35kV-voltage-class heavy-load power supply system and substation

Abstract

The invention relates to a 35kV voltage class large-load power supply system and a substation. The system comprises a double-winding main transformer group, a first bus group, a second bus group, a three-winding main transformer group and a third bus group, wherein the capacity of the 35kV side of the main transformer can be ensured to be large enough through the double-winding main transformer group, and the power utilization requirement of 35kV large load is met; the connection between 220kV and 110kV power grids can be realized through the three-winding main transformer group, and the power supply reliability of the low-voltage 35kV side is ensured; the power supply of the first high-voltage winding side is directly taken from the power supply of the first bus group, so that the power supply reliability and power supply efficiency of the main transformer are improved; a three-winding main transformer in a conventional design is replaced by the double-winding main transformer bank, the scale of a 110kV power distribution device in the transformer substation is reduced, in addition, the appearance size of the double-winding main transformer bank is small, the occupied area of the transformer substation is saved, and the maintenance cost is reduced.

Description

Technical Field

[0001] The present application relates to the field of electric power technology, and in particular to a 35kV voltage level heavy load power supply system and a substation. Background Art

[0002] Substation refers to the place in the power system where voltage and current are transformed, electric energy is received and distributed. At present, there are usually two ways to supply power to large loads at 35kV voltage level in the power system: the first way, such as Figure 1 As shown in the figure, a 110kV three-winding main transformer is used to reduce the 110kV voltage to 35kV and 10kV, and the busbar on the medium voltage side of the main transformer is connected to the 35kV load. Figure 2 As shown, a 220kV three-winding main transformer is used to reduce the 220kV voltage to 110kV and 35kV, and the low-voltage side bus of the main transformer is connected to a 35kV load.

[0003] In the existing way of supplying power to a large load at a voltage level of 35kV, for the first method mentioned above, when the 110kV bus fails or is under maintenance, the entire station will be shut down. In addition, when a short circuit fault occurs on the 10kV side of the main transformer, the main transformer will be shut down, and the 35kV bus will also be shut down. The power supply reliability of the 35kV load is low, and the capacity available for the 35kV load is small, the power supply efficiency is low, and multiple substations need to be built to meet the load requirements, which is costly. For the second method mentioned above, the 220kV three-winding main transformer mainly supplies 110kV loads, and the capacity allocated to the 35kV side is small, which makes it difficult to meet the power demand of the 35kV large load. When a short circuit fault occurs on the low-voltage side of 35kV, the main transformer will be shut down, and even the normal operation of the 220kV and 110kV busbars will be affected, and the power supply reliability of the substation is low; in addition, the 220kV three-winding main transformer has a large appearance and volume, and needs to be designed with power distribution devices of different voltage levels, which occupies a large area and has a high maintenance cost in the later stage. Summary of the invention

[0004] Based on this, it is necessary to provide a 35kV voltage level large load power supply system and substation that can ensure that the capacity of the 35kV side of the main transformer is large enough, improve the power supply reliability and efficiency on the 35kV side, and reduce the footprint and subsequent maintenance costs in order to address the technical problems existing in the above-mentioned existing methods of supplying power to large loads at the 35kV voltage level.

[0005] In order to achieve the above object, an embodiment of the present invention provides a 35kV voltage level heavy load power supply system, comprising:

[0006] A double-winding main transformer group, the double-winding main transformer group includes a plurality of double-winding main transformers, the double-winding main transformer includes a first high-voltage winding side and a first low-voltage winding side; the first high-voltage winding side is a 220kV high-voltage winding side, and the first low-voltage winding side is a 35kV low-voltage winding side;

[0007] The first busbar group is connected to each first high-voltage winding side respectively; the first busbar group is a 220kV busbar group;

[0008] The second busbar group includes a plurality of first busbar sections and second busbar sections; each first busbar section is connected to each first low-voltage winding side in a one-to-one correspondence; the first busbar section is a 35kV busbar, and the second busbar section is a 35kV busbar;

