CN113851991A - Method for replacing box type transformer with low-voltage side having short-time power failure - Google Patents
Method for replacing box type transformer with low-voltage side having short-time power failure Download PDFInfo
- Publication number
- CN113851991A CN113851991A CN202110918150.0A CN202110918150A CN113851991A CN 113851991 A CN113851991 A CN 113851991A CN 202110918150 A CN202110918150 A CN 202110918150A CN 113851991 A CN113851991 A CN 113851991A
- Authority
- CN
- China
- Prior art keywords
- low
- voltage
- box
- type transformer
- power supply
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02B—BOARDS, SUBSTATIONS OR SWITCHING ARRANGEMENTS FOR THE SUPPLY OR DISTRIBUTION OF ELECTRIC POWER
- H02B3/00—Apparatus specially adapted for the manufacture, assembly, or maintenance of boards or switchgear
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02G—INSTALLATION OF ELECTRIC CABLES OR LINES, OR OF COMBINED OPTICAL AND ELECTRIC CABLES OR LINES
- H02G1/00—Methods or apparatus specially adapted for installing, maintaining, repairing or dismantling electric cables or lines
-
- 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
- H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
- H02J3/381—Dispersed generators
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A30/00—Adapting or protecting infrastructure or their operation
- Y02A30/14—Extreme weather resilient electric power supply systems, e.g. strengthening power lines or underground power cables
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Supply And Distribution Of Alternating Current (AREA)
Abstract
The invention discloses a method for replacing a box-type transformer with a low-voltage side short-time power failure, which is characterized in that during the replacement, maintenance or migration of the box-type transformer, a low-voltage cable branch box on a power supply link of the box-type transformer and a medium-low voltage terminal user are supplied with power by adopting a low-voltage temporary mobile power supply one-time grid-connected mode, after the replacement, maintenance or migration of the box-type transformer is finished, the box-type transformer is switched back to the box-type transformer to supply power by adopting a cold-down mode, short-time power failure of several minutes can be generated in the whole process, compared with the replacement of the box-type transformer with normal power failure, the low-voltage terminal users are completely stopped until the box-type transformer is completely replaced, the loss of the number of users during the low-voltage power failure is greatly reduced, and the reliability of the low-voltage power supply and the power operator environment are effectively improved. Brings great economic benefit and social benefit for enterprises.
Description
Technical Field
The invention relates to the field of distribution network operation and maintenance, in particular to a method for replacing a box type transformer with a low-voltage side in short-time power failure.
Background
The box-type transformer is a complete set of distribution equipment which combines high-voltage switch equipment, a transformer and low-voltage distribution equipment into a whole according to a certain wiring scheme. As shown in fig. 1, in a general box-type transformer structure, a power supply is input through a high-voltage side high-voltage switch, and after voltage transformation is performed through a fusion tube and a box-type transformer body, a plurality of low-voltage outgoing lines are formed in the form of low-voltage side low-voltage main switches, low-voltage busbars and low-voltage branch lines cables to a plurality of low-voltage cable branch boxes arranged nearby low-voltage terminal users on site, and then the low-voltage cable branch boxes supply power to the low-voltage terminal users in the form of cables or overhead cable hybrid lines. Common low-voltage cable branch boxes are generally arranged in green belts of a community or at a position close to downstairs of a unit building.
Generally, the low-voltage end users of the box-type transformer have and only have one upper power supply, namely the box-type transformer, as the only power supply, and supply power to a plurality of low-voltage end users in a radial structure.
Generally, through years of use, when a box-type transformer needs to be replaced and maintained due to equipment operation or needs to be integrally transferred due to urban construction, for a low-voltage terminal user, accompanying power failure is caused due to integral replacement, maintenance and transfer of a superior incoming line power supply. Moreover, a common service object of a mode of converting medium-voltage power distribution into low-voltage power supply like a common box-type transformer is the masses of residents and small and micro businesses which are closely related to the residents, once the box-type transformer is overhauled, moved and modified, the satisfaction degree of electricity utilization of a large number of the residents and the users can be seriously influenced, complaints are brought to power supply enterprises, and the formation of a good operator environment is not facilitated.
Disclosure of Invention
The invention provides a method for replacing a box type transformer with low-voltage side short-time power failure, aiming at the problem that a low-voltage terminal user accompanies power failure during replacement of the box type transformer in the prior art.
The technical scheme of the invention is as follows.
