35kV power distribution network system, power supply method and relay protection method thereof

Abstract

The invention discloses a 35kV power distribution network system, a power supply method and a relay protection method thereof, the 35kV power distribution network system comprises a section I bus, a section II bus and a section III bus, the section I bus is powered by a first main transformer through a first incoming line, the section II bus is powered by a second main transformer through a second incoming line, and the section III bus is powered by a third main transformer through a third incoming line; the first incoming line is provided with a first incoming line switch, the second incoming line is provided with a second incoming line switch, and the third incoming line is provided with a third incoming line switch; a first bus coupler cabinet is arranged between the section II bus and the section III bus, and a second bus coupler cabinet is arranged between the section I bus and the section III bus; a first bus interconnection switch is arranged in the first bus coupler cabinet, and a second bus interconnection switch is arranged in the second bus coupler cabinet. According to the invention, the problem that the unique bus coupler of the existing distribution network system goes wrong is solved, the influence on the power utilization condition of the whole area due to the problem of the unique bus coupler is avoided, stable and reliable power supply is realized, and the loss caused by power supply stopping can be effectively reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of power supply and distribution, and in particular to a 35 kV power distribution network system, a power supply method and a relay protection method thereof. Background Art

[0002] In the actual application process of the existing power distribution network system, there are still certain limitations and defects. In the existing total step-down power distribution network system, the 35 kV power distribution network system has a section I busbar and a section II busbar. The section I busbar is powered by a first main transformer through a first incoming line, and the section II busbar is powered by a second main transformer through a second incoming line. A first bus coupler cabinet is arranged between the section I busbar and the section II busbar. During normal operation, the bus coupler switch in the first bus coupler cabinet is disconnected, and the first main transformer and the second main transformer are independently powered. When one of the main transformers loses power due to faults, maintenance, etc., the bus coupler switch in the first bus coupler cabinet is closed to connect the section I busbar and the section II busbar, so that the load can be connected to the powered main transformer to ensure the power supply to users until the power supply of the transformer that has lost power is restored, then the bus coupler switch in the first bus coupler cabinet is disconnected, and the independent power supply state of the first main transformer and the second main transformer is restored. According to the above existing technology, once the bus coupler has a problem, it may affect the power consumption of the entire area. If this problem cannot be solved in time, it will lead to power outages of some important facilities and even cause serious accident consequences. At present, there are still no corresponding measures that can effectively deal with such accident situations. Summary of the Invention

[0003] In order to overcome the above-mentioned disadvantages of the existing technology, the purpose of the present invention is to provide a 35 kV power distribution network system, a power supply method and a relay protection method thereof that can effectively improve the operation efficiency and reliability of the power grid.

[0004] The technical solution adopted by the present invention to solve its technical problems is: a 35 kV power distribution network system, including a section I busbar, a section II busbar and a section III busbar,

[0005] The section I busbar is powered by a first main transformer through a first incoming line, the section II busbar is powered by a second main transformer through a second incoming line, and the section III busbar is powered by a third main transformer through a third incoming line;

[0006] A first incoming line switch is arranged on the first incoming line, a second incoming line switch is arranged on the second incoming line, and a third incoming line switch is arranged on the third incoming line;

[0007] A first bus coupler cabinet is arranged between the section II busbar and the section III busbar, and a second bus coupler cabinet is arranged between the section I busbar and the section III busbar;

[0008] A first bus coupler switch is arranged in the first bus coupler cabinet, and a second bus coupler switch is arranged in the second bus coupler cabinet.

[0009] A power supply method for a 35kV power distribution network system, comprising the following steps:

[0010] S1. Obtain the power supply status of the first main transformer, the second main transformer, and the third main transformer;

[0011] S2. According to the power supply status, adjust the disconnection or closing of the first bus coupler switch in the first bus coupler cabinet and the second bus coupler switch in the second bus coupler cabinet, so that the first main transformer, the second main transformer, and the third main transformer supply power independently.

