Rail transit intelligent grounding control system and method

Abstract

The invention discloses a rail transit intelligent grounding control system and method, and relates to the field of rail transit, the system is characterized in that a control unit is respectively connected with a data acquisition unit and a grounding switch, and the data acquisition unit is also connected with a working condition parameter sensor; the electric signal sensor comprises a current sensor or a voltage sensor; the working condition parameter sensor is used for reading working condition parameters corresponding to a transmission cable shielding layer in the grounding switch; the data acquisition unit is used for acquiring the working condition parameters read by the working condition parameter sensor and sending the acquired working condition parameters to the control unit; the control unit is used for sending a corresponding indication instruction to the grounding switch when the relation between the received working condition parameter and the switch action threshold meets the connection change condition, and the indication instruction is used for indicating the grounding switch to change the connection state of the grounding point and the ground; and the grounding switch is used for changing the connection state of the grounding point and the ground according to the received indication instruction. The driving safety can be practically guaranteed.

Description

Technical Field

[0001] The present application relates to the field of rail transit, and in particular to a rail transit intelligent grounding control system and method. Background Art

[0002] The safe and stable operation of the rail transit system is of vital importance, and the grounding system plays a key role in ensuring the normal operation of electrical equipment, personnel safety, and preventing electromagnetic interference.

[0003] In the electrified railway environment, the information transmission cables of the weak current system are usually laid parallel to the tracks. When the train passes, the core wire of the information transmission cable is subjected to a large electromagnetic induction effect. According to the law of electromagnetic induction, when the cable shielding layer is in a changing magnetic field, an induced electromotive force will be generated in the core wire. This induced longitudinal potential and its harmonics will interfere with data transmission. If the shielding layer forms a closed loop, an induced current will be generated. This reverse current will generate a secondary induced longitudinal potential on the core wire, and the direction is opposite to the primary induced longitudinal potential, thereby shielding and protecting the data transmission of the core wire. When the shielding layer is grounded at both ends to form a closed loop, when there is an instantaneous large current and high voltage in the outside world to form a path with it, the shielding layer will be burned, and driving safety cannot be guaranteed. Summary of the invention

[0004] The purpose of this application is to provide a rail transit intelligent grounding control system and method, which can effectively protect the cable shielding layer from being burned and effectively ensure driving safety.

[0005] To achieve the above objectives, this application provides the following solutions: In a first aspect, the present application provides a rail transit intelligent grounding control system, the rail transit intelligent grounding control system comprising: A front-end control device, comprising: an operating parameter sensor, a data acquisition unit, a control unit and a grounding switch; The control unit is connected to the data acquisition unit and the grounding switch respectively, and the data acquisition unit is also connected to the operating parameter sensor; the operating parameter sensor includes: an electrical signal sensor and / or a temperature sensor; the electrical signal sensor includes: a current sensor or a voltage sensor; The operating parameter sensor is used to read the operating parameters corresponding to the shielding layer of the transmission cable in the grounding switch; The data acquisition unit is used to acquire the operating parameters read by the operating parameter sensor and send the acquired operating parameters to the control unit; The control unit is used to send a corresponding instruction to the grounding switch when the relationship between the received operating condition parameter and the switch action threshold meets the connection change condition, wherein the instruction is used to instruct the grounding switch to change the connection state between the grounding point and the ground; The grounding switch is used to change the connection state between the grounding point and the ground according to the received instruction.

[0006] In a second aspect, the present application provides a rail transit intelligent grounding control method, including the rail transit intelligent grounding control system as described in the first aspect, the rail transit intelligent grounding control system includes: a front-end control device, the front-end control device includes: an operating parameter sensor, a data acquisition unit, a control unit and a grounding switch, the method includes: The operating condition parameter sensor reads the operating condition parameter corresponding to the shielding layer of the transmission cable in the grounding switch, and the operating condition parameter sensor includes: an electrical signal sensor and / or a temperature sensor; the electrical signal sensor includes: a current sensor or a voltage sensor; The data acquisition unit acquires the operating condition parameters read by the operating condition parameter sensor, and sends the acquired operating condition parameters to the control unit; The control unit detects whether the relationship between the received operating condition parameter and the switch action threshold satisfies a connection change condition, and when it is detected that the relationship between the received operating condition parameter and the switch action threshold satisfies the connection change condition, sends a corresponding instruction to the grounding switch, wherein the instruction is used to instruct the grounding switch to change the connection state between the grounding point and the ground; The grounding switch changes the connection state between the grounding point and the ground according to the received instruction.

