Extremely fast transient overvoltage detection apparatus and method
By designing a very fast transient overvoltage detection device in a hydropower station, and using high-frequency sensors and voltage divider circuits to monitor and voltage divider voltage signals, the threat of lightning overvoltage and transient overvoltage to the power system is solved, and the high-frequency Signal response and equipment safety monitoring and early warning.
Patent Information
- Application Number
- CN202411344127.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-25
- Publication Date
- 2025-01-03
AI Technical Summary
In hydropower stations with high voltage levels, lightning overvoltage and extremely fast transient overvoltage lead to a transient ground potential, endangering personal safety, and posing a threat to secondary equipment with poor insulation capabilities. It is difficult for the existing technology to effectively monitor and Early warning.
A very fast transient overvoltage detection device is designed, including a sensor module, a resistive-capacitance voltage division module and an on-site acquisition module. It adopts a high-frequency sensor and a voltage division circuit, which can monitor and divide voltage signals in real time, reduce noise and filter. , provide voltage detection results.
It realizes response to signals with frequency tens of MHz or even higher, ensures measurement accuracy and normal operation of equipment, provides immediate monitoring and early warning for the power system, and has a small size and is easy to integrate into the existing monitoring system.
Smart Images
Figure CN119246934A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of overvoltage detection, and in particular relates to an ultra-fast transient overvoltage detection device. Background Art
[0002] When designing and building high-voltage hydropower station switch stations, lightning overvoltage and very fast transient overvoltage are key issues, which are related to the safety and reliability of hydropower stations. Due to the limitations of the natural environment and working space, gas-insulated switchgear GIS stands out with its compact structure, small footprint, reliable operation, and small maintenance workload, and has been widely used in hydropower station booster stations. When the energized disconnector on one side of the GIS is disconnecting and connecting the unloaded bus on the other side, due to its poor arc extinguishing ability and slow contact movement speed of the disconnector, the SF6 gas medium between the contacts will be broken down many times during the operation of the switch, resulting in a step voltage wave that propagates from the gap along the bus to both sides, triggering a fast electromagnetic transient process, and finally forming a steep wavefront overvoltage, namely a very fast transient overvoltage (VFTO). VFTO increases the transient ground potential, endangering personal safety. VFTO is applied to secondary equipment through the electrostatic coupling of stray capacitance inside the current transformer and voltage transformer, which poses a great threat to secondary equipment with poor insulation capability and sensitive to the electromagnetic environment. In addition, the switching operation process is often accompanied by multiple consecutive VFTOs. Such multiple pulses in a short period of time will cause cumulative damage to the insulation of the winding. Summary of the invention
[0003] The purpose of the present invention is to solve the above problems and provide an ultra-fast transient overvoltage detection device, which adopts the following technical solutions: The ultra-fast transient overvoltage detection device comprises a sensor module, a resistor-capacitor voltage divider module and an on-site acquisition module connected in sequence; the sensor module comprises an internal acquisition component and an external acquisition component, the sensor module is used to collect voltage signals at high voltage and low voltage of the detection object, and responds to high-frequency voltage and low-frequency voltage; the resistor-capacitor voltage divider module is used for secondary voltage division, and responds to the low frequency of the sensor signal; the on-site acquisition module is used to reduce noise, filter and identify the signal, and obtain the voltage detection result of the detection object.
[0004] Furthermore, the internal acquisition component includes a high-voltage arm probe, one end of the high-voltage arm probe is connected to the high-voltage guide rod via a distributed capacitor, and the other end of the high-voltage arm probe is electrically connected to the external acquisition component.
[0005] Preferably, the external acquisition component includes a low-voltage arm capacitor, one end of the low-voltage arm capacitor is electrically connected to the high-voltage arm probe, the other end of the low-voltage arm capacitor is grounded via a parasitic inductor, and the low-voltage arm capacitor is electrically connected to the resistor-capacitor voltage divider module at the connection end of the high-voltage arm probe.
[0006] Preferably, the RC voltage divider module includes a high-voltage arm resistor, stray capacitance and a compensation capacitor, one end of the high-voltage arm resistor is connected to the output end of the sensor module, and the other end of the high-voltage arm resistor is grounded via the compensation capacitor; the stray capacitance is connected to the high-voltage arm resistor in parallel; the connection end of the high-voltage arm resistor and the compensation capacitor serves as the output end of the RC voltage divider module, and is connected to the input end of the local acquisition module.
[0007] Furthermore, the on-site acquisition module includes an input resistor, an input capacitor and an oscilloscope, one end of the input capacitor is connected to the output end of the resistor-capacitor voltage divider module, the other end of the input capacitor is grounded, the input resistor and the input capacitor are connected in parallel; the connection end of the input capacitor and the resistor-capacitor voltage divider module is connected to the input end of the oscilloscope.