[0009] A three-winding main transformer group and a third busbar group; the three-winding main transformer group includes a number of three-winding main transformers, and the three-winding main transformer includes a second high-voltage winding side, a second medium-voltage winding side and a second low-voltage winding side; each second high-voltage winding side is respectively connected to the first busbar group, each second medium-voltage winding side is respectively connected to the third busbar group, and each second low-voltage winding side is connected to each second busbar section in a one-to-one correspondence; the voltage of the first busbar group is greater than the voltage of the third busbar group, and the voltage of the third busbar group is greater than the voltage of the second busbar group; the second high-voltage winding side is a 220kV high-voltage winding side, the second medium-voltage winding side is a 110kV medium-voltage winding side, the second low-voltage winding side is a 35kV low-voltage winding side, and the third busbar group is a 110kV busbar group.

[0010] In one embodiment, the first high-voltage winding side and the second high-voltage winding side respectively adopt double busbar connection, the second medium-voltage winding side adopts double busbar connection, and the first low-voltage winding side and the second low-voltage winding side respectively adopt single busbar connection.

[0011] In one embodiment, the incoming line circuit between the first low-voltage winding side and the corresponding first bus section is a double circuit breaker incoming line, and the incoming line circuit between the second low-voltage winding side and the corresponding second bus section is a double circuit breaker incoming line.

[0012] In one of the embodiments, the 35kV voltage level heavy load power supply system further includes a plurality of first section circuit breakers;

[0013] A first section circuit breaker is arranged between two adjacent first bus sections, two adjacent second bus sections and / or between an adjacent first bus section and a second bus section.

[0014] In one embodiment, the 35kV voltage level heavy load power supply system further includes a busbar tie circuit breaker, the second busbar group includes a plurality of busbar sections, and the plurality of busbar sections are a plurality of first busbar sections and a second busbar section;

[0015] The busbar connecting circuit breaker is arranged between the two busbar sections which are farthest apart.

[0016] In one embodiment, the 35kV voltage level heavy load power supply system further includes a second section circuit breaker; the number of double-winding main transformers is 2, and the number of three-winding main transformers is 2; the first busbar group includes a third busbar section and a fourth busbar section;

[0017] The second section circuit breaker is connected between the third bus section and the fourth bus section; the first high-voltage winding side of a double-winding main transformer is connected to the third bus section, and the first high-voltage winding side of another double-winding main transformer is connected to the fourth bus section; the second high-voltage winding side of a three-winding main transformer is connected to the third bus section, and the second high-voltage winding side of another three-winding main transformer is connected to the fourth bus section.

[0018] In one embodiment, the 35kV voltage level heavy load power supply system further includes a third section circuit breaker; the third busbar group includes a fifth busbar section and a sixth busbar section; the third section circuit breaker is connected between the fifth busbar section and the sixth busbar section;

[0019] The second medium voltage winding side of one three-winding main transformer is connected to the fifth bus section, and the second medium voltage winding side of another three-winding main transformer is connected to the sixth bus section.

[0020] In one embodiment, the capacity of the two-winding main transformer is the same as the capacity of the three-winding main transformer.

[0021] In one embodiment, both the three-winding main transformer and the two-winding main transformer adopt on-load voltage regulation of the neutral point on the high-voltage winding side, and the high-voltage and low-voltage transformation ratios are the same; and / or

[0022] The windings on the first high-voltage winding side and the second high-voltage winding side adopt a Y-type connection method, the windings on the second medium-voltage winding side adopt a Y-type connection method, and the first low-voltage winding side and the second low-voltage winding side adopt a triangle connection method.

[0023] On the other hand, an embodiment of the present invention further provides a substation, comprising a 35kV voltage level heavy load power supply system as any one of the above items.

[0024] One of the above technical solutions has the following advantages and beneficial effects:

[0025] In each embodiment of the above-mentioned 35kV voltage level large-load power supply system, a double-winding main transformer group, a first bus group, a second bus group, a three-winding main transformer group and a third bus group are included; it not only ensures the connection between the substation and the 220kV and 110kV power grids through the three-winding main transformer, but also ensures that when any equipment of the high- and medium-voltage side distribution device is overhauled, it will not affect the normal power supply on the low-voltage 35kV side, thereby ensuring the power supply reliability on the low-voltage 35kV side; it also takes into account the direct power supply to the 35kV load through the large-capacity double-winding main transformer to meet the 35kV large-load power demand; at the same time, the high-voltage side power supply of the double-winding main transformer is taken from the 220kV system, thereby improving the power supply reliability of the main transformer.