[0007] According to the specific embodiments provided in this application, this application discloses the following technical effects: The present application provides a rail transit intelligent grounding control system and method, the rail transit intelligent grounding control system includes: a front-end control device, the front-end control device includes: an operating parameter sensor, a data acquisition unit, a control unit and a grounding switch; the control unit is respectively connected to the data acquisition unit and the grounding switch, and the data acquisition unit is also connected to the operating parameter sensor; the operating parameter sensor includes: an electrical signal sensor, and / or a temperature sensor; the electrical signal sensor includes: a current sensor or a voltage sensor; the operating parameter sensor is used to read the operating parameters corresponding to the shielding layer of the transmission cable in the grounding switch; the data acquisition unit is used to collect the operating parameters read by the operating parameter sensor and send the collected operating parameters to the control unit; the control unit is used to send a corresponding indication instruction to the grounding switch when the relationship between the received operating parameter and the switch action threshold meets the connection change condition, the indication instruction is used to instruct the grounding switch to change the connection state between the grounding point and the ground; the grounding switch is used to change the connection state between the grounding point and the ground according to the received indication instruction. The present invention analyzes the operating parameters and automatically controls the grounding state of the grounding switch according to the operating parameters. If the relationship between the operating parameters and the switch action threshold satisfies the connection change condition, an instruction is sent to the grounding switch to instruct the grounding switch to change the connection state between the grounding point and the ground. This can effectively protect the cable shielding layer from being burned when there is a risk of burning, protect the weak current equipment along the line, and automatically restore the normal operation of the cable to protect the cable information transmission from electromagnetic interference and dangerous influences. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0009] Figure 1 The structure of the intelligent grounding control system for rail transit is shown according to an exemplary embodiment. Figure 1 ; Figure 2 is a structural schematic diagram of an automatic air switch in the related art according to an exemplary embodiment; Figure 3 The structure of the intelligent grounding control system for rail transit is shown according to an exemplary embodiment. Figure 2 ; Figure 4 The structure of the intelligent grounding control system for rail transit is shown according to an exemplary embodiment. Figure 3 ; Figure 5The figure is a flow chart of a rail transit intelligent grounding control method according to an exemplary embodiment.

[0010] Description of reference numerals: 1-main contact; 2-free release mechanism; 3-overcurrent release; 4-shunt release; 5-thermal release; 6-undervoltage release; 7-stop button; 8-front-end control equipment; 81-operating parameter sensor; 82-data acquisition unit; 83-control unit; 84-grounding switch; 86-alarm unit; 9-communication transmission unit; 10-monitoring center. DETAILED DESCRIPTION

[0011] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0012] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0013] The electromagnetic compatibility of the grounding system of the weak current control equipment along the railway / trackside is an important factor in ensuring the normal operation of the equipment, and it is also one of the signs of the perfection and maturity of railway communication signal technology.

[0014] At present, the grounding of weak-current equipment along electrified railways generally adopts the method of setting up a separate grounding body or uniformly connecting to a through-ground wire; or, a comprehensive through-ground wire is laid along the line to provide a grounding terminal for the equipment; or, the grounding rail, return line and contact network support foundation grounding electrode constitute the main grounding device in the ground section; or, the national railway's grounding protection device mainly includes dischargers (lightning arresters), grounding wires and grounding electrodes.

[0015] The main purpose of the grounding system is to prevent lightning, electric shock, corrosion, reduce electromagnetic induction voltage and electrostatic induction voltage, and provide a unified reference potential for equipment and information transmission cables along the line. In order to effectively protect the weak current equipment and information transmission cables along the line from electromagnetic interference and dangerous influences inside and outside the road, various countries have made detailed considerations and experimental improvements in the design of grounding schemes, lightning arresters, signal cable shielding protection design, and electromagnetic compatibility protection measures.

[0016] There are a large number of electromagnetic fields around the rail transit system, such as the alternating magnetic field generated by the traction power supply system. According to the law of electromagnetic induction, when the cable shield is grounded at one end, the alternating electromagnetic field will generate an induced electromotive force in the shield; the greater the traction current of the traction power supply system, the greater the alternating electromagnetic field generated, and correspondingly, the greater the induced longitudinal potential generated by the cable shield. The long-term accumulation of high induced longitudinal potential in the cable shield may cause interference to data transmission and affect the normal operation of the control system; at the same time, it will cause problems such as heating of the shield, accelerated aging, and shortened cable service life.

[0017] When the shielding layer is grounded at both ends, the shielding layer and the ground wire form a closed loop. At this time, if there is a large instantaneous traction return current in the ground wire, a shunt will occur on the shielding layer. This instantaneous large current may cause the cable shielding layer to burn.

[0018] Burning of the cable shield will cause serious damage to the equipment and system: 1. Damage to electrical equipment.

