35kv voltage class heavy load supply system and substation

Abstract

The application relates to a 35kV voltage grade heavy load power supply system and a transformer substation, which 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 double-winding main transformer group can ensure that the capacity of the main transformer 35kV side is large enough to meet the power demand of the 35kV heavy load; the three-winding main transformer group can realize the connection between the 220kV and 110kV power grids and ensure the power supply reliability of the low-voltage 35kV side; the power supply of the first high-voltage winding side is directly taken from the power supply of the first bus group, thereby improving the power supply reliability and power supply efficiency of the main transformer; the double-winding main transformer group is used to replace the three-winding main transformer in the conventional design, the scale of the 110kV power distribution device in the transformer substation is reduced, the size of the double-winding main transformer group is small, and thus the land occupation of the transformer substation is saved and the maintenance cost is reduced.

Description

Technical Field

[0001] This application relates to the field of power technology, and in particular to a 35kV high-load power supply system and substation. Background Technology

[0002] A substation is a location in a power system that transforms voltage and current, receives electrical energy, and distributes electrical energy. Currently, there are generally two ways to supply power to large loads at the 35kV voltage level in a power system: the first method, such as... Figure 1 As shown, a 110kV three-winding main transformer is used to step down the 110kV voltage to 35kV and 10kV, with the 35kV load connected to the medium-voltage busbar of the main transformer. The second method, as... 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 busbar of the main transformer is connected to a 35kV load.

[0003] In existing methods for supplying power to large loads at the 35kV voltage level, the first method, as mentioned above, results in a complete power outage when the 110kV busbar fails or is under maintenance. Furthermore, a short-circuit fault on the 10kV side of the main transformer causes the main transformer to shut down, consequently affecting the 35kV busbar. This leads to low reliability of power supply to 35kV loads, limited capacity for 35kV loads, low power supply efficiency, and the need for multiple substations to meet load requirements, resulting in high costs. The second method, using a 220kV three-winding main transformer primarily to supply 110kV loads, has a limited capacity allocated to the 35kV side, insufficient to meet the power demands of large 35kV loads. A short-circuit fault on the low-voltage side at 35kV will cause the main transformer to shut down, potentially affecting the normal operation of the 220kV and 110kV busbars, resulting in low power supply reliability for the substation. Additionally, the 220kV three-winding main transformer is bulky and requires the design of distribution equipment for different voltage levels, resulting in a large footprint and high maintenance costs. Summary of the Invention

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

[0005] To achieve the above objectives, embodiments of the present invention provide a 35kV high-load power supply system, comprising:

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

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

[0008] The second busbar group comprises a plurality of first busbar segments and second busbar segments; each first busbar segment is connected with each first low-voltage winding side one by one; the first busbar segment is a 35 kV busbar, and the second busbar segment is a 35 kV busbar;

[0009] The third busbar group is connected with each second low-voltage winding side one by one; 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 220 kV high-voltage winding side, the second medium-voltage winding side is a 110 kV medium-voltage winding side, the second low-voltage winding side is a 35 kV low-voltage winding side, and the third busbar group is a 110 kV busbar group.

[0010] In one of the embodiments, the first high-voltage winding side and the second high-voltage winding side are connected with double-busbar wiring respectively, the second medium-voltage winding side is connected with double-busbar wiring, and the first low-voltage winding side and the second low-voltage winding side are connected with single-busbar wiring respectively.

[0011] In one of the embodiments, the incoming line circuit between the first low-voltage winding side and the corresponding first busbar segment is a double-breaker incoming line circuit, and the incoming line circuit between the second low-voltage winding side and the corresponding second busbar segment is a double-breaker incoming line circuit.

[0012] In one of the embodiments, the 35 kV voltage grade large-load power supply system further comprises a plurality of first sectional breakers.

[0013] The first sectional breakers are arranged between adjacent two first busbar segments, adjacent two second busbar segments, and / or adjacent first busbar segments and second busbar segments.

[0014] In one of the embodiments, the 35 kV voltage grade large-load power supply system further comprises a busbar tie breaker, and the second busbar group comprises a plurality of busbar segments, which are a plurality of first busbar segments and second busbar segments.

[0015] The bus tie circuit breaker is arranged between the two bus sections farthest apart.

