Method and device for replacing double-bus switch cabinet of transformer substation and medium

Abstract

The invention discloses a substation double-bus switch cabinet replacement method and device and a medium. Relates to the technical field of substation power supply, upgrade and reconstruction are implemented in an original switch cabinet position area, single-power-supply operation is avoided, the power failure time is reduced to the maximum extent by gradually transferring loads and stopping a transformer, and continuity and reliability of power supply are guaranteed. Through temporary connection of the contact power cable, dual-power supply of a user is kept, long-time single-bus power supply is avoided, the influence of power supply interruption is minimized, and stable operation of the system is kept. Investment cost can be effectively reduced, many difficult problems of difficult examination and approval, large construction difficulty, high single-power-supply operation safety risk and the like of the renovation land are solved, and operation safety of operation equipment in the renovation period is ensured.

Description

Technical Field

[0001] The present application relates to the technical field of power supply for substations, and in particular to a method, device and medium for replacing a double-bus switch cabinet for a substation. Background Art

[0002] In order to improve the reliability and stability of power supply, and the flexibility of adjusting the power supply operation mode of the power grid, large substations usually adopt a double busbar power supply wiring structure, and the incoming power lines are generally set up with four lines. In some substations, after years of operation, the 35kV double busbar air insulated switchgear has degraded in performance, the knife switch mechanism has deformed, and the busbar switch equipment has frequent failures. It is no longer suitable for overhaul and needs to be completely withdrawn and replaced with a new switchgear for upgrading and transformation. Figure 1 The present invention is a schematic diagram of the principle of a primary system of an existing substation double-bus double-segment power supply system. The substation double-bus double-segment power supply system has four bus sections, namely, I, II, III and IV. When the substation is in normal power supply operation mode, the first transformer connects the I and II bus sections and each feeder line through the 3501 circuit breaker and the corresponding knife switch, the second transformer connects the I and II bus sections and each feeder line through the 3502 circuit breaker and the corresponding knife switch, the third transformer connects the III and IV bus sections and each feeder line through the 3503 circuit breaker and the corresponding knife switch, the fourth transformer connects the III and IV bus sections and each feeder line through the 3504 circuit breaker and the corresponding knife switch, and the I and II bus sections are controlled to supply power to the same feeder line according to the switching control of the knife switch; the III and IV bus sections are supplied power to the same feeder line. The PT (potential transformer) of section I is connected to the bus section I through the isolating knife switch, the PT of section II is connected to the bus section II, the 1# station transformer is connected to the bus section I and the bus section II through its high-voltage side isolating switch, the PT of section III is connected to the bus section III, the PT of section IV is connected to the bus section IV, and the 2# station transformer is connected to the bus section III and the bus section IV through its high-voltage side isolating switch, the bus section I is connected to the bus section III through 3500EI and III sections, the bus section II is connected to the bus section IV through 3500FⅡ and IV sections, the bus section I and the bus section II are connected through the bus tie breaker 3500A, and the bus section III and the bus section IV are connected through the bus tie breaker 3500B. 3500E I and III sections include 3500E section switch cabinet and section isolating cabinet, and 3500FⅡ and IV sections include 3500F section switch cabinet and section isolating cabinet.

[0003] There are generally two methods for overall renewal and renovation of switchgear. One is to replace and renovate at a different location, but a new switch room needs to be built nearby, which requires land approval and civil construction, which will inevitably lead to problems such as increased construction difficulty and increased investment costs. In addition, the transition of 35kV feeder lines (generally power cable lines or lines common to power cables and overhead lines) will also cause a large waste of investment and increase construction difficulty (because the cables may not be long enough, and many cable intermediate boxes need to be made, etc.); the other is to replace and renovate at the original switchgear location, for example, at the location of the 35kV I and II busbar system switchgear, all the switchgear of the 35kV I and II busbar system needs to be dismantled and replaced and renovated in this area, but this renovation method will inevitably cause all electricity users of the power supply system to operate with a single power supply for a long time (only powered by the 35kV III and IV busbar system switchgear), and the entire switchgear upgrade and renovation cycle is long. For some important power supply loads, long-term single power supply operation is unsafe and unreliable, and the operation safety risk is very high.

[0004] Therefore, how to implement upgrading and reconstruction in the original switch cabinet location area and avoid single power supply operation is a technical problem that needs to be solved urgently by people in this field. Summary of the invention

[0005] The purpose of the present application is to provide a method, device and medium for replacing a double-bus switchgear in a substation, so as to implement upgrading and reconstruction in the original switchgear location area and avoid single power supply operation.

[0006] In order to solve the above technical problems, the present application provides a method for replacing a double-bus switch cabinet in a substation, comprising:

[0007] Determine the length to be removed based on the number of GIS switch cabinets to be installed and the size of the GIS switch cabinets;

[0008] Determine the area of ​​the original air switch cabinet including the sectional cabinet to be removed according to the length to be removed;

[0009] When it is detected that the load cable in the feeder switch cabinet of the busbar in the to-be-removed area has been transferred to the standby feeder switch cabinet of the corresponding busbar in the non-to-be-removed area, an electrical connection instruction is sent to establish an electrical connection between the busbar sections I and II and the busbar sections III and IV through the connecting power cable;

[0010] Control the third transformer and the fourth transformer on the bus sections III and IV to stop operating; wherein the low-voltage side switch cabinet of the third transformer is in the area to be dismantled;

[0011] After the first edge switch cabinet connecting the area to be removed with bus sections III and IV is cut off, control the access of the contact power cable;

[0012] Controlling the fourth transformer to supply power to bus sections III and IV;

[0013] Control the first transformer and the second transformer on the bus sections I and II to stop operating, cut off the second edge switch cabinet connecting the area to be demolished with the bus sections I and II, and restore power supply after cutting off;

[0014] When all the switch cabinets in the area to be removed are removed and the GIS switch cabinet to be installed is installed, the GIS switch cabinet is controlled to be powered on.

[0015] As an optional solution, in the above-mentioned substation double bus switch cabinet replacement method, the sending of an electrical connection instruction to establish an electrical connection between bus sections I and II and bus sections III and IV through a connecting power cable includes:

[0016] Sending an electrical connection instruction to establish a connecting power cable, one end of the connecting power cable is connected to the bus sections I and II, and the other end of the connecting power cable is connected to the bus sections III and IV; wherein both ends of the connecting power cable are disconnected and not electrically connected to the bus;

[0017] Correspondingly, the controlling the access of the communication power cable includes:

[0018] Control the access of both ends of the connecting power cable, one end of the connecting power cable is connected to the busbar of section I and section II, and the other end of the connecting power cable is connected to the busbar of section III.

[0019] As an optional solution, in the above-mentioned method for replacing the double-bus switchgear of the substation, the first edge switchgear connected to the busbar sections III and IV in the area to be removed is cut off, including:

[0020] Cut off the electrical connection between the area to be removed and the first edge switch cabinet connected to the busbar sections III and IV;

[0021] An instruction to perform insulation blocking on a first retained switch cabinet located in a non-removal area and connected to the first edge switch cabinet is sent.

[0022] As an optional solution, in the above-mentioned method for replacing the double-bus switchgear of the substation, the controlling the fourth transformer to supply power to the bus sections III and IV includes:

[0023] Removing the grounding wires on both sides of the high and low voltage of the fourth transformer;

[0024] When the withstand voltage test of busbar sections III and IV is passed, the fourth transformer is controlled to supply power to busbar sections III and IV.

[0025] As an optional solution, in the above-mentioned method for replacing the double-bus switchgear of the substation, the first transformer and the second transformer on the bus sections I and II are controlled to stop operating, the second edge switchgear connecting the area to be removed and the bus sections I and II is cut off, and the power supply is restored after the cut-off, including:

[0026] Control the high-voltage side circuit breakers and isolating switches of the first transformer and the second transformer on the busbars of sections Ⅰ and Ⅱ to disconnect respectively;

[0027] Control the power off of busbar sectionalizing cabinets of sections I and III, and busbar sectionalizing cabinets of sections II and IV;

[0028] Cut off the electrical connection between the area to be removed and the second edge switch cabinet connected to the busbar sections I and II;

[0029] When the second edge switch cabinet is removed, an instruction is issued to conduct a withstand voltage test on the busbars of sections I and II;

[0030] After the withstand voltage test is passed, the first transformer and the second transformer are controlled to supply power to the bus section I and the bus section II.