[0012] As a further improvement of the present invention: in the step S2, it includes:

[0013] When the power supply status of the first main transformer, the second main transformer, and the third main transformer is operating normally, control the disconnection of the first bus coupler switch in the first bus coupler cabinet and the second bus coupler switch in the second bus coupler cabinet, and the first main transformer, the second main transformer, and the third main transformer supply power independently.

[0014] As a further improvement of the present invention: in the step S2, it further includes:

[0015] When the first main transformer loses power, control the closing of the second bus coupler switch in the second bus coupler cabinet to connect the I-section bus with the third main transformer until the first main transformer resumes power supply, then disconnect the second bus coupler switch in the second bus coupler cabinet to restore the state where the first main transformer, the second main transformer, and the third main transformer supply power independently.

[0016] As a further improvement of the present invention: in the step S2, it further includes:

[0017] When the second main transformer loses power, control the closing of the first bus coupler switch in the first bus coupler cabinet to connect the II-section bus with the third main transformer until the second main transformer resumes power supply, then disconnect the first bus coupler switch in the first bus coupler cabinet to restore the state where the first main transformer, the second main transformer, and the third main transformer supply power independently.

[0018] As a further improvement of the present invention: in the step S2, it further includes:

[0019] When the third main transformer loses power, control the closing of the first bus coupler switch in the first bus coupler cabinet or the second bus coupler switch in the second bus coupler cabinet to connect the III-section bus with the first main transformer or connect the III-section bus with the second main transformer until the third main transformer resumes power supply, then disconnect the first bus coupler switch in the first bus coupler cabinet or the second bus coupler switch in the second bus coupler cabinet to restore the state where the first main transformer, the second main transformer, and the third main transformer supply power independently.

[0020] As a further improvement of the present invention: in the step S2, it further includes:

[0021] When the first main transformer loses power and the second main transformer loses power, control the first bus tie switch in the first main bus coupler cabinet and the second bus tie switch in the second main bus coupler cabinet to close, so that the I-section bus and the II-section bus are respectively connected to the third main transformer;

[0022] When the first main transformer resumes power supply but the second main transformer does not resume power supply, disconnect the second bus tie switch in the second main bus coupler cabinet to restore the state where the first main transformer is powered independently of the third main transformer;

[0023] When the second main transformer resumes power supply but the first main transformer does not resume power supply, disconnect the first bus tie switch in the first main bus coupler cabinet to restore the state where the second main transformer is powered independently of the third main transformer;

[0024] When both the first main transformer and the second main transformer resume power supply, disconnect the first bus tie switch in the first main bus coupler cabinet and the second bus tie switch in the second main bus coupler cabinet to restore to the state where the first main transformer, the second main transformer and the third main transformer are powered independently.

[0025] As a further improvement of the present invention: in the step S2, it further includes:

[0026] When the first main transformer loses power and the third main transformer loses power, control the first bus tie switch in the first main bus coupler cabinet and the second bus tie switch in the second main bus coupler cabinet to close, so that the I-section bus and the III-section bus are respectively connected to the second main transformer;

[0027] When the first main transformer resumes power supply but the third main transformer does not resume power supply, keep the first bus tie switch in the first main bus coupler cabinet and the second bus tie switch in the second main bus coupler cabinet closed, so that the III-section bus connects the first main transformer and the second main transformer;

[0028] When the third main transformer resumes power supply but the first main transformer does not resume power supply, keep the first bus tie switch in the first main bus coupler cabinet and the second bus tie switch in the second main bus coupler cabinet closed, so that the I-section bus connects the first main transformer and the third main transformer;

[0029] When both the first main transformer and the third main transformer resume power supply, disconnect the first bus tie switch in the first main bus coupler cabinet and the second bus tie switch in the second main bus coupler cabinet to restore to the state where the first main transformer, the second main transformer and the third main transformer are powered independently.