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

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

[0018] In one of the embodiments, the 35kV voltage level heavy load power supply system further comprises a third sectionalizing circuit breaker; the third bus group comprises a fifth bus section and a sixth bus section; the third sectionalizing circuit breaker is connected between the fifth bus section and the sixth bus 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 the other three-winding main transformer is connected to the sixth bus section.

[0020] In one of the embodiments, the capacity of the double-winding main transformer is the same as that of the three-winding main transformer.

[0021] In one of the embodiments, the three-winding main transformer and the double-winding main transformer both adopt high-voltage winding side neutral point on-load voltage regulation, and the high-voltage to low-voltage transformer ratio is the same; and / or

[0022] The windings in the first high-voltage winding side and the second high-voltage winding side adopt Y-type connection mode, the windings in the second medium-voltage winding side adopt Y-type connection mode, and the first low-voltage winding side and the second low-voltage winding side adopt delta-type connection mode.

[0023] On the other hand, the embodiments of the present application also provide a substation comprising the 35kV voltage level heavy load power supply system according to any one of the above.

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

[0025] In each of the above embodiments of the 35kV voltage level large load power supply system, the double-winding main transformer set, the first bus set, the second bus set, the three-winding main transformer set and the third bus set are included. The substation is connected to the 220kV and 110kV power grid through the three-winding main transformer, and when any equipment of the high-voltage and medium-voltage distribution devices is under maintenance, the normal power supply of the low-voltage 35kV side is not affected, and the power supply reliability of the low-voltage 35kV side is ensured. In addition, the large capacity double-winding main transformer is directly used to supply power to the 35kV load, which meets the demand of 35kV large load power supply. At the same time, the high-voltage side power supply of the double-winding main transformer is taken from the 220kV system, which improves the power supply reliability of the main transformer.

[0026] In addition, the 35kV voltage level large load power supply system combines the double-winding main transformer and the three-winding main transformer. Compared with the parallel operation of multiple three-winding main transformers in the conventional substation, the short-circuit current of the low-voltage side is greatly reduced, and the investment in short-circuit resistance of the low-voltage side equipment is saved. In addition, the scale of the 110kV distribution device in the substation can be reduced, and the land area and construction investment of the substation can be saved. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 FIG. 1 is a first structural schematic diagram of a traditional 35kV voltage level large load power supply system;

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

[0029] Figure 3 FIG. 3 is a first structural schematic diagram of a 35kV voltage level large load power supply system in an embodiment;

[0030] Figure 4 FIG. 4 is a second structural schematic diagram of a 35kV voltage level large load power supply system in an embodiment;

[0031] Figure 5 FIG. 5 is a third structural schematic diagram of a 35kV voltage level large load power supply system in an embodiment;

[0032] Figure 6 FIG. 6 is a fourth structural schematic diagram of a 35kV voltage level large load power supply system in an embodiment;

[0033] Figure 7 FIG. 7 is a fifth structural schematic diagram of a 35kV voltage level large load power supply system in an embodiment.

[0034] REFERENCE SIGNS:

[0035] 110, double-winding main transformer bank; 112, double-winding main transformer; 120, first busbar bank; 122, third busbar section; 124, fourth busbar section; 130, second busbar bank; 132, first busbar section; 134, second busbar section; 140, three-winding main transformer bank; 142, three-winding main transformer; 150, third busbar bank; 152, fifth busbar section; 154, sixth busbar section; 160, first section circuit breaker; 170, second section circuit breaker; 180, third section circuit breaker; 190, busbar tie circuit breaker; 200, circuit breaker. DETAILED DESCRIPTION

[0036] In order to make the persons skilled in the art better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described in the following with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those of ordinary skill in the art without creative work should belong to the scope of protection of the present application.

[0037] It should be noted that the terms "first", "second" and the like in the description and the claims of the present application and the above-mentioned accompanying drawings are used to distinguish similar objects, and do not necessarily indicate a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented. In addition, the terms "comprise" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device comprising a series of steps or units does not necessarily limit to those clearly listed steps or units, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0038] In addition, the term "a plurality of" should mean two and more than two.

