A platform and method for measuring transient shell voltage of enclosed busbar in a nuclear power plant

Abstract

The present invention provides a closed bus transient shell voltage measurement platform for a nuclear power plant, comprising a closed bus, a voltage divider A, a main transformer, a voltage divider B and a digital oscilloscope. The voltage divider A is connected to the closed bus and the digital oscilloscope respectively; the voltage divider B is connected to the main transformer and the digital oscilloscope respectively. The closed bus, the main transformer and the digital oscilloscope are all grounded. The present invention also provides a method for measuring the transient shell voltage of a closed bus in a nuclear power plant. The test results of the present invention can be used as a basis for improving the insulation performance of the insulation base of the closed bus online monitoring components, ensuring the reliability of the closed bus operation monitoring and the closed bus micro-positive pressure function. It effectively avoids the occurrence of grounding accidents that may be caused by the damp insulation of the closed bus, and reduces the loss of frequent damage to spare parts.

Description

Technical Field

[0001] The invention belongs to the field of electrical technology, and in particular relates to a closed bus transient shell voltage measurement platform and method for a nuclear power plant. Background Art

[0002] During the no-load closing of the 500kV main transformer of Unit 3 of Fuqing Nuclear Power Plant, transient discharge occurred between the flange of the oil pillow balancing valve of phase B of the main transformer and the short-circuit board of the 24kV isolated phase closed busbar casing on the low-voltage side of the main transformer. Several infrared temperature sensors, transmitter modules, DC power supply modules, pressure sensors, PLCs and other components on the main transformer and the closed busbar casing were frequently damaged, and the closed busbar temperature, pressure and micro-positive pressure devices failed.

[0003] Analysis shows that the cause of the damage is that during the switching process of the No. 3 main transformer in the 500kV switch station, the transient voltage of the main transformer casing and the enclosed busbar casing rose to above the insulation tolerance value of the sensor, causing the insulation of the sensor to break down. The transient voltage and current waves were transmitted along its cable to the power module, PLC and other components, causing their breakdown damage.

[0004] In view of the above problems, it is urgent to design a measurement method and device that can improve the insulation performance of components according to the measurement results. Summary of the invention

[0005] The main purpose of the present invention is to provide a closed bus transient shell voltage measurement platform and method for a nuclear power plant, and to improve the insulation performance of components according to the measurement results.

[0006] The technical solution adopted by the present invention is:

[0007] A nuclear power plant enclosed bus transient shell voltage measurement platform includes an enclosed bus, a voltage divider A, a main transformer, a voltage divider B, and a digital oscilloscope. The voltage divider A is connected to the enclosed bus and the digital oscilloscope respectively; the voltage divider B is connected to the main transformer and the digital oscilloscope respectively.

[0008] The enclosed busbar, main transformer and digital recorder are all grounded.

[0009] The nuclear power plant enclosed busbar transient shell voltage measurement platform is also provided with an enclosed busbar grounding down conductor A1, and the enclosed busbar shell is connected to the enclosed busbar grounding down conductor A1.

[0010] The nuclear power plant closed bus transient shell voltage measurement platform is also provided with a main transformer grounding down conductor B, and the shell of the main transformer is connected to the main transformer grounding down conductor B.

[0011] The nuclear power plant enclosed bus transient shell voltage measurement platform is also provided with a 50kV high-voltage line, and the voltage divider A and the voltage divider B are respectively connected to the enclosed bus and the main transformer through the 50kV high-voltage line.

[0012] The nuclear power plant enclosed busbar transient shell voltage measurement platform is also provided with a shielded cable, and the voltage divider A and the voltage divider B are respectively connected to the digital recorder through the shielded cable.

[0013] The nuclear power plant enclosed bus transient shell voltage measurement platform is also provided with an insulated wire, and the voltage divider A and the voltage divider B are respectively connected to the enclosed bus grounding down conductor A through the insulated wire.

[0014] The digital recorder is placed in a shielding box, which is grounded.

[0015] The nuclear power plant enclosed busbar transient shell voltage measurement platform is also provided with a 500kV circuit breaker, and the 500kV circuit breaker is connected to the main transformer.

[0016] The voltage divider ratio of voltage divider A and voltage divider B is 500:1.

[0017] Zc=50Ω with shielded cable.

[0018] The enclosed busbar grounding down conductor A and the main transformer grounding down conductor B are both 185mm 2 Bare copper cable.