[0026] In addition, the 35kV voltage level large-load power supply system combines a double-winding main transformer with a three-winding main transformer. Compared with the conventional substation where multiple three-winding main transformers are operated in parallel on the high and medium voltage sides, it greatly reduces the short-circuit current on the low-voltage side and saves the investment in short-circuit protection of low-voltage equipment. It can also reduce the scale of 110kV distribution equipment in the substation, saving the substation's floor space and construction investment. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a first structural schematic diagram of a conventional 35kV voltage level heavy load power supply system;

[0028] Figure 2 It is a second structural schematic diagram of a traditional 35kV voltage level heavy load power supply system;

[0029] Figure 3 It is a first structural schematic diagram of a 35kV voltage level heavy load power supply system in one embodiment;

[0030] Figure 4 A second structural schematic diagram of a 35kV voltage level heavy load power supply system in one embodiment;

[0031] Figure 5 A third structural schematic diagram of a 35kV voltage level heavy load power supply system in one embodiment;

[0032] Figure 6 A fourth structural schematic diagram of a 35kV voltage level heavy load power supply system in one embodiment;

[0033] Figure 7 This is a fifth structural schematic diagram of a 35kV voltage level heavy load power supply system in one embodiment.

[0034] Reference numerals:

[0035] 110. Double-winding main transformer group; 112. Double-winding main transformer; 120. First bus group; 122. Third bus section; 124. Fourth bus section; 130. Second bus group; 132. First bus section; 134. Second bus section; 140. Three-winding main transformer group; 142. Three-winding main transformer; 150. Third bus group; 152. Fifth bus section; 154. Sixth bus section; 160. First section circuit breaker; 170. Second section circuit breaker; 180. Third section circuit breaker; 190. Bus connection circuit breaker; 200. Circuit breaker. DETAILED DESCRIPTION

[0036] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings 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 should fall within the scope of protection of the present application.

[0037] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present application described here. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0038] In addition, the term "plurality" shall mean two or more.

[0039] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0040] In one embodiment, Figure 3As shown, a 35kV voltage level heavy load power supply system is provided, including a double-winding main transformer group 110, a first bus group 120, a second bus group 130, a three-winding main transformer group 140 and a third bus group 150. The double-winding main transformer group 110 includes a plurality of double-winding main transformers 112, and the double-winding main transformer 112 includes a first high-voltage winding side and a first low-voltage winding side, the first high-voltage winding side is a 220kV high-voltage winding side, and the first low-voltage winding side is a 35kV low-voltage winding side; the first bus group 120 is respectively connected to each first high-voltage winding side, and the first bus group is a 220kV bus group; the second bus group 130 includes a plurality of first bus sections 132 and a plurality of second bus sections 134; each first bus section 132 is connected to each first low-voltage winding side in a one-to-one correspondence; the first bus section 132 is a 35kV bus, and the second bus section 134 is a 35kV bus. The three-winding main transformer group 140 includes a plurality of three-winding main transformers 142, and the three-winding main transformer 142 includes a second high-voltage winding side, a second medium-voltage winding side and a second low-voltage winding side; each second high-voltage winding side is respectively connected to the first busbar group 120, each second medium-voltage winding side is respectively connected to the third busbar group 150, and each second low-voltage winding side is connected to each second busbar section 134 in a one-to-one correspondence; the voltage of the first busbar group 120 is greater than the voltage of the third busbar group 150, and the voltage of the third busbar group 150 is greater than the voltage of the second busbar group 130; the second high-voltage winding side is a 220kV high-voltage winding side, the second medium-voltage winding side is a 110kV medium-voltage winding side, the second low-voltage winding side is a 35kV low-voltage winding side, and the third busbar group is a 110kV busbar group.