[0039] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. 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, as Figure 3As shown, a 35kV voltage level heavy load power supply system is provided, which includes a double-winding main transformer set 110, a first bus set 120, a second bus set 130, a three-winding main transformer set 140, and a third bus set 150. The double-winding main transformer set 110 includes a plurality of double-winding main transformers 112, each of which includes a first high-voltage winding side and a first low-voltage winding side, the first high-voltage winding side being a 220kV high-voltage winding side, and the first low-voltage winding side being a 35kV low-voltage winding side; the first bus set 120 is connected to each first high-voltage winding side, and the first bus set is a 220kV bus set; the second bus set 130 includes a plurality of first bus segments 132 and a plurality of second bus segments 134; each first bus segment 132 is connected to a corresponding first low-voltage winding side; the first bus segment 132 is a 35kV bus, and the second bus segment 134 is a 35kV bus. The three-winding main transformer set 140 includes a plurality of three-winding main transformers 142, each of which 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 connected to the first bus set 120, each second medium-voltage winding side is connected to the third bus set 150, and each second low-voltage winding side is connected to a corresponding second bus segment 134; the voltage of the first bus set 120 is greater than the voltage of the third bus set 150, and the voltage of the third bus set 150 is greater than the voltage of the second bus set 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 bus set is a 110kV bus set.

[0041] The double-winding main transformer set 110 can include a plurality of double-winding main transformers 112, for example, the double-winding main transformer set 110 includes two double-winding main transformers 112. The double-winding main transformer 112 can be used to transform the power supply of the first bus set 120 to a 35kV power supply. The double-winding main transformer 112 includes a first high-voltage winding side and a first low-voltage winding side, and the windings in the first high-voltage winding side can adopt a Y-type (star-type) connection mode; the first low-voltage winding side can adopt a delta-type connection mode.

[0042] The first bus set 120 is a first double bus set (i.e., the first high-voltage winding side and the second high-voltage winding side adopt double bus connection). It should be noted that the first single bus set refers to a bus set composed of one first bus, and the first double bus set refers to a bus set composed of two first buses.

[0043] The second bus group 130 is a single bus group (i.e., the first low-voltage winding side and the second low-voltage winding side are connected by single bus wiring), and the second bus group 130 can be divided into a plurality of first bus segments 132; the number of the first bus segments 132 is the same as the number of the first low-voltage winding side, that is, the first bus segment 132 is connected with the corresponding first low-voltage winding side.

[0044] Based on the first bus group 120 connected with the first high-voltage winding side of each double-winding main transformer 112, the first low-voltage winding side of the double-winding main transformer 112 is connected with the corresponding first bus segment 132, and then the double-winding main transformer 112 can transform the power supply of the first bus group 120 to obtain a 35kV power supply, and transmit the 35kV power supply to the corresponding first bus segment 132, so that the first bus segment 132 can realize power supply for 35kV load.

[0045] Correspondingly, the three-winding main transformer group 140 can include a plurality of three-winding main transformers 142, for example, the three-winding main transformer group 140 can include two three-winding main transformers 142. The three-winding main transformer 142 can be used to transform and output the power supply of the first bus group 120 as 110kV and 35kV 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 winding in the second high-voltage winding side can be obtained by Y-type (star-type) wiring; the winding in the second medium-voltage winding side can be obtained by Y-type (star-type) wiring; and the first low-voltage winding side can be obtained by delta-type wiring.

[0046] The third bus group 150 is a third double bus group (i.e., the second medium-voltage winding side adopts double bus wiring), and it should be noted that the third double bus group refers to a bus group composed of two third buses. The second bus group 130 can also be divided into a plurality of second bus segments 134; the number of the second bus segments 134 is the same as the number of the second low-voltage winding side, that is, the second bus segment 134 is connected with the corresponding second low-voltage winding side.

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

[0048] In the above embodiment, the 35 kV voltage level large load power supply system combines the double-winding main transformer and the three-winding main transformer, which ensures that the substation is connected to the 220 kV and 110 kV power grid through the three-winding main transformer, and when any device of the high-voltage and medium-voltage side power distribution device is under maintenance, the normal power supply of the low-voltage 35 kV side is not affected, and the power supply reliability of the low-voltage 35 kV side is ensured. The large-capacity double-winding main transformer is also used to directly supply power to the 35 kV load, which meets the demand of 35 kV large load power supply. At the same time, the high-voltage side power supply of the double-winding main transformer is taken from the 220 kV system, which improves the power supply reliability of the main transformer. In addition, compared with the conventional substation in which multiple three-winding main transformers are used for parallel operation of the high-voltage and medium-voltage sides, the short-circuit current of the low-voltage side is greatly reduced, and the investment in short-circuit resistance of the low-voltage side equipment is saved. The scale of the 110 kV power distribution device in the substation is also reduced, which saves the land area and construction investment of the substation.