[0030] As a further improvement of the present invention: in the step S2, it further includes:

[0031] When the second main transformer loses power and the third main transformer loses power, control the first bus tie switch in the first main bus coupler cabinet and the second bus tie switch in the second main bus coupler cabinet to close, so that the II-section bus and the III-section bus are respectively connected to the first main transformer;

[0032] When the second main transformer resumes power supply but the third main transformer does not, keep the first bus tie switch in the first bus coupler cabinet and the second bus tie switch in the second bus coupler cabinet closed, so that the III-section bus connects the first main transformer and the second main transformer;

[0033] When the third main transformer resumes power supply but the first main transformer does not, keep the first bus tie switch in the first bus coupler cabinet and the second bus tie switch in the second bus coupler cabinet closed, so that the I-section bus connects the second main transformer and the third main transformer;

[0034] When both the first main transformer and the third main transformer resume power supply, disconnect the first bus tie switch in the first bus coupler cabinet and the second bus tie switch in the second bus coupler cabinet, and restore to the state where the first main transformer, the second main transformer and the third main transformer are independently powered.

[0035] A relay protection method for a 35kV power distribution network system includes the power supply method of the 35kV power distribution network system as described above, and also includes gas protection, longitudinal differential protection, overcurrent protection, overload protection and temperature protection for the first main transformer, the second main transformer and the third main transformer.

[0036] Compared with the prior art, the beneficial effects of the present invention are:

[0037] 1. By adding a III-section bus, a third main transformer and a second bus coupler cabinet to the existing 35kV power distribution network system, the present invention solves the problem of the only bus coupler in the existing distribution network system, avoids the influence of the problem of the only bus coupler on the power consumption of the entire area, realizes stable and reliable power supply in various situations, and can effectively reduce the huge losses caused by power outage. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a schematic structural diagram of the present invention.

[0039] Figure 2 It is a schematic flowchart of the power supply method of the present invention.

[0040] Reference numerals: 1, the first main transformer; 2, the first incoming line switch; 3, the second main transformer; 4, the second incoming line switch; 5, the third main transformer; 6, the third incoming line switch; 7, the first bus coupler cabinet; 8, the second bus coupler cabinet. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0041] In order to clearly and completely understand the technical solution, the present invention will be further described below in conjunction with the embodiments and the drawings. Obviously, the described embodiments are only part of the embodiments of the present invention. All other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present invention.

[0042] It should be understood that when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, wholes, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components, and / or their combinations.

[0043] It should also be understood that the terms used in this specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. As used in this specification of the present invention and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an", and "the" are intended to include the plural forms.

[0044] It should be further understood that the term "and / or" used in this specification of the present invention and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0045] An embodiment of the present invention provides a 35 kV power distribution network system, including a section I busbar, a section II busbar, and a section III busbar. The section I busbar is powered by a first main transformer through a first incoming line, the section II busbar is powered by a second main transformer through a second incoming line, and the section III busbar is powered by a third main transformer through a third incoming line. A first incoming line switch is provided on the first incoming line, a second incoming line switch is provided on the second incoming line, and a third incoming line switch is provided on the third incoming line. A first bus coupler cabinet is provided between the section II busbar and the section III busbar, and a second bus coupler cabinet is provided between the section I busbar and the section III busbar. A first bus tie switch is provided in the first bus coupler cabinet, and a second bus tie switch is provided in the second bus coupler cabinet.

[0046] It should be noted that in this embodiment, by adding a section III busbar, a third main transformer, and a second bus coupler cabinet to the existing 35 kV power distribution network system, and changing the connection mode of the section I busbar and the first bus coupler cabinet, the first bus coupler cabinet is reconnected between the section II busbar and the section III busbar, and the second bus coupler cabinet is connected between the section I busbar and the section III busbar.

[0047] On the other hand, an embodiment of the present invention provides a power supply method for a 35 kV power distribution network system, including the following steps:

[0048] S1. Obtain the power supply states of the first main transformer, the second main transformer, and the third main transformer;

[0049] S2. Adjust the first bus tie switch in the first bus coupler cabinet and the second bus tie switch in the second bus coupler cabinet to be opened or closed according to the power supply states, so that the first main transformer, the second main transformer, and the third main transformer supply power independently.

[0050] In the present invention, by adding a third-section busbar, a third main transformer, and a second bus-coupler cabinet to the existing 35 kV power distribution network system, obtaining the power supply states of the first main transformer, the second main transformer, and the third main transformer, and controlling the disconnection or closing of the tie switches to restore the busbar power supply, the problem that the only bus-coupler in the existing power distribution system affects the power consumption of the entire area is solved, stable and reliable power supply in multiple situations is achieved, and huge losses caused by power supply interruption can be effectively reduced.