[0019] When the grounding system is burned out, it may cause grounding failure and electrical equipment to lose effective protection. Abnormal current cannot be introduced into the earth in time, which may cause overvoltage and overcurrent inside the equipment, damaging the insulation, electronic components and other key components of the equipment. For example, sensitive electronic components in signal equipment may burn out due to overvoltage, resulting in interruption or error in signal transmission, affecting the normal operation and dispatching of trains. For traction power supply systems, grounding burnout may cause damage to important equipment such as transformers and circuit breakers. This will not only cause power outages and affect the running power of the train, but may also cause more serious electrical accidents such as explosions and fires.

[0020] 2. Affect the communication system.

[0021] The communication system in rail transit relies on stable grounding to prevent electromagnetic interference. Grounding burnout will destroy the ground reference potential of the communication system, interfere with the communication signal, reduce the communication quality and even cause communication interruption. For example, wireless communication between the train and the dispatching center may have problems such as noise and signal loss, affecting the timeliness and accuracy of dispatching command. If the shielding layer of the communication cable loses its function due to grounding burnout, the cable will be more susceptible to external electromagnetic interference, which may cause data transmission errors and affect the normal operation of key information systems such as train automatic control systems and ticketing systems.

[0022] 3. Damage the track circuit.

[0023] Track circuits are important equipment for detecting train positions and controlling signals, and their normal operation depends on good grounding. Grounding burnout may interfere with the signal transmission of the track circuit, causing the track circuit to be unable to accurately detect the train position, thereby affecting the normal operation of the signal system. For example, erroneous signal displays may occur, misleading train drivers or automatic control systems and increasing the risk of train collisions. Severe grounding burnout may also damage track circuit equipment, such as transmitters and receivers, which need to be repaired or replaced, increasing maintenance costs and downtime.

[0024] In order to protect the cable shielding layer from being burned and to ensure driving safety, the present invention proposes a rail transit intelligent grounding control system and method.

[0025] Figure 1 is a schematic diagram of a structure of a rail transit intelligent grounding control system according to an exemplary embodiment. Figure 1 As shown, the rail transit intelligent grounding control system includes: A front-end control device 8, the front-end control device 8 comprises: an operating parameter sensor 81, a data acquisition unit 82, a control unit 83 and a grounding switch 84; The control unit 83 is connected to the data acquisition unit 82 and the grounding switch 84 respectively, and the data acquisition unit 82 is also connected to the operating parameter sensor 81; The operating parameter sensor 81 is used to read the operating parameters corresponding to the shielding layer of the transmission cable in the grounding switch 84 .

[0026] The operating parameter sensor 81 mentioned above includes: an electrical signal sensor, and / or a temperature sensor.

[0027] For example, the electrical signal sensor includes: a current sensor or a voltage sensor, wherein the current sensor may be a platinum resistance temperature sensor.

[0028] The data acquisition unit 82 is used to acquire the operating parameters read by the operating parameter sensor 81 and send the acquired operating parameters to the control unit 83 .

[0029] In the present disclosure, the acquisition frequency of the data acquisition unit 82 can be adjusted. Specifically, the control unit 83 is also used to obtain the parameter acquisition frequency and send the parameter acquisition frequency to the data acquisition unit 82; the data acquisition unit 82 is used to collect the operating parameters read by the operating parameter sensor 81 according to the parameter acquisition frequency.

[0030] In one possible implementation, the control unit 83 may include a human-computer interaction function, and the staff can manually input the parameter collection frequency through the human-computer interaction interface. A parameter collection frequency table can also be built into the control unit 83. In this table, a mapping relationship between different times and parameter collection frequencies will be set. The control unit 83 also needs to obtain the current time and then obtain the parameter collection frequency by looking up the table.

[0031] The data acquisition frequency of the data acquisition unit 82 is adjustable, with a maximum sampling frequency of 3 MHz, so as to achieve high-frequency acquisition and intelligent analysis of hazardous current and temperature.

[0032] The operating parameter sensor 81 may also include a photocoupler, such as TLP718.

[0033] For example, when obtaining temperature, the temperature sensor is responsible for measuring the temperature of the environment or equipment and converting the temperature signal into an electrical signal. This electrical signal may be interfered by surrounding electrical equipment. At this time, the electrical isolation characteristics of the photoelectric coupler can be used to isolate and transmit the signal output by the temperature sensor to ensure that the signal is not interfered during transmission to the data acquisition unit 82, so that the temperature value can be obtained more accurately.

[0034] When acquiring current, the current signal measured by the current sensor needs to be transmitted to the data acquisition unit 82. The photoelectric coupler has good electrical isolation performance and signal unidirectional transmission characteristics, and can isolate and transmit the signal output by the current sensor, avoiding electrical interference and common ground problems between different circuits, and improving the reliability of the current value. For example, the current sensor measures the current in the conductor in the shielding layer of the transmission cable, and transmits the signal to the data acquisition unit 82 through the photoelectric coupler to prevent the interference of other conductors from causing fluctuations in the current value.

