CN113178794A - Zero-sequence overcurrent protection method for spare power automatic switching (BACK) induced circuit of high-voltage built-in transformer - Google Patents
Zero-sequence overcurrent protection method for spare power automatic switching (BACK) induced circuit of high-voltage built-in transformer Download PDFInfo
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- CN113178794A CN113178794A CN202110544006.5A CN202110544006A CN113178794A CN 113178794 A CN113178794 A CN 113178794A CN 202110544006 A CN202110544006 A CN 202110544006A CN 113178794 A CN113178794 A CN 113178794A
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02B—BOARDS, SUBSTATIONS OR SWITCHING ARRANGEMENTS FOR THE SUPPLY OR DISTRIBUTION OF ELECTRIC POWER
- H02B1/00—Frameworks, boards, panels, desks, casings; Details of substations or switching arrangements
- H02B1/26—Casings; Parts thereof or accessories therefor
- H02B1/46—Boxes; Parts thereof or accessories therefor
- H02B1/48—Mounting of devices therein
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
- G01R19/25—Arrangements for measuring currents or voltages or for indicating presence or sign thereof using digital measurement techniques
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
- G01R31/52—Testing for short-circuits, leakage current or ground faults
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02B—BOARDS, SUBSTATIONS OR SWITCHING ARRANGEMENTS FOR THE SUPPLY OR DISTRIBUTION OF ELECTRIC POWER
- H02B1/00—Frameworks, boards, panels, desks, casings; Details of substations or switching arrangements
- H02B1/015—Boards, panels, desks; Parts thereof or accessories therefor
- H02B1/04—Mounting thereon of switches or of other devices in general, the switch or device having, or being without, casing
- H02B1/052—Mounting on rails
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
- H02H3/26—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to difference between voltages or between currents; responsive to phase angle between voltages or between currents
- H02H3/32—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to difference between voltages or between currents; responsive to phase angle between voltages or between currents involving comparison of the voltage or current values at corresponding points in different conductors of a single system, e.g. of currents in go and return conductors
- H02H3/34—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to difference between voltages or between currents; responsive to phase angle between voltages or between currents involving comparison of the voltage or current values at corresponding points in different conductors of a single system, e.g. of currents in go and return conductors of a three-phase system
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/007—Arrangements for selectively connecting the load or loads to one or several among a plurality of power lines or power sources
- H02J3/0073—Arrangements for selectively connecting the load or loads to one or several among a plurality of power lines or power sources for providing alternative feeding paths between load and source when the main path fails, e.g. transformers, busbars
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- General Physics & Mathematics (AREA)
- Protection Of Transformers (AREA)
Abstract
The invention discloses a zero sequence overcurrent protection method for a spare power automatic switching (BACK) triggering circuit of a high-voltage built-in transformer, which comprises a handle, a first rack, a gear, a second rack, a second spring and a second limiting groove, wherein the handle is connected with the first rack; the protection method comprises the following steps of firstly, data acquisition; secondly, starting the spare power automatic switching device; setting a zero-sequence overcurrent protection criterion; step four, judging short lines of the current transformer; judging the effective value of the three-phase current; step six, resetting the transformer; the invention is safe and reliable, and avoids the malfunction of the zero sequence overcurrent protection device and the safe and stable operation of the power grid by setting the protection criterion of the zero sequence overcurrent protection device, judging whether the current transformer is broken and judging the effective value of the three-phase current; the zero-sequence overcurrent protection method for the spare power automatic switching-on induced line of the high-voltage built-in transformer does not change the original zero-sequence overcurrent protection strategy, can be realized on the existing platform, and is convenient to popularize and use.
Description
Technical Field
The invention relates to the technical field of power grid relay protection, in particular to a zero-sequence overcurrent protection method for a spare power automatic switching (BACK) induced circuit of a high-voltage built-in transformer.
Background
With the continuous development of economy, the requirement of a power system on the power supply reliability is higher and higher, and the spare power automatic switching is used as one of important methods for maintaining the power supply continuity of a power grid and improving the power supply reliability and is started to be applied to a transformer substation with 330kV or more, so that a zero-sequence overcurrent protection method for a circuit caused by the spare power automatic switching of a high-voltage built-in transformer in the market has certain requirements; however, the existing zero-sequence overcurrent protection mode is simple, the zero-sequence overcurrent protection misoperation is easily caused, the standby power supply operation failure is caused, and the load connected to the downstream of the transformer substation cannot recover power supply in time; most of the existing spare power automatic switching devices are fixed to temples of the power distribution cabinet in a bolt connection mode, and are inconvenient to detach, maintain and replace; therefore, the invention discloses a zero sequence overcurrent protection method for a spare power automatic switching triggering line of a high-voltage built-in transformer in the current stage.