[0051] In an alternative embodiment, in the step S2, it includes:

[0052] When the power supply states of the first main transformer, the second main transformer, and the third main transformer are operating normally, control the first bus-tie switch in the first bus-coupler cabinet and the second bus-tie switch in the second bus-coupler cabinet to disconnect, and the first main transformer, the second main transformer, and the third main transformer supply power independently.

[0053] In an alternative embodiment, in the step S2, it further includes:

[0054] When the first main transformer loses power, control the second bus-tie switch in the second bus-coupler cabinet to close, so that the first-section busbar is connected to the third main transformer until the first main transformer resumes power supply, then disconnect the second bus-tie switch in the second bus-coupler cabinet, and restore the independent power supply state of the first main transformer, the second main transformer, and the third main transformer. In this embodiment, when the first main transformer loses power, that is, the first incoming line switch is disconnected. By controlling the second bus-tie switch in the second bus-coupler cabinet to close, the first-section busbar is connected to the third main transformer, and the first-section busbar is connected to the third-section busbar, so that the load originally powered by the first main transformer is connected to the powered third main transformer for power supply until the first main transformer resumes power supply, then disconnect the second bus-tie switch in the second bus-coupler cabinet, and restore the independent power supply state of the first main transformer, the second main transformer, and the third main transformer.

[0055] In an alternative embodiment, in the step S2, it further includes:

[0056] When the second main transformer loses power, control the first bus-tie switch in the first bus-coupler cabinet to close, so that the second-section busbar is connected to the third main transformer until the second main transformer resumes power supply, then disconnect the first bus-tie switch in the first bus-coupler cabinet, and restore the independent power supply state of the first main transformer, the second main transformer, and the third main transformer. In this embodiment, when the second main transformer loses power, that is, the second incoming line switch is disconnected. By controlling the first bus-tie switch in the first bus-coupler cabinet to close, the second-section busbar is connected to the third main transformer, and the second-section busbar is connected to the third-section busbar, so that the load originally powered by the second main transformer is connected to the powered third main transformer for power supply until the second main transformer resumes power supply, then disconnect the first bus-tie switch in the first bus-coupler cabinet, and restore the independent power supply state of the first main transformer, the second main transformer, and the third main transformer.

[0057] In an alternative embodiment, in the step S2, it further includes:

[0058] When the third main transformer loses power, control the first bus tie switch in the first bus-coupler cabinet or the second bus tie switch in the second bus-coupler cabinet to close, so that the III-section bus is connected to the first main transformer or the III-section bus is connected to the second main transformer, until the third main transformer resumes power supply, then disconnect the first bus tie switch in the first bus-coupler cabinet or the second bus tie switch in the second bus-coupler cabinet, and restore the independent power supply state of the first main transformer, the second main transformer, and the third main transformer. In this embodiment, when the third main transformer loses power, that is, the third incoming line switch is disconnected. By controlling the first bus tie switch in the first bus-coupler cabinet to close, the III-section bus is connected to the first main transformer, and the II-section bus is connected to the III-section bus, so that the load originally powered by the third main transformer is connected to the powered second main transformer until the third main transformer resumes power supply, then disconnect the first bus tie switch in the first bus-coupler cabinet, and restore the independent power supply state of the first main transformer, the second main transformer, and the third main transformer; or, by controlling the second bus tie switch in the second bus-coupler cabinet to close, the III-section bus is connected to the second main transformer, and the II-section bus is connected to the III-section bus, so that the load originally powered by the third main transformer is connected to the powered first main transformer until the third main transformer resumes power supply, then disconnect the second bus tie switch in the second bus-coupler cabinet, and restore the independent power supply state of the first main transformer, the second main transformer, and the third main transformer.

