Extra-high voltage converter station with overlapped structure

Abstract

The invention discloses an extra-high voltage converter station with an overlapping structure. The extra-high voltage converter station comprises a valve hall, a converter unit, a polar line unit, a starting loop, an alternating current field, a bridge reactor unit, a limited reactor unit, a metal return line unit and a grounding electrode outgoing line unit, the valve hall comprises a valve tower and converter valves, and the converter units and the polar line units are distributed on the two sides of the valve hall to form a first-layer framework. The first-layer framework further comprises a metal loop unit which is arranged in the middle of the valve hall. The starting loop, the alternating current field, the bridge reactance unit, the limited reactance unit and the grounding electrode outgoing line unit form a second-layer framework; the starting loop and the alternating current field are arranged above the commutation unit, and the starting loop is connected with the alternating current field; the bridge reactance unit, the limited reactance unit and the grounding electrode outgoing line unit are arranged above the polar line unit; the first-layer framework and the second-layer framework are constructed through a supporting type platform. According to the method, each area of the converter station is split, and a space overlapping structure is adopted for optimization, so that the field utilization rate is improved, and the occupied area is saved.

Description

Technical Field

[0001] The present invention relates to the technical field of converter stations, and in particular to an ultra-high voltage converter station with an overlapping structure. Background Art

[0002] The overall planning and general layout of the converter station are directly related to the construction investment benefits and subsequent operation quality of the converter station and related lines. Reasonable electrical general layout is crucial to saving precious land resources, ensuring smooth process of the converter station, and convenient operation and maintenance. Conventional converter stations are mainly composed of converter areas, DC fields, AC fields and front-of-station areas. Due to technical and economic limitations, the construction of converter stations requires certain spatial terrain conditions. However, renewable energy sources such as hydropower and photovoltaics are concentrated in mountainous canyon areas. The terrain in this area is complex and diverse, with high altitudes, large height differences, high earthquake intensity, fragile ecological environment, and frequent geological disasters. As a result, the available land resources suitable for station construction are very limited and relatively scattered. At present, there is a lack of mature solutions for the design of UHV converter stations in mountainous and canyon areas. Faced with such complex situations, it is necessary to comprehensively consider unfavorable factors such as high altitude, high earthquake intensity, and high temperature difference, and conduct selection research on distribution devices; at the same time, under limited and complex terrain conditions, in-depth layout optimization is carried out for each distribution device area. By studying its layout and occupation, while ensuring safe operation, it is possible to reduce the occupied area, reduce the difficulty of construction, and make the converter station more neat and beautiful, which is of great significance to improving the overall design level of the converter station.

[0003] The existing ±800kV UHV flexible DC converter station adopts a single-layer layout of open DC field equipment. The converter area of ​​the ±800kV converter station consists of four parts: high-end and low-end valve halls, bridge arm reactor area, high-end and low-end connecting transformers, and connecting transformer square. The valve hall and connecting transformer area consider the one-line layout of high-end and low-end valve halls and the one-line tight valve hall layout of connecting transformers. The connecting transformer square is located in the open space between the valve hall and the AC distribution device. The connecting transformer incoming line is located above the connecting transformer and is connected to the AC distribution device using overhead lines. The DC field adopts a typical UHV bipolar connection, and each valve group is equipped with a bypass circuit breaker and an isolating switch circuit. The DC field is arranged according to pole symmetry. The DC neutral point equipment and grounding pole outlet equipment are arranged in the center of the DC distribution device, and the DC high-voltage pole line equipment is arranged on both sides of the DC distribution device. The DC bypass switch circuit equipment is arranged between the high and low-end valve halls of each pole. The one bypass circuit breaker and three bypass isolating switches of each valve group are arranged in a U-shaped pattern, installed close to the valve hall, and connected to the valve hall equipment through a wall bushing. The neutral busbar equipment and the grounding electrode lead-out equipment are arranged between the low-end valve halls of the two poles. The AC power distribution device uses sulfur hexafluoride enclosed combination electrical appliances (hereinafter referred to as GIS). The low-voltage power distribution device and amplitude phase corrector are arranged outdoors, in a straight line with the AC GIS equipment or arranged in the open space between the AC field and the DC field.