Disclosure of Invention
The invention aims to provide a zero-sequence overcurrent protection method for a circuit caused by spare power automatic switching of a high-voltage built-in transformer, which aims to solve the problems of the prior art that the zero-sequence overcurrent protection is in misoperation and the spare power automatic switching equipment is inconvenient to disassemble and maintain.
In order to solve the technical problems, the invention provides the following technical scheme: a zero sequence overcurrent protection device for a spare power automatic switching (BACK) triggering line of a high-voltage built-in transformer comprises a distribution box, a guide rail, a BACK main body, a first chute, a second chute, a handle, a first rack, a first limit groove, a limit block, a first spring, a rotating shaft, a gear, a third chute, a second rack, a second spring, a connecting shaft and a second limit groove, wherein the BACK main body is arranged on the inner wall of one side of the distribution box, the second chute is symmetrically arranged on the inner wall of one side of the BACK main body, the handle is slidably connected on the inner wall of one side of the second chute, the first rack is symmetrically and fixedly connected at two ends of the handle and is slidably connected in the second chute, the first spring is sleeved on the outer wall of one side of the first rack, the rotating shaft is rotatably connected on the inner wall of one side of the BACK main body in a distributed manner, and fixedly connected on the outer wall of one side of the rotating shaft, and the gear is meshed and connected with the outer wall of one side of the first rack, a third sliding groove is distributed on the inner wall of one side of the spare power automatic switching body, a second rack is connected with the inner wall of one side of the third sliding groove in a sliding mode, and the gear is meshed and connected with the outer wall of one side of the second rack.
Preferably, the inner wall of block terminal distributes symmetry fixedly connected with guide rail, distribute the symmetry on the outer wall of spare power automatic switching body and seted up first spout, and guide rail sliding connection is in the inside of first spout.
Preferably, one side inner wall of the spare power automatic switching body is provided with a first limiting groove in a distributed mode, the outer wall of one end of the first rack is fixedly connected with a limiting block, and the limiting block is connected to the inside of the first limiting groove in a sliding mode.
Preferably, a second spring is fixedly connected to the inner wall of one side of the third sliding groove, and one end of the second spring is fixedly connected to the outer wall of one end of the second rack.
Preferably, fixedly connected with connecting axle on the one end outer wall of second rack, the second spacing groove has been seted up in the distribution on the inner wall of block terminal, and connecting axle sliding connection in the inside of second spacing groove.
A zero sequence overcurrent protection method for a spare power automatic switching (BACK) triggering circuit of a high-voltage built-in transformer comprises the following steps of firstly, data acquisition; secondly, starting the spare power automatic switching device; setting a zero-sequence overcurrent protection criterion; step four, judging short lines of the current transformer; judging the effective value of the three-phase current; and step six, resetting the transformer.
In the first step, the three-phase current on the line before and after the action of the spare power automatic switching body is collected in real time, and the zero-sequence current sampling sequence of the line is calculated according to the collected three-phase current data.
In the second step, when a ground fault occurs, the spare power automatic switching body is automatically started, the main line of the transformer is automatically disconnected, then a spare power automatic switching body device line zero-sequence inrush current identification criterion is constructed according to the line zero-sequence current sampling sequence data in the first step, identification and judgment are carried out, if the identification result is a non-inrush current working condition, line zero-sequence overcurrent protection is not locked, and if the identification result is an inrush current working condition, zero-sequence overcurrent protection is locked.
In the third step, firstly, the zero-mode inrush current parameter of the transformer is obtained through the line zero-sequence current sampling sequence calculated in the first step, then, the zero-mode inrush current waveform is obtained by using the zero-mode inrush current parameter of the transformer and a zero-mode inrush current analytic expression, and finally, the obtained zero-mode inrush current waveform is used as a protection criterion of the zero-sequence overcurrent protection device.