[0035] The control unit 83 is used to send a corresponding instruction to the grounding switch 84 when the relationship between the received operating condition parameter and the switch action threshold meets the connection change condition. The instruction is used to instruct the grounding switch 84 to change the connection state between the grounding point and the ground.

[0036] The indication instruction may include a grounding point disconnection signal or a grounding point connection signal. When the relationship between the received operating condition parameter and the switch action threshold satisfies the connection change condition, the control unit 83 sends the corresponding indication instruction to the grounding switch 84, specifically for: If the grounding point is in a connected state with the ground, when it is detected that the operating condition parameter meets the switch action threshold, a grounding point disconnection signal is sent to the grounding switch 84 .

[0037] The switch action threshold corresponding to when the operating parameter is current and the switch action threshold corresponding to when the operating parameter is temperature may be different.

[0038] Specifically, when it is detected that the change value of the operating condition parameter within the preset time period meets the switch action threshold, a grounding point disconnection signal is sent to the grounding switch 84. If the grounding point is disconnected from the ground, when it is detected that the operating condition parameter does not meet the switch action threshold, a grounding point connection signal is sent to the grounding switch 84 .

[0039] Specifically, when it is detected that the change value of the operating condition parameter within the preset time period does not meet the switch action threshold, a grounding point connection signal is sent to the grounding switch 84 .

[0040] The indication instruction includes a grounding point disconnection signal or a grounding point connection signal.

[0041] The switch operating threshold is determined according to the probability of shielding layer burning.

[0042] In one embodiment, based on the heat balance equation, when the heat generated is greater than the heat dissipated to a certain extent, and the temperature exceeds the tolerance limit (such as the melting point or decomposition temperature) of the shielding layer material, burning may occur. Combined with the probability distribution of parameters such as the working current and the working environment temperature of the cable (for example, the probability distribution of the working current can be obtained by analyzing the load characteristics of the power system), the burning probability of the shielding layer is calculated by methods such as Monte Carlo simulation.

[0043] In another embodiment, based on the fault tree analysis (FTA), the shielding layer burnout can be taken as the top event, and various possible factors leading to the burnout, such as overcurrent, overvoltage, external fire, mechanical damage, etc., can be analyzed as intermediate events and bottom events. Each event is assigned a probability of occurrence (which can be obtained through historical data, experimental data or expert evaluation), and then the probability of the shielding layer burnout is calculated based on the logical relationship of the fault tree (such as AND gate, OR gate). For example, if the shielding layer burnout is caused by the simultaneous action of overcurrent and overvoltage, then the two events are in an AND gate relationship; if the burnout can be caused by overcurrent or mechanical damage, then they are in an OR gate relationship.

[0044] It can also be obtained through experimental testing. In a laboratory environment, stress higher than normal working conditions is applied to cable samples, such as increasing current, voltage, or increasing ambient temperature, to simulate extreme working conditions to accelerate the aging and damage process of the shielding layer. For example, for power cables, the operating current can be increased to 1.5-2 times the rated current, the ambient temperature can be increased to 70-90°C, and the operation can be continued for a period of time (such as 1000-2000 hours) to observe the burning of the shielding layer. By testing multiple samples, the burning probability is estimated based on the ratio of the number of burned samples to the total number of samples. At the same time, statistical methods such as Weibull distribution can be used to analyze test data and extrapolate the burning probability under normal working conditions.

[0045] It can also simulate possible fault conditions that the cable may encounter, such as short-circuit test, lightning strike test, etc. In the short-circuit test, a low impedance is applied to both ends of the cable to allow the short-circuit current to pass through the shielding layer and observe the response of the shielding layer; in the lightning strike test, an impulse voltage generator is used to simulate the high voltage and large current generated by lightning strikes passing through the shielding layer. The burning of the shielding layer in each test is recorded, and after multiple tests (such as 100-200 times), the burning probability is calculated.

[0046] For example, the above-mentioned switch action threshold can be obtained based on the cable burn test data. For example, when the current suddenly changes (the increase in amplitude exceeds 10A within 100ms), the probability that the current causes the shielding layer to burn is 90%; when the temperature suddenly changes (the increase in amplitude exceeds 20°C within 20s), the probability that the shielding layer burns is more than 90%. When it is determined that the probability of cable burn is more than 90%, a grounding point disconnection signal is sent to the grounding switch 84. When there is no probability of harm, a grounding point connection signal is sent to the grounding switch 84 to restore grounding.

[0047] Then, when the operating parameter is current, the switch action threshold can be that the current increases by more than 10A within 100ms; when the operating parameter is temperature, the switch action threshold can be that the temperature increases by more than 20°C within 20s; when the operating parameters are both current and temperature, the switch action threshold is that the current increases by more than 10A within 100ms and the temperature increases by more than 20°C within 20s.

