Motor train unit roof high-voltage electrical box with lightning arrester on-line monitoring function

Abstract

The invention relates to the technical field of high-voltage electrical appliances for railway locomotives, in particular to a motor train unit roof high-voltage electrical appliance box with a lightning arrester on-line monitoring function, and can solve the problems that a traditional high-voltage electrical appliance box is lack of real-time monitoring of the state of a lightning arrester and cannot give an early warning of degradation risks in time, and consequently maintenance lags. The electric appliance box comprises a box body, a circuit breaker A, a grounding switch, a connecting bar, a circuit breaker B, a current transformer, a voltage transformer and a lightning arrester. The incoming cable passes through the current transformer and is connected with the front side end of the circuit breaker A, and the voltage transformer is connected with the front side end of the circuit breaker A; the contact cable is connected to the front side end of the circuit breaker B; the connecting bar is connected with the rear side ends of the circuit breaker A and the circuit breaker B. The outgoing cable and the lightning arrester are installed on the connecting bar. A lightning arrester monitoring unit is arranged in the box body, a grounding wire at the bottom of a lightning arrester penetrates through the lightning arrester monitoring unit and then is connected to the box body, and a secondary end of the voltage transformer is connected with the lightning arrester monitoring unit through a signal wire.

Description

Technical Field

[0001] The present application relates to the technical field of high-voltage electrical appliances for railway locomotives, and in particular to a high-voltage electrical box on the roof of an EMU with an online monitoring function for lightning arresters. Background Art

[0002] A lightning arrester is installed in the high-voltage electrical box. When overvoltage occurs in the high-voltage circuit, the lightning arrester absorbs a certain amount of overvoltage energy and generates a relatively large leakage current. The overvoltage is limited below the allowable value, thereby providing reliable protection for electrical equipment. Under the rated voltage of the lightning arrester and the normal operating voltage of the high-voltage circuit, only a very small leakage current flows through the lightning arrester, which plays a role in insulation from the system.

[0003] Although lightning arresters can absorb overvoltage, accidents of high-voltage electrical equipment explosions due to overvoltage still occur. After the accident, it is impossible to reproduce the overvoltage state of the high-voltage circuit at the time of the accident, and it is impossible to thoroughly analyze the root cause of the problem, so it is impossible to take effective measures to prevent the accident from happening again.

[0004] However, after the arrester has been running for a period of time, its performance will inevitably deteriorate due to the impact of large current and the influence of the external environment. If the performance of the arrester deteriorates to a certain extent and is not dealt with in time, the arrester itself will not be able to withstand the impact of overvoltage and will explode, or its protection function will be weakened, causing other high-voltage equipment to explode. Therefore, it is necessary to perform online monitoring of the arrester in the high-voltage electrical box. Summary of the Invention

[0005] In order to solve the problem that lightning arresters are installed in the high-voltage electrical box of existing EMUs to absorb overvoltage energy, but the performance degradation of the lightning arresters after long-term operation can easily cause explosion accidents, and the causes of the accidents are difficult to trace. The traditional high-voltage electrical box lacks real-time monitoring of the lightning arrester status and cannot timely warn of degradation risks, resulting in delayed maintenance. This application provides an EMU roof high-voltage electrical box with an online monitoring function for lightning arresters.

[0006] The embodiment of the present application is implemented as follows:

[0007] In a first aspect, the present application provides a high-voltage electrical box on the roof of an EMU with an online monitoring function for a lightning arrester, comprising a box body, a first circuit breaker, a grounding switch, a connecting bar, a second circuit breaker, a current transformer, a voltage transformer, and a lightning arrester.

[0008] The incoming cable passes through the current transformer and is connected to the front end of the first circuit breaker, the voltage transformer is connected to the front end of the first circuit breaker, and the contact cable is connected to the front end of the second circuit breaker;

[0009] The connecting bar connects the rear ends of the first circuit breaker and the second circuit breaker, and the outgoing cable and the lightning arrester are installed on the connecting bar;

[0010] The box is provided with a lightning arrester monitoring unit, the grounding wire of the bottom flange of the lightning arrester passes through the lightning arrester monitoring unit and is connected to the box, and the secondary end of the voltage transformer is connected to the connection terminal of the lightning arrester monitoring unit through a signal line.