In the fourth step, firstly, judging whether the zero-sequence overcurrent protection starting is met or not according to the protection criterion of the zero-sequence overcurrent protection device obtained in the third step, if yes, starting the zero-sequence overcurrent protection, and if not, locking the zero-sequence overcurrent protection; then judging whether the current transformer is broken, if the current transformer is not broken, the second harmonic content in the neutral point zero sequence current of the side of the transformer is larger than the second harmonic content fixed value, and the neutral point zero sequence current waveform of the transformer is saturated, opening the zero sequence overcurrent protection of the side after the set T time; and if the CT is not disconnected, and the content of the second harmonic in the neutral point zero-sequence current of the current side of the transformer is not larger than the fixed value of the content of the second harmonic or the waveform of the neutral point zero-sequence current of the transformer is unsaturated, immediately opening the zero-sequence overcurrent protection of the current side.
And step five, acquiring a three-phase current effective value, judging whether the maximum value of the three-phase current effective value is larger than a first preset value of the zero-sequence protection current, if so, keeping the zero-sequence overcurrent protection in the existing state, and if so, opening the zero-sequence overcurrent protection.
In the sixth step, maintenance personnel maintain the earth leakage fault of the line connection and restore the main circuit of the transformer, after the maintenance is finished, the spare power automatic switching body is automatically disconnected, and the zero sequence overcurrent protection automatically restores the original state.
Preferably, in the first step, a three-phase current is collected through a current transformer.
Preferably, in the second step, when the spare power automatic switching device body is started, an indication signal is sent.
Preferably, in the third step, the zero-mode inrush current analytic expression includes a saturation mutual inductance reactance, a high-voltage side self-leakage reactance, a low-voltage side self-leakage reactance, a system zero-sequence reactance, a system voltage, a system flux density, an unsaturated iron core flux density and a flux density of residual magnetism of the transformer.
Preferably, in the fourth step, the method for judging that the current transformer has no line break includes that the amplitude of the three-phase self-produced zero-sequence voltage at the current side of the transformer is greater than the zero-sequence overvoltage fixed value, and the amplitude of the zero-sequence current at the neutral point at the current side of the transformer is greater than the secondary rated value of the current transformer.
Preferably, in the fifth step, a fourier analysis method is adopted to obtain the three-phase current effective value.
Compared with the prior art, the invention has the following beneficial effects: the invention is safe and reliable, and avoids the malfunction of the zero sequence overcurrent protection device and the safe and stable operation of the power grid by setting the protection criterion of the zero sequence overcurrent protection device, judging whether the current transformer is broken and judging the effective value of the three-phase current; by controlling the zero-sequence overcurrent protection not to be opened within the set time T, the malfunction of the zero-sequence overcurrent protection of the transformer can be effectively avoided, and the malfunction of the zero-sequence overcurrent protection of the transformer caused by the zero-sequence current when the current transformer is disconnected can be avoided, so that the safe and stable operation of a power grid is ensured; the zero-sequence overcurrent protection method for the spare power automatic switching-on induced line of the high-voltage built-in transformer does not change the original zero-sequence overcurrent protection strategy, can be realized on the existing platform, and is convenient to popularize and use; through the cooperation of handle, first rack, stopper, first spring, gear, second rack, second spring and second spacing groove, simple structure will be equipped with the automatic switching equipment block inside the switch board through the spring block structure that hidden handle is connected, realizes stable installation, and convenient to detach's purpose.
Drawings
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention. In the drawings:
fig. 1 is an overall front sectional structure schematic diagram of the invention.
Fig. 2 is a partially cut-away side view of the spare power automatic switching body according to the present invention.
Fig. 3 is a top view partially cut-away view of the present invention as a whole.
Fig. 4 is a schematic perspective view of a second rack according to the present invention.
Fig. 5 is a schematic perspective view of the handle of the present invention.
Fig. 6 is an enlarged view of the structure of the region a in fig. 1 according to the present invention.
FIG. 7 is a flow chart of the method of the present invention.
