Background technology
At present, the extinguishing arc harmonic elimination apparatus of using in China 3~35kV medium voltage network, its major function is broadly divided into arc eliminator, overvoltage Limiting function, emergency review and data remote function, route selection function and five aspects of harmonic elimination function.Based on the fault direct extinguishing arc harmonic elimination apparatus of ground connection principle mutually; should be able to play the effect of extinguish arcs and control fault development from the analysis of theory and technology aspect; yet; usually only arc eliminator, overvoltage Limiting function, emergency review and data remote function as standard configuration; route selection function and harmonic elimination function are selected voluntarily by the user, usually can have following problem in this actual at the scene use:
First, the user who has has only selected the extinguishing arc harmonic elimination apparatus of standard configuration when signing purchase order, owing to do not possess the route selection function, even extinguished ground arc after the action of extinguishing arc harmonic elimination apparatus, for the route selection handle assembly of having to again repeatedly resets by force, make repeatedly arcing of fault point, to such an extent as to finally cause the generation of phase fault accident;
Second, though the supply of material manufacturer also to customer presentation route selection function and route selection principle, yet be configured at the scene under the situation of little electric current line selection apparatus, for fear of overlapping investment, the user has still selected the extinguishing arc harmonic elimination apparatus of standard configuration usually, the inaccurate problem of route selection when not only there is single-phase arc grounding in this, and because the action of extinguishing arc harmonic elimination apparatus can't be carried out route selection, consequently or abandoning route selection causes earth fault not obtain to handle, or finally cause the phase fault accident because of the extinguishing arc harmonic elimination apparatus repeatedly resets by force;
The 3rd, the extinguishing arc harmonic elimination apparatus is installed in and always falls on electric substation's main bus bar, with be installed in outer drawing on transformer substation's bus of power supply, the emphasis that functional configuration is required is different, if when function match, do not distinguished well, will when a single-phase earthing, cause many extinguishing arc harmonic elimination apparatus to move and the problem that can't reset;
The 4th, except that arc eliminator, overvoltage Limiting function and emergency review and data remote function are configured in the same cabinet as standard configuration, route selection function and harmonic elimination function realize by modular construction, all be to adopt separately independently cabinet, in case during customer requirements configuration repertoire, will cause on control room's door too much to seem very crowded because of installed device;
The 5th, usually the microcomputerized controller in the extinguishing arc harmonic elimination apparatus does not possess overvoltage and under voltage protection function, for replacing conventional voltage transformer cabinet, need to set up microcomputer in addition and combine and protective device in the control room, this has further increased the difficulty of control room's apparatus arrangement and secondary wiring again;
The 6th, usually the extinguishing arc harmonic elimination apparatus can only adopt stationary structure, element maintenance inconvenience in the cabinet, component interchangeability is poor, in case produce the expansion that electric arc is easy to cause the accident in the cabinet, if the user need be transformed into the extinguishing arc harmonic elimination apparatus to the existing voltage transformer cabinet in scene, not only on-the-spot retrofit work amount is big, and need all have a power failure whole bus, this makes on-the-spot the transformation be difficult to realize.
Embodiment
Single-phase grounding comprehensive protecting device of electric network comprises cabinet shell 50, and the internal operation situation that observation window 52 is observed this device for the user is set on the cabinet shell 50, also is provided for indicating the handcart position indicator 51 of isolating handcart 31 operating states on the cabinet shell 50.Metal partion (metp) is divided into main bus bar chamber 10 with the enclosure space that cabinet shell 50 surrounds by function, earthed switch chamber 20, voltage transformer chamber 30 and secondary meter chamber 40, in the described secondary meter chamber 40 microcomputer general controller 41 is set, microcomputer general controller 41 is connected with the circuit zero sequence current mutual inductor by secondary cable, the circuit zero sequence current mutual inductor is installed in the line switching cabinet, the needed circuit zero sequence current signal of route selection function can only be obtained by the circuit zero sequence current mutual inductor, and the circuit zero sequence current mutual inductor must be installed in the line switching cabinet, the circuit zero sequence current mutual inductor can not only with this matched with devices, also can be supporting with the little electric current line selection apparatus of other principles, as shown in Figure 2.Usually be connected with many circuits on the bus of electric substation, the single-phase arc grounding fault of system may occur on the bus, also may take place on the line.The route selection function is meant utilizes circuit zero sequence current mutual inductor Monitoring Line zero-sequence current, and judge that single phase ground fault occurs on the bus or take place on the line, and further judge fault and specifically occur on any bar circuit by the variation of circuit zero-sequence current.