A method for replacing a box type transformer with a low-voltage side in short-time power failure comprises the following steps:
s01, firstly, when the box-type transformer is normally powered, arranging a low-voltage temporary mobile power supply near the low-voltage cable branch box;
s02, arranging a low-voltage flexible cable between the low-voltage temporary mobile power supply and the low-voltage cable branch box, and laying the low-voltage flexible cable on a damp-proof canvas or an insulating pad;
s03, connecting a low-voltage bus bar in a box-type transformer low-voltage cable branch box with a load side of a low-voltage temporary mobile power supply grid-connected switch TB by using the laid flexible cable in a live-line operation mode;
s04, under the condition that the phase sequence is consistent, a grid-connected switch TB is switched on, so that the low-voltage cable branch box is powered by the low-voltage temporary mobile power supply and the box-type transformer at the same time;
s05, after the load transfer is completed, namely after the output current of the low-voltage temporary power supply reaches a preset value, disconnecting the incoming line switch of the low-voltage cable branch box, and switching the power supply of the low-voltage cable branch box to the power supply of the low-voltage temporary mobile power supply by the box-type transformer;
s06, sequentially opening a low-voltage main switch and a high-voltage switch of the box type transformer, and replacing the box type sample transformer in a power failure maintenance mode;
and S07, after the power failure maintenance and replacement of the box type transformer are finished, closing the high-voltage switch and the low-voltage main switch of the box type transformer, after phase sequences are checked on two sides of the inlet switch of the low-voltage cable branch box to be consistent, disconnecting the grid-connected switch TB at the low-voltage temporary mobile power supply, then quickly closing the inlet switch of the low-voltage cable branch box, and recovering power supplied by the box type transformer after the maintenance and replacement after the terminal user experiences short-time power failure in the process.
In the process, the low-voltage temporary mobile power supply is used, a one-time grid-connected mode is adopted to supply power to the low-voltage cable branch box and the medium-voltage and low-voltage terminal users on the power supply link of the box type transformer during the replacement (maintenance and transfer) of the box type transformer, and the low-voltage cable branch box and the medium-voltage and low-voltage terminal users are switched back to the box type transformer to supply power in a cold-falling mode after the replacement (maintenance and transfer) of the box type transformer is finished, so that short-time power failure of several minutes can be generated in the whole process, the low-voltage terminal users are completely accompanied and stopped until the replacement of the box type transformer is finished compared with the normal power failure for at least several hours, the loss of the number of users during the low-voltage accompanying power failure is greatly reduced, and the reliability of low-voltage power supply and the power operator environment are effectively improved.
Preferably, step S03 includes: confirming that the low-voltage temporary mobile power supply grid-connected switch TB and the commercial power access switch MB are both in a brake-off state, adopting a live working mode, under the condition that a low-voltage busbar in a low-voltage cable branch box is electrified, connecting the low-voltage cable branch box busbar with a load socket of the grid-connected switch TB on the temporary mobile power supply through a low-voltage flexible cable by using a busbar clamp.
Preferably, step S04 includes: starting a low-voltage temporary mobile power supply, closing a temporary mobile power supply outlet switch GB, transmitting power to a low-voltage temporary mobile power supply busbar, performing synchronous detection after checking phase sequence consistency on two sides of a grid-connected switch TB, adjusting voltage difference, frequency and phase angle difference of the low-voltage temporary mobile power supply and the busbar side of a low-voltage cable branch box of a box-type transformer until the grid-connected requirement is met, and then closing the grid-connected switch TB to perform low-voltage load transfer.
Preferably, the repair and replacement of the box-type transformer includes: disconnecting the incoming line switch of the low-voltage cable branch box, pulling the high-voltage switch, the low-voltage main switch and all the low-voltage outgoing line switches of the box-type transformer open, and performing maintenance and replacement on the box-type transformer after safety measures are taken; after the box-type transformer is subjected to power failure, maintenance and replacement, the safety measures are removed, the high-voltage switch, the low-voltage main switch and all the low-voltage outgoing switches of the box-type transformer are sequentially switched on, power is transmitted to the power side of the incoming switch of the low-voltage cable branch box, the load side of the incoming switch of the low-voltage cable branch box supplies power to the low-voltage temporary mobile power supply, and the power side supplies power to the box-type transformer.
Preferably, step S07 includes: checking phase sequences on two sides of a low-voltage cable branch box incoming line switch, if the phase sequences are inconsistent, opening a box type transformer low-voltage outgoing line switch, stopping power to adjust the lapping phase of incoming cables of the low-voltage cable branch box until the phase sequences are consistent, finally opening a low-voltage temporary mobile power supply grid-connected switch, and quickly closing the low-voltage cable branch box incoming line switch to enable the low-voltage cable branch box and branch low-voltage terminal users thereof to switch back to the box type transformer for power supply.