[0048] When the operating parameter is voltage, the voltage can be converted into current.

[0049] The switch action threshold can also be set according to the actual situation of each specific railway line.

[0050] The grounding switch 84 is used to change the connection state between the grounding point and the ground according to the received instruction.

[0051] The grounding switch 84 can change the connection state between the grounding point and the ground by controlling the switch terminal of the grounding switch. When the switch terminal of the grounding switch is disconnected, the connection between the grounding point and the ground is disconnected. When the switch terminal of the grounding switch is closed, the connection between the grounding point and the ground is connected.

[0052] At present, the device similar to the above-mentioned grounding switch is the automatic air switch, which is also called a low-voltage circuit breaker. It can be used to connect and disconnect the load circuit, and can also be used to control the motor that is not frequently started. Its function is equivalent to the sum of some or all functions of electrical appliances such as knife switches, overcurrent relays, pressure loss relays, thermal relays and leakage protectors. It is an important protective electrical appliance in the low-voltage distribution network.

[0053] like Figure 2As shown, the automatic air switch includes: a main contact 1, a free unhooking mechanism 2, an overcurrent release 3, a shunt release 4, a thermal release 5, an undervoltage release 6 and a stop button 7.

[0054] The main contact 1 of the automatic air switch is closed manually or electrically. After the main contact 1 is closed, the free release mechanism 2 locks the main contact 1 in the closed position. The coil of the overcurrent release 3 and the thermal element of the thermal release 5 are connected in series with the main circuit. When a short circuit or severe overload occurs in the circuit, the armature of the overcurrent release 3 is attracted, causing the free release mechanism 2 to operate, and the main contact 1 disconnects the main circuit. When the circuit is overloaded, the thermal element of the thermal release 5 heats up to bend the bimetallic strip, pushing the free release mechanism 2 to operate. The shunt release 4 is used for remote control. During normal operation, its coil is de-energized. When distance control is required, the stop button 7 is pressed to energize the coil, and the armature drives the free release mechanism 2 to operate, disconnecting the main contact 1. When the line voltage is normal, the undervoltage release 6 generates sufficient suction force to overcome the tension spring of the overcurrent release 3 and close the armature. The armature of the overcurrent release 3 is separated from the lever, and the free release mechanism 2 is locked, so that the main contact 1 can be closed. When the voltage on the line disappears completely or the voltage drops to a certain value, the suction force of the undervoltage release disappears or decreases, the armature of the overcurrent release 3 is pulled apart by the tension spring and hits the lever, and the main circuit power supply is disconnected.

[0055] Existing air switches can cut off the circuit in time when the circuit is overloaded to protect the safety of electrical equipment, but they cannot flexibly set the voltage and current thresholds for cutting off the circuit according to actual needs, and cannot remotely control the on and off of the circuit, and cannot automatically recover after power failure, and do not have the characteristics of intelligence and automation. In addition, they are single devices, suitable for small-power ordinary life electricity current, and are not suitable for autonomous control of instantaneous high-power and high-current in railway scenarios.

[0056] The grounding switch 84 in the present disclosure adopts a high-power IGBT element suitable for industrial scenarios. The IGBT element changes the connection status between the grounding point and the ground according to the received instruction command, and realizes the rapid closing and disconnecting function of the grounding control body through the IGBT element. The fastest action time of the switch is 100μs, which can realize the rapid cutting off of instantaneous large current surge on site and effectively avoid burning of the cable shielding layer.

[0057] By analyzing the operating parameters and automatically controlling the grounding state of the cable shielding layer according to the operating parameters, if the change value of the operating parameters within the preset time period meets the switch action threshold, a grounding point disconnection signal is sent to the grounding switch 84 to disconnect the grounding switch 84 from the ground, thereby preventing the grounding switch 84 from continuing to work, thereby effectively protecting the cable shielding layer from being burned and protecting the weak current equipment along the line. If the change value of the operating parameters within the preset time period does not meet the switch action threshold, a grounding point connection signal is sent to the grounding switch 84, thereby restoring the normal operation of the cable and protecting the cable's information transmission from electromagnetic interference and dangerous influences.

[0058] In one embodiment, Figure 3 As shown, the rail transit intelligent grounding control system also includes: a communication transmission unit 9 and a monitoring center 10; The communication transmission unit 9 is used to send the operating parameters received by the control unit 83 to the monitoring center 10; the monitoring center 10 is used to send a corresponding indication instruction to the grounding switch 84 when the relationship between the received operating parameters and the switch action threshold meets the connection change condition.

[0059] The communication transmission unit 9 adopts a wireless communication method or a wired communication method.