[0049] In one example, as Figure 4As shown, the double-winding main transformer set 110 includes two double-winding main transformers 112, and the triple-winding main transformer set 140 includes two triple-winding main transformers 142. The first bus set 120 is a 220 kV bus set, the second bus set 130 is a 35 kV bus set (i.e., the first bus section 132 is a 35 kV bus, and the second bus section 134 is a 35 kV bus), and the third bus set 150 is a 110 kV bus set. The first high-voltage winding side of the double-winding main transformer 112 is a 220 kV high-voltage winding side, the first low-voltage winding side of the double-winding main transformer 112 is a 35 kV low-voltage winding side, and the double-winding main transformer 112 is used to transform a 220 kV power supply into a 35 kV power supply. The second high-voltage winding side of the triple-winding main transformer 142 is a 220 kV high-voltage winding side, the second medium-voltage winding side of the triple-winding main transformer 142 is a 110 kV medium-voltage winding side, the second low-voltage winding side of the triple-winding main transformer 142 is a 35 kV low-voltage winding side, and the triple-winding main transformer 142 is used to transform a 220 kV power supply into a 110 kV power supply and a 35 kV power supply. Based on the first bus set 120 connecting the first high-voltage winding side of each double-winding main transformer 112 and the second high-voltage winding side of each triple-winding main transformer 142, respectively, the third bus set 150 connecting the second medium-voltage winding side of each triple-winding main transformer 142, the first bus section 132 connecting the first low-voltage winding side of the corresponding double-winding main transformer 112, and the second bus section 134 connecting the second low-voltage winding side of the corresponding triple-winding main transformer 142, the contact between the triple-winding main transformer 142 and the 220 kV and 110 kV power grids, respectively, can be ensured, the high reliability of the substation can be maintained, the direct power supply to the 35 kV load through the double-winding main transformer 112 is taken into account, the 110 kV load does not need to be supplied separately, and the 35 kV large load power demand is met. In addition, when any one of the power distribution devices of the second high-voltage winding side and the second medium-voltage winding side of the triple-winding main transformer 142 is under maintenance, the normal power supply of the 35 kV load is not affected, and the power supply reliability of the 35 kV load is improved.

[0050] Meanwhile, by adopting the power distribution mode of two double-winding main transformers 112 and two triple-winding main transformers 142, compared with the traditional mode of four triple-winding main transformers 142, the short-circuit current of the low-voltage winding side of the main transformer is greatly reduced, and the hardware cost of the low-voltage winding side equipment for resisting short-circuit is saved. Moreover, because two double-winding main transformers 112 are selected instead of the triple-winding main transformer in the conventional design, the scale of the 110 kV power distribution device in the substation is reduced, the external dimensions and transportation weight of the main transformer are greatly reduced, and the land occupation and construction investment of the substation are saved.

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

[0052] For example, based on the first sectional circuit breakers 160 arranged between adjacent two first bus sections 132, sectional interconnection between the first bus sections 132 is realized. Based on the first sectional circuit breakers 160 arranged between adjacent first bus section 132 and second bus section 134, sectional interconnection between the first bus section 132 and the second bus section 134 is realized. It should be noted that the second bus group 130 can be provided with sectional interconnection according to engineering needs.

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

[0054] The first low-voltage winding side of the double-winding main transformer 112 is a 35kV low-voltage winding side. 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.

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

[0056] Since the main power supply load is of 35kV voltage level, the capacity of the main transformer 35kV side can be ensured to be large enough by reasonably selecting the capacity of the main transformer. For example, by arranging the double-winding main transformer 112, it is avoided that all the main transformers in the substation are three-winding main transformers 142; by reasonably designing the number of voltage levels in the substation, it is tried to realize direct reduction from the power supply voltage level to the 35kV voltage level, so as to ensure the power consumption capacity of the 35kV heavy load and improve the reliability of the 35kV side power supply; by reducing the number of other voltage levels, the land occupation area and hardware cost of the substation are reduced.