[0031] As an optional solution, in the above-mentioned substation double bus switch cabinet replacement method, when all the switch cabinets in the to-be-removed area are removed and the GIS switch cabinet to be installed is installed, the GIS switch cabinet is controlled to be powered on, including:

[0032] When all switch cabinets in the area to be removed are removed, an instruction is issued to remove the low-voltage side enclosed busbar bridge and wall bushing of the third transformer;

[0033] When the GIS switch cabinet to be installed is installed, an instruction to install the copper tube insulated busbar on the low-voltage side of the third transformer is issued;

[0034] After the second transformer is controlled to be out of service, an instruction is issued to remove the enclosed busbar bridge and wall bushing on the low-voltage side of the second transformer, and an instruction is issued to install the copper tube insulated busbar on the low-voltage side;

[0035] Issue an impact test instruction to carry out impact tests on the busbars of sections III, IV, I and II of the GIS switchgear in sequence;

[0036] Control the third transformer to supply power to the busbar section III of the GIS switch cabinet, and then control the busbar sections IV, I and II of the installed GIS switch cabinet to operate without load;

[0037] When the impact test is passed, an instruction is issued to perform secondary voltage test and secondary phase verification on the bus voltage transformers of sections I, II, III and IV of the GIS switch cabinet under the same power supply condition;

[0038] When the secondary voltage test and phase verification are passed, the busbar circuit breakers and isolating switches of sections I and II of the GIS switch cabinet are controlled to close;

[0039] Monitor whether the circuit operation indicators are normal;

[0040] Control the disconnection of bus tie circuit breakers of sections I and II of GIS switch cabinet, control the disconnection of bus section circuit breakers of sections I and III, and stop the operation of bus section I of GIS switch cabinet;

[0041] Control the second transformer to perform an impact test on the power supply of bus section I;

[0042] Issue a secondary voltage test on the busbar section I of the GIS switchgear; issue a secondary phase check command for the voltage transformers of the busbar sections I and III of the GIS switchgear under different power supplies;

[0043] When the secondary voltage test and phase verification are passed, the busbar section circuit breakers of sections I and III of the GIS switch cabinet are controlled to close;

[0044] Monitor whether the circuit operation indicators are normal;

[0045] Control the GIS switch cabinet to disconnect the busbar section circuit breakers of sections I and III, and run the busbars of the GIS switch cabinet without load for 24 hours;

[0046] When the load of the original air-insulated switchgear feeder line in the area not to be demolished is transferred to the installed GIS switchgear feeder line switchgear line, the GIS switchgear power supply is controlled.

[0047] As an optional solution, in the above-mentioned substation double bus switch cabinet replacement method, when the original air insulated switch cabinet feeder line load in the non-to-be-removed area is transferred to the installed GIS switch cabinet feeder line switch cabinet line, the GIS switch cabinet power supply connection is controlled, including:

[0048] Control the transition of the original air-insulated switchgear feeder load in the non-to-be-removed area to the installed GIS switchgear feeder switchgear;

[0049] Controlling the fourth transformer to stop operating;

[0050] After the closed busbar bridge and wall bushing on the low-voltage side of the fourth transformer are removed and the copper tube insulated busbar on the low-voltage side is installed, the protection device of the fourth transformer is replaced, debugged, and linked tested. After the test is passed, the fourth transformer is operated at no load, and the second transformer, the third transformer, and the fourth transformer are phase checked respectively;

[0051] When the phase analysis is completed, the first transformer is controlled to stop operating;

[0052] After the low-voltage side closed busbar bridge and wall bushing of the first transformer are removed and the low-voltage side copper tube insulated busbar is installed, the first transformer protection device is replaced, debugged, and linked tested. After the test is passed, the first transformer is operated at no load, and the first transformer, the second transformer, the third transformer, and the fourth transformer are respectively phase checked;

[0053] When the phase checking is completed, the GIS switch cabinet is controlled to be powered on.

[0054] In order to solve the above technical problems, the present application also provides a substation double bus switch cabinet replacement device, comprising:

[0055] A size determination module, used to determine the length to be removed according to the number of GIS switch cabinets to be installed and the size of the GIS switch cabinets;

[0056] A selection module is used to determine the area to be removed of the original air switch cabinet including the sectional cabinet according to the length to be removed;

[0057] The transfer contact module is used to send an electrical connection instruction to establish an electrical connection between the bus sections I and II and the bus sections III and IV through the contact power cable when it is detected that the load cable in the feeder switch cabinet of the busbar in the to-be-removed area has been transferred to the standby feeder switch cabinet of the corresponding busbar in the non-to-be-removed area;

[0058] The first area shutdown control module is used to control the shutdown of the third transformer and the fourth transformer on the bus sections III and IV; wherein the low-voltage side switch cabinet of the third transformer is in the area to be removed;

[0059] A contact power access module, used to control the access of the contact power cable after the first edge switch cabinet connecting the area to be removed with the busbar sections III and IV is cut off;

[0060] The first area recovery control module is used to control the fourth transformer to supply power to the bus sections III and IV;

[0061] The second area shutdown and restoration control module is used to control the shutdown of the first transformer and the second transformer on the bus sections I and II, cut off the second edge switch cabinet connecting the area to be removed with the bus sections I and II, and restore power supply after cutting off;

[0062] The replacement and transformation module is used to control the power supply access of the GIS switch cabinet after all the switch cabinets in the area to be demolished are demolished and the GIS switch cabinet to be installed is installed.

[0063] In order to solve the above technical problems, the present application also provides a substation double bus switch cabinet replacement device, comprising:

[0064] Memory for storing computer programs;

[0065] The processor is used to implement the steps of the above-mentioned method for replacing a double-bus switch cabinet in a substation when executing the computer program.

[0066] In order to solve the above technical problems, the present application also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the above-mentioned method for replacing a double bus switch cabinet in a substation are implemented.

[0067] The method for replacing the double-bus switchgear of a substation provided in the present application comprises: determining the length to be removed according to the number of GIS switchgears to be installed and the size of the GIS switchgear; determining the area to be removed of the original air switchgear including the sectionalized cabinet according to the length to be removed; when it is detected that the load cable in the feeder switchgear of the bus in the area to be removed is transferred to the spare feeder switchgear in the corresponding bus area not to be removed, sending an electrical connection instruction to establish an electrical connection between the bus sections I and II and the bus sections III and IV through the connecting power cable; controlling the third transformer on the bus section III and the bus section IV to connect the load cable in the feeder switchgear of the bus in the area to be removed. The fourth transformer of the to-be-removed area is shut down; the low-voltage side switchgear of the third transformer is in the area to be removed; when the first edge switchgear connecting the area to be removed and the busbars of sections III and IV are cut off, the access of the liaison power cable is controlled; the fourth transformer is controlled to supply power to the busbars of sections III and IV; when the first and second transformers on the busbars of sections I and II are shut down, the second edge switchgear connecting the area to be removed and the busbars of sections I and II are cut off and the power supply is restored after the cut-off; when all the switchgears in the area to be removed are removed and the GIS switchgear to be installed is installed, the GIS switchgear is controlled to be connected to the power supply. By gradually transferring the load and shutting down the transformer, the scheme minimizes the power outage time and ensures the continuity of power supply. By temporarily connecting the liaison power cable to maintain power connection, long-term single bus power supply is avoided, the impact of power supply interruption is minimized, and the stable operation of the power supply system is maintained. It can effectively reduce investment costs, solve many difficult problems such as difficult land approval for relocation and transformation, high construction difficulty, and high safety risks of single power supply operation, and ensure the safe operation of equipment during the transformation.

[0068] In addition, the present application also provides a device and a medium, which correspond to the above-mentioned substation double bus switch cabinet replacement method and have the same effect as above. BRIEF DESCRIPTION OF THE DRAWINGS

[0069] In order to more clearly illustrate the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0070] Figure 1 It is a schematic diagram of the principle of a primary system of an existing substation double-bus double-segment power supply system;

[0071] Figure 2 A flowchart of a method for replacing a double-bus switch cabinet in a substation provided in an embodiment of the present application;

[0072] Figure 3 A schematic diagram of the planar structure of a substation double-busbar air-insulated switch upgraded and replaced with a GIS switch cabinet provided in an embodiment of the present application;

[0073] Figure 4 A structural diagram of a substation double bus switch cabinet replacement device provided in an embodiment of the present application;

[0074] Figure 5 A structural diagram of another substation double bus switch cabinet replacement device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0075] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0076] The core of this application is to provide a method, device and medium for replacing a double-bus switch cabinet in a substation.

[0077] In order to enable those skilled in the art to better understand the present application, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0078] In order to improve the reliability of power supply and the flexibility of adjusting the power supply operation mode, the 35kV system of the more important 110kV substation mostly adopts a double-busbar double-segment power supply wiring structure, and the 35kV switchgear is an air-insulated switchgear. The primary system principle diagram of the existing substation double-busbar double-segment power supply system is as follows: Figure 1As shown. In recent years, gas insulated switchgear (GIS) switchgear has been widely used in substation power supply and distribution systems because it uses sulfur hexafluoride (SF6) gas as an insulating medium, has the advantages of small cabinet, small footprint, high operating reliability, maintenance-free, anti-pollution and strong earthquake resistance. Many substations have upgraded and replaced 35kV air-insulated switchgear with 35kV GIS switchgear. However, due to the small space in the substation switch room, the following two transformation methods are adopted. For example, the transformation in a different location faces many difficulties such as land approval, which will greatly increase the transformation cost and cause a huge waste of investment. The transformation method of stopping half of the 35kV busbar system in situ and supplying power with a single power supply (for example, the 35kV I and II busbars are shut down, and the GIS switchgear transformation is implemented in the 35kV I and II busbar areas, which can only be powered by the 35kV III and IV busbars. In this case, the user side is powered by a single power supply), and the user side faces a very high operation safety risk.