In the figure: 1. a distribution box; 2. a guide rail; 3. the spare power automatic switching body; 4. a first chute; 5. a second chute; 6. a handle; 7. a first rack; 8. a first limit groove; 9. a limiting block; 10. a first spring; 11. a rotating shaft; 12. a gear; 13. a third chute; 14. a second rack; 15. a second spring; 16. a connecting shaft; 17. a second limit groove.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Referring to fig. 1-6, the present invention provides a technical solution: a zero sequence overcurrent protection device for a spare power automatic switching (BACK) triggering line of a high-voltage built-in transformer comprises a distribution box 1, a guide rail 2, a spare power automatic switching body 3, a first chute 4, a second chute 5, a handle 6, a first rack 7, a first limit groove 8, a limit block 9, a first spring 10, a rotating shaft 11, a gear 12, a third chute 13, a second rack 14, a second spring 15, a connecting shaft 16 and a second limit groove 17, wherein the spare power automatic switching body 3 is arranged on the inner wall of one side of the distribution box 1, the second chute 5 is symmetrically arranged on the inner wall of one side of the spare power automatic switching body 3, the handle 6 is slidably connected on the inner wall of one side of the second chute 5, the first rack 7 is symmetrically and fixedly connected on two ends of the handle 6, the first rack 7 is slidably connected inside the second chute 5, the first spring 10 is sleeved on the outer wall of one side of the first rack 7, the rotating shaft 11 is rotatably connected on the inner wall of one side of the spare power automatic switching body 3, a gear 12 is fixedly connected to the outer wall of one side of the rotating shaft 11, the gear 12 is meshed and connected to the outer wall of one side of the first rack 7, a third chute 13 is distributed on the inner wall of one side of the spare power automatic switching body 3, a second rack 14 is connected to the inner wall of one side of the third chute 13 in a sliding manner, and the gear 12 is meshed and connected to the outer wall of one side of the second rack 14; the inner wall of the distribution box 1 is symmetrically and fixedly connected with guide rails 2, the outer wall of the spare power automatic switching body 3 is symmetrically provided with first sliding chutes 4, and the guide rails 2 are connected inside the first sliding chutes 4 in a sliding manner; a first limiting groove 8 is distributed on the inner wall of one side of the spare power automatic switching body 3, a limiting block 9 is fixedly connected to the outer wall of one end of the first rack 7, and the limiting block 9 is connected to the inside of the first limiting groove 8 in a sliding manner; a second spring 15 is fixedly connected to the inner wall of one side of the third chute 13, and one end of the second spring 15 is fixedly connected to the outer wall of one end of the second rack 14; fixedly connected with connecting axle 16 on the one end outer wall of second rack 14, second spacing groove 17 has been seted up in the distribution on the inner wall of block terminal 1, and connecting axle 16 sliding connection is in the inside of second spacing groove 17.
Referring to fig. 7, the present invention provides a technical solution: a zero sequence overcurrent protection method for a spare power automatic switching (BACK) triggering circuit of a high-voltage built-in transformer comprises the following steps of firstly, data acquisition; secondly, starting the spare power automatic switching device; setting a zero-sequence overcurrent protection criterion; step four, judging short lines of the current transformer; judging the effective value of the three-phase current; and step six, resetting the transformer.
In the first step, the three-phase current on the line before and after the action of the automatic bus transfer device body 3 is collected through the current transformer in real time, and the zero sequence current sampling sequence of the line is calculated according to the collected three-phase current data.
In the second step, when a ground fault occurs, the spare power automatic switching body 3 is automatically started, an indication signal is sent out, the main line of the transformer is automatically disconnected, then a zero-sequence inrush current identification criterion of the spare power automatic switching body 3 device line is constructed according to the line zero-sequence current sampling sequence data in the first step, identification judgment is carried out, if the identification result is a non-inrush current working condition, line zero-sequence overcurrent protection is not locked, and if the identification result is an inrush current working condition, zero-sequence overcurrent protection is locked.
In the third step, firstly, the zero-mode inrush current parameter of the transformer is obtained through the line zero-sequence current sampling sequence calculated in the first step, then, the zero-mode inrush current waveform is obtained by utilizing the zero-mode inrush current parameter of the transformer and a zero-mode inrush current analytic expression, and finally, the obtained zero-mode inrush current waveform is used as a protection criterion of the zero-sequence overcurrent protection device, wherein the zero-mode inrush current analytic expression comprises the saturation mutual inductance, the high-voltage side self-leakage inductance, the low-voltage side self-leakage inductance, the system zero-sequence reactance, the system voltage, the system magnetic density, the magnetic density of the unsaturated iron core and the magnetic density of the residual magnetism of the transformer.
