Protection system for grounding backflow failure in electric leakage detection of traction transformer
By introducing electric spark dischargers and monitoring modules into the traction transformer system, the problem of grounding return failure is solved, and rapid fault identification and system safety improvement is achieved.
Patent Information
- Application Number
- CN202510768643.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-10
- Publication Date
- 2025-07-22
AI Technical Summary
In the existing traction transformer leakage detection system, the grounding return line may fail due to loosening or corrosion, resulting in the leakage current not being able to return normally, increasing the safety risks of equipment and personnel.
An electric spark discharger is arranged between the second end of the traction transformer and the wheel pair assembly, and a second current transformer is connected in parallel to form a high voltage breakdown when the ground return fails to prevent damage to the transformer, while quickly failing to identify and recover through the leakage monitoring module and the control module.
It effectively avoids high voltage damage caused by ground return failure, quickly identify and repair faults, reduces fault repair time, and improves system safety and reliability.
Smart Images
Figure CN120348158A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of train control, and particularly to a protection system for the failure of the grounding return in the leakage detection of a traction transformer. Background Art
[0002] The traction transformer is a key device in railway locomotives and rail transit systems, and its main function is to convert high-voltage electrical energy into low-voltage electrical energy suitable for traction motors. However, during operation, the traction transformer may experience leakage, which not only reduces the operating efficiency of the system but may also pose serious safety hazards, such as equipment damage, fires, and even electric shock accidents to personnel. Therefore, leakage detection is an important means to ensure the safe operation of the traction transformer.
[0003] In existing traction transformer leakage detection systems, the grounding return line is manually set up to provide a return path for the leakage current. Although the grounding return line plays an important role in leakage detection, in actual operation, the grounding return line may fail for various reasons. For example, the connection points in the grounding return line may become loose or corroded; even in some extreme cases, the grounding return line may be accidentally cut off. The failure of the grounding return causes the leakage current to be unable to return normally, resulting in the leakage detection device being unable to accurately detect the leakage phenomenon and increasing the safety risks of the equipment and personnel. Summary of the Invention
[0004] In view of this, the purpose of this application is to propose a solution to the above problems.
[0005] To achieve the above purpose, the present invention provides a protection system for the failure of the grounding return in the leakage detection of a traction transformer, including a pantograph, a vacuum circuit breaker, a traction transformer, and a wheel set assembly;
[0006] as well as a line current transformer connecting the pantograph and the vacuum circuit breaker, a first current transformer connecting the vacuum circuit breaker and the first end of the traction transformer, and a second current transformer connecting the second end of the traction transformer and the wheel set assembly;
[0007] A grounding return cable is provided between the second end of the traction transformer and the wheel set assembly. During normal operation, the current at the second end of the traction transformer can reach the wheel set assembly through the grounding return cable to achieve normal grounding return;
[0008] An electric spark discharger is also provided between the second end of the traction transformer and the wheel set assembly, and the electric spark discharger is connected in parallel with the second current transformer.
[0009] In some embodiments, the electric spark discharger is a gap discharger with a breakdown threshold, and the breakdown threshold is between 300V and 900V;
[0010] When a leakage occurs and the grounding return cable fails, the grounding return cannot be achieved. High voltages are formed at both ends of the spark discharger and the second current transformer. When the high voltage reaches the breakdown threshold of the spark discharger, the internal gap of the spark discharger is broken down, and the spark discharger becomes a conductor.
[0011] In some embodiments, a leakage monitoring module and a control module are further included. The leakage monitoring module real-time detects the current values of the network current transformer, the first current transformer, and the second current transformer, and performs a difference comparison. Once the difference exceeds a preset protection value, the monitored alarm information is fed back to the control module. The control module controls the vacuum circuit breaker to disconnect, and the preset protection value is between 20 - 40 A.
[0012] In some embodiments, a reset detection module is further included. After the vacuum circuit breaker disconnects, the reset detection module starts to monitor the spark discharger and feeds back the monitoring result of the spark discharger to the control module.
[0013] In some embodiments, the control module receives the monitoring result of the spark discharger. When the monitoring result indicates that the spark discharger has been reset, the control module resumes the real-time monitoring of the monitoring module. After the control module does not receive the alarm information from the monitoring module for a preset time, it determines that the grounding return of the train is in a normal state. The preset time ranges from 10 - 30 s.
[0014] In some embodiments, a vehicle body power resistor is provided between the spark discharger and the wheel set assembly.
[0015] In some embodiments, the first end of the traction transformer is the upper end of the primary side of the traction transformer.
[0016] In some embodiments, the second end of the traction transformer is the lower end of the primary side of the traction transformer.