[0060] Communication adopts both wireless and wired methods to meet different usage requirements. The wireless method uses 4G / 5G wireless communication to transmit data, and the wired method uses USB, UART bus interface (4G), MiniPCIe (Mini PeripheralComponent Interconnect Express), Ethernet port and RS485 multi-communication interface setting scheme.

[0061] For example: when in use, the operating parameters can be sent to the monitoring center via RS485 or antenna at the same time.

[0062] The grounding switch 84 can be remotely controlled through the monitoring center 10, thereby improving the flexibility of control.

[0063] In one embodiment, the front-end control device 8 also includes a data storage unit; the data storage unit is respectively connected to the data acquisition unit, the control unit 83 and the communication transmission unit 9; the data acquisition unit 82 is used to send the collected operating parameters to the data storage unit; the data storage unit is used to send the operating parameters stored in the data storage unit to the control unit 83; the communication transmission unit 9 is used to send the operating parameters in the data storage unit to the monitoring center 10.

[0064] In order to ensure the reliable transmission of operating condition parameters, the present disclosure may also set up a data storage unit. The data acquisition unit will send the collected operating condition parameters to the data storage unit, which will first store them. Then, when the control unit 83 needs to perform detection, it will actively read the operating condition parameters from the data storage unit. When the monitoring center 10 needs to control, the communication transmission unit 9 will read the operating condition parameters from the data storage unit and transmit them to the monitoring center 10.

[0065] In one embodiment, Figure 4 As shown, the front-end control device 8 also includes an alarm unit 86; the alarm unit is connected to the control unit 83; the control unit 83 is also used to send an alarm signal to the alarm unit 86 when it is detected that the operating parameters meet the switch action threshold; the alarm unit 86 is used to execute a preset alarm operation according to the alarm signal.

[0066] In the present disclosure, the front-end control device 8 can also be provided with an alarm unit 86. When it is detected that the operating parameters meet the switch action threshold and the connection between the grounding point and the ground needs to be disconnected, an alarm operation can be issued through the alarm unit 86. This allows the staff to pay attention. If it is found that the connection between the grounding point and the ground is not disconnected at this time, the connection between the grounding point and the ground can be manually disconnected. This can avoid the failure of automatic control and the inability to disconnect the connection between the grounding point and the ground, thereby improving reliability.

[0067] In one embodiment, the control unit 83 also includes: a power supply module, which is used to provide an operating voltage for the control unit 83. For example, if the operating voltage of the control unit 83 is 3.3V, the power supply module provides a 3.3V operating voltage for the control unit 83. When the voltage input to the power supply module is higher than the voltage input to the main controller by the power supply module, the power supply module can convert the voltage into a voltage that meets the requirements of the control unit 83. At this time, the power supply module can also have a built-in voltage conversion module to convert the voltage into a voltage that meets the requirements of the control unit 83 through the voltage conversion module.

[0068] The control unit 83 in the present disclosure may adopt STM32F407VET6.

[0069] In one embodiment, the control unit 83 can also be provided with a manual switch, and can also manually control the connection status between the grounding point of the grounding switch 84 and the ground as needed. At the same time, the monitoring center 10 can also remotely control the connection status between the grounding point of the on-site grounding switch 84 and the ground by sending instructions.

[0070] The monitoring center 10 can be understood as a host computer.

[0071] From the above analysis, it can be known that the present invention can control the connection status between the grounding point and the ground of the grounding switch 84 in three ways: automatic control, on-site manual control and remote control through the monitoring center 10, thereby improving the flexibility of control. When it is monitored that it is restored to normal, the circuit connection between the grounding point and the ground is restored, and the data transmission of the cable core wire is protected in real time from external electromagnetic interference.

[0072] In the present disclosure, the main switch device adopts a high-power fast switch device, which is suitable for autonomous control of high power and high current in industrial scenarios. The control unit 83 can independently judge the hazard. When the judgment result is: the probability of cable burning is more than 90%, the control unit 83 controls the IGBT high-power switch device to quickly cut off the circuit connection with the ground terminal.

[0073] Through the above methods, the function of controlling the grounding state of the cable shielding layer in an autonomous, intelligent and automatic manner is realized; through this method and corresponding equipment, the purpose of not affecting the safety of the cable and the connected equipment and protecting the data transmission of the information transmission cable from electromagnetic interference is achieved.

[0074] In summary, the present disclosure forms a closed loop in the shielding layer under normal working conditions, and disconnects the grounding wire of the shielding layer under fault conditions, thereby protecting the core wire from external electromagnetic interference and protecting the shielding layer from being burned. The present application can be widely used in control systems that require flexible setting of on-off thresholds in industrial environments. When applied to the shielding protection field of railway information transmission cables, it can effectively protect the cable shielding layer from being burned while shielding the electromagnetic interference of external magnetic induction coupling (magnetic induction coupling is a professional term) on the core wire data transmission, thereby effectively ensuring driving safety.