In the fourth step, firstly, judging whether the zero-sequence overcurrent protection starting is met or not according to the protection criterion of the zero-sequence overcurrent protection device obtained in the third step, if yes, starting the zero-sequence overcurrent protection, and if not, locking the zero-sequence overcurrent protection; then judging whether the current transformer is broken, if the current transformer is not broken, the second harmonic content in the neutral point zero sequence current of the side of the transformer is larger than the second harmonic content fixed value, and the neutral point zero sequence current waveform of the transformer is saturated, opening the zero sequence overcurrent protection of the side after the set T time; if the CT is not broken, and the secondary harmonic content in the neutral point zero-sequence current of the current transformer at the side is not larger than the secondary harmonic content fixed value or the waveform of the neutral point zero-sequence current of the current transformer is unsaturated, the zero-sequence overcurrent protection at the side is opened immediately, and the method for judging that the current transformer is not broken is that the amplitude of the three-phase self-produced zero-sequence voltage at the side of the current transformer is larger than the zero-sequence overvoltage fixed value and the amplitude of the neutral point zero-sequence current at the side of the current transformer is larger than the secondary rated value of the current transformer.
And in the fifth step, obtaining a three-phase current effective value, judging whether the maximum value of the three-phase current effective value is larger than a first preset value of the zero-sequence protection current, and obtaining the three-phase current effective value by adopting a Fourier analysis method, wherein if the maximum value of the three-phase current effective value is smaller than or equal to the preset value of the zero-sequence protection current, the zero-sequence overcurrent protection is kept in the existing state, and if the maximum value of the three-phase current effective value is larger than the preset value of the zero-sequence protection current, the zero-sequence overcurrent protection is opened.
In the sixth step, maintenance personnel maintain the earth leakage fault of the line connection and restore the main circuit of the transformer, after the maintenance is finished, the spare power automatic switching body 3 is automatically disconnected, and the zero sequence overcurrent protection automatically restores the original state.
Based on the above, the invention has the advantages that the invention is safe and reliable, the zero sequence overcurrent protection method of the spare power automatic switching initiation line of the high-voltage built-in transformer adopts three judgment methods of setting the protection criterion of the zero sequence overcurrent protection device, judging whether the current transformer is broken and judging the effective value of three-phase current, thereby preventing the malfunction of the zero sequence overcurrent protection device under various conditions and facilitating the safe and stable operation of a power grid; the method can be used on the original platform, and is convenient to popularize and use; when the spare power automatic switching body 3 is damaged or needs to be maintained and replaced, the handle 6 is pulled manually to drive the first rack 7 to move, so that the first spring 10 is compressed, the gear 12 is driven to rotate under the action of the first rack 7, the second rack 14 is driven to move under the action of the gear 12, the connecting shaft 16 on the second rack 14 is separated from the second limiting groove 17, the handle 6 is pulled continuously, and the spare power automatic switching body 3 is taken out.
It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.
Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that changes may be made in the embodiments and/or equivalents thereof without departing from the spirit and scope of the invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (11)
1. The utility model provides a built-in type transformer spare power automatic switching causes circuit zero sequence overcurrent protection device of high pressure, includes block terminal (1), guide rail (2), spare power automatic switching body (3), first spout (4), second spout (5), handle (6), first rack (7), first spacing groove (8), stopper (9), first spring (10), axis of rotation (11), gear (12), third spout (13), second rack (14), second spring (15), connecting axle (16) and second spacing groove (17), its characterized in that: the automatic spare power switching device is characterized in that a spare power automatic switching body (3) is arranged on the inner wall of one side of the distribution box (1), a second sliding groove (5) is symmetrically formed in the inner wall of one side of the spare power automatic switching body (3), a handle (6) is slidably connected to the inner wall of one side of the second sliding groove (5), first racks (7) are symmetrically and fixedly connected to the two ends of the handle (6), the first racks (7) are slidably connected to the inner portion of the second sliding groove (5), a first spring (10) is sleeved on the outer wall of one side of the first racks (7), a rotating shaft (11) is rotationally connected to the inner wall of one side of the spare power automatic switching body (3) in a distributed mode, a gear (12) is fixedly connected to the outer wall of one side of the rotating shaft (11), the gear (12) is connected to the outer wall of one side of the first racks (7) in a meshed mode, third sliding grooves (13) are distributed on the inner wall of one side of the spare power automatic switching body (3), and a second rack (14) is connected to the inner wall of one side of the third sliding chute (13) in a sliding manner, and the gear (12) is meshed and connected to the outer wall of one side of the second rack (14).