[0041] The dual-winding main transformer group 110 may include a plurality of dual-winding main transformers 112. For example, the dual-winding main transformer group 110 includes two dual-winding main transformers 112. The dual-winding main transformer 112 may be used to transform the power supply of the first busbar group 120 into a 35 kV power supply. The dual-winding main transformer 112 includes a first high-voltage winding side and a first low-voltage winding side. The windings in the first high-voltage winding side may be obtained by a Y-type (star) connection method; the first low-voltage winding side may be obtained by a delta connection method.

[0042] The first busbar group 120 is a first double busbar group (i.e., the first high-voltage winding side and the second high-voltage winding side respectively use double busbar connections). It should be noted that the first single busbar group refers to a busbar group consisting of one first busbar, and the first double busbar group refers to a busbar group consisting of two first busbars.

[0043] The second busbar group 130 is a single busbar group (i.e., the first low-voltage winding side and the second low-voltage winding side respectively adopt single busbar connection), and the second busbar group 130 can be divided into a plurality of first busbar segments 132; the number of the first busbar segments 132 is the same as the number of the first low-voltage winding side, i.e., the first busbar segment 132 is connected to the corresponding first low-voltage winding side.

[0044] Based on the first busbar group 120 being respectively connected to the first high-voltage winding side of each dual-winding main transformer 112, the first low-voltage winding side of the dual-winding main transformer 112 is connected to the corresponding first busbar section 132, and then the dual-winding main transformer 112 can transform the power supply of the first busbar group 120 to obtain 35kV power supply, and transmit the 35kV power supply to the corresponding first busbar section 132, so that the first busbar section 132 can supply power to the 35kV load.

[0045] Accordingly, the three-winding main transformer group 140 may include a plurality of three-winding main transformers 142. For example, the three-winding main transformer group 140 may include two three-winding main transformers 142. The three-winding main transformer 142 may be used to transform the power supply of the first busbar group 120 into 110 kV and 35 kV power supplies. The three-winding main transformer 142 includes a second high-voltage winding side, a second medium-voltage winding side, and a second low-voltage winding side. The windings in the second high-voltage winding side may be obtained by Y-type (star) connection; the windings in the second medium-voltage winding side may be obtained by Y-type (star) connection; and the first low-voltage winding side may be obtained by delta connection.

[0046] The third busbar group 150 is a third double busbar group (i.e., the second medium voltage winding side adopts double busbar connection). It should be noted that the third double busbar group refers to a busbar group consisting of two third busbars. The second busbar group 130 can also be divided into a plurality of second busbar sections 134; the number of the second busbar sections 134 is the same as the number of the second low voltage winding side, i.e., the second busbar section 134 is connected to the corresponding second low voltage winding side.

[0047] Exemplarily, the voltage of the first busbar group 120 is 220 kV, the voltage of the second busbar group 130 is 35 kV, and the voltage of the third busbar group 150 is 110 kV. Based on the second high-voltage winding side of each three-winding main transformer 142 being respectively connected to the first busbar group 120, the second medium-voltage winding side of each three-winding main transformer 142 being respectively connected to the third busbar group 150, and the second low-voltage winding side of the three-winding main transformer 142 being connected to the corresponding second busbar section 134, the three-winding main transformer 142 can transform the 220 kV power supply of the first busbar group 120 to obtain 110 kV and 35 kV power supplies, and transmit the 110 kV power supply to the third busbar group 150, and transmit the 35 kV power supply to the corresponding second busbar section 134, so that the third busbar group 150 can realize 110 kV load power supply, and the second busbar section 134 can realize 35 kV load power supply.