[0075] Figure 5 is a flow chart of a rail transit intelligent grounding control method according to an exemplary embodiment. Figure 5 As shown, the rail transit intelligent grounding control system includes: a front-end control device, the front-end control device includes: an operating parameter sensor, a data acquisition unit, a control unit and a grounding switch, and the method includes, the method includes S101-S105: S101, a working condition parameter sensor reads working condition parameters corresponding to a shielding layer of a transmission cable in a grounding switch, the working condition parameter sensor comprising: an electrical signal sensor and / or a temperature sensor; the electrical signal sensor comprising: a current sensor or a voltage sensor; S102: The data acquisition unit acquires the operating parameters read by the operating parameter sensor.

[0076] S103, sending the collected operating condition parameters to the control unit; S104, the control unit detects whether the relationship between the received operating condition parameter and the switch action threshold satisfies the connection change condition, and when it is detected that the relationship between the received operating condition parameter and the switch action threshold satisfies the connection change condition, sends a corresponding indication instruction to the grounding switch, where the indication instruction is used to instruct the grounding switch to change the connection state between the grounding point and the ground; S105: The grounding switch changes the connection state between the grounding point and the ground according to the received instruction.

[0077] In one embodiment, the rail transit intelligent grounding control system further includes: a communication transmission unit and a monitoring center; The communication transmission unit sends the operating condition parameters received by the control unit to the monitoring center; The monitoring center detects whether the relationship between the received operating condition parameter and the switch action threshold satisfies the connection change condition, and sends a corresponding indication instruction to the grounding switch when it is detected that the relationship between the received operating condition parameter and the switch action threshold satisfies the connection change condition.

[0078] In one embodiment, when it is detected that the relationship between the received operating condition parameter and the switch action threshold satisfies the connection change condition, sending a corresponding indication instruction to the grounding switch includes: If the grounding point is connected to the ground, when it is detected that the operating condition parameters meet the switch action threshold, a grounding point disconnection signal is sent to the grounding switch; If the grounding point is disconnected from the ground, when it is detected that the operating condition parameters do not meet the switch action threshold, a grounding point connection signal is sent to the grounding switch; The indication instruction includes the grounding point disconnection signal or the grounding point connection signal.

[0079] In one embodiment, when it is detected that the operating condition parameter satisfies the switch action threshold, sending a grounding point disconnection signal to the grounding switch includes: When it is detected that the change value of the operating condition parameter within a preset time period meets the switch action threshold, a grounding point disconnection signal is sent to the grounding switch, In one embodiment, when it is detected that the operating condition parameter does not meet the switch action threshold, sending a grounding point connection signal to the grounding switch includes: When it is detected that the change value of the operating condition parameter within the preset time period does not meet the switch action threshold, the grounding point connection signal is sent to the grounding switch.

[0080] In one embodiment, the communication transmission unit adopts a wireless communication method or a wired communication method.

[0081] In one embodiment, the front-end control device further includes a data storage unit; The data acquisition unit sends the acquired operating condition parameters to the data storage unit; The data storage unit sends the operating condition parameters stored in the data storage unit to the control unit; The communication transmission unit sends the operating condition parameters stored in the data storage unit to the monitoring center.

[0082] In one embodiment, the grounding switch comprises: an IGBT element; changing the connection state between the grounding point and the ground according to the received instruction comprises: The connection state between the IGBT element and the ground is changed according to the received instruction.

[0083] In one embodiment, the front-end control device further includes an alarm unit; the method further includes: When the control unit detects that the operating condition parameter meets the switch action threshold, the control unit sends an alarm signal to the alarm unit; The alarm unit performs a preset alarm operation according to the alarm signal.

[0084] In one embodiment, the control unit acquires a parameter acquisition frequency, and sends the parameter acquisition frequency to the data acquisition unit; the data acquisition unit acquires the operating condition parameter read by the operating condition parameter sensor according to the parameter acquisition frequency.

[0085] The technical features of the above embodiments may be arbitrarily combined. 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.

[0086] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A rail transit intelligent grounding control system, characterized in that: The rail transit intelligent grounding control system comprises: A front-end control device, comprising: an operating parameter sensor, a data acquisition unit, a control unit and a grounding switch; The control unit is connected to the data acquisition unit and the grounding switch respectively, and the data acquisition unit is also connected to the operating parameter sensor; the operating parameter sensor includes: an electrical signal sensor and / or a temperature sensor; the electrical signal sensor includes: a current sensor or a voltage sensor; The operating parameter sensor is used to read the operating parameters corresponding to the shielding layer of the transmission cable in the grounding switch; The data acquisition unit is used to acquire the operating parameters read by the operating parameter sensor and send the acquired operating parameters to the control unit; The control unit is used to send a corresponding instruction to the grounding switch when the relationship between the received operating condition parameter and the switch action threshold meets the connection change condition, wherein the instruction is used to instruct the grounding switch to change the connection state between the grounding point and the ground; The grounding switch is used to change the connection state between the grounding point and the ground according to the received instruction.