[0004] The layout of conventional flexible DC converter stations has clear functional divisions, relatively smooth processes, and convenient operation and maintenance. However, this layout occupies a large area. When carrying out the plan layout at the UHV station site in the high mountain valley, it is necessary to comprehensively consider the restrictions of the harsh terrain and the process requirements of the electrical layout, and the overall plan layout should be adapted to the site conditions as much as possible. Under this premise, some common modules and equipment selection principles are often no longer applicable, that is, conventional distribution device modules cannot adapt to the complex terrain requirements, and conventional equipment selection cannot meet the actual needs of the project. At present, there is a plan to use DC GIS equipment instead of the conventional open DC field layout. This plan can significantly reduce the area occupied by the DC field, but because the valve hall, converter square, AC area, station front area and other areas still require a large site, the overall space optimization for the ±800kV flexible DC converter station is relatively limited. Summary of the invention

[0005] To solve the above problems, the present invention provides an ultra-high voltage converter station with an overlapping structure. Combining the power distribution device and site layout characteristics of the ±800kV flexible DC converter station, each area is split and optimized with a spatial overlapping structure, which significantly improves the site utilization rate and saves floor space.

[0006] The present invention provides an ultra-high voltage converter station with an overlapping architecture, and the specific technical solution is as follows:

[0007] It includes valve hall, commutation unit, pole line unit, starting circuit, AC field, bridge reactor unit, limiting reactor unit, metal return line unit and grounding pole outlet unit;

[0008] The valve hall includes a valve tower and a converter valve, and the converter unit and the polar line unit are distributed on both sides of the valve hall to form a first layer of architecture; the first layer of architecture also includes a metal return line unit, and the metal return line unit is arranged in the middle of the valve hall;

[0009] The starting circuit, AC field, bridge impedance unit, impedance limiting unit and grounding electrode outlet unit constitute a second layer architecture; the starting circuit and the AC field are arranged above the commutation unit, and the starting circuit is connected to the AC field; the bridge impedance unit, impedance limiting unit and grounding electrode outlet unit are arranged above the pole line unit; the impedance limiting unit is connected to the metal return line unit below; the bridge impedance unit and the grounding electrode unit are arranged on both sides of the impedance limiting unit;

[0010] The first-layer structure and the second-layer structure are constructed through a supporting platform, and the supporting platform corresponding to the area where the valve hall is located is provided with a DC wall bushing, which vertically passes through the supporting platform where the valve hall area is located.

[0011] Furthermore, the commutation unit includes a converter transformer, and the pole line unit includes a smoothing reactor and a switching device.

[0012] Furthermore, the valve hall and the converter unit form a straight-line distribution structure, and the valve-side bushing of the converter transformer is directly inserted into the valve hall.

[0013] Furthermore, a firewall is provided between the converter transformers, and the outgoing wires of the converter transformers vertically penetrate the supporting platform through a GIL pipeline.

[0014] Furthermore, the starting circuit includes a starting resistor and a lightning arrester, and the starting circuit is connected in series with the converter transformer.

[0015] Furthermore, the AC field includes an indoor GIS, a station transformer and an AC outgoing line frame, the starting circuit is arranged above the AC field, and the starting circuit is connected to the indoor GIS of the AC field below.

[0016] Furthermore, the outgoing line frame in the AC field is a 500kV AC outgoing line frame.

[0017] Furthermore, the bridge impedance unit includes a bridge arm reactor and a switch device; the limiting impedance unit includes a current limiting reactor, an isolating switch, a lightning arrester and a resistor; and the grounding electrode unit includes a grounding electrode outlet frame, a reactor and an isolating switch.

[0018] Furthermore, the bridge impedance unit is connected to the pole line unit through a GIL pipe or cable.

[0019] Furthermore, the DC wall bushing is connected to the valve tower outlet and the bridge arm reactor on both sides.

[0020] The beneficial effects of the present invention are as follows:

[0021] The present invention divides the converter station into valve hall, converter unit, pole line unit, starting circuit, AC field, bridge reactor unit, limiting reactor unit, metal return line unit and grounding pole outlet line unit by dividing the functional area of ​​the converter station into the smallest unit, and optimizes it by adopting spatial overlapping structure. Through GIS, each area is compactly arranged, and the areas are electrically connected to each other, which improves the site utilization rate, facilitates operation and maintenance, and reduces the influence of terrain. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the cross-sectional structure of the converter station of the present invention.

[0023] Figure 2 It is a schematic diagram of the first-layer architecture of the converter station of the present invention.

[0024] Figure 3 It is a schematic diagram of the second-layer architecture of the converter station of the present invention.