[0048] In the above embodiment, the above 35kV voltage level large load power supply system is combined with a double-winding main transformer and a three-winding main transformer, which not only ensures the connection between the substation and the 220kV and 110kV power grids through the three-winding main transformer, but also ensures that the normal power supply of the low-voltage 35kV side is not affected when any equipment of the high- and medium-voltage side distribution device is overhauled, thereby ensuring the power supply reliability of the low-voltage 35kV side; and also takes into account the direct power supply of the 35kV load through the large-capacity double-winding main transformer to meet the 35kV large-load power demand; at the same time, the high-voltage side power supply of the double-winding main transformer is taken from the 220kV system, thereby improving the power supply reliability of the main transformer; in addition, compared with the conventional substation, which uses multiple three-winding main transformers in parallel operation on the high and medium voltage sides, the short-circuit current on the low-voltage side is greatly reduced, saving the investment in short-circuit protection of low-voltage side equipment; it can also reduce the scale of the 110kV distribution device in the substation, saving the area and construction investment of the substation.

[0049] In one example, if Figure 4As shown, the double-winding main transformer group 110 includes two double-winding main transformers 112, and the three-winding main transformer group 140 includes two three-winding main transformers 142. The first busbar group 120 is a 220kV busbar group, the second busbar group 130 is a 35kV busbar group (that is, the first busbar section 132 is a 35kV busbar, and the second busbar section 134 is a 35kV busbar), and the third busbar group 150 is a 110kV busbar group. The first high-voltage winding side of the double-winding main transformer 112 is a 220kV high-voltage winding side, and the first low-voltage winding side of the double-winding main transformer 112 is a 35kV low-voltage winding side. The double-winding main transformer 112 is used to transform the 220kV power supply into a 35kV power supply. The second high-voltage winding side of the three-winding main transformer 142 is a 220kV high-voltage winding side, the second medium-voltage winding side of the three-winding main transformer 142 is a 110kV medium-voltage winding side, and the second low-voltage winding side of the three-winding main transformer 142 is a 35kV low-voltage winding side. The three-winding main transformer 142 is used to transform the 220kV power supply into a 110kV power supply and a 35kV power supply. Based on the first busbar group 120 being respectively connected to the first high-voltage winding side of each double-winding main transformer 112 and the second high-voltage winding side of each three-winding main transformer 142, the third busbar group 150 being respectively connected to the second medium-voltage winding side of each three-winding main transformer 142, the first busbar section 132 is connected to the first low-voltage winding side of the corresponding double-winding main transformer 112, and the second busbar section 134 is connected to the second low-voltage winding side of the corresponding three-winding main transformer 142, thereby ensuring the connection between the three-winding main transformer 142 and the 220kV and 110kV power grids respectively, maintaining the high reliability of the substation, and at the same time taking into account the direct power supply of the 35kV load through the double-winding main transformer 112, without the need to distribute the 110kV load, thereby meeting the 35kV large load power demand. In addition, when any of the power distribution devices on the second high-voltage winding side and the power distribution devices on the second medium-voltage winding side of the three-winding main transformer 142 is under maintenance, the normal power supply of the 35kV load is not affected, thereby improving the power supply reliability of the 35kV load;

[0050] At the same time, by adopting the distribution method of two double-winding main transformers 112 and two three-winding main transformers 142, compared with the traditional method of adopting four three-winding main transformers 142, the short-circuit current on the low-voltage winding side of the main transformer is greatly reduced, saving the hardware cost of the short-circuit resistance of the low-voltage winding side equipment; moreover, because two double-winding main transformers 112 are selected to replace the three-winding main transformers in the conventional design, the scale of the 110kV distribution device in the substation is reduced, and the overall size and transportation weight of the main transformer are also greatly reduced, saving the substation's floor space and construction investment.

[0051] In one embodiment, Figure 5As shown, the 35 kV voltage level heavy load power supply system also includes a plurality of first section circuit breakers 160 ; first section circuit breakers 160 are arranged between two adjacent first bus sections 132 , two adjacent second bus sections 134 and / or between adjacent first bus sections 132 and second bus sections 134 .

[0052] For example, a first segmented circuit breaker 160 is provided between two adjacent first bus sections 132, thereby realizing segmented interconnection between the first bus sections 132 and the first bus sections 132. A first segmented circuit breaker 160 is provided between the adjacent first bus sections 132 and the second bus sections 134, thereby realizing segmented interconnection between the first bus sections 132 and the second bus sections 134. It should be noted that segmented interconnection can be provided for the second bus group 130 according to engineering needs.