[0008] Furthermore, the resistor-capacitor voltage divider module is connected to the output end of the sensor module via a coaxial cable and a matching resistor.
[0009] Furthermore, the ultra-fast transient voltage detection method comprises the following steps: Step 1: Connect the high voltage arm probe to the test object; Step 2: Collect the voltage signal of the detection object; Step 3: Use a resistor-capacitor voltage divider module to divide the voltage signal of step S2; Step 4: Filter the voltage signal of step S3 using the local acquisition module; Step 5: Input the signal obtained in step S5 into an oscilloscope to obtain a detection result.
[0010] Compared with the prior art, the beneficial effects of the present invention include: 1) The present invention realizes the measurement of VFTO based on the capacitive voltage division of the built-in UHF sensor, can provide good wave impedance matching, monitor the VFTO in the power system in real time, and respond to signals with a frequency of tens of MHz or even higher.
[0011] 2) The present invention will not significantly affect the electric field distribution in the inner cavity of GIS or gas insulated line GIL, thus ensuring the accuracy of measurement and the normal operation of the equipment, and providing real-time monitoring and early warning for the safe operation of the power system.
[0012] 3) The ultra-fast transient overvoltage detection device of the present invention is small in size and can be easily integrated into the existing monitoring system. It is compatible with the partial discharge monitoring system and realizes the simultaneous monitoring of VFTO and partial discharge. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.
[0014] Figure 1 It is a structural schematic diagram of the ultra-fast transient overvoltage detection device of the present invention; Figure 2 It is a schematic diagram of the equivalent circuit structure of the ultra-fast transient overvoltage detection device of the present invention.
[0015] Figure numerals: 1. sensor module; 2. RC voltage divider module; 3. local acquisition module; 4. internal acquisition component; 5. external acquisition component; 6. input voltage; 7. high-voltage arm probe; 8. distributed capacitance; 9. high-voltage guide rod; 10. low-voltage arm capacitance; 11. high-voltage arm resistance; 12. stray capacitance; 13. entry resistance; 14. entry capacitance; 15. detection voltage output terminal; 16. matching resistance; 17. coaxial cable; 18. stray inductance; 19. parasitic inductance; 20. compensation capacitance. DETAILED DESCRIPTION
[0016] like Figure 1 and Figure 2 As shown, the technical solution of the present invention is further described below in conjunction with embodiments and drawings.
[0017] The ultra-fast transient overvoltage detection device comprises a sensor module 1, a resistor-capacitor voltage divider module 2 and an on-site acquisition module 3 which are connected in sequence; the sensor module 1 comprises an internal acquisition component 4 and an external acquisition component 5, the sensor module 1 is used to acquire voltage signals at high voltage and low voltage of the detection object, and respond to high frequency voltage and low frequency voltage; the resistor-capacitor voltage divider module 2 is used for secondary voltage division, and responds to the low frequency of the sensor signal; the on-site acquisition module 3 is used to reduce noise, filter and identify the signal, and obtain the voltage detection result of the detection object.
[0018] The end of the sensor module 1 adopts an N-type adapter with high pressure resistance and good sealing performance, and the shell of the sensor module 1 is cast with epoxy resin as an insulating medium.
[0019] The internal acquisition component 4 includes a high-voltage arm probe 7 , one end of the high-voltage arm probe 7 is connected to a high-voltage guide rod 9 via a distributed capacitor 8 , and the other end of the high-voltage arm probe 7 is electrically connected to the external acquisition component 5 .
[0020] The external acquisition component 5 includes a low-voltage arm capacitor 10, one end of which is electrically connected to the high-voltage arm probe 7, and the other end of the low-voltage arm capacitor 10 is grounded via a parasitic inductor 19. The low-voltage arm capacitor 10 is electrically connected to the connection end resistance-capacitance voltage divider module 2 of the high-voltage arm probe 7.
[0021] The resistor-capacitor voltage divider module 2 includes a high-voltage arm resistor 11, a stray capacitor 12 and a compensation capacitor 20; One end of the high-voltage arm resistor 11 is connected to the output end of the sensor module 1, and the other end of the high-voltage arm resistor 11 is grounded via the compensation capacitor 20; the stray capacitor 12 is connected in parallel with the high-voltage arm resistor 11; The connection end of the high-voltage arm resistor 11 and the compensation capacitor 20 serves as the output end of the resistor-capacitor voltage divider module 2 and is connected to the input end of the local acquisition module 3 .
[0022] The high-voltage arm resistor 11 and the stray capacitor 12 form a high-voltage arm of the two-stage voltage division system.