2. The rail transit intelligent grounding control system according to claim 1 is characterized in that: The rail transit intelligent grounding control system also includes: a communication transmission unit and a monitoring center; The control unit is connected to the communication transmission unit; The communication transmission unit is used to send the operating condition parameters received by the control unit to the monitoring center; The monitoring center is used to send the corresponding indication instruction to the grounding switch when the relationship between the received operating condition parameter and the switch action threshold satisfies the connection change condition.

3. The rail transit intelligent grounding control system according to claim 1 is characterized in that: In the aspect of sending a corresponding instruction to the grounding switch when the relationship between the received operating condition parameter and the switch action threshold satisfies the connection change condition, the control unit is specifically configured to: If the grounding point is in a connected state with the ground, when it is detected that the operating condition parameter meets the switch action threshold, a grounding point disconnection signal is sent to the grounding switch; If the grounding point is disconnected from the ground, when it is detected that the operating condition parameter does not meet the switch action threshold, a grounding point connection signal is sent to the grounding switch; The indication instruction includes the grounding point disconnection signal or the grounding point connection signal.

4. The rail transit intelligent grounding control system according to claim 3 is characterized in that: In the aspect of sending a grounding point disconnection signal to the grounding switch when it is detected that the operating condition parameter meets the switch action threshold, the control unit is specifically configured to: When it is detected that the change value of the operating condition parameter within a preset time period meets the switch action threshold, a grounding point disconnection signal is sent to the grounding switch; In the aspect of sending a grounding point connection signal to the grounding switch when it is detected that the operating condition parameter does not meet the switch action threshold, the control unit is specifically configured to: When it is detected that the change value of the operating condition parameter within the preset time period does not meet the switch action threshold, the grounding point connection signal is sent to the grounding switch.

5. The rail transit intelligent grounding control system according to claim 2 is characterized in that: The communication transmission unit adopts a wireless communication mode or a wired communication mode.

6. The rail transit intelligent grounding control system according to claim 2, characterized in that: The front-end control device also includes a data storage unit; The data storage unit is connected to the data acquisition unit, the control unit and the communication transmission unit respectively; The data acquisition unit is used to send the acquired operating condition parameters to the data storage unit; The data storage unit is used to send the operating condition parameters stored in the data storage unit to the control unit; The communication transmission unit is used to send the operating condition parameters stored in the data storage unit to the monitoring center.

7. The rail transit intelligent grounding control system according to claim 1, characterized in that: The grounding switch comprises: an IGBT element; In terms of changing the connection state between the grounding point and the ground according to the received instruction, the grounding switch is specifically used to: The connection state between the IGBT element and the ground is changed according to the received instruction.

8. The rail transit intelligent grounding control system according to claim 3 is characterized in that: The front-end control device also includes: an alarm unit; The alarm unit is connected to the control unit; The control unit is further configured to send an alarm signal to the alarm unit when it is detected that the operating condition parameter meets the switch action threshold; The alarm unit is used to perform a preset alarm operation according to the alarm signal.

9. The rail transit intelligent grounding control system according to claim 1, characterized in that: The control unit is further used to obtain a parameter acquisition frequency and send the parameter acquisition frequency to the data acquisition unit; The data acquisition unit is used to acquire the operating parameters read by the operating parameter sensor according to the parameter acquisition frequency.

10. A rail transit intelligent grounding control method, characterized in that: The method is applied to the rail transit intelligent grounding control system according to any one of claims 1 to 9, the rail transit intelligent grounding control system comprises: a front-end control device, the front-end control device comprises: an operating parameter sensor, a data acquisition unit, a control unit and a grounding switch, the method comprises: The operating condition parameter sensor reads the operating condition parameter corresponding to the shielding layer of the transmission cable in the grounding switch, and the operating condition parameter sensor includes: an electrical signal sensor and / or a temperature sensor; the electrical signal sensor includes: a current sensor or a voltage sensor; The data acquisition unit acquires the operating condition parameters read by the operating condition parameter sensor, and sends the acquired operating condition parameters to the control unit; The control unit detects whether the relationship between the received operating condition parameter and the switch action threshold satisfies a connection change condition, and when it is detected that the relationship between the received operating condition parameter and the switch action threshold satisfies the connection change condition, sends a corresponding instruction to the grounding switch, wherein the instruction is used to instruct the grounding switch to change the connection state between the grounding point and the ground; The grounding switch changes the connection state between the grounding point and the ground according to the received instruction.

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