Alternating current-direct current conversion area structure applied to urban suburban dual-system traction power supply system
By setting up components such as segmented insulators, contact isolation switches and grounding wires in the AC-DC conversion area, the safety and fault relief problems of trains in the AC-DC dual-standard traction power supply system are solved, and higher safety and fault emergency response capabilities are achieved.
Patent Information
- Application Number
- CN202421953142.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-13
- Publication Date
- 2025-07-08
- Estimated Expiration
- 2034-08-13
AI Technical Summary
In the prior art, AC and DC dual-standard traction power supply system lacks theoretical and structural support in the cross-tracking scheme of trains, resulting in insufficient safety and reliability, especially in the event of train failure, it is difficult to get out of trouble quickly.
An AC-DC conversion zone structure is designed, including a segmented insulator and a contact isolation switch on the contact network, a power-free zone and a connection area are set, early warning and emergency response are achieved through grounding wires and current transformers, and the position of rail insulation sections is optimized to ensure the safe operation of the train between different power supply systems.
It improves the safety and emergency response capabilities of the train in the AC and DC dual-standard traction power supply system, avoids short circuits of the AC and DC system, and ensures the stable operation of the train under normal and fault conditions.
Smart Images
Figure CN223079766U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of basic molds, and particularly relates to a structure of an AC-DC conversion area applied to an urban-rural dual-mode traction power supply system. Background Art
[0002] In China, electrified railways adopt single-phase industrial frequency AC power supply, while urban rail transit mostly adopts DC power supply system. However, with the continuous acceleration of urbanization in China, the interconnection between trunk railways and urban rails has become a demand. The AC-DC dual-mode traction power supply mode represents the development direction of the interconnection between urban rail transit systems and suburban railways, and has broad application prospects. In order to achieve the through operation with the fifth line of rail transit in Chongqing, its traction power supply system adopts the AC-DC dual-mode traction power supply method. This scheme saves the investment in the civil engineering of tunnels and stations in the underground section compared with the AC power supply scheme; it saves a large amount of investment cost of line power supply equipment compared with the DC power supply scheme, and the vehicle has a high speed in the AC power supply section, which can improve the travel speed of the whole line.
[0003] Although the dual-mode traction vehicle has been successfully tested in China, due to the lack of practical operation experience of the AC-DC dual-mode traction power supply scheme in China, there is still a lack of theoretical and structural support for the train's cross-line scheme in the AC-DC section of this system in China. In order to improve the safety of the train crossing the dual-mode traction power supply system and provide strong technical support for the safe, high-quality and efficient operation of the traction power supply system, it is urgent to establish a structure of an AC-DC conversion area applied to the urban-rural dual-mode traction power supply system. Summary of the Utility Model
[0004] The utility model solves its technical problems by adopting the following technical solutions:
[0005] A structure of an AC-DC conversion area applied to an urban-rural dual-mode traction power supply system includes an overhead contact line connecting a DC section and an AC section. A first section insulator, a second section insulator, a third section insulator, and a fourth section insulator are sequentially arranged on the overhead contact line. A first dead zone is formed between the first section insulator and the second section insulator, a second dead zone is formed between the third section insulator and the fourth section insulator, and a grounding zone is formed between the second section insulator and the third section insulator;
[0006] It further includes a first connection disconnector. One end of the first connection disconnector is connected to the DC section, and the other end is respectively connected to a second connection disconnector, a third connection disconnector, a fourth connection disconnector, and a fifth connection disconnector. The other end of the second connection disconnector is connected to the first dead zone, the other end of the third connection disconnector is connected to the grounding zone, the other end of the fourth connection disconnector is connected to the second dead zone, and the other end of the fifth connection disconnector is connected to the AC section;
[0007] The first insulating joint and the second insulating joint are respectively arranged at the positions of the steel rails directly below the second sectional insulator and the third sectional insulator.
[0008] Furthermore, the grounding area is connected to the steel rail through a grounding wire, and a normally closed first grounding switch and a current transformer are sequentially arranged on the grounding wire.