[0059] In an alternative embodiment, in the step S2, it further includes:

[0060] When the first main transformer loses power and the second main transformer loses power, control the first bus tie switch in the first bus-coupler cabinet and the second bus tie switch in the second bus-coupler cabinet to close, so that the I-section bus and the II-section bus are respectively connected to the third main transformer;

[0061] When the first main transformer resumes power supply but the second main transformer has not resumed power supply, disconnect the second bus tie switch in the second bus-coupler cabinet, and restore the state where the first main transformer is independently powered from the third main transformer;

[0062] When the second main transformer resumes power supply but the first main transformer has not resumed power supply, disconnect the first bus tie switch in the first bus-coupler cabinet, and restore the state where the second main transformer is independently powered from the third main transformer;

[0063] When both the first main transformer and the second main transformer resume power supply, disconnect the first bus tie switch in the first bus-coupler cabinet and the second bus tie switch in the second bus-coupler cabinet, and restore to the state where the first main transformer, the second main transformer, and the third main transformer are independently powered.

[0064] In this embodiment, when the first main transformer loses power and the second main transformer loses power, that is, the first incoming line switch and the second incoming line switch are disconnected, control the first bus tie switch in the first bus-coupler cabinet to close, and the second bus tie switch in the second bus-coupler cabinet to close, so that the loads originally powered by the first main transformer are connected to the third main transformer with power supply, and the loads originally powered by the second main transformer are connected to the third main transformer with power supply; when the first main transformer resumes power supply but the second main transformer does not resume power supply, that is, the first incoming line switch resumes closing but the second incoming line switch is disconnected, control to disconnect the second bus tie switch in the second bus-coupler cabinet to restore the state where the first main transformer supplies power independently of the third main transformer; when the second main transformer resumes power supply but the first main transformer does not resume power supply, that is, the second incoming line switch resumes closing but the first incoming line switch is disconnected, control to disconnect the first bus tie switch in the first bus-coupler cabinet to restore the state where the second main transformer supplies power independently of the third main transformer; when both the first main transformer and the second main transformer resume power supply, that is, the first incoming line switch and the second incoming line switch resume closing, control to disconnect the first bus tie switch in the first bus-coupler cabinet and disconnect the second bus tie switch in the second bus-coupler cabinet to restore to the state where the first main transformer, the second main transformer, and the third main transformer supply power independently.

[0065] In an alternative embodiment, in the step S2, it further includes:

[0066] When the first main transformer loses power and the third main transformer loses power, control the first bus tie switch in the first bus-coupler cabinet and the second bus tie switch in the second bus-coupler cabinet to close, so that the I-section bus and the III-section bus are respectively connected to the second main transformer;

[0067] When the first main transformer resumes power supply but the third main transformer does not resume power supply, keep the first bus tie switch in the first bus-coupler cabinet and the second bus tie switch in the second bus-coupler cabinet closed, so that the III-section bus connects the first main transformer and the second main transformer;

[0068] When the third main transformer resumes power supply but the first main transformer does not resume power supply, keep the first bus tie switch in the first bus-coupler cabinet and the second bus tie switch in the second bus-coupler cabinet closed, so that the I-section bus connects the first main transformer and the third main transformer;

[0069] When both the first main transformer and the third main transformer resume power supply, disconnect the first bus tie switch in the first bus-coupler cabinet and the second bus tie switch in the second bus-coupler cabinet to restore to the state where the first main transformer, the second main transformer, and the third main transformer supply power independently.