[0053] In one embodiment, Figure 4 As shown, the first busbar group 120 is a 220 kV busbar group; the third busbar group 150 is a 110 kV busbar group; and the first high-voltage winding side is a 220 kV high-voltage winding side.

[0054] Among them, the first low-voltage winding side of the double-winding main transformer 112 is the 35kV low-voltage winding side. The second high-voltage winding side of the three-winding main transformer 142 is the 220kV high-voltage winding side, the second medium-voltage winding side of the three-winding main transformer 142 is the 110kV medium-voltage winding side, and the second low-voltage winding side of the three-winding main transformer 142 is the 35kV low-voltage winding side.

[0055] The double-winding main transformer 112 transforms the 220 kV power supply of the first busbar group 120 into a 35 kV power supply, and transmits the 35 kV power supply to the first busbar section 132, so as to supply power to the 35 kV load of the first busbar section 132. The three-winding main transformer 142 transforms the 220 kV power supply of the first busbar group 120 into a 110 kV power supply and a 35 kV power supply, and transmits the 110 kV power supply to the third busbar group 150, and transmits the 35 kV power supply to the second busbar section 134, so as to supply power to the 110 kV load of the third busbar group 150 and the 35 kV load of the first busbar section 132.

[0056] Since the main power supply load is at a voltage level of 35kV, the capacity of the main transformer can be reasonably selected to ensure that the capacity of the 35kV side of the main transformer is large enough. For example, by setting a double-winding main transformer 112, it is avoided that all main transformers in the substation are three-winding main transformers 142; by reasonably designing the number of voltage levels in the substation, the voltage level of the power supply is directly reduced to 35kV as much as possible, ensuring the power consumption capacity of the 35kV large load, and improving the power supply reliability of the 35kV side; by reducing the number of other voltage levels, the area occupied by the substation and the hardware cost are reduced.

[0057] In one embodiment, Figure 5 As shown, the 35kV voltage level heavy load power supply system also includes a second section circuit breaker 170; the number of double-winding main transformers 112 is 2, and the number of three-winding main transformers 142 is 2; the first bus group 120 includes a third bus section 122 and a fourth bus section 124; the second section circuit breaker 170 is connected between the third bus section 122 and the fourth bus section 124; the first high-voltage winding side of one double-winding main transformer 112 is connected to the third bus section 122, and the first high-voltage winding side of another double-winding main transformer 112 is connected to the fourth bus section 124; the second high-voltage winding side of one three-winding main transformer 142 is connected to the third bus section 122, and the second high-voltage winding side of another three-winding main transformer 142 is connected to the fourth bus section 124.

[0058] For example, based on the second segmented circuit breaker 170 being set between the third bus section 122 and the fourth bus section 124, the third bus section 122 and the fourth bus section 124 are interconnected in sections, and then when the main transformer (double-winding main transformer 112 or three-winding main transformer 142) connected to the third bus section 122, or the main transformer (double-winding main transformer 112 or three-winding main transformer 142) connected to the fourth bus section 124 needs maintenance, the second segmented circuit breaker 170 can be operated, thereby not affecting the normal power supply of the 35kV load of the second bus group 130, thereby ensuring the reliability of the 35kV load power supply.

[0059] In one example, two three-winding main transformers 142 and two double-winding main transformers 112 all use on-load voltage regulation at the neutral point on the high-voltage winding side, and the high-low voltage transformation ratio is the same, so that the voltage quality of the low-voltage winding side (i.e., the first low-voltage winding side and the second low-voltage winding side) of the four main transformers (i.e., two three-winding main transformers 142 and two double-winding main transformers 112) is consistent, which facilitates short-term parallel operation of different second busbar groups 130 and improves the reliability of 35kV load power supply.

[0060] In one embodiment, Figure 5 As shown, the 35kV voltage level heavy-load power supply system also includes a third section circuit breaker 180; the third busbar group 150 includes a fifth busbar section 152 and a sixth busbar section 154; the third section circuit breaker 180 is connected between the fifth busbar section 152 and the sixth busbar section 154; the second medium voltage winding side of a three-winding main transformer 142 is connected to the fifth busbar section 152, and the second medium voltage winding side of another three-winding main transformer 142 is connected to the sixth busbar section 154.