Preferably, when the load of the low-voltage cable branch box is too large and a single low-voltage temporary mobile power supply cannot completely meet the power supply requirement, a plurality of low-voltage temporary mobile power supplies can be connected in series at a pre-stage unit of the low-voltage temporary mobile power supply to increase the output capacity and meet the power consumption requirement of a low-voltage cable branch box terminal user.
Preferably, when there are a plurality of low-voltage cable branch boxes on the low-voltage side of one box-type transformer, a plurality of low-voltage temporary mobile power supplies are distributed, the low-voltage temporary mobile power supplies and the box-type transformer low-voltage cable branch boxes are electrically connected by using low-voltage flexible cables and a confluence clamp, and the power supply switching of the low-voltage cable branch boxes is performed by executing the steps S04 and S05.
The substantial effects of the invention include: during the replacement (overhaul and migration) of the box-type transformer, a low-voltage cable branch box on a power supply link of the box-type transformer and a medium-low voltage terminal user are powered by adopting a mode of once grid connection of a low-voltage temporary mobile power supply, after the replacement (overhaul and migration) of the box-type transformer is finished, the mode of cold falling is switched back to the box-type transformer for power supply, short-time power failure of several minutes can be generated in the whole process, at least several hours of replacement of the box-type transformer are compared with normal power failure, all the low-voltage terminal users are accompanied and stopped until the box-type transformer is replaced, the number loss of users during low-voltage accompanying and power failure is greatly reduced, and the reliability of low-voltage power supply and the power operator environment are effectively improved. Brings great economic benefit and social benefit for enterprises.
Drawings
FIG. 1 is a schematic diagram of a conventional box transformer and low voltage cable breakout box wiring;
FIG. 2 is a schematic diagram of a primary grid connection in the present embodiment;
FIG. 3 is a schematic diagram of the wiring before one-time grid connection in the present embodiment;
FIG. 4 is a schematic diagram of the connection of the box-type transformer after one-time grid connection and before power failure replacement in the present embodiment;
fig. 5 is a wiring diagram of the low-voltage temporary mobile power supply in the embodiment after being completely withdrawn.
Detailed Description
The technical solution of the present application will be described with reference to the following examples. In addition, numerous specific details are set forth below in order to provide a better understanding of the present invention. It will be understood by those skilled in the art that the present invention may be practiced without some of these specific details. In some instances, methods, means, elements and circuits that are well known to those skilled in the art have not been described in detail so as not to obscure the present invention.
Example (b):
a method for replacing a box type transformer with a low-voltage side in short-time power failure comprises the following steps:
firstly, when the box-type transformer is normally powered, a low-voltage temporary mobile power supply is arranged nearby the low-voltage cable branch box.
Set up the low pressure flexible cable between low pressure temporary mobile power source and low pressure cable feeder pillar, the low pressure flexible cable should lay on damp-proofing canvas or insulating pad, and when many low pressure flexible cable connection were continued the use, should use special quick connect to use the splice box to externally protect.
Confirming that the low-voltage temporary mobile power supply grid-connected switch TB and the commercial power access switch MB are both in a brake-off state, adopting a live working mode, under the condition that a low-voltage bus bar in a low-voltage cable branch box is electrified, connecting the low-voltage cable branch box bus bar with the load side of a grid-connected switch TB plug board on the temporary mobile power supply through a low-voltage flexible cable by using a bus clamp, and electrically connecting the outlet low voltage of a box-type transformer to the single side of the temporary mobile power supply grid-connected switch TB.
The method comprises the steps of starting a low-voltage temporary mobile power supply, turning on a temporary mobile power supply outlet switch GB, transmitting power to a low-voltage temporary mobile power supply busbar, checking phase sequence consistency on two sides of a grid-connected switch TB, carrying out synchronous detection, automatically adjusting voltage difference, frequency and phase angle difference of the low-voltage temporary mobile power supply and a box-type transformer low-voltage cable branch box busbar side to meet grid-connected requirements, turning on the grid-connected switch TB under the condition that the phase sequence consistency is achieved, and simultaneously supplying power to the low-voltage cable branch box by the low-voltage temporary mobile power supply and the box-type transformer.