[0070] In this embodiment, when the first main transformer loses power and the third main transformer loses power, that is, the first incoming line switch and the third incoming line switch are disconnected, control the first bus tie switch in the first bus-coupler cabinet to close, and the second bus tie switch in the second bus-coupler cabinet to close, so that the loads originally powered by the first main transformer are connected to the second main transformer with power supply, and the loads originally powered by the third main transformer are connected to the second main transformer with power supply; when the first main transformer resumes power supply but the third main transformer has not resumed power supply, that is, the first incoming line switch resumes closing but the third incoming line switch remains disconnected, still keep the first bus tie switch in the first bus-coupler cabinet closed, and the second bus tie switch in the second bus-coupler cabinet closed, so that the loads originally powered by the first main transformer, the loads originally powered by the second main transformer, and the loads originally powered by the third main transformer are all powered by the first main transformer and the second main transformer together; when the third main transformer resumes power supply but the first main transformer has not resumed power supply, that is, the third incoming line switch resumes closing but the first incoming line switch remains disconnected, still keep the first bus tie switch in the first bus-coupler cabinet closed, and the second bus tie switch in the second bus-coupler cabinet closed, so that the loads originally powered by the first main transformer, the loads originally powered by the second main transformer, and the loads originally powered by the third main transformer are all powered by the first main transformer and the third main transformer together; when both the first main transformer and the third main transformer resume power supply, that is, the first incoming line switch and the third incoming line switch resume closing, control to disconnect the first bus tie switch in the first bus-coupler cabinet and disconnect the second bus tie switch in the second bus-coupler cabinet, and restore to the state where the first main transformer, the second main transformer, and the third main transformer are independently powered.

[0071] In an alternative embodiment, in the step S2, it further includes:

[0072] When the second main transformer loses power and the third main transformer loses power, control the first bus tie switch in the first bus-coupler cabinet and the second bus tie switch in the second bus-coupler cabinet to close, so that the II-section bus and the III-section bus are respectively connected to the first main transformer;

[0073] When the second main transformer resumes power supply but the third main transformer has not resumed power supply, keep the first bus tie switch in the first bus-coupler cabinet and the second bus tie switch in the second bus-coupler cabinet closed, so that the III-section bus connects the first main transformer and the second main transformer;

[0074] When the third main transformer resumes power supply but the first main transformer has not resumed power supply, keep the first bus tie switch in the first bus-coupler cabinet and the second bus tie switch in the second bus-coupler cabinet closed, so that the I-section bus connects the second main transformer and the third main transformer;

[0075] When both the first main transformer and the third main transformer resume power supply, disconnect the first bus tie switch in the first bus-coupler cabinet and the second bus tie switch in the second bus-coupler cabinet, and restore to the state where the first main transformer, the second main transformer, and the third main transformer are independently powered.

[0076] In this embodiment, when the second main transformer loses power and the third main transformer loses power, that is, the second incoming line switch and the third incoming line switch are disconnected, control the first bus tie switch in the first bus-coupler cabinet to close, and the second bus tie switch in the second bus-coupler cabinet to close, so that the loads originally powered by the second main transformer are connected to the powered first main transformer, and the loads originally powered by the third main transformer are connected to the powered first main transformer; when the second main transformer resumes power supply but the third main transformer has not resumed power supply, that is, the second incoming line switch resumes closing but the third incoming line switch remains disconnected, still keep the first bus tie switch in the first bus-coupler cabinet closed, and the second bus tie switch in the second bus-coupler cabinet closed, so that the loads originally powered by the first main transformer, the loads originally powered by the second main transformer, and the loads originally powered by the third main transformer are all powered by the first main transformer and the second main transformer together; when the third main transformer resumes power supply but the second main transformer has not resumed power supply, that is, the third incoming line switch resumes closing but the second incoming line switch remains disconnected, still keep the first bus tie switch in the first bus-coupler cabinet closed, and the second bus tie switch in the second bus-coupler cabinet closed, so that the loads originally powered by the first main transformer, the loads originally powered by the second main transformer, and the loads originally powered by the third main transformer are all powered by the first main transformer and the third main transformer together; when both the second main transformer and the third main transformer resume power supply, that is, the second incoming line switch and the third incoming line switch resume closing, control to disconnect the first bus tie switch in the first bus-coupler cabinet, disconnect the second bus tie switch in the second bus-coupler cabinet, and restore to the state where the first main transformer, the second main transformer, and the third main transformer are independently powered.

[0077] On the other hand, the present invention also discloses a relay protection method for a 35 kV power distribution network system, which is comprehensively and effectively protected and can effectively improve the operation efficiency and reliability of the power grid; the method includes gas protection, longitudinal differential protection, overcurrent protection, overload protection, and temperature protection for the first main transformer, the second main transformer, and the third main transformer.