[0011] In a possible implementation, the arrester monitoring unit is used to analyze the arrester's leakage current parameters, overvoltage waveform, and harmonic components in real time, and transmit the analysis results to an in-vehicle monitoring device via an optical fiber.

[0012] In one possible implementation, a metal mounting plate is provided in the box, an insulating partition is provided between the arrester and the mounting plate, an insulating sleeve is provided on the other side of the mounting plate, and bolts pass through the insulating partition and the insulating sleeve to fix the arrester to the mounting plate.

[0013] In one possible implementation, the box is provided with an explosion-proof valve, which includes a valve, a spring and a deflector; when the air pressure inside the box increases due to the explosion of a high-voltage electrical appliance, the valve is compressed by the air pressure to open the spring, and the deflector will guide the released airflow to the roof in a directional manner.

[0014] In a possible implementation, the arrester monitoring unit monitors parameters including voltage, frequency, harmonics, leakage current peak value, and overvoltage number of the high-voltage circuit, and records the overvoltage impact current waveform during an accident.

[0015] In a possible implementation, the insulating partition and the insulating sleeve are made of epoxy resin material, and are used to block the leakage current generated by the lightning arrester from flowing directly to the box, thereby ensuring the accuracy of the monitoring data.

[0016] In a possible implementation, the air deflector is an arc-shaped structure, with its outlet facing the outside of the roof to prevent the released high-pressure gas from flowing back into the box.

[0017] In a possible implementation, the arrester monitoring unit obtains a leakage current signal of the arrester through a grounding wire, and obtains a voltage signal of a voltage transformer through a signal wire.

[0018] In a possible implementation, the lightning arrester and the connecting bar are fixed via a detachable copper connector, which facilitates replacement and maintenance of the lightning arrester.

[0019] In a possible implementation, the arrester monitoring unit has a built-in data storage module for storing operating parameters for at least 30 days, supporting the retrieval of historical data for analysis after an accident occurs.

[0020] The technical solution provided by this application can achieve at least the following beneficial effects:

[0021] The present application provides a high-voltage electrical box on the roof of an EMU with an online monitoring function for lightning arresters. By installing a lightning arrester monitoring unit, the voltage, frequency, harmonics, leakage current peak, overvoltage number and other parameters of the high-voltage circuit in the high-voltage electrical box can be monitored and recorded in real time. When an accident occurs, the data of the corresponding time period can be retrieved to analyze the overvoltage and leakage current waveforms of the high-voltage circuit when the accident occurs, and the cause of the problem can be clarified. The degree of deterioration of the lightning arrester can also be judged in real time, and the lightning arrester can be replaced in time to avoid accidents. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0023] Figure 1 This is a structural diagram of a high-voltage electrical box on the roof of an EMU with an arrester online monitoring function, shown in an exemplary embodiment of the present application;

[0024] Figure 2 This is an enlarged schematic diagram of a partial structure of a high-voltage electrical box on the roof of an EMU with an arrester online monitoring function, shown in an exemplary embodiment of the present application;

[0025] Figure 3 It is a schematic diagram of an insulating spacer for a high-voltage electrical box on the roof of an EMU with an arrester online monitoring function, shown as an exemplary embodiment of the present application.

[0026] Reference numerals:

[0027] 1. Box; 2. First circuit breaker; 3. Grounding switch; 4. Connecting bar; 5. Second circuit breaker; 6. Current transformer; 7. Voltage transformer; 8. Lightning arrester; 81. Grounding wire; 82. Insulating partition; 83. Insulating sleeve; 84. Mounting plate; 9. Incoming cable; 10. Outgoing cable; 11. Communication cable; 12. Lightning arrester monitoring unit; 121. Signal line; 13. Explosion-proof valve; 131. Valve; 132. Spring; 133. Air deflector. DETAILED DESCRIPTION

[0028] In order to make the purpose, implementation methods and advantages of the present application clearer, the exemplary implementation methods of the present application will be clearly and completely described below in conjunction with the drawings in the exemplary embodiments of the present application. Obviously, the described exemplary embodiments are only part of the embodiments of the present application, not all of the embodiments. It should be understood that the specific embodiments described here are only used to explain the present application and are not used to limit the present application.