[0017] In some embodiments, the traction transformer, the cooling system, and the installation framework form a traction transformer box body. The traction transformer box body is located on the roof or under the bottom of the train, and the traction transformer box body is short-circuited with the train body.
[0018] In some embodiments, the wheel set assembly includes at least two wheel sets, and the wheel set connected by the grounding return cable is the same as the wheel set connected to the spark discharger.
[0019] The beneficial effects that this application can achieve:
[0020] 1. By setting an electric spark discharger, it is possible to avoid damage to the second current transformer caused by high voltage when the ground return cable fails and the ground return becomes ineffective.
[0021] 2. By setting a reset detection module for monitoring the reset of the electric spark discharger, it is possible to more quickly identify the situation of fault repair and reduce the time required for fault repair and resuming normal operation.
[0022] To make the above objects, features, and advantages of the present application more obvious and understandable, the following provides preferred embodiments in conjunction with the accompanying drawings and detailed descriptions are as follows. Description of the Drawings
[0023] To more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for the embodiments. It should be understood that the following drawings only show some embodiments of the present application and should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other relevant drawings can be obtained based on these drawings.
[0024] Figure 1 The structure diagram of a protection system for ground return failure in the leakage detection of a traction transformer of the present application is shown.
[0025] Main element symbol description: 1 - vacuum circuit breaker; 2 - traction transformer; 3 - axle assembly; 4 - line current transformer; 5 - first current transformer; 6 - second current transformer; 7 - ground return cable; 8 - electric spark discharger; 9 - car body. Detailed Embodiments
[0026] The terms "comprising" and "including", "containing" or "characterized by" in the specification and claims of the present application are synonymous, and are inclusive of endpoints or open-ended, and do not exclude additional unrecited elements or method steps. "Comprising" is a technical term used in claim language, meaning that the elements exist, but other elements can also be added and still form a structure or method within the scope of the claims.
[0027] It should be noted that similar reference numerals and letters represent similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. In addition, the terms "first", "second", "third", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance. The term "about" in the present application means including a small change (up to + / - 10%) of the stated value.
[0028] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.
[0029] As used herein, the phrase "embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the present application. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.
[0030] A protection system for the failure of the ground return in the leakage detection of a traction transformer is provided in an embodiment of the present application. Refer to Figure 1 , including a pantograph, a vacuum circuit breaker 1, a traction transformer 2, and a wheel set assembly 3;
[0031] and a line current transformer 4 connecting the pantograph and the vacuum circuit breaker 1, a first current transformer 5 connecting the vacuum circuit breaker 1 and the first end of the traction transformer 2, and a second current transformer 6 connecting the second end of the traction transformer 2 and the wheel set assembly 3;
[0032] A ground return cable 7 is provided between the second end of the traction transformer 2 and the wheel set assembly 3. During normal operation, the current at the second end of the traction transformer 2 can reach the wheel set assembly 3 through the ground return cable 7 to achieve normal ground return;
[0033] An electric spark discharger 8 is also provided between the second end of the traction transformer 2 and the wheel set assembly 3. The electric spark discharger 8 is connected in parallel with the second current transformer 6.
[0034] In some embodiments, the electric spark discharger 8 is a gap discharger and has a breakdown threshold, and the breakdown threshold is between 300V and 900V.
[0035] The breakdown threshold is determined by the discharge gap, and the discharge gap is determined by the production process level. The discharge gaps of different products are controlled within an error range of 1mm to 2mm.
[0036] When a leakage occurs and the ground return cable 7 fails, the ground return cannot be achieved. High voltages are formed at both ends of the electric spark discharger 8 and the second current transformer 6. When the high voltage reaches the breakdown threshold of the electric spark discharger 8, the internal gap of the electric spark discharger 8 is broken down, and the electric spark discharger 8 becomes a conductor.
[0037] In some embodiments, a leakage current monitoring and control module is further included. The leakage current monitoring and control module detects the current values of the network current transformer 4, the first current transformer 5, and the first current transformer 5 in real time, and conducts a difference comparison. Once the difference exceeds a preset protection value, the monitored alarm information is fed back to the control module, and the control module controls the vacuum circuit breaker 1 to disconnect. The preset protection value controls the vacuum circuit breaker 1 to disconnect when it is between 20 - 40A.
[0038] In some embodiments, a reset detection module is further included. After the vacuum circuit breaker 1 disconnects, the reset detection module starts to monitor the spark discharger 8 and feeds back the monitoring result of the spark discharger 8 to the control module.
[0039] In some embodiments, the control module receives the monitoring result of the spark discharger 8. When the monitoring result indicates that the spark discharger 8 has been reset, the control module resumes the real-time monitoring of the monitoring module. After the control module does not receive the alarm information of the monitoring module for more than a preset time, it is determined that the ground return of the train is in a normal state. The value range of the preset time is 10 - 30s.