[0078] In an optional embodiment, the method further includes short-circuit fault protection in the first bus-coupler cabinet and short-circuit fault protection in the second bus-coupler cabinet.

[0079] In an optional embodiment, the method further includes ground fault protection in the first bus-coupler cabinet and ground fault protection in the second bus-coupler cabinet.

[0080] In an optional embodiment, for a relay protection method of a 35 kV power distribution network system, the 35 kV power distribution network system further includes a relay protection device, and the relay protection device is used to implement overcurrent protection, overload protection, and temperature protection for the first main transformer, the second main transformer, and the third main transformer, short-circuit fault protection in the first bus-coupler cabinet and short-circuit fault protection in the second bus-coupler cabinet, and ground fault protection in the first bus-coupler cabinet and ground fault protection in the second bus-coupler cabinet.

[0081] The relay protection method of the present invention includes gas protection, pilot differential protection, overcurrent protection, overload protection and temperature protection for the first main transformer, the second main transformer and the third main transformer, includes short-circuit fault protection in the first bus-coupler cabinet and short-circuit fault protection in the second bus-coupler cabinet, and also includes ground fault protection in the first bus-coupler cabinet and ground fault protection in the second bus-coupler cabinet. The protection is comprehensive and effective, and can effectively improve the operation efficiency and reliability of the power grid.

[0082] The 35kV power distribution network system, power supply method and relay protection method of the present invention are highly practical and can ensure that the distribution network contributes to the stable economy of enterprises safely, stably, reliably and continuously and efficiently.

[0083] In summary, after reading the documents of the present invention, various other corresponding transformation schemes made by ordinary technicians in the art without creative mental labor according to the technical solutions and technical concepts of the present invention all fall within the scope protected by the present invention.

Claims

1. A 35kV power distribution network system, characterized in that: Including busbar section I, busbar section II and busbar section III, The bus section I is powered by the first main transformer through the first incoming line, the bus section II is powered by the second main transformer through the second incoming line, and the bus section III is powered by the third main transformer through the third incoming line. A first incoming line switch is provided on the first incoming line, a second incoming line switch is provided on the second incoming line, and a third incoming line switch is provided on the third incoming line; A first busbar coupling cabinet is provided between the busbar section II and the busbar section III, and a second busbar coupling cabinet is provided between the busbar section I and the busbar section III; A first busbar connecting switch is arranged in the first bus coupling cabinet, and a second busbar connecting switch is arranged in the second bus coupling cabinet.

2. A power supply method for a 35kV power distribution network system, characterized in that: The following steps are involved: S1. Obtain the power supply status of the first main transformer, the second main transformer and the third main transformer; S2. According to the power supply status, the first busbar connecting switch in the first bus coupling cabinet and the second busbar connecting switch in the second bus coupling cabinet are opened or closed to enable the first main transformer, the second main transformer and the third main transformer to be powered independently.

3. A power supply method for a 35kV power distribution network system according to claim 2, characterized in that: In the step S2, it includes: When the power supply status of the first main transformer, the second main transformer and the third main transformer is working normally, the first busbar connecting switch in the first bus coupling cabinet and the second busbar connecting switch in the second bus coupling cabinet are controlled to be disconnected, and the first main transformer, the second main transformer and the third main transformer are powered independently.

4. A power supply method for a 35kV power distribution network system according to claim 3, characterized in that: In the step S2, it also includes: When the first main transformer loses power, the second busbar connecting switch in the second bus coupling cabinet is controlled to close, so that the I section bus is connected to the third main transformer until the first main transformer resumes power supply. The second busbar connecting switch in the second bus coupling cabinet is disconnected to restore the independent power supply state of the first main transformer, the second main transformer and the third main transformer.

5. A power supply method for a 35kV power distribution network system according to claim 4, characterized in that: In the step S2, it also includes: When the second main transformer loses power, the first busbar connecting switch in the first bus coupling cabinet is controlled to close, so that the II section bus is connected to the third main transformer until the second main transformer resumes power supply. The first busbar connecting switch in the first bus coupling cabinet is disconnected to restore the independent power supply state of the first main transformer, the second main transformer and the third main transformer.