[0029] It should be noted that the brief descriptions of terms in this application are only for the purpose of facilitating the understanding of the embodiments described below, and are not intended to limit the embodiments of this application. Unless otherwise specified, these terms should be understood according to their ordinary and usual meanings.

[0030] In the specification and claims of this application and the accompanying drawings, the terms "first," "second," "third," etc. are used to distinguish similar or similar objects or entities, and are not necessarily intended to limit a particular order or sequence, unless otherwise noted. It should be understood that the terms used in this manner are interchangeable under appropriate circumstances.

[0031] The terms "comprise," "include," and "have," and any variations thereof, are intended to cover but not exclude inclusion; for example, a product or device comprising a list of components is not necessarily limited to all the components expressly listed but may include other components not expressly listed or inherent to such product or device.

[0032] Before explaining the EMU roof high-voltage electrical box with a lightning arrester online monitoring function provided in the embodiment of the present application, the application scenario and implementation environment of the embodiment of the present application are first introduced.

[0033] A lightning arrester is installed in the high-voltage electrical box. When overvoltage occurs in the high-voltage circuit, the lightning arrester absorbs a certain amount of overvoltage energy and generates a relatively large leakage current. The overvoltage is limited below the allowable value, thereby providing reliable protection for electrical equipment. Under the rated voltage of the lightning arrester and the normal operating voltage of the high-voltage circuit, only a very small leakage current flows through the lightning arrester, which plays a role in insulation from the system.

[0034] Although lightning arresters can absorb overvoltage, accidents of high-voltage electrical equipment explosions due to overvoltage still occur. After the accident, it is impossible to reproduce the overvoltage state of the high-voltage circuit at the time of the accident, and it is impossible to thoroughly analyze the root cause of the problem, so it is impossible to take effective measures to prevent the accident from happening again.

[0035] However, after the arrester has been running for a period of time, its performance will inevitably deteriorate due to the impact of large current and the influence of the external environment. If the performance of the arrester deteriorates to a certain extent and is not dealt with in time, the arrester itself will not be able to withstand the impact of overvoltage and will explode, or its protection function will be weakened, causing other high-voltage equipment to explode. Therefore, it is necessary to perform online monitoring of the arrester in the high-voltage electrical box.

[0036] The lightning arrester monitoring unit can monitor and record the voltage, frequency, harmonics, leakage current peak, overvoltage number and other parameters of the high-voltage circuit in the box in real time. When an accident occurs, the data can be retrieved to analyze the overvoltage and impact current waveforms of the high-voltage circuit at the time of the accident and clarify the cause of the problem.

[0037] Although conventional high-voltage electrical cabinets are equipped with lightning arresters, their performance inevitably deteriorates after a period of operation due to high current surges and environmental influences. If the arrester's performance deteriorates to a certain point and is not promptly addressed, the arrester itself may be unable to withstand the surge current and explode, or its weakened protective function may cause explosions in other high-voltage equipment. After an incident, the inability to reproduce the overvoltage state of the power supply system at the time of the incident makes it impossible to thoroughly analyze the root cause of the problem and, therefore, to take effective measures to prevent it from happening again.

[0038] After installing the arrester monitoring unit, the voltage, frequency, harmonics, leakage current peak, overvoltage frequency and other parameters of the high-voltage circuit in the high-voltage electrical box can be monitored and recorded in real time. When an accident occurs, the data of the corresponding period can be retrieved to analyze the overvoltage and leakage current waveforms of the high-voltage circuit at the time of the accident and clarify the cause of the problem. It can also make real-time judgments on the degree of deterioration of the arrester and replace it in time to avoid accidents.

[0039] Based on this, the present application provides a high-voltage electrical box on the roof of an EMU with an online monitoring function for lightning arresters. By integrating a lightning arrester monitoring unit, an explosion-proof valve and an insulating isolation structure, it can realize real-time monitoring of the lightning arrester status, pressure release and precise measurement of leakage current, thereby improving the operation safety and maintenance efficiency of the EMU.

[0040] Next, the technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems will be described in detail through embodiments and in conjunction with the accompanying drawings. The various embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. Obviously, the described embodiments are only part of the embodiments of the present application, not all of them.

[0041] Figure 1It is a structural schematic diagram of a high-voltage electrical box on the roof of an EMU with an arrester online monitoring function, shown as an exemplary embodiment of the present application.