[0025] Explanation of the reference numerals: 1-valve hall, 101-valve tower, 2-pole line unit, 201-smoothing reactor, 3-bridge reactor unit, 4-starting circuit, 5-limiting reactor unit, 6-current converter unit, 601-converter transformer, 7-grounding pole outgoing line frame, 8-metal return line unit, 9-AC field, 901-AC outgoing line frame. DETAILED DESCRIPTION

[0026] The following description clearly and completely describes the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] In the description of the embodiments of the present invention, it should be noted that the indicated orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the invention product is usually placed when in use, or the orientation or positional relationship commonly understood by those skilled in the art, or the orientation or positional relationship in which the invention product is usually placed when in use, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first" and "second" are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0028] In the description of the embodiments of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0029] Example 1

[0030] Embodiment 1 of the present invention discloses an ultra-high voltage converter station with an overlapping architecture, such as Figure 1 As shown, the details are as follows:

[0031] The converter station includes a valve hall 1, a converter unit 6, a pole line unit 2, a start-up circuit 4, an AC field 9, a bridge impedance unit 3, a limiting impedance unit 5, a metal return line unit 8, and a grounding pole outgoing line unit;

[0032] Combination Figure 2As shown, the valve hall 1 includes a valve tower 101 and a converter valve, and the converter unit 6 and the polar line unit 2 are distributed on both sides of the valve hall 1 to form a first layer of architecture; the first layer of architecture also includes a metal return line unit 8, and the metal return line unit 8 is arranged in the middle of the valve hall 1;

[0033] Based on the principle of main electrical connection and convenience of electrical connection, the metal return line is arranged on the bottom layer, between the pole line units 2.

[0034] The commutation unit 6 includes a converter transformer 601 , and the pole line unit 2 includes a smoothing reactor 201 and a switch device.

[0035] The valve hall 1 and the converter unit 6 form a straight-line distribution structure, and the valve-side bushing of the converter transformer 601 is directly inserted into the valve hall 1 .

[0036] Specifically, the valve hall 1 includes two areas, corresponding to the two polar line units 2 and the two bridge resistance units 3, respectively including the low-end valve hall 1 and the high-end valve hall 1.

[0037] A firewall is provided between the converter transformers 601 in each valve hall 1. The 500kV outgoing line of the converter transformer 601 vertically penetrates the supporting platform through a GIL pipeline (gas insulated metal enclosed transmission line) and is connected to the 500kV AC field 9. The converter transformers 601 are arranged in a straight line outside the valve hall 1. After the valve-side bushing is inserted into the valve hall 1, the connection is completed inside the valve hall 1.

[0038] Combination Figure 3 As shown, the starting circuit 4, the AC field 9, the bridge impedance unit 3, the impedance limiting unit 5 and the grounding electrode outlet unit constitute the second layer architecture;

[0039] The starting circuit 4 and the AC field 9 are arranged above the commutation unit 6, and the starting circuit 4 is connected to the AC field 9;

[0040] The starting circuit 4 includes a starting resistor and a lightning arrester, and the starting circuit 4 is connected in series with the converter transformer 601 .

[0041] The bridge impedance unit 3, the limiting impedance unit 5 and the grounding electrode outlet unit are arranged above the electrode line unit 2; the limiting impedance unit 5 is connected to the metal return line unit 8; the bridge impedance unit 3 and the grounding electrode unit are arranged on both sides of the limiting impedance unit 5;

[0042] The bridge impedance unit 3 includes a bridge arm reactor and a switch device; specifically, the boundary of the area where the bridge impedance unit 3 is located is aligned with the valve hall 1, and the bridge impedance unit 3 is connected to the pole line unit 2 through a GIL pipeline or cable.

[0043] Since the boundary of the bridge impedance area is aligned with the valve hall 1, the limiting impedance unit 5 and the grounding electrode outlet unit are set in the blank space between the two bridge impedance areas, and a hanging point is set at the edge of the upper platform to install the pole line unit 2 outlet. The down lead is connected to the pole line unit 2 on the bottom layer. Except for the reactor and resistor, the DC field equipment adopts DC GIS equipment for compact arrangement. Among them, the pole line unit 2, the metal return line unit 8, the limiting impedance unit 5, the bridge impedance unit 3 and the grounding electrode outlet are all the smallest units split from the DC field.

[0044] The resistance limiting unit 5 includes a current limiting reactor, an isolating switch, a lightning arrester and a resistor; the grounding electrode unit includes a grounding electrode outgoing line frame 7, a reactor and an isolating switch.