And after the load transfer is finished, namely the output current of the low-voltage temporary power supply reaches a preset value, disconnecting the incoming line switch of the low-voltage cable branch box, and switching the power supply of the low-voltage cable branch box to the power supply of the low-voltage temporary mobile power supply by the box-type transformer.
And (3) sequentially pulling the low-voltage main switch and the high-voltage switch of the box-type transformer open, and replacing (overhauling and transferring) the box-type sample transformer by adopting a power failure overhauling mode after corresponding safety measures are taken.
After the box-type transformer is completely replaced (repaired and moved) in a power failure mode, the high-voltage switch, the low-voltage main switch and the low-voltage outgoing switch are sequentially switched on, power is transmitted to the power side of the incoming line switch of the low-voltage cable branch box, the load side of the incoming line switch of the low-voltage cable branch box supplies power to the low-voltage temporary mobile power supply, and the power side supplies power to the box-type transformer after being repaired and replaced.
Checking that the phase sequence is consistent between the power supply side and the load side of the incoming switch of the low-voltage cable branch box, if the phase sequence is inconsistent, adjusting the A, C phase of the incoming low-voltage cable of the low-voltage cable branch box in a power failure state, recovering the power supply of the incoming cable of the low-voltage cable branch box, and checking the phase sequence again.
After phase sequences of a power supply side and a load side of a low-voltage cable branch box incoming line switch are checked to be consistent, two groups of workers are arranged, after a grid-connected switch TB is disconnected at a low-voltage temporary mobile power supply by one group of workers, the other group of workers immediately and rapidly switch on the incoming line switch of the low-voltage cable branch box. At the moment, after the terminal user experiences short-time power failure, the power supply of the box-type transformer after maintenance and replacement is recovered.
When the load of the low-voltage cable branch box is large, when a single low-voltage temporary mobile power supply cannot completely meet the power supply requirement, a plurality of low-voltage temporary mobile power supplies can be connected in series at the pre-stage unit of the low-voltage temporary mobile power supply to increase the output capacity and meet the power consumption requirement of a low-voltage cable branch box terminal user.
When a plurality of low-voltage cable branch boxes are arranged on the low-voltage side of one box-type transformer, a plurality of low-voltage temporary mobile power supplies can be arranged in a distributed mode, and the power supply is switched by sequentially and temporarily cutting off power in the mode.
And the low-voltage temporary mobile power supply is electrically connected with the low-voltage cable branch box by using a quick connection mode consisting of a low-voltage flexible cable, a confluence clamp and a special connecting device.
The low-voltage flexible cable is connected with the low-voltage temporary mobile power supply in a form of a quick plugging interface, so that the connection speed is further increased, and the connection efficiency is improved.
The low-voltage temporary mobile power supply is used in the process, during the replacement (maintenance and migration) of the box-type transformer, the low-voltage cable branch box on the power supply link of the box-type transformer and the medium-low voltage terminal users are powered in a one-time grid-connected mode, after the replacement (maintenance and migration) of the box-type transformer is finished, the box-type transformer is switched back to be powered in a cold-falling mode, short-time power failure of several minutes can be generated in the whole process, the box-type transformer can be replaced for at least several hours compared with normal power failure, all the low-voltage terminal users accompany and stop until the box-type transformer is replaced, the loss of the number of households during low-voltage accompanying power failure is greatly reduced, and the reliability of low-voltage power supply and the power operator environment are effectively improved.
The following description will be made with reference to specific drawings.
Fig. 2-4 are schematic diagrams before and after a grid connection, wherein as shown in fig. 3: due to the needs of equipment operation and maintenance or municipal construction, the box-type transformer in the drawing needs to be replaced (overhauled and transferred), and at the moment, a mode of once grid-connected access of the low-voltage temporary mobile power supply is adopted to ensure that power is continuously supplied to a low-voltage terminal user connected out of the low-voltage cable branch box during the replacement (overhauling and transfer) of the box-type transformer. The box-type transformer has a plurality of low-voltage outgoing lines, and a plurality of low-voltage cable branch boxes are correspondingly arranged, and one of the low-voltage cable branch boxes is taken as an example in fig. 3 for description.
In fig. 3, the low-voltage temporary mobile power supply is provided with an AC-220V single-phase output and a load/pre-stage unit interface capable of being connected with a plurality of low-voltage temporary mobile power supplies in series. And confirming that the outlet switch GB, the grid-connected switch TB and the mains supply switch MB are all in the off position. The incoming line switch JK1 of the low-voltage cable branch box 1 is in a switch-on position, and the outgoing line switches YK1 and YK2 of the low-voltage terminal user are in a switch-on state. The low voltage cable branch box 1 is now powered by a box transformer.