[0042] In an exemplary embodiment, Figure 1 As shown, a high-voltage electrical box on the roof of an EMU with an online monitoring function of a lightning arrester 8 is provided. The electrical box may include a box body 1, a first circuit breaker 2, a grounding switch 3, a connecting bar 4, a second circuit breaker 5, a current transformer 6, a voltage transformer 7 and a lightning arrester 8.

[0043] The incoming cable 9 passes through the current transformer 6 and is connected to the front end of the first circuit breaker 2 , the voltage transformer 7 is connected to the front end of the first circuit breaker 2 , and the contact cable 11 is connected to the front end of the second circuit breaker 5 ;

[0044] The connecting bar 4 connects the rear ends of the first circuit breaker 2 and the second circuit breaker 5, and the outgoing cable 10 and the lightning arrester 8 are installed on the connecting bar 4;

[0045] The box body 1 is provided with a lightning arrester 8 monitoring unit. The grounding wire 81 of the bottom flange of the lightning arrester 8 passes through the lightning arrester 8 monitoring unit and is connected to the box body 1. The secondary end of the voltage transformer 7 is connected to the connection terminal of the lightning arrester 8 monitoring unit through the signal line 121.

[0046] Figure 2 This is an enlarged schematic diagram of a partial structure of a high-voltage electrical box on the roof of an EMU with an arrester online monitoring function, shown in an exemplary embodiment of the present application. Figure 3 It is a schematic diagram of an insulating spacer for a high-voltage electrical box on the roof of an EMU with an arrester online monitoring function, shown as an exemplary embodiment of the present application.

[0047] In one possible implementation, Figure 1 、 Figure 2 and Figure 3 As shown, the specific structure of the high-voltage electrical box on the roof of the EMU includes a sealed box body 1 with a box cover, a first circuit breaker 2, a grounding switch 3, a connecting bar 4, a second circuit breaker 5, a current transformer 6, a voltage transformer 7, and a lightning arrester 8.

[0048] The incoming cable 9 passes through the current transformer 6 and is connected to the front end of the first circuit breaker 2, and the voltage transformer 7 is connected to the front end of the first circuit breaker 2; the connecting cable 11 is connected to the front end of the second circuit breaker 5; the connecting bar 4 connects the rear end of the first circuit breaker 2 and the rear end of the second circuit breaker 5, and the outgoing cable 10 and the lightning arrester 8 are connected to the connecting bar 4.

[0049] A lightning arrester monitoring unit 12 is installed in the box 1. The grounding wire 81 connected to the bottom flange of the lightning arrester 8 passes through the lightning arrester monitoring unit 12 and the other end is connected to the box 1. The secondary end of the voltage transformer 7 is connected to the signal line 121 to the connection terminal of the lightning arrester monitoring unit 12.

[0050] The arrester 8 will generate leakage current when absorbing the overvoltage of the high-voltage circuit in the box 1. The arrester monitoring unit 12 can analyze the parameters of the leakage current and the overvoltage waveform of the high-voltage circuit when leakage occurs, and transmit the analysis results to the in-vehicle monitoring device through optical fiber.

[0051] A metal mounting plate 84 is installed in the box body 1 and the mounting plate 84 is welded to the box body 1. An insulating partition 82 is installed between the lightning arrester 8 and the mounting plate 84. An insulating spacer 83 is installed on the other side of the mounting plate 84. Bolts pass through the insulating partition 82 and the insulating spacer 83 to fix the lightning arrester 8 on the mounting plate 84.

[0052] An explosion-proof valve 13 is installed on the box body 1. When the air pressure inside the box body 1 increases due to the explosion of the high-voltage electrical appliance, the valve 131 of the explosion-proof valve 13 is compressed by the air pressure to compress the spring 132, the valve (131) opens, the pressurized gas inside the box body 1 is released, and the deflector 133 guides the air flow to the roof.

[0053] It can be seen that in some embodiments of the present application, after installing the lightning arrester monitoring unit, the voltage, frequency, harmonics, leakage current peak, overvoltage frequency and other parameters of the high-voltage circuit in the high-voltage electrical box can be monitored and recorded in real time. When an accident occurs, the data of the corresponding period can be retrieved to analyze the overvoltage and leakage current waveforms of the high-voltage circuit at the time of the accident and clarify the cause of the problem. It is also possible to make a real-time judgment on the degree of deterioration of the lightning arrester and replace the lightning arrester in time to avoid accidents.