[0045] The first-layer structure and the second-layer structure are constructed through a supporting platform. The supporting platform corresponding to the area where the valve hall 1 is located is provided with a DC wall bushing, which vertically passes through the supporting platform where the valve hall 1 area is located. The two sides of the DC wall bushing are connected to the valve tower 101 output line and the bridge arm inductor.

[0046] The AC field 9 includes an indoor GIS (sulfur hexafluoride enclosed switchgear), a station transformer and an AC outgoing line frame 901. The starting circuit 4 is arranged above the AC field 9, and the starting circuit 4 is connected to the indoor GIS of the AC field 9 below.

[0047] The outgoing line frame in the AC field 9 is a 500kV AC outgoing line frame. Specifically, the 500kV AC power distribution device in the AC field 9 area adopts indoor GIS. The width of the GIS room is 16m. The outgoing line voltage transformer is integrated in the GIS equipment. The lightning arrester adopts an open type device. The 500kV AC outgoing line frame is located on the roof of the GIS room. The starting circuit 4 is arranged above the GIS room. The entire AC field 9 platform is 25m wide, and the area protruding from the firewall is reinforced with diagonal braces.

[0048] The present invention is not limited to the above-mentioned specific embodiments, but extends to any new features or any new combination disclosed in this specification, as well as any new method or process steps or any new combination disclosed.

Claims

1. A UHV converter station with overlapping structure, characterized in that: It includes valve hall, commutation unit, pole line unit, starting circuit, AC field, bridge reactor unit, limiting reactor unit, metal return line unit and grounding pole outlet unit; The valve hall includes a valve tower and a converter valve, and the converter unit and the polar line unit are distributed on both sides of the valve hall to form a first layer of architecture; the first layer of architecture also includes a metal return line unit, and the metal return line unit is arranged in the middle of the valve hall; The starting circuit, AC field, bridge impedance unit, impedance limiting unit and grounding electrode outlet unit constitute a second layer architecture; the starting circuit and the AC field are arranged above the commutation unit, and the starting circuit is connected to the AC field; the bridge impedance unit, impedance limiting unit and grounding electrode outlet unit are arranged above the pole line unit; the impedance limiting unit is connected to the metal return line unit below; the bridge impedance unit and the grounding electrode unit are arranged on both sides of the impedance limiting unit; The first-layer structure and the second-layer structure are constructed through a supporting platform, and the supporting platform corresponding to the area where the valve hall is located is provided with a DC wall bushing, which vertically passes through the supporting platform where the valve hall area is located.

2. The UHV converter station with overlapping structure according to claim 1, characterized in that: The commutation unit includes a converter transformer, and the pole line unit includes a smoothing reactor and a switch device.

3. The UHV converter station with overlapping structure according to claim 2, characterized in that: The valve hall and the converter unit form a straight-line distribution structure, and the valve-side bushing of the converter transformer is directly inserted into the valve hall.

4. The UHV converter station with overlapping structure according to claim 3, characterized in that: A firewall is arranged between the converter transformers, and the outgoing wires of the converter transformers vertically penetrate the supporting platform through a GIL pipeline.

5. The UHV converter station with overlapping structure according to claim 2, characterized in that: The starting circuit comprises a starting resistor and a lightning arrester, and the starting circuit is connected in series with the converter transformer.

6. The UHV converter station with overlapping structure according to claim 1, characterized in that: The AC field includes an indoor GIS, a station transformer and an AC outgoing line frame. The starting circuit is arranged above the AC field, and the starting circuit is connected to the indoor GIS of the AC field below.

7. The UHV converter station with overlapping structure according to claim 6, characterized in that: The outgoing line frame in the AC field is a 500kV AC outgoing line frame.

8. The UHV converter station with overlapping structure according to claim 1, characterized in that: The bridge impedance unit includes a bridge arm reactor and a switch device; the limiting impedance unit includes a current limiting reactor, an isolating switch, a lightning arrester and a resistor; and the grounding electrode unit includes a grounding electrode outlet frame, a reactor and an isolating switch.

9. The UHV converter station with overlapping structure according to claim 8, characterized in that: The bridge impedance unit is connected to the pole line unit through a GIL pipe or a cable.

10. The UHV converter station with overlapping structure according to claim 9, characterized in that: The DC wall bushing is connected to the valve tower outlet and the bridge arm reactor on both sides.

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