[0023] The local acquisition module 3 includes an input resistor 13, an input capacitor 14 and an oscilloscope. One end of the input capacitor 14 is connected to the output end of the resistor-capacitor voltage divider module 2, and the other end of the input capacitor 14 is grounded. The input resistor 13 and the input capacitor 14 are connected in parallel; the connection end of the input capacitor 14 and the resistor-capacitor voltage divider module 2 is connected to the input end of the oscilloscope.
[0024] The compensation capacitor 20, the inlet resistor 13 and the inlet capacitor 14 are connected in parallel to form a low-voltage arm of the two-stage voltage division system.
[0025] The RC voltage divider module 2 is connected to the output end of the sensor module 1 via a coaxial cable and a matching resistor 16 .
[0026] The ultra-fast transient overvoltage detection method comprises the following steps: Step 1: Connect the high voltage arm probe 7 to the test object; Step 2: Collect the voltage signal of the detection object; Step 3: Use the resistor-capacitor voltage divider module 2 to divide the voltage signal of step S2; Step 4: Filter the voltage signal of step S3 using the local acquisition module 3; Step 5: Input the signal obtained in step S5 into an oscilloscope to obtain a detection result.
Claims
1. An ultra-fast transient overvoltage detection device, characterized in that: The invention comprises a sensor module (1), a resistor-capacitor voltage divider module (2) and an on-site acquisition module (3) which are connected in sequence; the sensor module (1) comprises an internal acquisition component (4) and an external acquisition component (5); the sensor module (1) is used to acquire voltage signals at high voltage and low voltage of a detection object, and respond to high-frequency voltage and low-frequency voltage; the resistor-capacitor voltage divider module (2) is used to perform two-level voltage division to respond to low-frequency of sensor signals; the on-site acquisition module (3) is used to perform noise reduction, filtering and identification on the signal, and obtain voltage detection results of the detection object.
2. The ultra-fast transient overvoltage detection device according to claim 1, characterized in that: The internal acquisition component (4) comprises a high-voltage arm probe (7), one end of the high-voltage arm probe (7) is connected to a high-voltage guide rod (9) via a distributed capacitor (8), and the other end of the high-voltage arm probe (7) is electrically connected to an external acquisition component (5).
3. The ultra-fast transient overvoltage detection device according to claim 2, characterized in that: The external acquisition component (5) comprises a low-voltage arm capacitor (10), one end of the low-voltage arm capacitor (10) is electrically connected to the high-voltage arm probe (7), the other end of the low-voltage arm capacitor (10) is grounded via a parasitic inductance (19), and the low-voltage arm capacitor (10) is electrically connected to a connection end resistance-capacitance voltage divider module (2) of the high-voltage arm probe (7).
4. The ultra-fast transient overvoltage detection device according to claim 2 or 3, characterized in that: The resistor-capacitor voltage divider module (2) comprises a high-voltage arm resistor (11), a stray capacitor (12) and a compensation capacitor (20); one end of the high-voltage arm resistor (11) is connected to the output end of the sensor module (1), and the other end of the high-voltage arm resistor (11) is grounded via the compensation capacitor (20); the stray capacitor (12) is connected in parallel with the high-voltage arm resistor (11); and the connection end of the high-voltage arm resistor (11) and the compensation capacitor (20) serves as the output end of the resistor-capacitor voltage divider module (2), and is connected to the input end of the local acquisition module (3).
5. The ultra-fast transient overvoltage detection device according to claim 4, characterized in that: The local acquisition module (3) comprises an input resistor (13), an input capacitor (14) and an oscilloscope; one end of the input capacitor (14) is connected to the output end of the resistor-capacitor voltage divider module (2); the other end of the input capacitor (14) is grounded; the input resistor (13) and the input capacitor (14) are connected in parallel; and the connection end between the input capacitor (14) and the resistor-capacitor voltage divider module (2) is connected to the input end of the oscilloscope.
6. The ultra-fast transient overvoltage detection device according to claim 5, characterized in that: The resistor-capacitor voltage divider module (2) is connected to the output end of the sensor module (1) via a coaxial cable and a matching resistor (16).
7. A method for voltage detection using the device according to any one of claims 1 to 6, characterized in that: The method comprises the following steps: Step 1: Connect the high voltage arm probe (7) to the test object; Step 2: Collect the voltage signal of the detection object; Step 3: using the resistor-capacitor voltage divider module (2) to divide the voltage signal of step S2; Step 4: Filter the voltage signal of step S3 using the local acquisition module (3); Step 5: Input the signal obtained in step S5 into an oscilloscope to obtain a detection result.