[0061] For example, based on the third segmented circuit breaker 180 being set between the fifth bus section 152 and the sixth bus section 154, the fifth bus section 152 and the sixth bus section 154 are interconnected in segments, and then when the three-winding main transformer 142 connected to the fifth bus section 152 or the three-winding main transformer 142 connected to the sixth bus section 154 needs maintenance, the third segmented circuit breaker 180 can be controlled, thereby not affecting the normal power supply of the 110kV load of the third bus group 150.

[0062] In one embodiment, the capacity of the two-winding main transformer 112 is the same as the capacity of the three-winding main transformer 142 .

[0063] For example, the double-winding main transformer 112 is a 220kV to 35kV transformer, and the three-winding main transformer 142 is a 220kV to 110kV, 35kV transformer. By setting the capacity of the double-winding main transformer 112 to be the same as the capacity of the three-winding main transformer 142, the double-winding main transformer 112 does not need to supply the 110kV load, ensuring that all double-winding main transformers 112 have the full capacity to supply the 35kV load, thereby meeting the power demand of the 35kV large load.

[0064] In one embodiment, Figure 6 As shown, the incoming line loop between the first low-voltage winding side and the corresponding first bus section is the double circuit breaker 200 incoming line, and the incoming line loop between the second low-voltage winding side and the corresponding second bus section is the double circuit breaker 200 incoming line.

[0065] It should be noted that after the voltage of the first high-voltage winding side of the dual-winding main transformer 112 and the second high-voltage winding side of the three-winding main transformer 142 rises to 220kV, the main transformer capacity also doubles, resulting in a doubling of the rated current of the first low-voltage winding side and the second low-voltage winding side, which has exceeded the existing 35kV circuit breaker manufacturing level. Therefore, the present invention optimizes the incoming line loop between the first low-voltage winding side and the corresponding first bus section 132 and the incoming line loop between the second low-voltage winding side and the corresponding second bus section 134 to a double circuit breaker 200 incoming line, and the two circuit breakers 200 share the loop current, which can effectively meet the operating requirements of various working conditions.

[0066] In one embodiment, Figure 7 As shown, the 35kV voltage level heavy load power supply system also includes a busbar connecting circuit breaker 190, and the second busbar group 130 includes a plurality of busbar sections, which are a plurality of first busbar sections 132 and a second busbar section 134; a busbar connecting circuit breaker 190 is arranged between the two busbar sections that are farthest apart.

[0067] In order to enhance the power supply reliability of the 35kV bus, a 35kV bus interconnecting circuit breaker 190 is installed between the two farthest bus sections (i.e., bus section Q1 and bus section Q4). When the first section circuit breaker 160 between the first bus section 132 and the second bus section 134 is under maintenance, if any of the three-winding main transformers 142 fails, the bus section Q1 or bus section Q4 can still be ensured to supply power normally, thereby greatly improving the 35kv power supply reliability.

[0068] In one embodiment, the present invention further provides a substation, comprising a 35 kV voltage level heavy load power supply system as any one of the above items.

[0069] Among them, for the specific description of the above-mentioned 35kV voltage level large-load power supply system, please refer to the description of the above-mentioned embodiment, which will not be repeated here.