[0079] To solve the above problems, this embodiment provides a method for replacing a double bus switch cabinet in a substation, such as Figure 2 As shown, including:

[0080] S11: Determine the length to be removed based on the number of GIS switch cabinets to be installed and the size of the GIS switch cabinets;

[0081] S12: Determine the area to be removed of the original air switch cabinet including the sectional cabinet according to the length to be removed;

[0082] S13: When it is detected that the load cable in the feeder switch cabinet of the busbar in the to-be-removed area has been transferred to the standby feeder switch cabinet of the corresponding busbar in the non-to-be-removed area, an electrical connection instruction is sent to establish an electrical connection between the busbar sections I and II and the busbar sections III and IV through the connecting power cable;

[0083] S14: Control the third transformer and the fourth transformer on the bus sections III and IV to stop operation; the low-voltage side switchgear of the third transformer is in the area to be dismantled;

[0084] S15: After the first edge switch cabinet connecting the area to be removed with the busbar sections III and IV is cut off, the access of the contact power cable is controlled;

[0085] S16: Control the fourth transformer to supply power to bus sections III and IV;

[0086] S17: Control the first transformer and the second transformer on the bus sections I and II to stop operating, cut off the second edge switchgear connecting the area to be demolished with the bus sections I and II, and restore power supply after cutting off;

[0087] S18: When all switch cabinets in the area to be removed are removed and the GIS switch cabinet to be installed is installed, the GIS switch cabinet is controlled to be powered on.

[0088] Figure 3 A schematic diagram of the planar structure of a substation double busbar air insulated switch upgraded and replaced with a GIS switch cabinet is provided in an embodiment of the present application, such as Figure 3 As shown, the 35kV busbar section I and section II have outgoing line loads such as 35kV Chenzhou line, cold rolling line I, Aishan line I, Huanyou line I, powder line, coking line I, and Nanling line I; the 35kV busbar section III and section IV have outgoing line loads such as 35kV Yijiang line, cold rolling line II, coking line VI, Nanling line II, coking line II, and Huanyou line II.

[0089] Step S11 determines the length to be removed according to the number of GIS switch cabinets to be installed and the size of the GIS switch cabinets, ensuring that the GIS switch cabinets can adapt to the existing space layout and avoid insufficient space or space waste.

[0090] Step S12 determines the area to be dismantled of the original air switch cabinet including the segmented cabinet according to the length to be dismantled; identifies and marks the area to be dismantled including the segmented cabinet.

[0091] For example, according to the number and total length of the newly installed 35kV GIS switch cabinets, the 35kV double busbar air insulated switch cabinet including the middle area switch cabinet of the section cabinet is measured to determine the location area of ​​the newly installed 35kV GIS switch cabinet. The new GIS switch cabinet has a total of 31 sides, of which the cabinet width of the 35kV section cabinet is 0.8m, with a total of 4 sides; the other 35kV GIS switch cabinets have a total of 27 sides, with a cabinet width of 0.6m, and the total length of the entire GIG cabinet is 19.4m; the original 35kV double busbar air insulated switch cabinet cabinet is 1.8m wide, and 12 sides need to be removed in the middle, a total of 21.6m, plus 2m of busbar aisle space, a total of 23.6 meters. 23.6-19.4=4.2m. Considering the construction space, the length of the area to be removed is greater than the GIS switch cabinet installation area, and about 2 meters are reserved on both sides. Therefore, it was determined that the area between the 3520 Nanling I line cabinet and the coking 2# station II line cabinet where the air-insulated switch cabinets will be removed is 12 switch cabinets in total, which meets the space requirements.

[0092] Step S13: Load cable transfer in the area to be removed, transfer the load of the busbar in the area to be removed to the spare switch cabinet in the corresponding busbar non-removal area. This ensures the continuity of power supply and reduces the possible power outage time caused by the transformation. After the load transfer is completed, the power connection between the busbar sections I and II and the busbar sections III and IV is established through the connecting power cable.

[0093] Exemplarily, the load in the area where the air-insulated switchgear is to be dismantled is relocated and modified, and a power supply method is adopted in which the load is transferred to the spare cabinets on both sides of the busbar and the load of the feeder line is connected in the cabinet in use.

[0094] Preferably, the cable loads of 3520 Nanling I line and 3531 Jiaohua VI line are shifted and modified. Disconnect the 3520 circuit breaker and its -1, -2, -3 isolating switches of the 3520 Nanling I line cabinet, and the 3517 circuit breaker and its -1, -2, -3 isolating switches of the 3517 Chenzhou line cabinet; disconnect the 3531 circuit breaker and its -1, -2, -3 isolating switches of the 3531 coking VI line cabinet, and disconnect the 3535 circuit breaker and its -1, -2, -3 isolating switches of the 3535 cold rolling II line cabinet; install an insulating partition on the upper busbar side of the -1 isolating switch of the 3520 Nanling I line cabinet, the 3517 Chenzhou line cabinet, the 3531 coking VI line cabinet, and the 3535 cold rolling II line cabinet, and install a set of grounding wires on the load outgoing line side of the -3 isolating switch of each switch cabinet; hang signs of "Stop, high voltage danger!" and "Someone is working, do not close the switch" on the high-voltage switch cabinets of the 3517 Chenzhou line and the 3535 cold rolling II line.

[0095] The load cables in the 3520 Nanling I line cabinet were transformed and transferred to the 3517 Chenzhou line cabinet, and the load cables in the 3531 Coking VI line cabinet were transferred to the 3535 Cold Rolling II line cabinet; the protection settings of the 3517 Chenzhou line cabinet and the 3535 Cold Rolling II line were readjusted and tested.

[0096] Not limited to the above-mentioned feeder line switch cabinet, according to the actual situation on site, the spare switch cabinet on the busbar outside the area to be dismantled can be moved out. When the current transformer ratio is not suitable, the current transformer can be replaced. Generally, the circuit breaker and disconnector of the feeder line cabinet can meet the technical requirements such as rated current.

[0097] For example, a connecting power cable (power cable model is ZR-YJV-26 / 35kV-1 (3×300mm) is laid from the connecting busbar between the 3500A 35kV I and II busbars and the 35kV III or IV busbars of the II line cabinet of the cold rolling station 2#. 2 ), length is 70 meters), cable terminal production, high voltage test, temporarily not connected to the switch cabinets on both sides. This contact cable can be used as an emergency power supply contact line between busbars I, II and busbars III, IV after the functions of 3500E 35kV I, III busbar segmentation and 3500F 35kV II, IV busbar segmentation are destroyed.

[0098] Step S14: The third transformer and the fourth transformer are shut down. The shut down of busbar sections III and IV creates conditions for safely removing old equipment and installing new interconnection cable equipment.

[0099] Step S15: connecting the communication power cable, after the first edge switch cabinet is cut off, connecting the communication power cable to maintain the power connection, thereby minimizing the impact of power outage and maintaining the stable operation of the power supply system.

[0100] Preferably, one end of the connecting power cable is connected to the connecting busbar between the isolating knife switch on the II bus side of the 3500A I, II section bus coupling cabinet and the 3500A I, II section bus coupling circuit breaker, and the other end can be connected to the III section busbar where the II cabinet of the 3536 cold rolling station 2# is located (busbar processing and reconnection of the small busbar on the top of the cabinet are required). The phase of the three-phase power supply voltage should be checked and tested before line wiring.

[0101] Step S16: Power supply is restored, and power is restored to bus sections III and IV through the fourth transformer. Power supply to key areas is quickly restored, reducing the single power supply time for users and reducing operational safety risks.

[0102] Remove the grounding wires on both sides of the high and low voltage of the fourth transformer, test the 35kV III and IV busbars, and after the test is qualified, supply power to the fourth transformer. The fourth transformer supplies power to the 35kV III and IV busbar loads.

[0103] Step S17 is to further shut down the transformer and restore the power supply, shut down the transformers on the busbars of sections I and II, cut off and restore the power supply to the second edge switch cabinet, and allow further transformation work to be carried out without affecting the critical load.

[0104] Step S18: New GIS switch cabinet installation and power supply connection, complete the switch cabinet removal and GIS switch cabinet installation in the area to be removed, and then connect the power supply. The entire replacement process is completed, improving the operating efficiency and reliability of the substation.