[0040] In some embodiments, a vehicle body 9 power resistor is provided between the spark discharger 8 and the wheel set assembly 3.
[0041] In some embodiments, the first end of the traction transformer 2 is the upper end of the primary side of the traction transformer.
[0042] In some embodiments, the second end of the traction transformer 2 is the lower end of the primary side of the traction transformer.
[0043] In some embodiments, the traction transformer 2, the cooling system, and the installation structure form a traction transformer box body. The traction transformer box body is located on the roof or the bottom of the train, and the traction transformer box body is short-circuited with the train body 9.
[0044] In some embodiments, the wheel set assembly 3 includes at least two wheel sets, and the wheel set connected by the ground return cable 7 is the same as the wheel set connected to the spark discharger 8.
[0045] The above has introduced the embodiments of the present application in detail. Specific examples are used in this article to elaborate on the principle and implementation manner of the present application. The description of the above embodiments is only used to help understand the method and its core idea of the present application; at the same time, for those of ordinary skill in the art, according to the idea of the present application, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present application.
Claims
1. A protection system for the failure of the grounding return in the leakage detection of a traction transformer, comprising a pantograph, a vacuum circuit breaker, a traction transformer and a wheel set assembly, as well as a line current transformer connecting the pantograph and the vacuum circuit breaker, a first current transformer connecting the vacuum circuit breaker and the first end of the traction transformer, and a second current transformer connecting the second end of the traction transformer and the wheel set assembly. A grounding return cable is provided between the second end of the traction transformer and the wheel set assembly. During normal operation, the current at the second end of the traction transformer can reach the wheel set assembly through the grounding return cable to achieve normal grounding return. It is characterized in that An electric spark discharger is also provided between the second end of the traction transformer and the wheel set assembly, and the electric spark discharger is connected in parallel with the second current transformer.
2. The protection system for the failure of the grounding return in the leakage detection of a traction transformer according to claim 1, characterized in that, The electric spark discharger is a gap discharger with a breakdown threshold, and the breakdown threshold is between 300V and 900V. When a leakage occurs and the grounding return cable fails, the grounding return cannot be achieved. High voltages are formed at both ends of the electric spark discharger and the second current transformer. When the high voltage reaches the breakdown threshold of the electric spark discharger, the internal gap of the electric spark discharger is broken down, and the electric spark discharger becomes a conductor.
3. The protection system for the failure of the grounding return in the leakage detection of a traction transformer according to claim 2, characterized in that, It also includes a leakage monitoring module and a control module. The leakage monitoring module continuously detects the current values of the line current transformer, the first current transformer, and the second current transformer, and performs a difference comparison. Once the difference exceeds a preset protection value, the monitored alarm information is fed back to the control module, and the control module controls the vacuum circuit breaker to open. The preset protection value is between 20 - 40A.
4. The protection system for the failure of the grounding return in the leakage detection of a traction transformer according to claim 3, characterized in that, It also includes a reset detection module. After the vacuum circuit breaker opens, the reset detection module starts to monitor the electric spark discharger and feeds back the monitoring result of the electric spark discharger to the control module.
5. The protection system for the failure of the grounding return current in the leakage detection of a traction transformer according to claim 4, characterized in that, The control module receives the monitoring result of the electric spark discharger. When the monitoring result indicates that the electric spark discharger has been reset, the control module resumes the real-time monitoring of the monitoring module. After the control module does not receive the alarm information from the monitoring module for more than a preset time, it is determined that the grounding return of the train is in a normal state. The preset time ranges from 10 - 30s.
6. The protection system for the failure of the grounding return in the leakage detection of a traction transformer according to claim 5, wherein, A vehicle body power resistor is provided between the electric spark discharger and the wheel set assembly.
7. The protection system for the failure of the grounding return current in the leakage detection of a traction transformer according to claim 6, characterized in that, The first end of the traction transformer is the upper end of the primary side of the traction transformer.
8. A protection system for the failure of the grounding return in the leakage detection of a traction transformer according to claim 7, characterized in that The second end of the traction transformer is the lower end of the primary side of the traction transformer.
9. A protection system for the failure of the grounding return in the leakage detection of a traction transformer according to claim 7 or 8, characterized in that, The traction transformer, the cooling system, and the installation structure form a traction transformer box body. The traction transformer box body is located on the roof or the bottom of the train, and the traction transformer box body is short-circuited with the train body.
10. A protection system for the failure of the grounding return in the leakage detection of a traction transformer according to claim 9, characterized in that, The wheel set assembly includes at least two wheel sets, and the wheel set connected by the grounding return cable is the same as the wheel set connected to the electric spark discharger.