Laying and setting up the low pressure flexible cable between interim portable power source of low pressure and low pressure cable feeder pillar 1 afterwards, the low pressure flexible cable should lay on damp-proof canvas or insulating pad, and when many low pressure flexible cable connection were used in succession, use special quick connect joint and use the splice box to protect. Meanwhile, when crossing a crossing where vehicles pass, the flexible cable is arranged in the cable cover plate to prevent the vehicles passing through from being crushed.
The power is tested at the load socket of the low-voltage temporary mobile power supply, after the fact that no voltage exists is verified, one end of the laid low-voltage flexible cable is connected with a quick interface on a load socket of a TB (transport block) of the low-voltage temporary mobile power supply through the quick interface, and the other end of the laid low-voltage flexible cable is connected with the confluence clamp in series beside the low-voltage cable branch box 1.
And after the low-voltage bus bar of the low-voltage cable branch box is verified to have voltage and the side of the confluence clamp is verified to have no voltage, the confluence clamp connected with the low-voltage flexible cable is fixed on the low-voltage bus bar of the low-voltage cable branch box in a live working mode. At the moment, the load side of the low-voltage temporary mobile power supply grid-connected switch TB supplies power to the box type transformer power supply.
Then the low-voltage temporary mobile power supply is started, after the normal start is confirmed, the outlet switch GB is switched on to transmit power to the low-voltage temporary mobile power supply busbar, at the moment, the power supply side of the grid-connected switch TB supplies power to the low-voltage temporary mobile power supply, the load side supplies power to the box-type transformer,
and at the moment, whether the phase sequences of the power supply side and the load side of the grid-connected switch TB are consistent or not needs to be detected, if the phase sequences of the power supply side and the load side of the grid-connected switch TB are not consistent, the lap joint positions of the low-voltage bus bar side bus clamp A, C of the low-voltage cable branch box are exchanged until the phase sequences are detected to be consistent.
And pressing down a grid-connected switch TB, starting synchronous detection by a grid-connected module in the low-voltage temporary mobile power supply grid-connected switch TB, automatically adjusting the voltage difference, the frequency and the phase angle difference between the low-voltage temporary mobile power supply and the busbar side of the low-voltage cable branch box of the box-type transformer to meet the grid-connected requirement, and automatically closing the grid-connected switch TB. At the moment, the low-voltage cable branch box 1 is simultaneously powered by the box-type transformer and the low-voltage temporary mobile power supply.
When the load transfer reaches a preset range, namely the output current of the low-voltage temporary power supply reaches a preset value, according to an instruction of a field work leader, a worker disconnects a wire inlet switch JK1 in the low-voltage cable branch box 1, and at the moment, the low-voltage terminal users 1 and 2 are powered by the low-voltage temporary mobile power supply, and one-time grid connection operation is completed.
The low-voltage main switch DK and the high-voltage switch GK of the box-type transformer and all the low-voltage outlet switches (comprising CK1) are sequentially pulled apart as shown in FIG. 4. And a power failure maintenance mode is adopted to replace (maintain and transfer) the box-type transformer.
After the box type transformer is replaced (repaired and moved), the high-voltage switch GK, the low-voltage main switch DK and the low-voltage outlet switch CK1 are sequentially switched on, and outlet wires at the low-voltage side of the box type transformer supply power to the inlet wire power side of the inlet wire switch JK1 of the low-voltage cable branch box. At the moment, the incoming line power side of the incoming line switch JK1 of the low-voltage cable branch box is supplied with power by the box-type transformer, and the outgoing line load side is supplied with power by the low-voltage temporary mobile power supply.
Checking whether the phase sequences are consistent on the power supply side and the load side of the incoming line switch JK1 of the low-voltage cable branch box, if not, opening a low-voltage outgoing line switch CK1 of the box-type transformer, adjusting the lapping position of the incoming line low-voltage cable A, C of the low-voltage cable branch box in a power failure state, closing the low-voltage outgoing line switch CK1, and checking the phase sequences on the two sides of the incoming line switch of the low-voltage cable branch box again until the phase sequences are consistent.
According to the instructions of the on-site working responsible persons, the working staff members are divided into two groups of working staff, one group of working staff disconnects the grid-connected switch TB at the low-voltage temporary mobile power supply and reports the completion condition to the on-site working responsible persons in time, and at the moment, the low-voltage terminal users 1 and 2 are powered off.