[0070] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0071] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A 35kV voltage level large load power supply system, characterized in that: include: A double-winding main transformer group, the double-winding main transformer group includes a plurality of double-winding main transformers, the double-winding main transformer includes a first high-voltage winding side and a first low-voltage winding side; the first high-voltage winding side is a 220kV high-voltage winding side, and the first low-voltage winding side is a 35kV low-voltage winding side; A first busbar group, wherein the first busbar group is respectively connected to each of the first high-voltage winding sides; the first busbar group is a 220kV busbar group; A second busbar group, wherein the second busbar group includes a plurality of first busbar sections and second busbar sections; each of the first busbar sections is connected to each of the first low-voltage winding sides in a one-to-one correspondence; the first busbar section is a 35kV busbar, and the second busbar section is a 35kV busbar; A three-winding main transformer group and a third busbar group; the three-winding main transformer group includes a number of three-winding main transformers, and the three-winding main transformer includes a second high-voltage winding side, a second medium-voltage winding side and a second low-voltage winding side; each of the second high-voltage winding sides is respectively connected to the first busbar group, each of the second medium-voltage winding sides is respectively connected to the third busbar group, and each of the second low-voltage winding sides is connected to each of the second busbar sections in a one-to-one correspondence; the voltage of the first busbar group is greater than the voltage of the third busbar group, and the voltage of the third busbar group is greater than the voltage of the second busbar group; the second high-voltage winding side is a 220kV high-voltage winding side, the second medium-voltage winding side is a 110kV medium-voltage winding side, the second low-voltage winding side is a 35kV low-voltage winding side, and the third busbar group is a 110kV busbar group.

2. The 35kV voltage level heavy load power supply system according to claim 1 is characterized in that: The first high-voltage winding side and the second high-voltage winding side respectively adopt double busbar connection, the second medium-voltage winding side adopts double busbar connection, and the first low-voltage winding side and the second low-voltage winding side respectively adopt single busbar connection.

3. The 35kV voltage level heavy load power supply system according to claim 1 is characterized in that: The incoming line circuit between the first low-voltage winding side and the corresponding first bus section is a double circuit breaker incoming line, and the incoming line circuit between the second low-voltage winding side and the corresponding second bus section is a double circuit breaker incoming line.

4. The 35kV voltage level heavy load power supply system according to claim 1 is characterized in that: Also included are a plurality of first section circuit breakers; The first section circuit breaker is arranged between two adjacent sections of the first bus sections, two adjacent sections of the second bus sections, and / or between an adjacent first bus section and a second bus section.

5. The 35kV voltage level heavy load power supply system according to claim 1 is characterized in that: It also includes a busbar tie circuit breaker, wherein the second busbar group includes a plurality of busbar sections, and the plurality of busbar sections are a plurality of first busbar sections and a second busbar section; The busbar connecting circuit breaker is arranged between the two busbar sections which are farthest apart.

6. The 35kV voltage level heavy load power supply system according to claim 1 is characterized in that: It also includes a second segmented circuit breaker; the number of the double-winding main transformers is 2, and the number of the three-winding main transformers is 2; the first busbar group includes a third busbar section and a fourth busbar section; The second section circuit breaker is connected between the third bus section and the fourth bus section; the first high-voltage winding side of one of the two-winding main transformers is connected to the third bus section, and the first high-voltage winding side of another two-winding main transformer is connected to the fourth bus section; the second high-voltage winding side of one of the three-winding main transformers is connected to the third bus section, and the second high-voltage winding side of another three-winding main transformer is connected to the fourth bus section.

7. The 35kV voltage level heavy load power supply system according to claim 6 is characterized in that: It also includes a third segmented circuit breaker; the third busbar group includes a fifth busbar segment and a sixth busbar segment; the third segmented circuit breaker is connected between the fifth busbar segment and the sixth busbar segment; The second medium voltage winding side of one of the three-winding main transformers is connected to the fifth bus section, and the second medium voltage winding side of another of the three-winding main transformers is connected to the sixth bus section.

8. The 35kV voltage level heavy load power supply system according to claim 1 is characterized in that: The capacity of the two-winding main transformer is the same as the capacity of the three-winding main transformer.

9. The 35kV voltage level heavy load power supply system according to claim 1 is characterized in that: The three-winding main transformer and the two-winding main transformer both adopt on-load voltage regulation of the neutral point on the high-voltage winding side, and the high-voltage and low-voltage transformation ratios are the same; and / or The windings in the first high-voltage winding side and the second high-voltage winding side adopt a Y-type connection method, the windings in the second medium-voltage winding side adopt a Y-type connection method, and the first low-voltage winding side and the second low-voltage winding side adopt a triangle connection method.

10. A substation, characterized in that: It comprises a 35kV voltage level heavy load power supply system as described in any one of claims 1 to 9.

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