[0105] The method for replacing the double-bus switchgear of a substation provided by the embodiment of the present application includes: determining the length to be removed according to the number of GIS switchgears to be installed and the size of the GIS switchgear; determining the area to be removed of the original air switchgear including the sectionalized cabinet according to the length to be removed; when it is detected that the load cable in the feeder switchgear of the bus in the area to be removed is transferred to the spare feeder switchgear in the corresponding bus area not to be removed, sending an electrical connection instruction to establish an electrical connection between the bus sections I and II and the bus sections III and IV through the connecting power cable; controlling the third transformer on the bus section III and the bus section IV to connect the load cable in the feeder switchgear of the bus in the area to be removed. The fourth transformer of the to-be-removed area is shut down; the low-voltage side switchgear of the third transformer is in the area to be removed; when the first edge switchgear connecting the area to be removed with the busbars of sections III and IV is cut off, the access of the liaison power cable is controlled; the fourth transformer is controlled to supply power to the busbars of sections III and IV; when the first transformer on the busbar of section I and the second transformer on the busbar of section II are shut down, the second edge switchgear connecting the area to be removed with the busbars of sections I and II is cut off and the power supply is restored after the cut-off; when all the switchgears in the area to be removed are removed and the GIS switchgear to be installed is installed, the GIS switchgear is controlled to be connected to the power supply. By gradually transferring the load and shutting down the transformer, the scheme minimizes the power outage time and ensures the continuity of power supply. By temporarily connecting the liaison power cable to maintain power connection, long-term single bus power supply is avoided, the impact of power supply interruption is minimized, and the stable operation of the power supply system is maintained. It can effectively reduce investment costs, solve many difficult problems such as difficult land approval for relocation and transformation, high construction difficulty, and high safety risks of single power supply operation, and ensure the safe operation of equipment during the transformation.

[0106] According to the above embodiment, specifically, in the method for replacing a double bus switch cabinet in a substation, sending an electrical connection instruction to establish an electrical connection between bus sections I and II and bus sections III and IV through a connecting power cable includes:

[0107] Send an electrical connection instruction to establish a connecting power cable, one end of the connecting power cable is connected to the bus sections I and II, and the other end of the connecting power cable is connected to the bus sections III and IV; wherein both ends of the connecting power cable are disconnected and not electrically connected to the bus;

[0108] Correspondingly, the access of the control liaison power cable includes:

[0109] The two ends of the control interconnection power cable are connected, one end of the interconnection power cable is connected to the busbar of section I and section II, and the other end of the interconnection power cable is connected to the busbar of section III.

[0110] Before sending the electrical connection command, ensure that the load cables in the feeder switch cabinet of the busbar in the area to be removed have been successfully transferred to the spare feeder switch cabinet in the corresponding busbar non-to-be-removed area.

[0111] Test the transferred system to ensure that the new cabling is connected correctly and that the power supply is stable.

[0112] Send a command to establish a tie power cable that will connect bus sections I and II or bus sections III and IV, depending on which two bus sections need to maintain electrical connection.

[0113] The interconnecting power cables are initially disconnected at both ends to ensure that they cannot be accidentally connected to a live busbar before the connection is established.

[0114] When the interconnecting power cable is ready to be connected, its two ends are controlled to be connected to the corresponding busbar sections. This step requires precise timing control to avoid power outages or equipment damage.

[0115] According to the above embodiment, specifically, in the method for replacing the double bus switch cabinet of a substation, the first edge switch cabinet connected to the bus sections III and IV in the area to be removed is cut off, including:

[0116] Cut off the electrical connection between the area to be removed and the first edge switch cabinet connected to the busbar sections III and IV;

[0117] An instruction to perform insulation blocking on a first retained switch cabinet located in a non-removal area and connected to the first edge switch cabinet is sent.

[0118] Before performing the cutting operation, ensure that all relevant personnel understand the operating procedures and safety measures.

[0119] Confirm that the load in the area to be removed has been successfully transferred to the spare feeder switchgear in the non-removal area. Operators gradually disconnect all electrical connections between the area to be removed and the first edge switchgear connected to the busbars of sections III and IV in accordance with safety regulations. This includes disconnecting circuit breakers, disconnectors, and any related secondary line connections.

[0120] Exemplarily, the high-voltage side circuit breakers and their isolating switches of the third transformer and the fourth transformer are disconnected respectively, and the circuit breakers 3503 on the low-voltage side of the third transformer and the circuit breakers 3504 on the low-voltage side of the fourth transformer and their -1, -2, -3 isolating switches are disconnected respectively; the 3500E 35kV I, III section cabinet 3500E circuit breaker and -1, -2 isolating switches are disconnected, and the 3500F 35kV II, IV section cabinet 3500F circuit breaker and -1, -2 isolating switches are disconnected; the 3534 coking 2# station II line cabinet 3534 circuit breaker and its -1, -2, -3 isolating switches are disconnected, the 3535 cold rolling II line cabinet 3535 circuit breaker and its -1, -2, -3 isolating switches are disconnected, and the 3500B 35kV III, IV section bus tie circuit breaker and its -1, -2 isolating switches are disconnected.

[0121] Verify that there is no voltage in the 3535 cold rolling II line cabinet, 3534 coking 2# station II line cabinet, and 3500B III and IV busbar cabinets. Install a set of grounding wires on the upper busbar side of the -1 isolating knife switch and the lower outgoing line side of the -3 isolating knife switch of the 3534 coking 2# station II line cabinet and the 3535 cold rolling II line cabinet; install a set of grounding wires on the upper busbar side of the -2 isolating knife switch of the 3500B III and IV busbar cabinets, 3500E I and III sectional isolating cabinets, and 3500F II and IV sectional isolating cabinets; install a set of grounding wires on the high and low voltage sides of the third transformer and the fourth transformer respectively.

[0122] Secondly, cut off the 35kV III and IV busbars between the 3534 coking 2# station II line cabinet and the 3535 cold rolling II line cabinet, including the small busbars on the top of the cabinet, communication lines, secondary circuit cables, etc.; cut off the 35kV III and IV busbars between the 3534 coking 2# station II line cabinet and the 3500B III and IV busbars, including the small busbars on the top of the cabinet; disconnect the feed lines inside the 3534 coking 2# station II line cabinet and the external secondary lines.

[0123] Confirm that all electrical connections of the first edge switch cabinet have been completely disconnected, and verify the voltage-free state through testing instruments. Send an insulation plugging instruction to the first retained switch cabinet located in the non-demolition area that is connected to the first edge switch cabinet. The purpose of insulation plugging is to prevent the demolition construction workers from maintaining sufficient safety insulation from the live equipment after the power failure of the busbar sections III and IV, and to ensure safety during the demolition and replacement operations. At the first retained switch cabinet, use appropriate insulating materials for plugging, such as insulating boards, insulating tapes or special insulating plugging devices. Ensure that the plugging is tight and there is no possibility of electrical connection outside the cabinet.

[0124] For example, after dismantling the 3534 coking 2# station II line cabinet, use steel plates to temporarily weld and seal the 3535 cold rolling II line cabinet, and the distance between the steel plate and the live equipment in the cabinet should be greater than 0.6m.

[0125] After the insulation plugging is completed, prepare for the next step, such as the connection of the liaison power cable or further demolition work. During the entire replacement process, the power supply status and safety status of the system are continuously monitored to ensure that any abnormalities can be discovered and handled in a timely manner. Through the above steps, the safety of the substation double bus switch cabinet replacement process can be ensured, while ensuring that the power supply of the non-demolition area is not affected.

[0126] According to the above embodiment, specifically, in the method for replacing the double-bus switch cabinet of a substation, controlling the fourth transformer to supply power to bus sections III and IV includes:

[0127] Remove the grounding wires on both sides of the high and low voltage of the fourth transformer;

[0128] When the withstand voltage test of busbars III and IV is passed, the fourth transformer is controlled to supply power to busbars III and IV.

[0129] Remove the grounding wires on both sides of the high and low voltage of the fourth transformer, test the 35kV III and IV busbars, and after the test is qualified, supply power to the fourth transformer. The fourth transformer supplies power to the 35kV III and IV busbar loads.

[0130] According to the above embodiment, specifically, in the method for replacing the double bus switchgear of a substation, the first transformer and the second transformer on the bus sections I and II are controlled to stop operating, the second edge switchgear connected to the bus sections I and II in the area to be removed is cut off, and the power supply is restored after the cut-off, including:

[0131] Control the high-voltage side circuit breakers and isolating switches of the first transformer and the second transformer on the busbars of sections Ⅰ and Ⅱ to disconnect respectively;

[0132] Control the power off of busbar sectionalizing cabinets of sections I and III, and busbar sectionalizing cabinets of sections II and IV;

[0133] Cut off the electrical connection between the area to be removed and the second edge switch cabinet connected to the busbar sections I and II;

[0134] When the second edge switch cabinet is removed, the instructions for the withstand voltage test of the busbars of sections I and II are issued;

[0135] After the withstand voltage test is passed, the first transformer and the second transformer are controlled to supply power to bus section I and bus section II.