[0019] The present invention also provides a method for measuring the transient shell voltage of a closed busbar in a nuclear power plant using the above-mentioned closed busbar transient shell voltage measurement platform for a nuclear power plant, comprising the following steps:

[0020] S1: Confirm that the closed busbar transient shell voltage measurement platform of the nuclear power plant has been built and the wiring is firm;

[0021] S2: Power on the digital recorder and set the sampling amplitude and frequency;

[0022] S3: Close the 500kV circuit breaker and confirm that the digital recorder has recorded the transient voltage of the enclosure of the enclosed busbar and the enclosure of the main transformer. At the same time, observe the discharge of the enclosure of the enclosed busbar and the enclosure of the main transformer, and the damage of the enclosed busbar online monitoring components;

[0023] S4: disconnect the 500kV circuit breaker;

[0024] S5: Repeat S3 twice, select the maximum value of the recorded transient voltage of the shell of the closed bus and the shell of the main transformer, so as to determine the insulation performance of the online monitoring components of the closed bus.

[0025] In S3, the transient voltage signal of the shell of the closed busbar is sent to the digital recorder through the 50kV high-voltage line, voltage divider A and shielded cable for collection, processing and storage; the transient voltage of the shell of the main transformer is sent to the digital recorder through the 50kV high-voltage line, voltage divider B and shielded cable for collection, processing and storage.

[0026] The technical effects of the present invention are:

[0027] 1. Confirm through measured data whether the performance of the closed busbar online monitoring components meets the insulation requirements under transient conditions;

[0028] 2. The test results can be used as a basis for improving the insulation performance of the insulation base of the closed busbar online monitoring components, ensuring the reliability of the closed busbar operation monitoring and closed busbar micro-positive pressure functions;

[0029] 3. Effectively avoid grounding accidents caused by moisture in the closed busbar insulation and reduce losses caused by frequent damage to spare parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a schematic diagram of the structure of the closed bus transient shell voltage measurement platform in a nuclear power plant.

[0031] Among them: 1 is the enclosed busbar; 2 is the main transformer; 3 is the voltage divider A; 4 is the voltage divider B; 5 is the digital recorder; 6 is the shielding box; 7 is the 50kV high-voltage line; 9 is the insulated wire; 11 is the shielded cable; 13 is the enclosed busbar grounding lead A; 14 is the main transformer grounding lead B; 15 is the 500kV circuit breaker DETAILED DESCRIPTION

[0032] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] like Figure 1 As shown, the present invention provides a closed bus transient shell voltage measurement platform for a nuclear power plant, comprising a closed bus 1, a voltage divider A3, a main transformer 2, a voltage divider B4, and a digital wave recorder 5. The voltage divider A3 is connected to the closed bus 1 and the digital wave recorder 5 respectively; the voltage divider B4 is connected to the main transformer 2 and the digital wave recorder 5 respectively.

[0034] The closed busbar 1, the main transformer 2, and the digital recorder 5 are all provided with grounding.

[0035] The nuclear power plant enclosed bus transient shell voltage measurement platform is also provided with an enclosed bus grounding down conductor A13, and the shell of the enclosed bus 1 is connected to the enclosed bus grounding down conductor A13.

[0036] The nuclear power plant closed bus transient shell voltage measurement platform is also provided with a main transformer grounding down conductor B14, and the shell of the main transformer 2 is connected to the main transformer grounding down conductor B14.

[0037] The nuclear power plant enclosed bus transient shell voltage measurement platform is also provided with a 50kV high-voltage line 7, and the voltage divider A3 and the voltage divider B4 are connected to the enclosed bus 1 and the main transformer 2 respectively through the 50kV high-voltage line 7.

[0038] The nuclear power plant enclosed busbar transient shell voltage measurement platform is also provided with a shielded cable 11, and the voltage divider A3 and the voltage divider B4 are connected to the digital wave recorder 5 through the shielded cable 11 respectively.

[0039] The nuclear power plant enclosed busbar transient shell voltage measurement platform is also provided with an insulated conductor 9, and the voltage divider A3 and the voltage divider B4 are respectively connected to the enclosed busbar grounding down conductor A13 through the insulated conductor 9.

[0040] The digital wave recorder 5 is placed in a shielding box 6. The shielding box 6 is provided with a ground connection.

[0041] The nuclear power plant enclosed busbar transient housing voltage measurement platform is also provided with a 500 kV circuit breaker 15 , and the 500 kV circuit breaker 15 is connected to the main transformer 2 .

[0042] The voltage divider ratios of the voltage divider A3 and the voltage divider B4 are both 500:1.

[0043] The shielded cable 11 has Zc=50Ω.

[0044] The enclosed busbar grounding down conductor A13 and the main transformer grounding down conductor B14 are both 185mm 2 Bare copper cable.