In conjunction with Fig. 2, described microcomputer general controller 41 is made up of system voltage collection plate, line current collection plate, signal-processing board, display driver plate and power panel.Each phase voltage of system voltage collection plate acquisition system, open delta voltage and earth current; The line current collection plate is used to gather the circuit zero-sequence current; The external switch amount is directly accepted and handled to signal-processing board, and be voltage acquisition plate and line current collection plate to above-mentioned two signal acquiring boards, and the employing data of the high frequency transient electric parameters that provides are handled; The display driver plate is handled the stable state power frequency sampled data of two signal acquiring board collections, and bears running status, data demonstration and storage; Power panel is used for providing working power to voltage acquisition plate, line current collection plate, signal-processing board and display driver plate, simultaneously outwards output action order.This structure can make full use of the software and hardware resource, reduces number of elements, reduces cost, and improves the operational reliability and the internal communication speed of protective device.
In conjunction with Fig. 2, described main bus bar chamber 10 is positioned at the rear of cabinet shell 50, the place ahead of cabinet shell 50 is furnished with secondary meter chamber 40 from top to bottom successively, voltage transformer chamber 30 and earthed switch chamber 20, the upper right quarter in described cabinet shell 50 the place aheads is secondary meter chamber 40, the lower left quarter in cabinet shell 50 the place aheads is earthed switch chamber 20, voltage transformer chamber 30 is between secondary meter chamber 40 and earthed switch chamber 20, described the place ahead is meant that the staff faces the direction of cabinet when operation. described main bus bar chamber 10, voltage transformer chamber 30, earthed switch chamber 20 all is provided with independently pressure release passage, to prevent to cause the gross distortion of cabinet body structure because of internal fault. secondary meter chamber 40 and main bus bar chamber 10, voltage transformer chamber 30, earthed switch chamber 20 isolates each other fully, guaranteed maintenance, the safety of debugging and in-service inspection, and any compartment interior fault all can't feed through to other compartments.
In conjunction with Fig. 1,2, be provided with in the described voltage transformer chamber 30 and isolate handcart 31, isolate handcart 31 and push cabinet or in cabinet, pull out installation voltage transformer 36 and high-tension fuse 35 on the isolation handcart 31 along guide rail 31a.Be provided with in the described main bus bar chamber 10 from wall bushing 12 across and into the three-phase main bus bar 11 in the cabinet shell 50, the three-phase main bus bar 11 that is positioned at cabinet shell 50 inside is supported by post insulator, and draw three branch bars 13 respectively with isolate handcart 31 on three upper static contacts 37 link to each other, upper static contact 37 is positioned at upper contact head box 37a.Go up moving contact 32 and fix for three of described isolation handcart 31 by the last contact arm 32b that is arranged in contact arm sleeve pipe 32a, the following contact arm 33b of contact arm sleeve pipe 33a fixes three lower moving contacts 33 of isolation handcart 31 by being arranged in down, last moving contact 32 and lower moving contact 33 are connected row's 34 connections by contact up and down, one of three high-tension fuses 35 terminate on the lower moving contact 33, the input of another termination voltage transformer 36, the other end ground connection of voltage transformer 36.Voltage transformer 36 in the described voltage transformer chamber 30, high-tension fuse 35 and the accessories such as dynamic/static contact of isolating on the handcart 31 are general parts, has good interchangeability, be pulled out to the maintenance position as long as will isolate handcart 31, just can change or overhaul said elements quickly and easily.In addition; the door of earthed switch chamber 20 is behind cabinet; as long as open the cabinet door; change and overhaul all very convenient to wherein phase-splitting earthed switch 21, overvoltage protection device 24, current transformer 23 etc.; above-mentioned this structure has realized the exchange of critical piece, for improving overhaul efficiency, shorten maintenance duration, reducing space for maintenance and created good condition.
