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CN-122000833-A - Quick isolation protection device for arc faults of high-voltage switch cabinet of thermal power plant

CN122000833ACN 122000833 ACN122000833 ACN 122000833ACN-122000833-A

Abstract

The invention discloses a rapid arc fault isolation protection device for a high-voltage switch cabinet of a thermal power plant, which relates to the technical field of high-voltage switch cabinets and aims to solve the problems that from sensor detection, signal transmission and logic judgment to breaker opening, more links and overlong accumulated time lead to full development of an arc and huge energy. The fault point detection device has the advantages that the fault operation probability is extremely low, the waiting for a current criterion is eliminated, the three-dimensional coordinates of the fault point can be output, the fault point can be accurately positioned to a specific compartment or even to the vicinity of specific equipment, and the effect of a protection mode of passive waiting for tripping is fundamentally changed.

Inventors

  • WEN YI

Assignees

  • 国能江油热电有限公司

Dates

Publication Date
20260508
Application Date
20260212

Claims (10)

  1. 1. The utility model provides a quick isolation protection device of thermal power plant's high tension switchgear arc light trouble, includes high tension switchgear (1), the front side of high tension switchgear (1) articulates and is connected with cabinet door (2), and the inner chamber dorsal part fixedly connected with electrical component mounting bracket (3) of high tension switchgear (1), install electrical component on electrical component mounting bracket (3), and electrical component passes through isolation contact connection busbar, its characterized in that: An arc light detector (6) is fixedly arranged in the center of the top of the high-voltage switch unit cabinet (1), ultrasonic sensors (7) are fixedly arranged in the high-voltage switch unit cabinet (1), and a plurality of ultrasonic sensors (7) are uniformly distributed on the periphery of the arc light detector (6); The arc light detector (6) and the ultrasonic sensor (7) are electrically connected with a central controller module through a data line, protection logic is preset in the central controller module, and a synchronous timing unit is arranged on the central controller module; the ultrasonic sensors (7) are fixedly arranged in the internal space of the switch cabinet in a non-collinear geometrical distribution mode; the high-voltage switch unit cabinet (1) is internally provided with a rapid isolation protection module, the rapid isolation protection module comprises an active arc extinction inhibition unit and a physical isolation unit, the active arc extinction inhibition unit is used for spraying arc extinction medium towards the calculated fault point coordinate position, and the physical isolation unit is used for driving a busbar connection separation isolation power supply of an electric element to form a physical isolation barrier.
  2. 2. The rapid arc fault isolation protection device for the high-voltage switch cabinet of the thermal power plant according to claim 1, wherein the synchronous timing unit is used for providing uniform high-precision time stamps for all ultrasonic sensors (7), at least one ultrasonic sensor (7) is arranged on the inner side of a top panel of the switch cabinet, and at least two ultrasonic sensors (7) are respectively arranged on the inner sides of adjacent vertical side plates.
  3. 3. The rapid arc fault isolation protection device for the high-voltage switch cabinet of the thermal power plant according to claim 2, wherein the synchronous timing unit adopts a GPS/Beidou dual-mode timing module and is used for providing a uniform microsecond clock synchronous signal for a central controller module and a timing circuit in each ultrasonic sensor (7) so as to ensure that time stamps generated by the ultrasonic sensors (7) are based on the same time reference.
  4. 4. The rapid arc fault isolation protection device for the high-voltage switch cabinet of the thermal power plant according to claim 3, wherein the ultrasonic sensors (7) are broadband acoustic emission sensors, a signal preprocessing circuit is arranged in each ultrasonic sensor (7) and is used for amplifying and bandpass filtering an original vibration signal, and a front edge detection circuit is arranged in each ultrasonic sensor (7) and is used for generating a trigger pulse with an accurate time stamp when a pressure wave signal exceeds a threshold value for the first time.
  5. 5. The rapid arc fault isolation protection device for a high-voltage switchgear of a thermal power plant according to claim 4, wherein the protection logic in the central controller module comprises the following steps: s1, continuously monitoring signals of an arc light detector (6), immediately starting high-speed data acquisition once a first trigger signal is received, and recording original waveform data and time stamp sequences of each ultrasonic sensor (7) from the moment; S2, carrying out waveform characteristic analysis on the first arriving pressure wave signal, namely the signal firstly arriving at any one ultrasonic sensor (7), and verifying whether the signal has typical characteristics of arc pressure waves or not; s3 precisely extracting from the recorded time series data the moments T1, T2, T3 of arrival of the pressure wave front at the at least three non-collinear ultrasonic sensors (7); S4, solving fault point coordinates P (x, y, z) meeting a 'distance difference = propagation speed x time difference' equation set by using a time difference positioning algorithm according to the known space coordinates (Si (x, y, z)) of each ultrasonic sensor (7) and the propagation speed v of a pressure wave in a medium in the switch cabinet; S5, comparing the calculated fault point coordinate P with the coordinate of a fault dangerous area defined in a three-dimensional digital model of the switch cabinet pre-stored in the central controller module; S6, if the P is located in the 'fault dangerous area', determining that arc faults are confirmed in the cabinet, immediately sending out tripping instructions and isolation protection instructions without any delay, and if the P is located outside the area, determining that external interference or non-fault discharge is caused, and starting an alarm but not tripping.
