual pressure measurement test device according to claim 1, characterized in that, The capacitor in the reactance-capacitance fusion device is composed of a plurality of single capacitors connected in series and parallel, the inductance coil in the reactance-capacitance fusion device is a wound circular coil, the coil is located in the center of the insulating cylinder, and each single capacitor is arranged around the outside of the inductance coil.

5. The integrated series resonance inductance-capacitance dual pressure measurement test equipment according to claim 1, characterized in that The insulating support cylinder is placed on the support base, and the lowermost reactance-capacitance fusion device is placed on the insulating support cylinder.

6. The integrated series-resonant inductance-capacitance dual pressure measurement test equipment according to claim 1, characterized in that, The interior of the reactance-capacitance fusion device is filled with dry air, dry nitrogen, or insulating oil.

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