In conjunction with Fig. 1; 2; in the described earthed switch chamber 20 phase-splitting earthed switch 21 is set; the secondary control loop of phase-splitting earthed switch 21 links to each other with microcomputer general controller 41 with secondary cable by aviation plug 25; the last leading-out terminal of phase-splitting earthed switch 21 is connected with the following fixed contact 38 of isolating handcart 31 by connecting copper bar; the lower wire end of phase-splitting earthed switch 21 is a common port by connecting the copper bar parallel connection; this common port passes current transformer 23 through earth cable 22 and receives on the earth bus 26; the input of overvoltage protection device 24 is connected on three following fixed contacts 38 of isolating handcart 31, the output head grounding of overvoltage protection device 24.Described phase-splitting earthed switch 21 is the phase-splitting Fast Speed Vacuum Circuit Breaker, perhaps is composed in series by high-voltage and current-limitation fuse and vacuum contactor.Described overvoltage protection device 24 comprises the zinc oxide valve plate FR that four head ends join; wherein the tail end of first, second and third zinc oxide valve plate FR1, FR2, FR3 is connected respectively and is connected on behind first, second and third discharging gap CG1, CG2, the CG3 on the following fixed contact 38 of isolating handcart 31, the tail end of the 4th zinc oxide valve plate FR4 ground connection behind the 4th discharging gap CG4 of connecting.The protective feature relatively and the alternate protective feature of overvoltage protection device 24 are identical, can not only limit lightning overvoltage and can also limit the electrical network internal overvoltage, and can not only limiting relatively, overvoltage can also limit alternate overvoltage.
Below in conjunction with Fig. 1,2,3 the invention will be further described.
Be pushed into the service position as long as will isolate handcart 31, it is just charged to be in the high pressure winding of isolating the voltage transformer 36 on the handcart 31, the upper contact head that is in three phase-splitting earthed switches 21 in the earthed switch chamber 20 is also charged simultaneously, and whole device enters the running status of warming-up exercise.
When system normally moves, the voltage signal that microcomputer general controller 41 is sent here by voltage transformer 36, system's working voltage to be monitored. the system voltage sampling plate of microcomputer general controller 41 carries out the power frequency sampling in real time to each phase-to-ground voltage of system and open delta voltage, simultaneously system's open delta voltage is carried out high frequency sampling; The display driver plate is handled the power frequency sampled data of system voltage collection plate collection, calculate the effective value of each phase voltage and open delta voltage, and on panel, show, in case the result of calculation of each phase voltage effective value surpasses predefined overvoltage limit value or is lower than the under voltage limit value, then microcomputer general controller 41 is in time sent and is reported to the police and output passive switch amount contact point signal, panel shows fault type and each phase voltage. meanwhile, signal-processing board is handled in real time to the open delta voltage high frequency sampled data that the system voltage collection plate provides, in case open delta voltage surpasses predefined limit value, then start immediately and interrupt; The system voltage collection plate is implemented high frequency sampling to each phase-to-ground voltage of system immediately, and the display driver plate is ended immediately to the processing of stable state electric parameters and demonstration, and the line current collection plate begins to carry out the high-frequency data collection of the first period circuit zero-sequence current.
Signal-processing board carries out analyzing and processing to the high frequency sampled data of each phase-to-ground voltage of system that the system voltage collection plate provides, make judgement to fault type and fault are separate rapidly, fault type comprises voltage transformer 36 broken strings, metallic earthing, arc grounding and ferro resonance.
If voltage transformer 36 disconnection faults; then microcomputer general controller 41 panels show fault type, separate and each phase-to-ground voltage of system; send alarm signal and export passive switch amount contact point signal, so that the user carries out locking to protective relaying device that might misoperation.