  6. 6. The rapid arc fault isolation protection device for the high-voltage switch cabinet of a thermal power plant according to claim 5, wherein the protection logic in the central controller module further comprises a self-checking and anti-interference step, the central controller module periodically sends out a self-checking instruction in normal operation, a simulation pressure wave is generated through a miniature calibration sound source arranged in a non-dangerous area of the high-voltage switch unit cabinet (1), each ultrasonic sensor (7) receives the calibration signal, the central controller module inverts the actual propagation velocity v' of the pressure wave in real time by calculating the arrival time difference of the calibration signal, and dynamically corrects the velocity parameter v in a positioning algorithm to compensate the sound velocity change caused by the temperature and gas density change of the high-voltage switch unit cabinet (1).
  7. 7. The rapid arc fault isolation protection device for the high-voltage switch cabinet of the thermal power plant according to claim 6 is characterized in that an arc extinguishing jet row (8) and an arc extinguishing medium bin (10) are arranged in the active arc extinguishing inhibition unit, the arc extinguishing jet row (8) is fixedly arranged at the front end of the inner wall of the high-voltage switch unit cabinet (1), and the arc extinguishing medium bin (10) is fixedly arranged at the lower end of the high-voltage switch unit cabinet (1); a plurality of arc extinguishing spray heads (9) are fixedly communicated with the inner side of the arc extinguishing spray row (8), and the nozzle outlets of the arc extinguishing spray heads (9) are obliquely arranged towards the wiring positions of the movable contact combining part and the fixed contact combining part of the electric element breaker and the isolating contact on the electric element installation frame (3); The utility model discloses an arc extinguishing medium storehouse, including arc extinguishing medium storehouse (10), gas circuit distributing valve (16) are connected with a plurality of arc extinguishing shower nozzles (9) and physical partition unit, arc extinguishing medium storehouse (10) are inside hollow structure, arc extinguishing medium storehouse (10) inner chamber bottom fixedly connected with super high-speed solenoid valve (15), and arc extinguishing medium storehouse (10) front side is inserted and is equipped with inert gas storage tank (14), fixed compression plug (17) are connected with the outside screw thread of arc extinguishing medium storehouse (10) inner wall, and fixed compression plug (17) offsets with the front side of inert gas storage tank (14), inert gas storage tank (14) bottleneck is fixed with super high-speed solenoid valve (15) air inlet grafting, the gas outlet end of super high-speed solenoid valve (15) is connected a plurality of arc extinguishing shower nozzles (9) and physical partition unit through gas circuit distributing valve (16).
  8. 8. The rapid arc fault isolation protection device for the high-voltage switch cabinet of the thermal power plant according to claim 7, wherein the gas path distribution valve (16) is communicated with the plurality of arc extinguishing spray heads (9) through embedded pipelines, and the plurality of arc extinguishing spray heads (9) are respectively communicated with branches of the embedded pipelines through independent stop valves (18).
  9. 9. The rapid arc fault isolation protection device for the high-voltage switchgear of the thermal power plant according to claim 7, wherein the physical isolation unit comprises an electricity connection base (11) and an isolation element wire holder (12), the electricity connection base (11) is arranged at the upper end of an arc extinguishing medium bin (10), and the isolation element wire holder (12) is arranged at the upper end of the electricity connection base (11); The insulation element wire holder (12) is provided with a wire connecting terminal (13), electric elements on the electric element mounting frame (3) are connected with a bus and an output cable through the wire connecting terminal (13), the upper ends of two sides of the electric connection base (11) are buried with expansion lifting rubber capsules (20), and the tops of the expansion lifting rubber capsules (20) are propped against the bottoms of two sides of the insulation element wire holder (12); The center of connect electric base (11) has seted up square recess, and square recess center is provided with fuse intercommunication row (21), correspond a plurality of intercommunication circuit in fuse intercommunication row (21) and be provided with the fuse protector, the bottom fixedly connected with of isolation element wire holder (12) connects electric plug (19), and a plurality of electric plug (19) respectively with a plurality of terminal electric connection on binding post (13), a plurality of connect electric plug (19) in the fuse protector isolation contact in the two liang of corresponding inserting fuse intercommunication row (21), both sides inflation jacking rubber capsule (20) are towards inside one side and are connected square recess in center through the choke valve intercommunication, and correspond binding post (13) bottom evenly offered a plurality of jet ports and run through on isolation element wire holder (12).
  10. 10. The arch breaking method of the rapid arc fault isolation protection device for the high-voltage switch cabinet of the thermal power plant is characterized in that the arc detector (6) is of an ultraviolet light sensor structure with a solar blind filter cover sleeved at the bottom, a reflecting frame (4) is fixedly connected to the back side of the cabinet door (2) corresponding to the position of the electric element mounting frame (3), a plurality of light gathering reflectors (5) are distributed at equal intervals on the inner side of the reflecting frame (4), and the light gathering reflectors (5) are obliquely arranged reflector arrays and are used for reflecting light rays of arc light generating points on the electric element mounting frame (3) towards the photosensitive position of the ultraviolet light sensor of the arc detector (6).