[0136] Confirm the load conditions of the first and second transformers and prepare for shutdown operations. Control the disconnection of the high-voltage side circuit breakers and isolating switches. Operators gradually disconnect the circuit breakers and isolating switches on the high-voltage sides of the first and second transformers in accordance with regulations. Ensure that the connection between the transformer and the power grid is safely isolated after the disconnection operation. Control the power-off operation of the busbar sectionalizers of sections I and III, and the busbar sectionalizers of sections II and IV to ensure the safe isolation of the area to be demolished from the power grid.

[0137] Exemplarily, disconnect the circuit breakers and isolating switches on the high-voltage side of the first transformer and the second transformer respectively, disconnect the circuit breakers and -1, -2, -3 isolating switches on the low-voltage side 3501 of the first transformer and the low-voltage side 3502 of the second transformer respectively, disconnect the circuit breaker 3520 of the 3520 Nanling I line cabinet and its -1, -2, -3 isolating switches, disconnect the circuit breaker 3519 of the 3519 coking I line cabinet and its -1, -2, -3 isolating switches; check and confirm that the 3500E 35kV I and III section cabinets and the 3500F 35kV II and IV section cabinets have all been powered off and disconnected.

[0138] Furthermore, disconnect all electrical connections of the second edge switchgear connected to the area to be removed and the busbars of sections I and II, including circuit breakers and isolating switches. After ensuring that all electrical connections have been disconnected, safely remove the second edge switchgear.

[0139] For example, verify that there is no voltage in the 3519 Coking I Line Cabinet, 3520 Nanling I Line Cabinet, and 3500E Sectioned Isolation Cabinet; install a set of grounding wires on the upper busbar side of the -1 isolating switch and the lower outgoing line side of the -3 isolating switch of the 3520 Nanling I Line Cabinet and 3519 Coking I Line Cabinet; check and confirm that a set of grounding wires have been installed on the upper busbar side of the -2 isolating switch of the 3500E I and III sectioned isolation cabinets and the 3500F II and IV sectioned switch cabinets; install a set of grounding wires on the high and low voltage sides of the first transformer and the second transformer. Secondly, cut off the 35kV section I and section II busbars between the 3519 Coking I line cabinet and the 3520 Nanling I line cabinet, including the small busbar on the cabinet top; cut off the 35kV section I and section II busbars between the 3520 Nanling I line cabinet and the 3500E section switch cabinet, including the small busbar on the cabinet top, communication lines, secondary circuit cables, etc.; disconnect the feeder lines in the 3520 Nanling I line cabinet and the external secondary lines.

[0140] Dismantle the 3520 Nanling I line cabinet, and temporarily weld and seal the 3519 coking I line cabinet with steel plates. The distance between the steel plates and the live parts should be greater than 0.6m; conduct a busbar withstand voltage test.

[0141] Issue an instruction to conduct a withstand voltage test on bus sections I and II to verify the insulation strength of the bus system. Perform a withstand voltage test on bus sections I and II in accordance with the instruction to ensure the safety of the system before re-powering. Evaluate the withstand voltage test results to confirm that bus sections I and II meet the safety power supply standards. After the withstand voltage test is passed, control the first transformer and the second transformer to re-power bus sections I and II.

[0142] The safety measures were removed and a withstand voltage test was carried out on the 35kV I and II sections of the busbars. After the test was passed, the first transformer and the second transformer energized the 35kV I and II sections of the busbars.

[0143] According to the above embodiment, specifically, in the method for replacing the double-bus switchgear in the substation, when all the switchgears in the area to be removed are removed and the GIS switchgear to be installed is installed, controlling the power supply access of the GIS switchgear includes:

[0144] When all switchgears in the area to be removed are removed, an instruction is issued to remove the low-voltage side enclosed busbar bridge and wall bushing of the third transformer;

[0145] When the GIS switchgear to be installed is installed, an instruction is issued to install the copper tube insulated busbar on the low-voltage side of the third transformer;

[0146] After the second transformer is shut down, an instruction is issued to remove the closed busbar bridge and wall bushing on the low-voltage side of the second transformer, and an instruction is issued to install the copper tube insulated busbar on the low-voltage side;

[0147] Issue an impact test instruction to carry out impact tests on the busbars of sections III, IV, I and II of the GIS switchgear in sequence;

[0148] Control the third transformer to supply power to the busbar section III of the GIS switchgear, and then control the busbar sections IV, I, and II of the installed GIS switchgear to operate without load;

[0149] First, close the 3503 circuit breaker on the 35kV side of the 3# main transformer, and then control the bus tie circuit breakers and their isolating switches of sections III and IV, the bus section circuit breakers and their isolating switches of sections I and III, and the bus section circuit breakers and their isolating switches of sections II and IV respectively.

[0150] When the impact test is passed, an instruction is issued to conduct secondary voltage test and secondary phase verification under the same power supply condition on the bus voltage transformers of Section I, Section II, Section III and Section IV of the GIS switch cabinet;

[0151] When the secondary voltage test and phase verification are passed, the busbar circuit breakers and isolating switches of sections I and II of the GIS switch cabinet are controlled to close;

[0152] Monitor whether the circuit operation indicators are normal;

[0153] Control the disconnection of bus tie circuit breakers of sections I and II of GIS switch cabinet, control the disconnection of bus section circuit breakers of sections I and III, and stop the operation of bus section I of GIS switch cabinet;

[0154] Control the second transformer to carry out impact test on the power supply of bus section I;

[0155] Issue a secondary voltage test on the busbar section I of the GIS switchgear; issue a secondary phase check command for the voltage transformers of the busbar sections I and III of the GIS switchgear under different power supplies;

[0156] When the secondary voltage test and phase verification are passed, the busbar section circuit breakers of sections I and III of the GIS switch cabinet are controlled to close;

[0157] Monitor whether the circuit operation indicators are normal;

[0158] Control the circuit breakers of busbar sectionalizers I and III of GIS switchgear to disconnect, and each busbar of GIS switchgear runs without load;

[0159] When the load of the original air-insulated switchgear feeder line in the area not to be demolished is transferred to the installed GIS switchgear feeder line switchgear line, the GIS switchgear power supply is controlled.

[0160] In this embodiment, after all switch cabinets in the area not to be demolished are demolished, an instruction to dismantle the enclosed busbar bridge and wall bushing of the third transformer is issued.

[0161] For example, the 12 high-voltage switch cabinets between the 3500EⅠ, Ⅲ segmented isolation cabinets and the 3500B Ⅲ, Ⅳ busbar cabinets are dismantled and transported; the closed busbar bridge and wall bushing on the low-voltage side of the third transformer are dismantled. Priority is given to plugging the holes from the low-voltage side of the original third transformer to the 35kV distribution room. Before dismantling, the drawings should be checked first, the secondary lines should be thoroughly checked (bus differential, main transformer low-voltage side, connection), the busbars and cabinet bushings should be dismantled, and all external secondary lines in the switch cabinet should be dismantled. Prevent the occurrence of protection malfunction accidents when the secondary lines are dismantled.

[0162] Confirm that the GIS switch cabinet has been installed and all connections and accessories meet the technical specifications. For example, the foundation and floor slab of the original air switch cabinet are removed, the steel beams at the new GIS switch cabinet are built, and the foundation is made. Before construction, the cables need to be safely protected, protective brackets are set up above the cables, and fire blankets and glass magnesium boards are installed; other operating switch cabinets are dust-proofed and fenced with temporary barriers of not less than 1.5m. The installation should be firm and reliable, and a signboard with the words "Stop, high voltage danger" should be hung. At the same time, the voltage paralleling and switching devices, telecontrol communication screen devices, and DC screens of the new GIS cabinets are replaced; the power UPS (capacity of 15kVA) is installed, and the microcomputer five-protection simulation screen is installed; the primary and secondary cables are laid.

[0163] Issue the installation instruction of the copper tube insulated busbar on the low voltage side of the third transformer to ensure that the newly installed GIS switchgear is compatible with the existing system. Specifically, the 35kV GIS switchgear is in place and installed, and the copper tube insulated busbar on the low voltage side of the third transformer is installed. Priority is given to ensuring the construction period. On-site measurements are carried out twice before and after the installation of the GIS switchgear. The manufacturer makes the copper tube insulated busbar in advance. The third transformer protection device is replaced, debugged, and linked. The power supply department accepts the new 35kV GIS switchgear busbar system.

[0164] The second transformer was shut down, and an order was issued to dismantle the closed busbar bridge and wall bushing on the low-voltage side and install the copper tube insulated busbar on the low-voltage side. Specifically, the second transformer was shut down, the closed busbar bridge and wall bushing on the low-voltage side of the second transformer were dismantled, the holes from the low-voltage side of the original second transformer to the 35kV distribution room were sealed, and the copper tube insulated busbar on the low-voltage side of the second transformer was installed. Priority was given to ensuring the construction period. On-site measurements were conducted twice before and after the GIS switch cabinet was installed in place, and the manufacturer made the copper tube insulated busbar in advance; the second transformer protection device was replaced, debugged, and linked tested. The 35kV I and II busbar loads are powered by the first transformer.