And after the on-site working responsible person obtains and confirms that the low-voltage temporary mobile power supply is disconnected from the grid-connected switch TB, another group of working personnel is instructed to quickly switch on the incoming line switch JK1 of the low-voltage cable branch box. At this time, the low-voltage end users 1 and 2 resume power supply, so that after a short-time power failure, the low-voltage end users 1 and 2 resume power supply by the box-type transformer.
Disconnecting a low-voltage temporary mobile power supply outgoing line switch GB; and then the unit in the low-voltage temporary mobile power supply is shut down (at the moment, the unit can be shut down according to a cooling operation and shut down mode, and the unit can also be shut down by skipping emergency braking in a cooling operation stage).
And (3) removing the confluence clamp and the low-voltage flexible cable on the low-voltage busbar in the low-voltage cable branch box 1 by adopting a live working mode, and removing the flexible cable using a quick interface at the load plug interface of the low-voltage temporary mobile power supply, as shown in fig. 5. And finally, the flexible cable and the confluence clamp are stored in the tool box.
When the load of the low-voltage cable branch box is large, when a single low-voltage temporary mobile power supply cannot completely meet the power supply requirement, a plurality of low-voltage temporary mobile power supplies can be connected in series at the pre-stage unit of the low-voltage temporary mobile power supply to increase the output capacity and meet the power consumption requirement of a low-voltage cable branch box terminal user.
When a plurality of low-voltage cable branch boxes are arranged on the low-voltage side of one box-type transformer, a plurality of low-voltage temporary mobile power supplies can be arranged in a distributed mode, and the power supply is switched by sequentially and temporarily cutting off power in the mode.
And the low-voltage temporary mobile power supply is electrically connected with the low-voltage cable branch box by using a quick connection mode consisting of a low-voltage flexible cable, a confluence clamp and a special connecting device.
The low-voltage flexible cable is connected with the low-voltage temporary mobile power supply in a form of a quick plugging interface, so that the connection speed is further increased, and the connection efficiency is improved.
In the embodiment, the temporary low-voltage mobile power supply uses a Huadong power HDV150 type power generation vehicle, the power generation unit adopts a Stamford power generation unit, the rated voltage is 0.4kV, the rated power is 150kVA/120kW, the rated output current is 217A, the power factor is 0.8 (hysteresis), and the temporary low-voltage mobile power supply can fully run for 8 hours under the condition of full oil.
The confluence clamp comprises: SFE company, france, strong locking insulated bus clamps with quick connect single sockets. The maximum voltage of the clamp is 1000V, the maximum current is 400A, the clamp is suitable for connection on a busbar, and the clamp is provided with a contact protection insulating handle.
The flexible cable is: french SFE corporation, 120mm2Low pressure insulation drainage cable, operating voltage is 1000V, and maximum current is 400A, cable weight: 1460g/m, quick male connectors are preassembled at the two ends of the cable, and a connector protective cover is arranged to prevent dust and impurities from entering.
The low-voltage cable branch box and the low-voltage terminal users on the power supply link of the box-type transformer are powered by adopting a low-voltage temporary mobile power supply one-time grid connection mode, the low-voltage cable branch box and the low-voltage terminal users are switched back to the box-type transformer to be powered by adopting a cold-falling mode, short-time power failure of several minutes can be generated during the period of disconnecting the grid connection switch TB and switching on the low-voltage cable branch box JK1, for example, 5 minutes is needed approximately, compared with the case that the box-type transformer is replaced by normal power failure for at least several hours, all the low-voltage terminal users accompany and stop until the box-type transformer is replaced, the loss of the number of the users during low-voltage accompanying power failure is greatly reduced, and the reliability of low-voltage power supply and the power operator environment are effectively improved. Brings great economic benefit and social benefit for enterprises.
Through the description of the above embodiments, those skilled in the art will understand that, for convenience and simplicity of description, only the division of the above functional modules is used as an example, and in practical applications, the above function distribution may be completed by different functional modules according to needs, that is, the internal structure of a specific device is divided into different functional modules to complete all or part of the above described functions.
In the embodiments provided in this application, it should be understood that the disclosed structures and methods may be implemented in other ways. For example, the above-described embodiments with respect to structures are merely illustrative, and for example, a module or a unit may be divided into only one logic function, and may have another division manner in actual implementation, for example, a plurality of units or components may be combined or may be integrated into another structure, or some features may be omitted or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, structures or units, and may be in an electrical, mechanical or other form.