2. The zero-sequence overcurrent protection device for the spare power automatic switching initiation line of the high-voltage built-in transformer according to claim 1, characterized in that: the automatic power distribution system is characterized in that guide rails (2) are symmetrically and fixedly connected to the inner wall of the distribution box (1), first sliding grooves (4) are symmetrically formed in the outer wall of the automatic power distribution device body (3), and the guide rails (2) are connected to the inner portions of the first sliding grooves (4) in a sliding mode.
3. The zero-sequence overcurrent protection device for the spare power automatic switching initiation line of the high-voltage built-in transformer according to claim 1, characterized in that: one side inner wall of the spare power automatic switching body (3) is provided with a first limiting groove (8) in a distributed mode, one end outer wall of the first rack (7) is fixedly connected with a limiting block (9), and the limiting block (9) is connected to the inside of the first limiting groove (8) in a sliding mode.
4. The zero-sequence overcurrent protection device for the spare power automatic switching initiation line of the high-voltage built-in transformer according to claim 1, characterized in that: and a second spring (15) is fixedly connected to the inner wall of one side of the third sliding groove (13), and one end of the second spring (15) is fixedly connected to the outer wall of one end of the second rack (14).
5. The zero-sequence overcurrent protection device for the spare power automatic switching initiation line of the high-voltage built-in transformer according to claim 1, characterized in that: fixedly connected with connecting axle (16) on the one end outer wall of second rack (14), second spacing groove (17) have been seted up in the distribution on the inner wall of block terminal (1), and connecting axle (16) sliding connection is in the inside of second spacing groove (17).
6. A zero sequence overcurrent protection method for a spare power automatic switching (BACK) triggering circuit of a high-voltage built-in transformer comprises the following steps of firstly, data acquisition; secondly, starting the spare power automatic switching device; setting a zero-sequence overcurrent protection criterion; step four, judging short lines of the current transformer; judging the effective value of the three-phase current; step six, resetting the transformer; the method is characterized in that:
in the first step, three-phase currents on the circuit before and after the action of the spare power automatic switching body (3) are collected in real time, and a zero-sequence current sampling sequence of the circuit is calculated according to the collected three-phase current data;
in the second step, when a ground fault occurs, the spare power automatic switching body (3) is automatically started, the main line of the transformer is automatically disconnected, then a zero-sequence inrush current identification criterion of the device line of the spare power automatic switching body (3) is constructed according to the zero-sequence current sampling sequence data of the line in the first step, identification and judgment are carried out, if the identification result is a non-inrush current working condition, zero-sequence overcurrent protection of the line is not locked, and if the identification result is an inrush current working condition, zero-sequence overcurrent protection is locked;
in the third step, firstly, the zero-mode inrush current parameter of the transformer is obtained through the line zero-sequence current sampling sequence calculated in the first step, then, the zero-mode inrush current waveform is obtained by using the zero-mode inrush current parameter of the transformer and a zero-mode inrush current analytic expression, and finally, the obtained zero-mode inrush current waveform is used as a protection criterion of the zero-sequence overcurrent protection device;
in the fourth step, firstly, judging whether the zero-sequence overcurrent protection starting is met or not according to the protection criterion of the zero-sequence overcurrent protection device obtained in the third step, if yes, starting the zero-sequence overcurrent protection, and if not, locking the zero-sequence overcurrent protection; then judging whether the current transformer is broken, if the current transformer is not broken, the second harmonic content in the neutral point zero sequence current of the side of the transformer is larger than the second harmonic content fixed value, and the neutral point zero sequence current waveform of the transformer is saturated, opening the zero sequence overcurrent protection of the side after the set T time; if the CT is not disconnected, and the content of the second harmonic in the neutral point zero-sequence current of the current side of the transformer is not larger than the fixed value of the content of the second harmonic or the waveform of the neutral point zero-sequence current of the transformer is unsaturated, immediately opening the zero-sequence overcurrent protection of the current side;
acquiring a three-phase current effective value, judging whether the maximum value of the three-phase current effective value is larger than a first preset value of the zero-sequence protection current or not, if so, keeping the zero-sequence overcurrent protection in the existing state, and if so, opening the zero-sequence overcurrent protection;
in the sixth step, maintenance personnel maintain the earth leakage fault of the line connection and restore the main circuit of the transformer, after the maintenance is finished, the spare power automatic switching body (3) is automatically disconnected, and the zero sequence overcurrent protection automatically restores the original state.