[0009] Furthermore, the steel rails between the first insulating joint and the second insulating joint are respectively electrically connected to the steel rails outside the first insulating joint and the second insulating joint through a second grounding switch and a third grounding switch.
[0010] Furthermore, the first connection disconnector, the second connection disconnector, the third connection disconnector, the fourth connection disconnector, and the fifth connection disconnector are in an open state during normal train operation.
[0011] Furthermore, the second grounding switch and the third grounding switch are in an open state during normal train operation.
[0012] Furthermore, one end of the grounding wire is connected to the catenary between the second sectional insulator and the third connection disconnector.
[0013] Furthermore, the length of the catenary between the first sectional insulator and the fourth sectional insulator in the AC / DC conversion area is greater than the maximum distance between the pantographs of two traction units of the train.
[0014] Furthermore, the lengths of the first power-off area and the second power-off area are greater than the distance between the two pantographs in the same traction unit.
[0015] The advantages and positive effects of the present utility model are:
[0016] The structure proposed by the present utility model can be used to solve the key problems of train operation between different power supply systems with different power supply modes under normal and fault conditions. At the same time, the structure of this application adds a current transformer compared with the existing structure to realize the early warning function, and also optimizes the setting position of the rail insulating joint, with stronger fault emergency handling capabilities. Description of the Drawings
[0017] The technical solutions of the present utility model will be further described in detail below in conjunction with the drawings and embodiments. However, it should be understood that these drawings are only for explanatory purposes and are not intended to limit the scope of the present utility model. In addition, unless otherwise specified, these drawings are only intended to conceptually illustrate the structural configuration described herein and are not necessarily drawn to scale.
[0018] Figure 1 It is a schematic structural diagram of the AC / DC conversion area structure applied to the urban and suburban dual-power traction power supply system provided by the embodiment of the present utility model;
[0019] Figure 2 It is a schematic diagram of the urban and suburban dual-mode traction power supply system provided by the embodiments of the present utility model. Detailed implementation manners
[0020] First of all, it should be noted that the following will specifically illustrate the specific structure, features, advantages, etc. of the present utility model by way of examples. However, all the descriptions are only for illustration and should not be construed as any limitation to the present utility model. In addition, any single technical feature described or implied in each of the embodiments mentioned in this article, or any single technical feature shown or implied in each of the drawings, can still be arbitrarily combined or deleted between these technical features (or their equivalents), so as to obtain more other embodiments of the present utility model that may not be directly mentioned in this article. In addition, for the sake of simplifying the drawings, the same or similar technical features may be marked only at one place in the same drawing.
[0021] It should be noted that, without conflict, the embodiments in this application and the features in the embodiments can be combined with each other.
[0022] Embodiment 1
[0023] As Figure 1 shown, the AC-DC conversion area structure applied to the urban and suburban dual-mode traction power supply system provided in this embodiment includes an overhead contact line connecting the DC section and the AC section. The overhead contact line is sequentially provided with a first sectional insulator a, a second sectional insulator b, a third sectional insulator c, and a fourth sectional insulator d. A first dead zone is formed between the first sectional insulator and the second sectional insulator, a second dead zone is formed between the third sectional insulator and the fourth sectional insulator, and a grounding zone is formed between the second sectional insulator and the third sectional insulator;
[0024] It further includes a first tie disconnecting switch d1. One end of the first tie disconnecting switch d1 is connected to the DC section, and the other end is respectively connected to a second tie disconnecting switch d2, a third tie disconnecting switch n, a fourth tie disconnecting switch a2, and a fifth tie disconnecting switch a1. The other end of the second tie disconnecting switch d2 is connected to the first dead zone, the other end of the third tie disconnecting switch n is connected to the grounding zone, the other end of the fourth tie disconnecting switch a2 is connected to the second dead zone, and the other end of the fifth tie disconnecting switch a1 is connected to the AC section;
[0025] The second segmented insulator b and the third segmented insulator c are respectively provided with a first insulating node M and a second insulating node N at the rails below, so that the two insulating nodes are provided to ensure that the AC and DC rail return currents are electrically insulated from each other, thereby reducing the influence of AC and DC conductivity coupling; at the same time, according to the train stopping in the power-free area, the traction network switch is closed to ensure smooth traction return flow and avoid rail burns; the rails between the first insulating node M and the second insulating node N are electrically connected to the rails outside the first insulating node M and the second insulating node N through the second grounding switch g1 and the third grounding switch g2 respectively.
[0026] The grounding area is connected to the rail through a grounding wire, on which a normally closed first grounding switch g3 and a current transformer jd1 are arranged in sequence; it should be noted that one end of the grounding wire is connected to the contact network between the second segmented insulator b and the third contact disconnector n.
[0027] The first contact isolating switch d1, the second contact isolating switch d2, the third contact isolating switch n, the fourth contact isolating switch a2, and the fifth contact isolating switch a1 are in a normally open state when the train is running normally; the second grounding switch g1 and the third grounding switch g2 are in a normally open state when the train is running normally.
[0028] The length of the first and second non-electrical zones is greater than the distance between the double pantographs connected to the contact line, that is, the length of the first and second non-electrical zones is greater than the distance between the two pantographs of the same traction unit. During normal operation, the first and second non-electrical zones will be overlapped and carried with DC and AC power, and the grounding area will always be de-energized, and a normally closed grounding switch g3 is set; at the same time, the length between the segmented insulator a and the segmented insulator d in the AC / DC conversion zone should be greater than the maximum distance between the pantographs of the two traction units of the train.
[0029] The specific method of applying the AC / DC conversion area structure of the present application to the urban suburban dual-standard traction power supply system is:
[0030] The AC / DC conversion area of the present application is set between the AC section and the DC section, as shown in the attached Figure 2 As shown, when the train enters and exits the AC / DC conversion area normally, there is no need to operate the contact isolating switch and the grounding switch; when the train enters the AC / DC conversion area abnormally, the AC / DC conversion area structure of the present application can send a warning or protection trip signal to the adjacent substation to avoid an AC / DC system short circuit between the traction substation and the train; when the train loses power and stops in the AC / DC conversion area, the train can be quickly rescued through the locking coordination of the contact isolating switch and the grounding switch.
[0031] Taking the example of a 6-car urban rail train entering the AC section from the DC section, the principle of the train passing through the DC conversion area submitted in this application is analyzed as follows: A 6-car urban rail train generally includes 2 traction units, and 2 pantographs on each traction unit are connected to the same busbar; before the train passes through the AC-DC conversion area, it will go through a series of processes such as acceleration, prompting, switching, coasting, and closing; first, after the train departs from the station, it enters the acceleration stage. An identifier is set at the end of the acceleration area, and in cooperation with the signal system, a specified signal is sent to the train to notify the driver that the AC-DC conversion area is approaching and the train should maintain a constant speed. Then, when it reaches the AC-DC switching prompt point, the signal system sends a signal to the train to automatically open the main circuit breaker switch of the train's incoming line and perform the switching of the AC-DC circuit inside the train. The driver will confirm the status of the pantograph and the switching status of the AC-DC circuit inside the train to prevent manual operation switching in case the automatic operation is unsuccessful. After confirming that the switching is successful and the main circuit breaker is successfully tripped, the train coasts through the coasting area and enters the power-off area. When the signal system detects that the train has completely passed through the power-off area and all pantographs are powered by AC, the main circuit breaker of the train closes and the train moves forward normally. Thus, the train has completed passing through the AC-DC conversion area, and the principle is the same when traveling from the AC side to the DC side.
[0032] Based on the above process, the principle of the train passing through the AC-DC conversion area composed of 4 section insulators in this application is analyzed as follows: Before the train enters the AC-DC conversion area, the main circuit breaker switch has been disconnected, so the train is in a coasting state with the pantograph raised but not taking current. When the front pantograph of the first traction unit of the train enters the catenary of the first power-off area, the catenary of the first power-off area is connected to the catenary of the DC section through the pantograph and the pantograph bus coupler, and at this time, the first power-off area will be energized with direct current; when both the front and rear pantographs of the first traction unit enter the first power-off area, the catenary of the first power-off area resumes the insulation state with the catenary of the DC section. Subsequently, the front pantograph of the first traction unit enters the grounding area. At this time, the first power-off area and the grounding area are connected through the double pantographs of the same traction unit, and both the first power-off area and the grounding area are in a grounded state. The charge in the first power-off area flows back to the ground through the grounding circuit of the grounding area; when both the front and rear pantographs of the first traction unit enter the catenary of the grounding area, the first power-off area resumes the insulated and non-energized state; as the train continues to move forward, the front pantograph of the first traction unit enters the second power-off area. At this time, the grounding area and the second power-off area are in a connected and grounded state. When both the front and rear pantographs enter the catenary of the second power-off area, the second power-off area resumes the insulated and non-energized state. The state when the double pantographs of the second traction unit of the train pass through is the same as above. Since the two traction units of the train are independent of each other, they do not interfere with each other when passing through in sequence.
[0033] If the circuit breaker on the train fails to open in time, an arc will be generated when the first pantograph of the train passes through the section insulator a. When the train slides into the grounding area, a grounding fault occurs. Jd1 sends a protection signal to the traction substation in the AC section. At this time, the protection of the traction substation on the AC side operates to cut off the power, ensuring that the catenary is de-energized when the train enters the AC catenary section, avoiding short circuits in the AC-DC systems between the traction substation and the train. At the same time, a warning signal is sent to the traction substation in the DC section.
[0034] The AC-DC conversion area structure of this application sets up connection disconnectors between each power-off area, between the second power-off area and the AC section catenary, and between the first power-off area and the DC section catenary. When the train stops in the power-off area due to reasons, the train can be safely and quickly separated from the AC-DC conversion area by reasonably setting the locking relationship of the connection disconnectors. The locking relationships of the connection disconnectors set for the following three trapped situations are as follows:
[0035] Situation 1:
[0036] When the pantograph of the first traction unit stops in the first power-off area, the first traction unit is confirmed to be in DC mode. The pantograph of the second traction unit rises and the circuit breaker on the train is adjusted to the open state. At this time, the grounding switch g3 is opened, the grounding switch g1 is closed in sequence, and the connection disconnectors d1, d2, and n are closed. The connection disconnectors a1, a2, and the grounding switch g2 remain open. The train travels with direct current until it stops when it reaches the grounding area. At this time, the connection disconnectors d1 and d2 and the grounding switch g1 are disconnected in sequence. The traction unit is adjusted to AC mode. The circuit breaker on the second traction unit train remains open. The grounding switch g2, the connection disconnectors a1 and a2 are closed in sequence. After the train completely exits the neutral zone, the circuit breaker of the second traction unit is closed according to the signal instruction, and the connection disconnectors a1, a2, n, and the grounding switch g2 are disconnected; the grounding switch g3 is closed, and the train completes its self-rescue;
[0037] Situation 2:
[0038] When the pantograph of the first traction unit stops in the grounding area, the two traction units are adjusted to AC mode. The circuit breaker of the first traction unit is closed, and the circuit breaker on the second traction unit train is open. At this time, the grounding switch g3 is opened, and then the grounding switch g2, the connection disconnectors a1, a2, and n are closed in sequence. The train travels with alternating current and after the train completely exits the neutral zone, the circuit breaker of the second traction unit is closed according to the signal instruction, and the connection disconnectors a1, a2, n, and the grounding switch g2 are disconnected. The grounding switch g3 is closed, and the train completes its self-rescue;
[0039] Situation 3:
[0040] When the pantograph of the first traction unit stops in the second power-off area, the two traction units are adjusted to the AC mode. The circuit breaker switch of the first traction unit is closed, and the circuit breaker on the train of the second traction unit is opened. Then, the connecting disconnector a1 and the connecting disconnector a2 are closed in sequence. After the train is powered by alternating current and the whole train has exited the neutral section, the circuit breaker of the second traction unit is closed according to the signal instruction, and the connecting disconnector a1 and the connecting disconnector a2 are disconnected, and the train completes its self-rescue.
[0041] It should be noted that the traction unit is the abbreviation of a complete set of traction power equipment, and the traction unit is generally composed of fixed motor cars and trailers; the above-mentioned first traction unit refers to the traction power equipment that first enters the conversion area in the driving direction, and the second traction unit refers to the traction power equipment that finally enters the conversion area.
[0042] The above embodiments have described the present invention in detail, but the content described is only the preferred embodiment of the present invention and cannot be considered as defining the scope of implementation of the present invention. Any equivalent changes and improvements made within the scope of the application of the present invention shall still fall within the scope covered by the patent of the present invention.
Claims
1. The structure of the AC-DC conversion area applied to the urban and suburban dual-mode traction power supply system is characterized in that It includes an overhead catenary connecting the DC section and the AC section. On the overhead catenary, a first sectional insulator, a second sectional insulator, a third sectional insulator, and a fourth sectional insulator are sequentially arranged. A first dead zone is formed between the first sectional insulator and the second sectional insulator, a second dead zone is formed between the third sectional insulator and the fourth sectional insulator, and a grounding zone is formed between the second sectional insulator and the third sectional insulator. It further includes a first tie disconnector. One end of the first tie disconnector is connected to the DC section, and the other end is respectively connected to a second tie disconnector, a third tie disconnector, a fourth tie disconnector, and a fifth tie disconnector. The other end of the second tie disconnector is connected to the first dead zone, the other end of the third tie disconnector is connected to the grounding zone, the other end of the fourth tie disconnector is connected to the second dead zone, and the other end of the fifth tie disconnector is connected to the AC section. First insulating joints are respectively arranged at the positions of the rails directly below the second sectional insulator and the third sectional insulator.
2. The AC-DC conversion area structure applied to the urban and suburban dual-mode traction power supply system according to claim 1, characterized in that: The grounding zone is connected to the rail through a grounding wire, and a normally closed first grounding switch and a current transformer are sequentially arranged on the grounding wire.
3. The AC-DC conversion area structure applied to the urban and suburban dual-mode traction power supply system according to claim 1, characterized in that: The rails between the first insulating joint and the second insulating joint are respectively electrically connected to the rails outside the first insulating joint and the second insulating joint through a second grounding switch and a third grounding switch.
4. The AC-DC conversion area structure applied to the urban and suburban dual-mode traction power supply system according to claim 1, wherein: The first tie disconnector, the second tie disconnector, the third tie disconnector, the fourth tie disconnector, and the fifth tie disconnector are in an open state during normal train operation.
5. The structure of the AC-DC conversion area applied to the urban and suburban dual-mode traction power supply system according to claim 3, characterized in that: The second grounding switch and the third grounding switch are in an open state during normal train operation.
6. The AC-DC conversion area structure applied to the urban and suburban dual-mode traction power supply system according to claim 2, wherein: One end of the grounding wire is connected to the overhead catenary between the second sectional insulator and the third tie disconnector.
7. The AC-DC conversion area structure applied to the urban and suburban dual-mode traction power supply system according to claim 1, characterized in that: The length of the overhead catenary between the first sectional insulator and the fourth sectional insulator in the AC / DC conversion area is greater than the maximum distance between the pantographs of two traction units of the train.
8. The AC / DC conversion area structure applied to the urban and suburban dual-mode traction power supply system according to claim 1, characterized in that: The lengths of the first dead zone and the second dead zone are greater than the distance between the two pantographs in the same traction unit.