[0165] Control the third transformer to supply power to the busbar section III of the GIS switchgear, and then supply power to the busbar sections I, II, III, and IV of the installed GIS switchgear for no-load operation. First, put the corresponding protection pressure plates of the second transformer and the third transformer into operation to supply power to the second transformer and the third transformer. Close the high-voltage side circuit breaker of the second transformer to supply power to the second transformer. Close the high-voltage side circuit breaker of the third transformer to supply power to the third transformer. The second transformer and the third transformer are running at no-load. Check that the sound, temperature, signal indication and external components of the main transformer and the 35kV tube bus are normal, and the excitation inrush current should not cause the protection to malfunction. After the power supply is completed and the inspection is normal, open the neutral point grounding knife switch of the second transformer and the neutral point grounding knife switch of the third transformer respectively. Put the corresponding protection plates of 35kV bus coupler, 35kV segment and 35kV four-section bus into operation, close the 3503-1 isolating switch on the 35kV side of the third transformer, and make the 3503 circuit breaker of the third transformer hot standby for 35kV section III bus; change the 35kV bus coupler 3500A, 3500B circuit breakers and 35kV segment 3500E, 3500F circuit breakers from cold standby state to hot standby state, and put the four-section 35kV bus PT and lightning arrester into operation respectively, that is, close the 35kV section I bus PT3581-1 isolating switch, section II bus PT3582-2 isolating switch, section III bus PT3583-1 isolating switch, section IV bus PT section bus PT3584-2 isolating switch.

[0166] Issue an impulse test command to conduct an impulse test on the busbars of Section III, Section IV, Section I, and Section II of the GIS switchgear in turn to verify the stability of the system. Close the -1 disconnector of all 35kV outgoing switchgears. Close the 3503 circuit breaker on the 35kV side of the third transformer, supply power to the 35kV III section bus of the GIS switch cabinet, impact it once, and observe whether all indications are normal; supply power to the 35kV IV section bus of the GIS switch cabinet from the 35kV III section bus via the 3500B III and IV section bus tie circuit breakers, impact it once, and observe whether all indications are normal; supply power to the 35kV I section bus of the GIS switch cabinet from the 35kV III section bus via the 3500E I and III section bus section circuit breakers, impact it once, and observe whether all indications are normal; supply power to the 35kV II section bus of the GIS switch cabinet from the 35kV IV section bus via the 3500F II and IV section bus section circuit breakers, impact it once, and observe whether all indications are normal.

[0167] When the impact test is passed, a secondary voltage test and a secondary phase check instruction are issued to the bus voltage transformers of Section I, Section II, Section III, and Section IV of the GIS switch cabinet under the same power supply condition.

[0168] When the secondary voltage test and phase verification are passed, the busbar circuit breakers and isolating switches of sections I and II of the GIS switch cabinet are controlled to close;

[0169] Monitor whether the circuit operation indicators are normal;

[0170] The PT secondary voltage on the 35kV side of the third transformer was measured and found to be qualified; the PT secondary voltage on the 35kV Ⅰ, Ⅱ, Ⅲ and Ⅳ busbars was measured and found to be qualified; the secondary phase check was performed on the PT on the 35kV Ⅰ, Ⅱ, Ⅲ and Ⅳ busbars under the same power supply condition.

[0171] When the phase test is passed, control the bus tie circuit breakers of section I and section II to close, monitor whether the circuit operation indicators are normal, and ensure the stability and safety of the system under power supply. Close the 35kV 3500A section I and II bus tie circuit breakers, run the 35kV four-section bus in parallel, and observe whether all indicators are normal.

[0172] Preferably, the metering secondary voltage values ​​measured at the 35kV voltage parallel and measurement and control panels Ⅰ and Ⅱ and at the power supply side of the 35kV bus PT secondary voltage small circuit breaker are both 60V, and the measuring protection secondary voltage values ​​are both 60V; the phases of the measured secondary voltages are measured as Ua leading Ub by 120°, Ub leading Uc by 120°, and Uc leading Ua by 120°, respectively; the phases of the measured protection secondary voltages are measured as Ua leading Ub by 120°, Ub leading Uc by 120°, and Uc leading Ua by 120°, respectively; the voltages of the open delta windings of the four-section bus PT are all zero.

[0173] In addition, it is measured that the voltage values ​​between the same phases of the three-phase voltage Ua, Ub, and Uc of each bus PT secondary metering (measurement and protection) are all zero, and the voltage values ​​between the different phases are all about 105V (for example, 105V±3V); when the above test results are obtained, it can be further indicated that the phase tests of the three-phase voltage of the PT secondary metering (measurement and protection) of each section of the bus are correct and are in positive phase sequence.

[0174] The non-demolition area section I was stopped from running to prepare for further testing and operation. The 35kV 3500AⅠ,Ⅱ busbars and 35kV 3500E Ⅰ,Ⅲ busbar section breakers were disconnected, and the 35kVⅠ busbar was shut down.

[0175] Control the second transformer to conduct an impact test on the power supply of bus section I to ensure the continuity and reliability of power supply. Control the closing and opening of the circuit breakers of the bus section cabinets of sections I and III to monitor the corresponding circuit operation indicators. Close the 3502-1 disconnector and 3502 circuit breaker on the 35kV side of the second transformer in sequence, supply power to the 35kV bus section I, impact once, and observe whether all indicators are normal; measure the secondary voltage of the 35kV bus section I PT to be qualified; perform secondary phase verification under the condition of different power supply of 35kV I and III bus PT; close the 3500E circuit breaker of 35kV I and III sections, close the loop, and observe whether all indicators are normal.

[0176] After completing the impact test and phase verification, control each busbar to run at no load to further verify the stability of the system. Disconnect the 35kV 3500E I and III busbar section breakers, and run each 35kV busbar at no load for 24 hours.

[0177] When the load of the original air-insulated switchgear feeder line in the area to be removed is transferred to the installed GIS switchgear feeder line switchgear line, the GIS switchgear is controlled to be powered on. After confirming that all tests and operations are normal, the GIS switchgear is controlled to be officially powered on to complete the entire replacement process.

[0178] Control the disconnection of bus tie circuit breakers of sections I and II of the GIS switch cabinet, and control the disconnection of bus section circuit breakers of sections I and III, and stop the operation of bus section I of the GIS switch cabinet;

[0179] Control the second transformer to carry out impact test on the busbar power supply of Section I of the GIS switch cabinet;

[0180] Issue a secondary voltage test on the busbar section I of the GIS switchgear; issue a secondary phase check command for the voltage transformers of the busbar sections I and III of the GIS switchgear under different power supplies;

[0181] When the secondary voltage test and phase verification are passed, the busbar section circuit breakers of sections I and III of the GIS switch cabinet are controlled to close;

[0182] Monitor whether the circuit operation indicators are normal;

[0183] Control the circuit breakers of busbar sectionalizers I and III of GIS switchgear to disconnect, and each busbar of GIS switchgear runs without load for 24 hours;

[0184] When the load of the original air-insulated switchgear feeder line in the area not to be demolished is transferred to the installed GIS switchgear feeder line switchgear line, the GIS switchgear power supply is controlled.

[0185] According to the above embodiment, specifically, in the method for replacing the double-bus switchgear of a substation, after the load of the feeder line of the original air-insulated switchgear in the non-to-be-removed area is transferred to the feeder line switchgear line of the installed GIS switchgear, the power supply access of the GIS switchgear is controlled, including:

[0186] Control the transition of the original air-insulated switchgear feeder load in the non-to-be-removed area to the installed GIS switchgear feeder switchgear;

[0187] Control the fourth transformer to shut down;

[0188] When the closed busbar bridge and wall bushing on the low-voltage side of the fourth transformer are removed and the copper tube insulated busbar on the low-voltage side is installed, the protection device of the fourth transformer is replaced, debugged, and linked tested. After the test is qualified, the fourth transformer is operated at no load, and the second transformer, the third transformer, and the fourth transformer are phase checked respectively;

[0189] When the phase analysis is completed, the first transformer is controlled to stop operating;

[0190] When the closed busbar bridge and wall bushing on the low-voltage side of the first transformer are removed and the copper tube insulated busbar on the low-voltage side is installed, the protection device of the fourth transformer is replaced, debugged, and linked tested. After the test is qualified, the fourth transformer is operated at no load, and the phases of the first transformer, the second transformer, the third transformer, and the fourth transformer are checked respectively;

[0191] When the phase checking is completed, the GIS switch cabinet is controlled to be powered on.