[0057] In one embodiment, as shown in FIG. 1, the 35kV voltage level heavy load power supply system further comprises a second sectional 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 busbar group 120 comprises a third busbar section 122 and a fourth busbar section 124; the second sectional circuit breaker 170 is connected between the third busbar section 122 and the fourth busbar section 124; the first high-voltage winding side of one double-winding main transformer 112 is connected to the third busbar section 122, and the first high-voltage winding side of the other double-winding main transformer 112 is connected to the fourth busbar section 124; the second high-voltage winding side of one three-winding main transformer 142 is connected to the third busbar section 122, and the second high-voltage winding side of the other three-winding main transformer 142 is connected to the fourth busbar section 124. Figure 5 For example, based on the second sectional circuit breaker 170 being arranged between the third busbar section 122 and the fourth busbar section 124, the third busbar section 122 and the fourth busbar section 124 are sectionally interconnected, and thus when the main transformer (double-winding main transformer 112 or three-winding main transformer 142) connected to the third busbar section 122 or the main transformer (double-winding main transformer 112 or three-winding main transformer 142) connected to the fourth busbar section 124 needs to be overhauled, the second sectional circuit breaker 170 can be operated, thereby not affecting the normal power supply of the 35kV load of the second busbar group 130, and the reliability of the 35kV load power supply is ensured.

[0058] In one example, the 2 three-winding main transformers 142 and the 2 double-winding main transformers 112 all adopt on-load voltage regulation at the neutral point of the high-voltage winding, and the transformation ratio between the high-voltage winding and the low-voltage winding 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 4 main transformers (i.e., the 2 three-winding main transformers 142 and the 2 double-winding main transformers 112) is consistent, and different second busbar groups 130 can be short-time parallelly operated, thereby improving the reliability of the 35kV load power supply.

[0059] In one embodiment, as shown in FIG. 2, the 35kV voltage level heavy load power supply system further comprises a third sectional circuit breaker 180; the third busbar group 150 comprises a fifth busbar section 152 and a sixth busbar section 154; the third sectional circuit breaker 180 is connected between the fifth busbar section 152 and the sixth busbar section 154; the second medium-voltage winding side of one three-winding main transformer 142 is connected to the fifth busbar section 152, and the second medium-voltage winding side of the other three-winding main transformer 142 is connected to the sixth busbar section 154.

[0060] Figure 5 For example, based on the third sectional circuit breaker 180 being arranged between the fifth busbar section 152 and the sixth busbar section 154, the fifth busbar section 152 and the sixth busbar section 154 are sectionally interconnected, and thus when the main transformer (three-winding main transformer 142) connected to the fifth busbar section 152 or the main transformer (three-winding main transformer 142) connected to the sixth busbar section 154 needs to be overhauled, the third sectional circuit breaker 180 can be operated, thereby not affecting the normal power supply of the 35kV load of the third busbar group 150, and the reliability of the 35kV load power supply is ensured.

[0061] ​For example, based on setting the third sectional circuit breaker 180 between the fifth bus section 152 and the sixth bus section 154, the sectional interconnection between the fifth bus section 152 and the sixth bus section 154 is formed, 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 to be overhauled, the third sectional circuit breaker 180 can be controlled, and then the normal power supply of the 110kV load of the third bus group 150 is not affected.

[0062] In one embodiment, the capacity of the double-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, and all the double-winding main transformer 112 capacity is fully supplied to the 35kV load, meeting the power demand of the 35kV large load.

[0064] In one embodiment, as shown in Figure 6 The incoming line circuit between the first low-voltage winding side and the corresponding first bus section is a double-break 200 incoming line, and the incoming line circuit between the second low-voltage winding side and the corresponding second bus section is a double-break 200 incoming line.

[0065] It should be noted that after the voltage of the first high-voltage winding side of the double-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 breaker manufacturing level. Therefore, the present application optimizes the incoming line circuit between the first low-voltage winding side and the corresponding first bus section 132 and the incoming line circuit between the second low-voltage winding side and the corresponding second bus section 134 to a double-break 200 incoming line, and the circuit current is shared by two breakers 200, which can effectively meet the operation requirements of each working condition.

[0066] In one embodiment, as shown in Figure 7 The 35kV voltage grade large load power supply system further includes a bus tie circuit breaker 190, the second bus group 130 includes a plurality of bus sections, and the plurality of bus sections are a plurality of first bus sections 132 and a plurality of second bus sections 134; the bus tie circuit breaker 190 is arranged between the two bus sections farthest apart.