Units described as separate parts may or may not be physically separate, and parts displayed as units may be one physical unit or a plurality of physical units, may be located in one place, or may be distributed to a plurality of different places. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.
In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit.
The integrated unit, if implemented in the form of a software functional unit and sold or used as a stand-alone product, may be stored in a readable storage medium. Based on such understanding, the technical solutions of the embodiments of the present application may be essentially or partially contributed to by the prior art, or all or part of the technical solutions may be embodied in the form of a software product, where the software product is stored in a storage medium and includes several instructions to enable a device (which may be a single chip, a chip, or the like) or a processor (processor) to execute all or part of the steps of the methods of the embodiments of the present application. And the aforementioned storage medium includes: various media capable of storing program codes, such as a usb disk, a removable hard disk, a Read Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk.
The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.
Claims (7)
1. A method for replacing a box type transformer with a low-voltage side in short-time power failure is characterized by comprising the following steps:
s01, firstly, when the box-type transformer is normally powered, arranging a low-voltage temporary mobile power supply near the low-voltage cable branch box;
s02, arranging a low-voltage flexible cable between the low-voltage temporary mobile power supply and the low-voltage cable branch box, and laying the low-voltage flexible cable on a damp-proof canvas or an insulating pad;
s03, connecting a low-voltage bus bar in a box-type transformer low-voltage cable branch box with a low-voltage temporary mobile power supply grid-connected switch TB load side by using a laid flexible cable in a live-line operation mode;
s04, under the condition that the phase sequence is consistent, a grid-connected switch TB is switched on, so that the low-voltage cable branch box is powered by the low-voltage temporary mobile power supply and the box-type transformer at the same time;
s05, after the load transfer is completed, namely after the output current of the low-voltage temporary power supply reaches a preset value, disconnecting the incoming line switch of the low-voltage cable branch box, and switching the power supply of the low-voltage cable branch box to the power supply of the low-voltage temporary mobile power supply by the box-type transformer;
s06, sequentially opening a low-voltage main switch and a high-voltage switch of the box type transformer, and replacing the box type sample transformer in a power failure maintenance mode;
and S07, after the power failure maintenance and replacement of the box type transformer are finished, closing the high-voltage switch and the low-voltage main switch of the box type transformer, after the phase sequence of the two sides of the incoming line switch of the low-voltage cable branch box is checked to be consistent, disconnecting the grid-connected switch TB at the low-voltage temporary mobile power supply, closing the incoming line switch of the low-voltage cable branch box, and recovering power supply after the terminal user experiences short-time power failure in the process.
2. The method for replacing a low-voltage side short-term power failure box type transformer of claim 1, wherein the step S03 comprises: confirming that the low-voltage temporary mobile power supply grid-connected switch TB and the commercial power access switch MB are both in a brake-off state, adopting a live working mode, under the condition that a low-voltage busbar in a low-voltage cable branch box is electrified, connecting the low-voltage cable branch box busbar with a load socket of the grid-connected switch TB on the temporary mobile power supply through a low-voltage flexible cable by using a busbar clamp.
3. The method for replacing a low-voltage side short-term power failure box type transformer of claim 2, wherein the step S04 comprises: starting a low-voltage temporary mobile power supply, closing a temporary mobile power supply outlet switch GB, transmitting power to a low-voltage temporary mobile power supply busbar, performing synchronous detection after checking phase sequence consistency on two sides of a grid-connected switch TB, adjusting voltage difference, frequency and phase angle difference of the low-voltage temporary mobile power supply and the busbar side of a low-voltage cable branch box of a box-type transformer until the grid-connected requirement is met, and then closing the grid-connected switch TB to perform low-voltage load transfer.
4. The method for replacing a low-voltage side short-term power failure box-type transformer according to claim 3, wherein the replacing of the box-type transformer comprises the following steps: disconnecting the incoming line switch of the low-voltage cable branch box, pulling the high-voltage switch, the low-voltage main switch and all the low-voltage outgoing line switches of the box-type transformer open, and performing maintenance and replacement on the box-type transformer after safety measures are taken; after the box-type transformer is completely replaced in a power failure mode, the safety measures are removed, the high-voltage switch, the low-voltage main switch and all the low-voltage outgoing switches of the box-type transformer are sequentially switched on, power is transmitted to the power supply side of the incoming switch of the low-voltage cable branch box, the load side of the incoming switch of the low-voltage cable branch box supplies power to the low-voltage temporary mobile power supply, and the power supply side supplies power to the box-type transformer.