If single phase ground fault, single phase ground fault is divided into two kinds of Single Phase Metal ground connection and single-phase arc grounding faults, then microcomputer general controller 41 is sent the order of closing a floodgate to the phase-splitting earthed switch 21 of fault phase, phase-splitting earthed switch 21 can close a floodgate about 30ms, with the direct mutually ground connection of fault, fault phase bus directly links to each other with ground network by phase-splitting earthed switch 21.The panel of microcomputer general controller 41 shows fault type and separate, each phase-to-ground voltage of system and the system single-phase earth fault current effective value under operational mode at that time.If single-phase arc grounding fault takes place, then can extinguish ground arc rapidly and the arc grounding overvoltage is stablized the lsafety level of on-Line Voltage, can effectively avoid the phase fault accident that causes because of arc grounding and accidents such as the ferro resonance that causes because of the arc grounding overvoltage and Explosion of on Arrester; If the metallic earthing fault takes place, then can reduce touch voltage and step voltage greatly, help support equipment and personal safety.After phase-splitting earthed switch 21 closes a floodgate, the line current collection plate carries out the high-frequency data collection of the second period circuit zero-sequence current, signal-processing board is selected faulty line by the analysis of circuit zero sequence current acquisition data before and after phase-splitting earthed switch 21 is closed a floodgate according to the principle of maximal increment method.By the current transformer 23 of ground connection, the system voltage collection plate collects the power frequency sampled signal of system single-phase earth fault electric current, and the display driver plate is presented on the panel of microcomputer general controller 41 after calculating effective value.As seen, when system's generation single phase ground fault, faulty line can also be selected and show to this device quickly and accurately.
If system's generation ferro resonance, then signal-processing board carries out the Fourier series analysis according to open delta voltage, and with reference to the variation of each phase-to-ground voltage, judge resonant type and frequency rapidly, and drop into corresponding damping resistance, show resonance frequency and each phase-to-ground voltage on the panel of microcomputer general controller 41, treat to remove damping resistance after resonance disappears.
In addition, this device has the emergency review function, and the associated electrical tolerance in the time of can writing down the type of time that 18 faults take place and fault and fault can be had access to for the user afterwards.This device also has the data remote function, and this device has disposed RS485 microcomputer communication interface, can realize transfer of data by network-bus and computer supervisory control system according to the communication protocol of user's appointment.The data that transmitted have: line voltage and three-phase voltage when system normally moves, line voltage when the time of system's generation overvoltage or low-voltage and fault between each phase, the time of voltage transformer 36 disconnection faults takes place, each phase voltage during separate and fault, the time of Single Phase Metal ground connection takes place, separate, each phase voltage when faulty line numbering and fault, the time of single-phase arc grounding fault takes place, separate, the faulty line numbering, and each phase voltage and system single-phase earth fault electric current during fault, the time of system's generation ferro resonance, the resonance frequency, resonance frequency.
In a word, core of the present invention is on the function setting of core control part one microcomputer general controller 41, except basic function arc eliminator and overvoltage Limiting function that conventional extinguishing arc harmonic elimination apparatus is possessed, also the route selection function is classified as standard configuration as basic function, effectively control fault further develops, can also provide the fault wire size for the user handles single phase ground fault. the microcomputer general controller 41 all right normal working voltages of display system, overvoltage and under voltage warning function have been set up, make that normal monitoring function is more complete. in addition, according to the difference of infield difference to the functional requirement emphasis, function to protective device has been carried out optimum organization, be divided into total site type and branch site type, made things convenient for user's lectotype selection, use and coordination at the scene. and utilize the isolation handcart 31 interior voltage transformer 36 and the high-tension fuses 35 thereof arranged at KYN28 type switch cabinet middle part, the while is as the parts removed of protective device; Utilize the outlet cable vault as earthed switch chamber 20, arrange elements such as phase-splitting earthed switch 21, overvoltage protection device 24 summation current transformers 23, solved protective device and realized the arrangements of elements space problem that miniaturization can't be gone beyond.