[0192] Ensure that the GIS switchgear feeder switchgear has been installed and tested, and is ready to receive the feeder load of the original air-insulated switchgear. Control the feeder load of the original air-insulated switchgear in the area to be removed to gradually transition to the installed GIS switchgear feeder switchgear. Specifically, the 35 kV GIS system I, II, III, and IV busbars operate normally without load, and the power supply voltage test and phase verification are correct. The feeder load of the 35kV air-insulated switchgear is transitioned to the 35kV GIS feeder switchgear. 35kV Chenzhou Line, Yijiang Line, Cold Rolling II Line, Coking VI Line, Nanling II Line, Coking II Line; Huanyou II Line, Cold Rolling I Line, Aishan I Line; Huanyou I Line, Powder Line, Coking I Line, Nanling I Line. During the transition transformation, the cables of some 35kV feeder switchgear were not long enough, and measurements have been made in advance to prepare cable intermediate boxes. According to the transition plan node arrangement, two feeder lines per day, a total of 13 feeder lines, are transitioned one by one. Try to shorten the transition time and reduce the risk of single power supply operation of the power supply line. Complete the production and installation of 35kV cold shrink cable terminals, 35kV cold shrink cable intermediate terminals, and 35kV KP cable terminals. During the transition transformation period: the first transformer and the fourth transformer carry the original 35kVⅠ, Ⅲ busbars and each outgoing line; the second transformer and the third transformer carry the new 35kVⅠ, Ⅲ busbars and each outgoing line.

[0193] After the load transition is completed, the fourth transformer is shut down to prepare for the replacement and transformation of the low-voltage side of the fourth transformer. The closed busbar bridge and wall bushing of the fourth transformer are removed, and the copper tube insulated busbar on the low-voltage side is installed.

[0194] Shut down the fourth transformer. Remove the enclosed busbar bridge and wall bushing of the fourth transformer, and seal the hole from the low-voltage side of the original fourth transformer to the 35kV distribution room. Install the busbar on the low-voltage side of the fourth transformer, replace, debug, and conduct linkage tests on the protection device of the fourth transformer. After passing the test, run it at no load.

[0195] The second transformer, the third transformer and the fourth transformer are respectively checked for phase to ensure that the phases of their power supply voltages are consistent.

[0196] The second transformer, the third transformer and the fourth transformer were phase checked. After the phase checking was correct, the entire 35kV system was put into normal operation.

[0197] After the phase check is completed, the first transformer is shut down to prepare for the replacement and transformation of the low-voltage side of the first transformer. The enclosed busbar bridge and wall bushing of the first transformer are removed, and the copper tube insulated busbar on the low-voltage side is installed.

[0198] Shut down the first transformer, dismantle the enclosed busbar bridge and wall bushing of the first transformer, seal the holes from the low-voltage side of the original first transformer to the 35kV distribution room, install the busbar on the low-voltage side of the first transformer, replace, debug and conduct linkage tests on the protection device of the first transformer, and operate it at no-load after passing the tests.

[0199] Perform phase checking on the first transformer, second transformer, third transformer, and fourth transformer to ensure that the power supply voltage phases of all transformers are consistent. After all phase checking tests are completed, perform a final system check to ensure that all equipment and connections meet power supply requirements. Control the power supply connection of the GIS switch cabinet and start transmitting power to the grid.

[0200] The phases of the first transformer, the second transformer, the third transformer and the fourth transformer were checked. After the phases were checked correctly, the entire 35kVGIS switchgear system was put into normal operation.

[0201] In the above embodiments, the substation double bus switch cabinet replacement method is described in detail, and the present application also provides a corresponding embodiment of the substation double bus switch cabinet replacement device. It should be noted that the present application describes the embodiments of the device part from two perspectives, one is based on the functional module perspective, and the other is based on the hardware perspective.

[0202] From the perspective of functional modules, Figure 4 A structural diagram of a substation double bus switch cabinet replacement device provided in an embodiment of the present application, such as Figure 4 As shown, a substation double bus switch cabinet replacement device comprises:

[0203] A size determination module 21, used to determine the length to be removed according to the number of GIS switch cabinets to be installed and the size of the GIS switch cabinets;

[0204] A selection module 22 is used to determine the area to be removed of the original air switch cabinet including the sectional cabinet according to the length to be removed;

[0205] The transfer contact module 23 is used to send an electrical connection instruction to establish an electrical connection between the bus sections I and II and the bus sections III and IV through the contact power cable when it is detected that the load cable in the feeder switch cabinet of the bus to be removed is transferred to the standby feeder switch cabinet of the corresponding bus area not to be removed;

[0206] The first area outage control module 24 is used to control the third transformer and the fourth transformer on the bus sections III and IV to shut down; wherein the low-voltage side switch cabinet of the third transformer is in the area to be removed;

[0207] The contact power access module 25 is used to control the access of the contact power cable after the first edge switch cabinet connecting the area to be removed with the busbar sections III and IV is cut off;

[0208] The first area recovery control module 26 is used to control the fourth transformer to supply power to the bus sections III and IV;

[0209] The second area shutdown and restoration control module 27 is used to control the shutdown of the first transformer and the second transformer on the bus sections I and II, cut off the second edge switch cabinet connected to the area to be removed and the bus sections I and II, and restore power supply after cutting off;

[0210] The replacement and transformation module 28 is used to control the power supply connection of the GIS switch cabinet after all the switch cabinets in the area to be removed are removed and the GIS switch cabinet to be installed is installed.

[0211] Since the embodiments of the apparatus part correspond to the embodiments of the method part, please refer to the description of the embodiments of the method part for the embodiments of the apparatus part, which will not be repeated here.

[0212] Figure 5 A structural diagram of another substation double bus switch cabinet replacement device provided in an embodiment of the present application, such as Figure 5 As shown, the substation double bus switch cabinet replacement device includes: a memory 30, for storing a computer program;

[0213] The processor 31 is used to implement the steps of the method for obtaining user operation habit information in the above embodiment (substation double bus switch cabinet replacement method) when executing the computer program.

[0214] The substation double-bus switch cabinet replacement device provided in this embodiment may include but is not limited to a smart phone, a tablet computer, a laptop computer or a desktop computer.

[0215] Among them, the processor 31 may include one or more processing cores, such as a 4-core processor, an 8-core processor, etc. The processor 31 may be implemented in at least one hardware form of a digital signal processor (DSP), a field-programmable gate array (FPGA), and a programmable logic array (PLA). The processor 31 may also include a main processor and a coprocessor. The main processor is a processor for processing data in the awake state, also known as a central processing unit (CPU); the coprocessor is a low-power processor for processing data in the standby state. In some embodiments, the processor 31 may be integrated with a graphics processing unit (GPU), and the GPU is responsible for rendering and drawing the content to be displayed on the display screen. In some embodiments, the processor 31 may also include an artificial intelligence (AI) processor, which is used to process computing operations related to machine learning.

[0216] The memory 30 may include one or more computer-readable storage media, which may be non-transitory. The memory 30 may also include a high-speed random access memory, and a non-volatile memory, such as one or more disk storage devices, flash memory storage devices. In this embodiment, the memory 30 is at least used to store the following computer program 301, wherein, after the computer program is loaded and executed by the processor 31, it can implement the relevant steps of the substation double bus switch cabinet replacement method disclosed in any of the aforementioned embodiments. In addition, the resources stored in the memory 30 may also include an operating system 302 and data 303, etc., and the storage method may be temporary storage or permanent storage. Among them, the operating system 302 may include Windows, Unix, Linux, etc. Data 303 may include but is not limited to data involved in implementing the substation double bus switch cabinet replacement method, etc.

[0217] In some embodiments, the substation double bus switch cabinet replacement device may also include a display screen 32 , an input and output interface 33 , a communication interface 34 , a power supply 35 and a communication bus 36 .

[0218] Those skilled in the art will understand that Figure 5 The structure shown in the figure does not constitute a limitation on the substation double bus switch cabinet replacement device, and may include more or fewer components than those shown in the figure.

[0219] The substation double-bus switch cabinet replacement device provided in the embodiment of the present application includes a memory and a processor. When the processor executes the program stored in the memory, it can implement the following method: a substation double-bus switch cabinet replacement method.

[0220] Finally, the present application also provides an embodiment corresponding to a computer-readable storage medium. The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps described in the embodiment of the method for replacing a double-bus switch cabinet in a substation are implemented.

[0221] It is understandable that if the method in the above embodiment is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), disk or optical disk and other media that can store program code.

[0222] The computer-readable storage medium provided in this embodiment stores a computer program, and when a processor executes the program, the following method can be implemented: a method for replacing a double-bus switch cabinet in a substation.

[0223] The above is a detailed introduction to the method, device and medium for replacing the double bus switch cabinet of the substation provided by the present application. The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same and similar parts between the embodiments can be referenced to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part description. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the scope of protection of the claims of the present application.