[0067] To enhance the power supply reliability of the 35kV bus, a 35kV bus tie circuit breaker 190 is installed between the two most distant bus sections (i.e., bus section Q1 and bus section Q4), so that when the first sectionalizing 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 transformer 142 fails, the bus section Q1 or the bus section Q4 can still be normally powered, greatly improving the power supply reliability of the 35kV bus.

[0068] In one embodiment, the embodiments of the present application also provide a substation comprising the 35kV voltage level large load power supply system according to any one of the above embodiments.

[0069] In the above embodiments, the 35kV voltage level large load power supply system is described in detail above, and will not be described here again.

[0070] The technical features of the above embodiments can be combined in any manner. To make the description concise, all possible combinations of the technical features in the above embodiments are not described, but as long as the combinations of the technical features do not contradict, they should be considered as the scope of the present application.

[0071] The above embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, but it should not be understood as a limitation on the scope of the patent. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present application, several modifications and improvements can be made, which are all within the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A 35kV high-load power supply system, characterized in that, include: A dual-winding main transformer group, comprising several dual-winding main transformers, each dual-winding main transformer including 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 busbar group is connected to each of the first high-voltage winding sides; the first busbar group is a 220kV busbar group. The second busbar group includes several first busbar segments and second busbar segments; each first busbar segment is connected to each first low-voltage winding side in a one-to-one correspondence; the first busbar segment is a 35kV busbar, and the second busbar segment is a 35kV busbar. A three-winding main transformer group and a third busbar group; the three-winding main transformer group includes several three-winding main transformers, each including 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 connected to the first busbar group, each second medium-voltage winding side is connected to the third busbar group, and each second low-voltage winding side is connected to each second busbar segment 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; The 35kV high-load power supply system also includes a second sectional circuit breaker; there are two dual-winding main transformers and two triple-winding main transformers; the first busbar group includes a third busbar section and a fourth busbar section; the second sectional circuit breaker is connected between the third busbar section and the fourth busbar section; the first high-voltage winding side of one dual-winding main transformer is connected to the third busbar section, and the first high-voltage winding side of the other dual-winding main transformer is connected to the fourth busbar section; the second high-voltage winding side of one triple-winding main transformer is connected to the third busbar section, and the second high-voltage winding side of the other triple-winding main transformer is connected to the fourth busbar section; The 35kV high-load power supply system also includes a third sectional circuit breaker; the third busbar group includes a fifth busbar section and a sixth busbar section; the third sectional circuit breaker is connected between the fifth busbar section and the sixth busbar section; the second medium-voltage winding side of one of the three-winding main transformers is connected to the fifth busbar section, and the second medium-voltage winding side of the other three-winding main transformer is connected to the sixth busbar section.

2. The 35kV high-load power supply system according to claim 1, characterized in that, The first high-voltage winding side and the second high-voltage winding side are respectively connected by double busbars, the second medium-voltage winding side is connected by double busbars, and the first low-voltage winding side and the second low-voltage winding side are respectively connected by single busbars.

3. The 35kV high-load power supply system according to claim 1, characterized in that, The incoming circuit between the first low-voltage winding side and the corresponding first busbar segment is a double circuit breaker incoming circuit, and the incoming circuit between the second low-voltage winding side and the corresponding second busbar segment is a double circuit breaker incoming circuit.

4. The 35kV high-load power supply system according to claim 1, characterized in that, It also includes several first-section circuit breakers; The first sectionalizing circuit breaker is installed between two adjacent first busbar sections, two adjacent second busbar sections, and / or between adjacent first busbar sections and second busbar sections.

5. The 35kV high-load power supply system according to claim 1, characterized in that, It also includes a bus tie circuit breaker, and the second bus group includes several bus sections, which are several first bus sections and second bus sections; The bus tie circuit breaker is installed between the two busbar sections that are furthest apart.

6. The 35kV high-load power supply system according to claim 1, characterized in that, The capacity of the dual-winding main transformer is the same as that of the three-winding main transformer.

7. The 35kV high-load power supply system according to claim 1, characterized in that, Both the three-winding main transformer and the two-winding main transformer adopt on-load tap changing at 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 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 delta connection method.

8. A substation, characterized in that, This includes the 35kV voltage level high-load power supply system as described in any one of claims 1 to 7.

Images