7. The zero-sequence overcurrent protection method for the spare power automatic switching initiation line of the high-voltage built-in transformer according to claim 6, characterized in that: and in the first step, three-phase current is collected through a current transformer.
8. The zero-sequence overcurrent protection method for the spare power automatic switching initiation line of the high-voltage built-in transformer according to claim 6, characterized in that: in the second step, when the spare power automatic switching body (3) is started, an indication signal is sent out.
9. The zero-sequence overcurrent protection method for the spare power automatic switching initiation line of the high-voltage built-in transformer according to claim 6, characterized in that: in the third step, the zero-mode inrush current analytic expression comprises a saturation mutual inductance reactance of the transformer, a high-voltage side self-leakage reactance, a low-voltage side self-leakage reactance, a system zero-sequence reactance, a system voltage, a system magnetic density, an unsaturated iron core magnetic density and a residual magnetic density.
10. The zero-sequence overcurrent protection method for the spare power automatic switching initiation line of the high-voltage built-in transformer according to claim 6, characterized in that: in the fourth step, the method for judging that the current transformer has no broken line is that the amplitude of the three-phase self-produced zero-sequence voltage of the current transformer side is larger than the zero-sequence overvoltage fixed value, and the amplitude of the neutral point zero-sequence current of the current transformer side is larger than the secondary rated value of the current transformer.
11. The zero-sequence overcurrent protection method for the spare power automatic switching initiation line of the high-voltage built-in transformer according to claim 6, characterized in that: and in the fifth step, a Fourier analysis method is adopted to obtain the three-phase current effective value.
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Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AU6693990A (en) * | 1989-11-24 | 1991-05-30 | Siemens Aktiengesellschaft | Electrical switchgear having an insertable and retractable apparatus rack |
| DE19748553A1 (en) * | 1997-11-04 | 1999-05-20 | Aeg Starkstrom Anlagenbau Magd | Push-in module for electrical switching gear |
| CN109119971A (en) * | 2018-09-03 | 2019-01-01 | 广东电网有限责任公司 | zero-sequence over-current protection method, system, device and computer readable storage medium |
| CN110556783A (en) * | 2019-09-10 | 2019-12-10 | 许昌许继软件技术有限公司 | zero sequence overcurrent protection method and device for transformer |
| CN210628922U (en) * | 2019-11-06 | 2020-05-26 | 珠海德鑫电气设备有限公司 | Hand-pulling mechanism for drawer of low-voltage switch cabinet |
| CN111711180A (en) * | 2020-06-19 | 2020-09-25 | 国网宁夏电力有限公司 | Method and system for preventing zero sequence overcurrent protection misoperation of ultrahigh voltage spare power automatic switching induced circuit |
| CN212277666U (en) * | 2020-06-16 | 2021-01-01 | 张志霞 | Electric power low-voltage switch cabinet |
-
2021
- 2021-05-19 CN CN202110544006.5A patent/CN113178794B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AU6693990A (en) * | 1989-11-24 | 1991-05-30 | Siemens Aktiengesellschaft | Electrical switchgear having an insertable and retractable apparatus rack |
| DE19748553A1 (en) * | 1997-11-04 | 1999-05-20 | Aeg Starkstrom Anlagenbau Magd | Push-in module for electrical switching gear |
| CN109119971A (en) * | 2018-09-03 | 2019-01-01 | 广东电网有限责任公司 | zero-sequence over-current protection method, system, device and computer readable storage medium |
| CN110556783A (en) * | 2019-09-10 | 2019-12-10 | 许昌许继软件技术有限公司 | zero sequence overcurrent protection method and device for transformer |
| CN210628922U (en) * | 2019-11-06 | 2020-05-26 | 珠海德鑫电气设备有限公司 | Hand-pulling mechanism for drawer of low-voltage switch cabinet |
| CN212277666U (en) * | 2020-06-16 | 2021-01-01 | 张志霞 | Electric power low-voltage switch cabinet |
| CN111711180A (en) * | 2020-06-19 | 2020-09-25 | 国网宁夏电力有限公司 | Method and system for preventing zero sequence overcurrent protection misoperation of ultrahigh voltage spare power automatic switching induced circuit |
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