Description

Quick isolation protection device for arc faults of high-voltage switch cabinet of thermal power plant Technical Field The invention relates to the technical field of high-voltage switch cabinets, in particular to a rapid arc fault isolation protection device for a high-voltage switch cabinet of a thermal power plant. Background The high-voltage switch cabinet is key equipment of a power system of a thermal power plant, and once arc short circuit fault occurs in the high-voltage switch cabinet, huge heat and pressure can be generated in a very short time, so that the equipment is seriously damaged and even personal injury is caused. At present, a common arc protection scheme mainly depends on that an arc sensor installed inside a switch cabinet is matched with an overcurrent signal to judge, and the arc sensor detects visible light or light with a specific wavelength, and a typical architecture is as follows: the method is characterized in that a plurality of point type arc light sensors are fixedly arranged in key compartments such as a bus chamber, a breaker chamber and a cable chamber of the switch cabinet, current signals are obtained from the current transformer, when the protection device detects that arc light signals and current out-of-limit signals exist simultaneously, a tripping instruction is sent after short time delay (misoperation prevention), a power supply of a fault loop is cut off, and in addition, a scheme is adopted to try to combine various sensors such as pressure, temperature and the like to carry out comprehensive judgment so as to improve the action accuracy. Although the prior art realizes arc protection to a certain extent, the specific defects that most schemes require that the double criteria of arc signal and overcurrent signal are simultaneously met to trigger tripping, however, the fault current can not reach an overcurrent fixed value at the initial stage of arc fault of a slight short circuit or a specific position, so that a protection device enters a waiting or locking state, the optimal isolation time is missed, and arc energy is continuously accumulated, meanwhile, the prior schemes only attempt to cut off a power supply, and direct physical intervention is not applied to the arc energy in a gold window period of arc generation and energy accumulation, and the arc is fully developed and energy is huge due to the fact that the arc is fully developed from sensor detection, signal transmission and logic judgment to the opening of a breaker. Disclosure of Invention The invention aims to provide the rapid arc fault isolation protection device for the high-voltage switch cabinet of the thermal power plant, which has the advantages of simple structure, convenience in installation and controllable cost. In order to achieve the above purpose, the present invention provides the following technical solutions: The quick arc fault isolation protection device for the high-voltage switch cabinet of the thermal power plant comprises a high-voltage switch unit cabinet, wherein the front side of the high-voltage switch unit cabinet is hinged with a cabinet door, the back side of an inner cavity of the high-voltage switch unit cabinet is fixedly connected with an electric element mounting rack, an electric element is mounted on the electric element mounting rack, the electric element is connected with a bus through an isolation contact, An arc light detector is fixedly arranged in the center of the top of the high-voltage switch unit cabinet, ultrasonic sensors are fixedly arranged in the high-voltage switch unit cabinet, and a plurality of ultrasonic sensors are uniformly distributed on the periphery of the arc light detector; The arc light detector and the ultrasonic sensor are electrically connected with a central controller module through a data line, protection logic is preset in the central controller module, and a synchronous timing unit is arranged on the central controller module; The ultrasonic sensors are fixedly arranged in the internal space of the switch cabinet in a non-collinear geometrical distribution mode; The high-voltage switch unit cabinet is internally provided with a rapid isolation protection module, the rapid isolation protection module comprises an active arc extinguishing suppression unit and a physical isolation unit, the active arc extinguishing suppression unit is used for spraying arc extinguishing medium towards the calculated fault point coordinate position, and the physical isolation unit is used for driving a busbar connection separation isolation power supply of an electric element to form a physical isolation barrier. According to the technical scheme, protection logic is preset in the central controller module, after the trigger signal of the arc light detector is received, the time stamps of the pressure wave signals received by the ultrasonic sensors are immediately acquired and analyzed, the three-dimensional space coordinates of fault points are