[0224] It should also be noted that, in this specification, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the statement "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

Claims

1. A method for replacing a double bus switch cabinet in a substation, characterized in that: include: Determine the length to be removed based on the number of GIS switch cabinets to be installed and the size of the GIS switch cabinets; Determine the area of ​​the original air switch cabinet including the sectional cabinet to be removed according to the length to be removed; When it is detected that the load cable in the feeder switch cabinet of the busbar in the to-be-removed area has been transferred to the standby feeder switch cabinet of the corresponding busbar in the non-to-be-removed area, an electrical connection instruction is sent to establish an electrical connection between the busbar sections I and II and the busbar sections III and IV through the connecting power cable; Control the third transformer and the fourth transformer on the bus sections III and IV to stop operating; wherein the low-voltage side switch cabinet of the third transformer is in the area to be dismantled; After the first edge switch cabinet connecting the area to be removed with bus sections III and IV is cut off, control the access of the contact power cable; Controlling the fourth transformer to supply power to bus sections III and IV; Control the first transformer and the second transformer on the bus sections I and II to stop operating, cut off the second edge switch cabinet connecting the area to be demolished with the bus sections I and II, and restore power supply after cutting off; When all the switch cabinets in the area to be removed are removed and the GIS switch cabinet to be installed is installed, the GIS switch cabinet is controlled to be powered on.

2. The method for replacing a double bus switch cabinet of a substation according to claim 1, characterized in that: The sending of the electrical connection instruction to establish the electrical connection between the bus sections I and II and the bus sections III and IV through the interconnecting power cable comprises: Sending an electrical connection instruction to establish a connecting power cable, one end of the connecting power cable is connected to the bus sections I and II, and the other end of the connecting power cable is connected to the bus sections III and IV; wherein both ends of the connecting power cable are disconnected and not electrically connected to the bus; Correspondingly, the controlling the access of the communication power cable includes: Control the access of both ends of the connecting power cable, one end of the connecting power cable is connected to the busbar of section I and section II, and the other end of the connecting power cable is connected to the busbar of section III.

3. The method for replacing a double bus switch cabinet of a substation according to claim 1, characterized in that: The first edge switch cabinet connecting the area to be removed and the busbar sections III and IV is cut off, including: Cut off the electrical connection between the area to be removed and the first edge switch cabinet connected to the busbar sections III and IV; An instruction to perform insulation blocking on a first retained switch cabinet located in a non-removal area and connected to the first edge switch cabinet is sent.

4. The method for replacing a double bus switch cabinet of a substation according to claim 1, characterized in that: The controlling the fourth transformer to supply power to bus sections III and IV includes: Removing the grounding wires on both sides of the high and low voltage of the fourth transformer; When the withstand voltage test of busbar sections III and IV is passed, the fourth transformer is controlled to supply power to busbar sections III and IV.

5. The method for replacing a double bus switch cabinet of a substation according to claim 1, characterized in that: Control the first transformer and the second transformer on the bus section I and II to stop operating, cut off the second edge switch cabinet connecting the area to be removed with the bus section I and II, and restore power supply after cutting off, including: Control the high-voltage side circuit breakers and isolating switches of the first transformer and the second transformer on the busbars of sections Ⅰ and Ⅱ to disconnect respectively; Control the power off of busbar sectionalizing cabinets of sections I and III, and busbar sectionalizing cabinets of sections II and IV; Cut off the electrical connection between the area to be removed and the second edge switch cabinet connected to the busbar sections I and II; When the second edge switch cabinet is removed, an instruction is issued to conduct a withstand voltage test on the busbars of sections I and II; After the withstand voltage test is passed, the first transformer and the second transformer are controlled to supply power to the bus section I and the bus section II.

6. The method for replacing a double bus switch cabinet in a substation according to claim 1, characterized in that: When all switch cabinets in the area to be removed are removed and the GIS switch cabinet to be installed is installed, the GIS switch cabinet is controlled to be powered on, including: When all switch cabinets in the area to be removed are removed, an instruction is issued to remove the low-voltage side enclosed busbar bridge and wall bushing of the third transformer; When the GIS switch cabinet to be installed is installed, an instruction to install the copper tube insulated busbar on the low-voltage side of the third transformer is issued; After the second transformer is controlled to be out of service, an instruction is issued to remove the enclosed busbar bridge and wall bushing on the low-voltage side of the second transformer, and an instruction is issued to install the copper tube insulated busbar on the low-voltage side; Issue an impact test instruction to carry out impact tests on the busbars of sections III, IV, I and II of the GIS switchgear in sequence; Control the third transformer to supply power to the busbar section III of the GIS switch cabinet, and then control the busbar sections IV, I and II of the installed GIS switch cabinet to operate without load; When the impact test is passed, an instruction is issued to perform secondary voltage test and secondary phase verification on the bus voltage transformers of sections I, II, III and IV of the GIS switch cabinet under the same power supply condition; When the secondary voltage test and phase verification are passed, the busbar circuit breakers and isolating switches of sections I and II of the GIS switch cabinet are controlled to close; Monitor whether the circuit operation indicators are normal; Control the disconnection of bus tie circuit breakers of sections I and II of GIS switch cabinet, control the disconnection of bus section circuit breakers of sections I and III, and stop the operation of bus section I of GIS switch cabinet; Control the second transformer to perform an impact test on the power supply of bus section I; Issue a secondary voltage test on the busbar section I of the GIS switchgear; issue a secondary phase check command for the voltage transformers of the busbar sections I and III of the GIS switchgear under different power supplies; When the secondary voltage test and phase verification are passed, the busbar section circuit breakers of sections I and III of the GIS switch cabinet are controlled to close; Monitor whether the circuit operation indicators are normal; Control the GIS switch cabinet to disconnect the busbar section circuit breakers of sections I and III, and run the busbars of the GIS switch cabinet without load for 24 hours; When the load of the original air-insulated switchgear feeder line in the area not to be demolished is transferred to the installed GIS switchgear feeder line switchgear line, the GIS switchgear power supply is controlled.

7. The method for replacing a double bus switch cabinet in a substation according to claim 6, characterized in that: When the load of the original air-insulated switchgear feeder line in the non-to-be-removed area is transferred to the installed GIS switchgear feeder line switchgear line, the GIS switchgear power supply access is controlled, including: Control the transition of the original air-insulated switchgear feeder load in the non-to-be-removed area to the installed GIS switchgear feeder switchgear; Controlling the fourth transformer to stop operating; After the closed busbar bridge and wall bushing on the low-voltage side of the fourth transformer are removed and the copper tube insulated busbar on the low-voltage side is installed, the protection device of the fourth transformer is replaced, debugged, and linked tested. After the test is passed, the fourth transformer is operated at no load, and the second transformer, the third transformer, and the fourth transformer are phase checked respectively; When the phase analysis is completed, the first transformer is controlled to stop operating; After the low-voltage side closed busbar bridge and wall bushing of the first transformer are removed and the low-voltage side copper tube insulated busbar is installed, the first transformer protection device is replaced, debugged, and linked tested. After the test is passed, the first transformer is operated at no load, and the first transformer, the second transformer, the third transformer, and the fourth transformer are respectively phase checked; When the phase checking is completed, the GIS switch cabinet is controlled to be powered on.

8. A substation double bus switch cabinet replacement device, characterized in that: include: A size determination module, used to determine the length to be removed according to the number of GIS switch cabinets to be installed and the size of the GIS switch cabinets; A selection module is used to determine the area to be removed of the original air switch cabinet including the sectional cabinet according to the length to be removed; The transfer contact module is used to send an electrical connection instruction to establish an electrical connection between the bus sections I and II and the bus sections III and IV through the contact power cable when it is detected that the load cable in the feeder switch cabinet of the busbar in the to-be-removed area has been transferred to the standby feeder switch cabinet of the corresponding busbar in the non-to-be-removed area; The first area shutdown control module is used to control the shutdown of the third transformer and the fourth transformer on the bus sections III and IV; wherein the low-voltage side switch cabinet of the third transformer is in the area to be removed; A contact power access module, used to control the access of the contact power cable after the first edge switch cabinet connecting the area to be removed with the busbar sections III and IV is cut off; The first area recovery control module is used to control the fourth transformer to supply power to the bus sections III and IV; The second area shutdown and restoration control module is used to control the shutdown of the first transformer and the second transformer on the bus sections I and II, cut off the second edge switch cabinet connecting the area to be removed with the bus sections I and II, and restore power supply after cutting off; The replacement and transformation module is used to control the power supply access of the GIS switch cabinet after all the switch cabinets in the area to be demolished are demolished and the GIS switch cabinet to be installed is installed.

9. A substation double bus switch cabinet replacement device, characterized in that: include: Memory for storing computer programs; A processor is used to implement the steps of the method for replacing a double-busbar switch cabinet in a substation as described in any one of claims 1 to 7 when executing the computer program.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the method for replacing a double-bus switch cabinet in a substation are implemented as described in any one of claims 1 to 7.

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