6. A power supply method for a 35kV power distribution network system according to claim 5, characterized in that: In the step S2, it also includes: When the third main transformer loses power, the first busbar connecting switch in the first bus coupling cabinet or the second busbar connecting switch in the second bus coupling cabinet is controlled to close, so that the section III bus is connected to the first main transformer or the section III bus is connected to the second main transformer until the third main transformer resumes power supply, and the first busbar connecting switch in the first bus coupling cabinet or the second busbar connecting switch in the second bus coupling cabinet is disconnected to restore the independent power supply state of the first main transformer, the second main transformer and the third main transformer.

7. A power supply method for a 35kV power distribution network system according to claim 6, characterized in that: In the step S2, it also includes: When the first main transformer loses power and the second main transformer loses power, the first busbar contact switch in the first busbar cabinet and the second busbar contact switch in the second busbar cabinet are controlled to close, so that the busbar section I and the busbar section II are connected to the third main transformer respectively; When the first main transformer resumes power supply but the second main transformer does not resume power supply, the second busbar tie switch in the second bus tie cabinet is disconnected to restore the state where the first main transformer is powered independently of the third main transformer; When the second main transformer resumes power supply but the first main transformer does not resume power supply, the first busbar tie switch in the first bus tie cabinet is disconnected to restore the state where the second main transformer is powered independently of the third main transformer; When the power supply of the first main transformer and the second main transformer is restored, the first busbar connecting switch in the first bus coupling cabinet and the second busbar connecting switch in the second bus coupling cabinet are disconnected to restore the state of independent power supply of the first main transformer, the second main transformer and the third main transformer.

8. A power supply method for a 35kV power distribution network system according to claim 7, characterized in that: In the step S2, it also includes: When the first main transformer loses power and the third main transformer loses power, the first busbar contact switch in the first busbar cabinet and the second busbar contact switch in the second busbar cabinet are controlled to close, so that the busbar section I and the busbar section III are connected to the second main transformer respectively; When the first main transformer resumes power supply but the third main transformer does not resume power supply, keep the first busbar contact switch in the first busbar cabinet and the second busbar contact switch in the second busbar cabinet closed, so that the busbar section III connects the first main transformer and the second main transformer; When the third main transformer resumes power supply but the first main transformer does not, the first busbar contact switch in the first bus coupling cabinet and the second busbar contact switch in the second bus coupling cabinet are kept closed, so that the I-section bus connects the first main transformer and the third main transformer; When the power supply of the first main transformer and the third main transformer is restored, the first busbar connecting switch in the first bus coupling cabinet and the second busbar connecting switch in the second bus coupling cabinet are disconnected to restore the state of independent power supply of the first main transformer, the second main transformer and the third main transformer.

9. A power supply method for a 35kV power distribution network system according to claim 8, characterized in that: In the step S2, it also includes: When the second main transformer loses power and the third main transformer loses power, the first busbar contact switch in the first busbar cabinet and the second busbar contact switch in the second busbar cabinet are controlled to close, so that the busbar section II and the busbar section III are connected to the first main transformer respectively; When the second main transformer resumes power supply but the third main transformer does not resume power supply, keep the first busbar contact switch in the first busbar cabinet and the second busbar contact switch in the second busbar cabinet closed, so that the busbar section III connects the first main transformer and the second main transformer; When the third main transformer resumes power supply but the first main transformer does not resume power supply, the first busbar contact switch in the first busbar cabinet and the second busbar contact switch in the second busbar cabinet are kept closed, so that the I-section busbar connects the second main transformer and the third main transformer; When the power supply of the first main transformer and the third main transformer is restored, the first busbar connecting switch in the first bus coupling cabinet and the second busbar connecting switch in the second bus coupling cabinet are disconnected to restore the state of independent power supply of the first main transformer, the second main transformer and the third main transformer.

10. A relay protection method for a 35kV power distribution network system, comprising the power supply method for a 35kV power distribution network system as described in any one of claims 2 to 9, and also comprising gas protection, longitudinal differential protection, overcurrent protection, overload protection and temperature protection for the first main transformer, the second main transformer and the third main transformer.

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