5. The method for replacing a low-voltage side short-term power failure box type transformer of claim 1, wherein the step S07 comprises: checking phase sequences on two sides of a low-voltage cable branch box incoming line switch, if the phase sequences are inconsistent, opening a box type transformer low-voltage outgoing line switch, stopping power to adjust the lapping phase of incoming cables of the low-voltage cable branch box until the phase sequences are consistent, finally opening a low-voltage temporary mobile power supply grid-connected switch, and quickly closing the low-voltage cable branch box incoming line switch to enable the low-voltage cable branch box and branch low-voltage terminal users thereof to switch back to the box type transformer for power supply.
6. The method for replacing the low-voltage side short-time power failure box type transformer of claim 1, wherein when the load of the low-voltage cable branch box is too large and a single low-voltage temporary mobile power supply cannot completely meet the power supply requirement, a plurality of low-voltage temporary mobile power supplies are connected in series at a pre-stage unit of the low-voltage temporary mobile power supply to increase the output capacity and meet the power consumption requirement of a low-voltage cable branch box terminal user.
7. The method of claim 3, wherein when there are a plurality of low voltage cable branch boxes on the low voltage side of the box-type transformer, a plurality of low voltage temporary mobile power sources are distributed, the low voltage temporary mobile power sources and the box-type transformer low voltage cable branch boxes are electrically connected by using the low voltage flexible cables and the converging clamp, and the steps S04 and S05 are performed to switch the power supply of the low voltage cable branch boxes.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110918150.0A CN113851991A (en) | 2021-08-11 | 2021-08-11 | Method for replacing box type transformer with low-voltage side having short-time power failure |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110918150.0A CN113851991A (en) | 2021-08-11 | 2021-08-11 | Method for replacing box type transformer with low-voltage side having short-time power failure |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN113851991A true CN113851991A (en) | 2021-12-28 |
Family
ID=78975686
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110918150.0A Pending CN113851991A (en) | 2021-08-11 | 2021-08-11 | Method for replacing box type transformer with low-voltage side having short-time power failure |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113851991A (en) |
-
2021
- 2021-08-11 CN CN202110918150.0A patent/CN113851991A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN203367955U (en) | Low voltage power cable isolation device | |
| KR20100054948A (en) | By-pass construction method for replacement of pole-top transformer (1phase/3phase) using 1phase portable transformer | |
| CN110994693A (en) | Uninterrupted parallel operation grid-connected system and grid-connected method of medium-voltage power supply vehicle | |
| CN101888070B (en) | 10KV bypass cable operation method | |
| WO2023000585A1 (en) | Low-voltage transformer area load non-power-cut switching system and working method thereof | |
| CN106451220A (en) | Bypass equipment and method for live replacement of equipment on same-tower multi-loop pole tower | |
| CN112310874B (en) | 220V double-charging four-feed direct current system uninterrupted safe replacement method | |
| CN104218457A (en) | Power distribution device and electric master system thereof | |
| CN113851991A (en) | Method for replacing box type transformer with low-voltage side having short-time power failure | |
| CN110224432A (en) | A kind of box-type substation and its microgrid system control method | |
| CN109245291A (en) | The maintenance safety measure method for arranging of the double sectional power supply systems of substation's double-bus | |
| CN113437795B (en) | Mobile box transformer substation vehicle with input voltage automatic switching function | |
| CN113851990A (en) | Method for replacing box-type transformer with low-voltage side completely uninterrupted | |
| CN211266433U (en) | High-voltage cable tapping device | |
| CN103972804A (en) | Outage-free operating method for temporarily obtaining electric power from ring main unit | |
| CN212649106U (en) | AC/DC power supply device | |
| CN114725827A (en) | 10kV line live-line breaker live-line voltage transformer disconnection and connection operation method | |
| KR102332571B1 (en) | An electric power supply method of the control unit for pad mounted type switchgear for underground line | |
| CN209329780U (en) | A kind of plant-grid connection device | |
| CN110445044B (en) | Transformation station transformation method for single-bus operation | |
| CN111697587A (en) | AC/DC power supply device | |
| HRP20210941T1 (en) | Electric vehicle charging station for connecting to high or extra high voltage transmission line and operation method thereof | |
| CN112049728A (en) | Uninterrupted operation system and method based on vehicle-mounted gas turbine generator set | |
| CN112103937A (en) | Direct current emergency transfer box and using method thereof | |
| CN114447918B (en) | Method for re-accessing external power supply to nuclear power plant after black start of power grid |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |