Rail vehicle on-board battery charging and discharging protection circuit and rail vehicle

Abstract

This application provides a charging and discharging protection circuit for an on-board battery of a rail vehicle and a rail vehicle, belonging to the field of rail transit technology. The charging and discharging protection circuit for the on-board battery of the rail vehicle has the following connection: the positive terminal of the charger is connected to the positive terminal of a second battery box via a first power line, and the other terminal is connected to one end of the vehicle's DC load via a second switch; the negative terminal of the second battery box is connected to the positive terminal of the first battery box via a second power line and a first fuse; the negative terminal of the first battery box is connected to the other end of the vehicle's DC load via a third power line and a first switch, and the other terminal is connected to the negative terminal of the charger via a fourth power line. This application, by using as few fuses and circuit breakers as possible, can promptly disconnect the battery's charging and discharging circuit in case of leakage, grounding, or short circuit, resulting in high safety.

Description

Technical Field

[0001] This application relates to the field of rail transit technology, and in particular to a charging and discharging protection circuit for an on-board battery of a rail vehicle and a rail vehicle having the circuit. Background Technology

[0002] Compared to other modes of transportation, rail transit vehicles have unique environmental, functional, and operational requirements. As a core component of the rail vehicle's control system and emergency power supply system, the rationality of the onboard battery's charging and discharging circuit directly determines the safety, reliability, and economy of the rail vehicle, requiring a reasonable design that considers the vehicle's structural characteristics.

[0003] Utility model patent CN202022455775.1 discloses a battery protection circuit, which includes an electronic switch between the vehicle battery and the charger. This electronic switch, controlled by the battery management system, can disconnect or connect the charger and the battery, avoiding contact arcing and potential tripping failures that can occur with relay control, thus improving the reliability of the battery protection circuit. However, if the electronic switch in this patent fails, it will cause the battery and charger to be permanently connected or disconnected, and cannot be reset. This could result in the vehicle charger continuously charging the battery or the battery failing to supply power to the vehicle, creating a safety hazard.

[0004] Existing technology for rail transit vehicles, constrained by installation space, necessitates splitting large-capacity battery packs into two smaller-capacity battery packs connected in series. These two battery packs (or packs) are then connected by power cables. During wiring construction and vehicle operation, leakage or short circuits in these power cables can generate electrical sparks and potentially cause fires, posing a significant safety hazard to the rail vehicle. Therefore, it is essential to employ the minimum necessary and most economical protection equipment to effectively protect the charging and discharging circuits between battery packs while ensuring the normal functioning of the batteries, thereby guaranteeing the safety of both the batteries and the entire vehicle. Summary of the Invention

[0005] To address the aforementioned technical deficiencies, this application provides a highly secure onboard battery charging and discharging protection circuit for rail vehicles and a rail vehicle.

[0006] According to a first aspect of the embodiments of this application, a charging and discharging protection circuit for an on-board battery of a rail vehicle is provided. The rail vehicle has a first electrical cabinet and a second electrical cabinet respectively located on both sides. The first electrical cabinet contains a charger and a first battery box, and the second electrical cabinet contains a second battery box. The charging and discharging protection circuit includes a first fuse located in the first electrical cabinet and a main circuit breaker located in the second electrical cabinet. The main circuit breaker includes a first switch and a second switch, wherein:

[0007] The positive terminal of the charger is connected to the positive terminal of the second battery box via the first power line, and the other terminal is connected to one end of the vehicle's DC load via the second switch.

[0008] The negative terminal of the second battery box is connected to the positive terminal of the first battery box via the second power line and the first fuse. The negative terminal of the first battery box is connected to the other end of the vehicle's DC load via the third power line and the first switch. The other path is connected to the negative terminal of the charger via the fourth power line.

[0009] According to a second aspect of the embodiments of this application, a rail vehicle is provided, including the above-described rail vehicle on-board battery charging and discharging protection circuit.

[0010] This application addresses the special structural requirements of rail vehicles by installing as few fuses and circuit breakers as possible in the charging and discharging circuits between the two sets of battery boxes and between the charger and the battery. In the event of leakage, grounding, or short circuit in the charging and discharging circuit, the charging and discharging circuit of the battery can be disconnected in a timely manner, thereby protecting the battery box, charger, and rail vehicle and avoiding safety hazards such as fires that could endanger the lives and property of passengers and the vehicle. Attached Figure Description

[0011] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0012] Figure 1 This is a schematic diagram showing the battery placement on a rail vehicle in the prior art.

[0013] Figure 2 This is a structural diagram of Embodiment 1 of the on-board battery charging and discharging protection circuit for rail vehicles in this application;

[0014] Figure 3 This is a structural diagram of Embodiment 2 of the on-board battery charging and discharging protection circuit for rail vehicles according to this application;

[0015] Figure 4This is a structural diagram of Embodiment 3 of the on-board battery charging and discharging protection circuit for rail vehicles in this application;

[0016] Figure 5 This is a structural diagram of Embodiment 4 of the on-board battery charging and discharging protection circuit for rail vehicles according to this application. Detailed Implementation

[0017] To make the technical solutions and advantages of the embodiments of this application clearer, the exemplary embodiments of this application will be described in further detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not an exhaustive list of all embodiments. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other.

[0018] To provide passengers with as much space as possible, rail vehicles need to maximize passenger compartment space and locate electrical equipment at the ends or under the vehicle. However, the onboard batteries need to meet the power requirements of the vehicle's control and emergency systems, requiring a certain capacity. Furthermore, as vehicle functions become increasingly complex, onboard battery capacities are growing larger. This results in excessively large and heavy battery boxes. If the battery box is located on one side of the vehicle, it shifts the vehicle's center of gravity to one side, complicates the structure, and affects operational safety and maintenance, failing to meet design requirements. Therefore, the battery box needs to be disassembled and installed in different locations on the rail vehicle.

[0019] like Figure 1 The diagram illustrates one arrangement of batteries on existing rail vehicles: a battery box is located on each side (first and second position sides) at one end of the passenger compartment (second position end in the diagram), and an electrical cabinet is located on each side at the other end (first position end in the diagram). The two battery boxes are connected by a power line / cable. Because there is a certain span between the two battery boxes, the power line connecting them needs to pass through areas and structures that are difficult or impossible to inspect, such as the roof or floor. If leakage, grounding, or short circuit occurs in the power line, it could cause serious safety accidents such as electric shock or fire.

[0020] To address the aforementioned issues, this application provides a charging and discharging protection circuit for an on-board battery of a rail vehicle, which may include the following embodiments.

[0021] Example 1

[0022] like Figure 2As shown, the on-board battery charging and discharging protection circuit of this embodiment of the rail vehicle has a first electrical cabinet 1 (i.e., the single-side electrical cabinet in the figure) and a second electrical cabinet 2 (i.e., the two-side electrical cabinet in the figure) respectively on both sides of the rail vehicle (specifically, on both sides of the vehicle end). The first electrical cabinet 1 contains a charger 11 and a first battery box 12 (i.e., the battery box 1 in the figure), and the second electrical cabinet 2 contains a second battery box 21 (i.e., the battery box 2 in the figure). The charging and discharging protection circuit includes a first fuse 13 located in the first electrical cabinet 1 and a main circuit breaker 22 located in the second electrical cabinet 2. The main circuit breaker 22 includes a first switch 221 and a second switch 222, wherein:

[0023] The positive terminal of the charger 11 is connected to the positive terminal of the second battery box 21 via the first power line (i.e., line ① in the figure), and the other terminal is connected to one end of the vehicle DC load 3 via the second switch 222.

[0024] The negative terminal of the second battery box 21 is connected to the positive terminal of the first battery box 12 via the second power line (i.e., line ② in the figure) and the first fuse 13. The negative terminal of the first battery box 12 is connected to the other end of the vehicle DC load 3 via the third power line (i.e., line ③ in the figure) and the first switch 221. One path is used to connect to the other end of the vehicle DC load 3, and the other path is connected to the negative terminal of the charger 11 via the fourth power line (i.e., line ④ in the figure).

[0025] In this embodiment, four power lines are connected between the two battery boxes, namely lines ①, ②, ③, and ④. During use, when the charger 11 needs to charge the battery boxes, the first switch 221 closes, forming a closed circuit consisting of the charger 11, line ①, the second battery box 21, line ②, the first fuse 13, the first battery box 12, line ③, the first switch 221, and line ④, allowing the charger 11 to charge the battery boxes. When a short circuit occurs between lines ① and ②, between lines ① and ③, between lines ① and ④, between lines ② and ③, or between lines ② and ④, the first switch 221 in the main circuit breaker 22 opens, thus protecting the battery power lines. If the main circuit breaker 22 fails, the first fuse 13 opens, thus protecting the battery power lines. Since lines ③ and ④ are at the same potential, a short circuit will not occur between them.

[0026] When the battery box needs to supply power to the vehicle's DC load 3, the first switch 221 and the second switch 222 are closed. The second battery box 21, the second switch 222, the vehicle's DC load 3, the first switch 221, line ③, the first battery box 12, the first fuse 13, and line ② form a closed circuit, and the battery box supplies power to the vehicle's DC load 3 (under normal conditions, it also charges while supplying power). When the vehicle's DC load 3 experiences a severe overload or short circuit, the first switch 221, the second switch 222, and the first fuse 13 in the main circuit breaker 22 can quickly disconnect, protecting the battery power line, the battery, and other loads.

[0027] This application addresses the special structural requirements of rail vehicles by installing as few fuses and circuit breakers as possible in the charging and discharging circuits between the two sets of battery boxes and between the charger and the battery. In the event of leakage, grounding, or short circuit in the charging and discharging circuit, the charging and discharging circuit of the battery can be disconnected in a timely manner, thereby protecting the battery box, charger, and rail vehicle and avoiding safety hazards such as fires that could endanger the lives and property of passengers and the vehicle.

[0028] To improve circuit safety, the main circuit breaker 22 may also include a third switch 223. In this case, the positive terminal of the charger 11, after passing through the first power line, is connected in two ways: one path is connected to the positive terminal of the second battery box 21 via the third switch 223, and the other path is connected to one end of the vehicle's DC load 3 via the second switch 222. Thus, when a short circuit occurs between the power lines, the first switch 221 and the third switch 223 in the main circuit breaker 22 will open, thereby protecting the battery power lines. If the main circuit breaker 22 fails, the first fuse 13 will open, thereby protecting the battery power lines.

[0029] Furthermore, the main circuit breaker 22 may also include a fourth switch 224, and the charge / discharge protection circuit may also include a second fuse 23 located in the second electrical cabinet 2. In this case, after the positive terminal of the charger 11 passes through the first power line, another path connects to one end of the battery status indicator light 4 via the fourth switch 224 and the second fuse 23. The other end of the battery status indicator light 4 is connected to the negative terminal of the charger 11 via the fourth power line. In specific implementation, the battery status indicator light 4 can be installed in the second electrical cabinet 2. In this way, the current status of the battery box can be displayed in a timely manner through the battery status indicator light 4. If a short circuit occurs in the power supply line of the battery status indicator light 4, the second fuse 23 will trip to ensure the safety of the battery; if the battery status indicator light 4 goes out, it indicates that the battery is low on power or has a fault, reminding maintenance personnel to maintain the battery in a timely manner.

[0030] To facilitate monitoring of the status of the main circuit breaker 22, a main circuit breaker status acquisition device 5 can be connected in parallel across the two ends of the vehicle's DC load 3. In practice, the main circuit breaker status acquisition device 5 can be installed inside the second electrical cabinet 2. Thus, when power is needed for the vehicle, the first switch 221, the second switch 222, and the third switch 223 of the main circuit breaker 22 must be closed. At this time, the fourth switch 224 can be opened, the battery status indicator light 4 will turn off, and the status of the main circuit breaker 22 will be acquired by the vehicle network system's I / O (i.e., the main circuit breaker status acquisition device 5). When the vehicle needs to be powered off, the second switch 222 of the main circuit breaker 22 must be opened, and the fourth switch 224 must be closed. At this time, the battery status indicator light 4 will illuminate, indicating that the battery still has power. The battery status indicator light 4 illuminates to remind the vehicle that it is in a power-off state. If the indicator light is off, it indicates that the vehicle is powered on or the battery is low on power.

[0031] In this embodiment, considering the working status of each line, preferably, the first switch 221 can be a normally open switch, the second switch 222 can be a normally open switch, the third switch 223 can be a normally open switch, and the fourth switch 224 can be a normally closed switch.

[0032] In summary, this embodiment uses two common protective devices—one main circuit breaker and one fuse (first fuse 13)—to ensure that in the event of minor leakage, grounding, or short circuit in all power lines between the two battery boxes, the main circuit breaker can quickly disconnect the battery's charging and discharging circuit, ensuring the safety of the battery and the vehicle. When a serious leakage, grounding, or short circuit occurs in the power lines between the two battery boxes, the first fuse can quickly disconnect the battery's charging and discharging circuit, ensuring the safety of the battery and the vehicle. After the fault is cleared, replacing the fuse will quickly restore the charging and discharging functions of the battery and charger.

[0033] Even if the main circuit breaker fails and cannot operate reliably, this embodiment can still ensure the safety of the battery charging and discharging circuit, the battery, and the vehicle.

[0034] In addition, when the main circuit breaker is closed, its status can be monitored by the vehicle's control network. If the circuit breaker is accidentally disconnected, the vehicle network system can promptly report to the driver and passengers to avoid the risk of unexpected power outages in the vehicle control system. When the main circuit breaker of the vehicle's parking battery is disconnected, the battery status can be displayed in real time to the vehicle's maintenance personnel via indicator lights. If the battery is depleted or has other faults, the indicator lights will turn off, reminding maintenance personnel to perform timely battery maintenance.

[0035] The technology presented in this application is simple, reliable, space-saving, economical, and practical. It has great potential for widespread application in battery-powered or hybrid-powered rail vehicles that require multiple battery boxes, as well as other battery-powered vehicles.

[0036] Example 2

[0037] This embodiment is basically the same as Embodiment 1, except that: Figure 3 As shown (the vehicle's DC load 3 is temporarily omitted), the charging and discharging protection circuit also includes a third fuse 14, a fourth fuse 15, and a fifth fuse 16 located in the first electrical cabinet 1, wherein:

[0038] After passing through the third fuse 14 and the first power line, the positive terminal of the charger 11 is connected to the positive terminal of the second battery box 21 via the third switch 223, and the other terminal is connected to one end of the vehicle DC load 3 via the second switch 222.

[0039] The negative terminal of the first battery box 12 is connected to the other end of the vehicle DC load 3 via the fourth fuse 15, the third power line and the first switch 221. The other terminal is connected to the negative terminal of the charger 11 via the fourth power line and the fifth fuse 16.

[0040] This embodiment uses a large number of fuses, which provides higher safety, but also increases the cost. Furthermore, the fuses have a large capacity and size, requiring a significant amount of installation and operating space, thus occupying a large amount of space. Therefore, it is not suitable for vehicles with limited space.

[0041] Example 3

[0042] like Figure 4 As shown (the vehicle's DC load 3 is temporarily omitted), the on-board battery charging and discharging protection circuit of this embodiment for rail vehicles has a first electrical cabinet 1 (i.e., the single-side electrical cabinet in the figure) and a second electrical cabinet 2 (i.e., the two-side electrical cabinet in the figure) on both sides of the rail vehicle. The first electrical cabinet 1 contains a charger 11 and a first battery box 12 (i.e., the battery box 1 in the figure), and the second electrical cabinet 2 contains a second battery box 21 (i.e., the battery box 2 in the figure). The charging and discharging protection circuit includes a first fuse 13 located in the first electrical cabinet 1 and a main circuit breaker 22 located in the second electrical cabinet 2. The main circuit breaker 22 includes a first switch 221 and a second switch 222. The first fuse 13 is omitted in the first electrical cabinet 1. The main circuit breaker 22 also includes a fifth switch 225, wherein:

[0043] After passing through the first power line, the positive terminal of the charger 11 is connected to the positive terminal of the second battery box 21, and the other terminal is connected to one end of the vehicle DC load 3 after passing through the second switch 222.

[0044] The negative terminal of the second battery box 21 is connected to the positive terminal of the first battery box 12 via the fifth switch 225 and the second power line. The negative terminal of the first battery box 12 is connected to the other end of the vehicle's DC load 3 via the third power line and the first switch 221, and the other end is connected to the negative terminal of the charger 11 via the fourth power line (i.e., line ④ in the figure). The fifth switch 225 can be a normally open switch.

[0045] Although the charging and discharging protection circuit of this embodiment eliminates all fuses on the power lines, saving costs and installation space, if the main circuit breaker 22 is not reliable enough and the contacts stick together, it will not be able to disconnect in time in the event of leakage, grounding or short circuit in the main line between the battery boxes, which will cause serious damage to the power lines, batteries, charger 11 and vehicle. Therefore, it is necessary to select a circuit breaker with higher reliability.

[0046] Example 4

[0047] This embodiment is basically the same as Embodiment 1, except that: Figure 5 As shown, the third power line and the fourth power line are the same power line. The negative terminal of the first battery box 12 is connected to the negative terminal of the charger 11, and is used to connect to the other end of the vehicle DC load 3 after passing through the third power line and the first switch 221.

[0048] The charging and discharging protection circuit in this embodiment eliminates the fourth power line, further saving cost and installation space. However, the negative terminal of the battery cannot be disconnected. If leakage, grounding, or short circuit occurs between the first and third power lines and cannot be disconnected in time, it will cause significant damage to the power lines, battery, charger 11, and vehicle. Therefore, a highly reliable circuit breaker needs to be selected.

[0049] On the other hand, embodiments of this application provide a rail vehicle including the aforementioned on-board battery charge / discharge protection circuit. Since the on-board battery charge / discharge protection circuit is the same as described above, it will not be repeated here.

[0050] This application addresses the special structural requirements of rail vehicles by installing as few fuses and circuit breakers as possible in the charging and discharging circuits between the two sets of battery boxes and between the charger and the battery. In the event of leakage, grounding, or short circuit in the charging and discharging circuit, the charging and discharging circuit of the battery can be disconnected in a timely manner, thereby protecting the battery box, charger, and rail vehicle and avoiding safety hazards such as fires that could endanger the lives and property of passengers and the vehicle.

[0051] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0052] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0053] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0054] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A charging and discharging protection circuit for an on-board battery of a rail vehicle, characterized in that, The rail vehicle is equipped with a first electrical cabinet and a second electrical cabinet on both sides, respectively. The first electrical cabinet contains a charger and a first battery box, and the second electrical cabinet contains a second battery box. The charging and discharging protection circuit includes a first fuse located in the first electrical cabinet and a main circuit breaker located in the second electrical cabinet. The main circuit breaker includes a first switch and a second switch, wherein: The positive terminal of the charger is connected to the positive terminal of the second battery box via the first power line, and the other terminal is connected to one end of the vehicle's DC load via the second switch. The negative terminal of the second battery box is connected to the positive terminal of the first battery box via the second power line and the first fuse. The negative terminal of the first battery box is connected to the other end of the vehicle's DC load via the third power line and the first switch. The other path is connected to the negative terminal of the charger via the fourth power line.

2. The on-board battery charging and discharging protection circuit for rail vehicles according to claim 1, characterized in that, The main circuit breaker also includes a third switch. After the positive terminal of the charger passes through the first power line, one path is connected to the positive terminal of the second battery box via the third switch, and the other path is connected to one end of the vehicle's DC load via the second switch.

3. The on-board battery charging and discharging protection circuit for rail vehicles according to claim 2, characterized in that, The main circuit breaker also includes a fourth switch, and the charging and discharging protection circuit also includes a second fuse located in the second electrical cabinet. After the positive terminal of the charger passes through the first power line, there is another path that connects to one end of the battery status indicator light via the fourth switch and the second fuse. The other end of the battery status indicator light is connected to the negative terminal of the charger via the fourth power line.

4. The on-board battery charging and discharging protection circuit for rail vehicles according to claim 2, characterized in that, The main circuit breaker status acquisition unit is connected in parallel across the two ends of the vehicle's DC load.

5. The on-board battery charging and discharging protection circuit for rail vehicles according to claim 3, characterized in that, The first switch is a normally open switch; And / or, the second switch is a normally open switch; And / or, the third switch is a normally open switch; And / or, the fourth switch is a normally closed switch.

6. The on-board battery charging and discharging protection circuit for rail vehicles according to any one of claims 2-5, characterized in that, The charge / discharge protection circuit further includes a third fuse, a fourth fuse, and a fifth fuse located within the first electrical cabinet, wherein: The positive terminal of the charger, after passing through the third fuse and the first power line, is connected to the positive terminal of the second battery box via the third switch, and the other terminal is connected to one end of the vehicle's DC load via the second switch. The negative terminal of the first battery box is connected to the other end of the vehicle's DC load via the fourth fuse, the third power line, and the first switch. The other terminal is connected to the negative terminal of the charger via the fourth power line and the fifth fuse.

7. The on-board battery charging and discharging protection circuit for rail vehicles according to any one of claims 1-5, characterized in that, The first fuse is omitted from the first electrical cabinet. The main circuit breaker includes a fifth switch. The negative terminal of the second battery box is connected to the positive terminal of the first battery box via the fifth switch and the second power line.

8. The on-board battery charging and discharging protection circuit for rail vehicles according to claim 7, characterized in that, The fifth switch is a normally open switch.

9. The on-board battery charging and discharging protection circuit for rail vehicles according to any one of claims 1-5, characterized in that, The third and fourth power lines are the same power line. The negative terminal of the first battery box is connected to the negative terminal of the charger and, after passing through the third power line and the first switch, is used to connect to the other end of the vehicle's DC load.

10. A rail vehicle, characterized in that, Includes the on-board battery charging and discharging protection circuit for rail vehicles as described in any one of claims 1-9.

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