[0045] The present invention also provides a method for measuring the transient shell voltage of a closed busbar in a nuclear power plant using the above-mentioned closed busbar transient shell voltage measurement platform for a nuclear power plant, comprising the following steps:

[0046] S1: Confirm that the closed busbar transient shell voltage measurement platform of the nuclear power plant has been built and the wiring is firm;

[0047] S2: Power on the digital oscilloscope 5 and set the sampling amplitude and frequency;

[0048] S3: Close the 500 kV circuit breaker 15, confirm that the digital recorder 5 has recorded the transient voltage of the enclosure of the closed bus 1 and the enclosure of the main transformer 2, and observe the discharge of the enclosures of the closed bus 1 and the main transformer 2, and the damage of the online monitoring components of the closed bus 1;

[0049] S4: disconnect 500kV circuit breaker 15;

[0050] S5: Repeat S3 twice, select the maximum values ​​of the transient voltages of the shell of the closed bus 1 and the shell of the main transformer 2 recorded, so as to determine the insulation performance of the online monitoring components of the closed bus 1.

[0051] In S3, the transient voltage signal of the shell of the closed busbar 1 is sent to the digital recorder 5 for collection, processing and storage through the 50kV high-voltage line 7, the voltage divider A3 and the shielded cable 11; the transient voltage of the shell of the main transformer 2 is sent to the digital recorder 5 for collection, processing and storage through the 50kV high-voltage line 7, the voltage divider B4 and the shielded cable 11.

[0052] The technical effects of the present invention are:

[0053] 1. Confirm through measured data whether the performance of the closed busbar online monitoring components meets the insulation requirements under transient conditions;

[0054] 2. The test results can be used as a basis for improving the insulation performance of the insulation base of the closed busbar online monitoring components, ensuring the reliability of the closed busbar operation monitoring and closed busbar micro-positive pressure functions;

[0055] 3. Effectively avoid grounding accidents caused by moisture in the closed busbar insulation and reduce losses caused by frequent damage to spare parts.

Claims

1. A nuclear power plant enclosed busbar transient shell voltage measurement platform, characterized by: The invention comprises a closed busbar (1), a voltage divider A (3), a main transformer (2), a voltage divider B (4) and a digital oscilloscope (5); wherein the voltage divider A (3) is connected to the closed busbar (1) and the digital oscilloscope (5) respectively; the voltage divider B (4) is connected to the main transformer (2) and the digital oscilloscope (5) respectively; the shell of the closed busbar (1) is connected to the closed busbar grounding down conductor A (13); the shell of the main transformer (2) is connected to the main transformer grounding down conductor B (14); the closed busbar grounding down conductor A (13) and the main transformer grounding down conductor B (14) are both 185 mm thick. 2 Bare copper cable; voltage divider A (3) and voltage divider B (4) are respectively connected to a closed busbar (1) and a main transformer (2) through a 50 kV high-voltage line (7); voltage divider A (3) and voltage divider B (4) are respectively connected to a digital oscilloscope (5) through a shielded cable (11); Zc of the shielded cable (11) is 50 Ω; voltage divider A (3) and voltage divider B (4) are respectively connected to a closed busbar grounding down conductor A (13) through an insulated conductor (9); the digital oscilloscope (5) is placed in a shielding box (6); the shielding box (6) is provided with a grounding connection; a 500 kV circuit breaker (15) is connected to the main transformer (2); the voltage divider ratios of voltage divider A (3) and voltage divider B (4) are both 500:

1.

2. The nuclear power plant enclosed bus transient shell voltage measurement platform according to claim 1, characterized in that: The enclosed busbar (1), the main transformer (2) and the digital wave recorder (5) are all provided with grounding.

3. A method for measuring the transient shell voltage of a closed busbar in a nuclear power plant using the closed busbar transient shell voltage measurement platform for a nuclear power plant as claimed in claim 2, comprising the following steps: S1: Confirm that the closed busbar transient shell voltage measurement platform of the nuclear power plant has been built and the wiring is firm; S2: Power on the digital oscilloscope (5) and set the sampling amplitude and frequency; S3: Close the 500 kV circuit breaker (15), confirm that the digital recorder (5) has recorded the transient voltage of the shell of the closed busbar (1) and the shell of the main transformer (2), and observe the discharge of the shells of the closed busbar (1) and the main transformer (2), and the damage of the online monitoring components of the closed busbar (1); wherein the transient voltage signal of the shell of the closed busbar (1) is sent to the digital recorder (5) through the 50 kV high-voltage line (7), the voltage divider A (3) and the shielded cable (11) for collection, processing and storage; the transient voltage of the shell of the main transformer (2) is sent to the digital recorder (5) through the 50 kV high-voltage line (7), the voltage divider B (4) and the shielded cable (11) for collection, processing and storage; S4: disconnect the 500 kV circuit breaker (15); S5: Repeat S3 twice, and select the maximum value of the transient voltage of the shell of the closed busbar (1) and the shell of the main transformer (2) recorded.

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