[0054] It should be understood that, although the various steps in the flowcharts involved in the above-described embodiments are displayed in sequence according to the instructions, these steps are not necessarily executed in the order indicated. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and these steps can be executed in other orders. Moreover, at least a portion of the steps in the flowcharts involved in the above-described embodiments may include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a portion of steps or stages in other steps.

[0055] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0056] The embodiments described above merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art could make various modifications and improvements without departing from the spirit of the present application, all of which fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A high-voltage electrical box on the roof of an EMU with an online monitoring function for lightning arresters, characterized in that: It includes a box, a first circuit breaker, a grounding switch, a connecting bar, a second circuit breaker, a current transformer, a voltage transformer and a lightning arrester. The incoming cable passes through the current transformer and is connected to the front end of the first circuit breaker, the voltage transformer is connected to the front end of the first circuit breaker, and the contact cable is connected to the front end of the second circuit breaker; The connecting bar connects the rear ends of the first circuit breaker and the second circuit breaker, and the outgoing cable and the lightning arrester are installed on the connecting bar; The box is provided with a lightning arrester monitoring unit, the grounding wire of the bottom flange of the lightning arrester passes through the lightning arrester monitoring unit and is connected to the box, and the secondary end of the voltage transformer is connected to the connection terminal of the lightning arrester monitoring unit through a signal line.

2. The EMU roof high-voltage electrical box with a lightning arrester online monitoring function as claimed in claim 1 is characterized in that: The arrester monitoring unit is used to analyze the arrester's leakage current parameters, overvoltage waveform and harmonic components in real time, and transmit the analysis results to the in-vehicle monitoring device via optical fiber.

3. The high-voltage electrical box on the roof of an EMU with an online monitoring function for lightning arresters according to claim 1 is characterized in that: A metal mounting plate is provided in the box body, an insulating partition is provided between the arrester and the mounting plate, an insulating sleeve is provided on the other side of the mounting plate, and bolts pass through the insulating partition and the insulating sleeve to fix the arrester to the mounting plate.

4. The high-voltage electrical box on the roof of an EMU with an online monitoring function for lightning arresters as claimed in claim 3, characterized in that: The box body is provided with an explosion-proof valve, which includes a valve, a spring and a deflector. When the air pressure inside the box body increases due to the explosion of high-voltage electrical appliances, the valve is compressed by the air pressure and the spring opens, and the deflector directs the released airflow to the roof.

5. The EMU roof high-voltage electrical box with a lightning arrester online monitoring function as claimed in claim 1, characterized in that: The parameters monitored by the arrester monitoring unit include the voltage, frequency, harmonics, leakage current peak value and overvoltage number of the high-voltage circuit, and records the overvoltage impact current waveform during an accident.

6. The EMU roof high-voltage electrical box with a lightning arrester online monitoring function as claimed in claim 5, characterized in that: The insulating partition and the insulating sleeve are made of epoxy resin material and are used to block the leakage current generated by the lightning arrester from directly flowing to the box body, thereby ensuring the accuracy of the monitoring data.

7. The high-voltage electrical box on the roof of an EMU with an online monitoring function for lightning arresters as claimed in claim 1, characterized in that: The deflector is an arc-shaped structure, and its outlet is directed toward the outside of the roof to prevent the released high-pressure gas from flowing back into the box.

8. The high-voltage electrical box on the roof of an EMU with an online monitoring function for lightning arresters as claimed in claim 1, characterized in that: The arrester monitoring unit obtains a leakage current signal of the arrester through a grounding wire, and obtains a voltage signal of a voltage transformer through a signal wire.

9. The high-voltage electrical box on the roof of an EMU with an online monitoring function for lightning arresters according to claim 1, characterized in that: The arrester is fixed to the connecting bar via a detachable copper connector, which facilitates replacement and maintenance of the arrester.

10. The high-voltage electrical box on the roof of an EMU with an online monitoring function for lightning arresters according to claim 1, characterized in that: The arrester monitoring unit has a built-in data storage module for storing operating parameters for at least 30 days, and supports the retrieval of historical data for analysis after an accident occurs.

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